From per.melin@REDACTED  Thu Jul  1 00:23:33 2010
From: per.melin@REDACTED (Per Melin)
Date: Thu, 1 Jul 2010 00:23:33 +0200
Subject: [erlang-questions] RE: TCP performance
In-Reply-To: <SNT123-W306D11981A2B11C915A41B84C00@phx.gbl>
References: <SNT123-W306D11981A2B11C915A41B84C00@phx.gbl>
Message-ID: <AANLkTila_vGGpSDuOzSTvy_4ol7jj1fjWBWxSeDR3Xh-@mail.gmail.com>

On Fri, Jun 18, 2010 at 10:21 PM, Chris Hicks
<silent_vendetta@REDACTED> wrote:

> Of course maybe my test case is too naive? I'm basically just
> bombarding the tcp connection from a single process as I figured
> it would give me a clear enough indication of how long it would
> take to handle the connections.

>From my experience I'd say that you should be able to do at least a
couple of thousand connects per second.

My first suggestion would be to increase the backlog option of
gen_tcp:listen/2 to 1000.

Your code looks like it will fire off connects faster than they can be
accepted, and once that queue grows past the max backlog the requests
will be dropped and retried, which kills your performance.

From comptekki@REDACTED  Thu Jul  1 00:43:31 2010
From: comptekki@REDACTED (Wes James)
Date: Wed, 30 Jun 2010 16:43:31 -0600
Subject: [erlang-questions] Re: try catch scope
In-Reply-To: <20100630141731.GA12774@erix.ericsson.se>
References: <AANLkTikMQ_Igql8jXU_osrIEJaKD_GD3jzBbV6Xf37-N@mail.gmail.com>
	<848w5wybwl.fsf@linux-b2a3.site>
	<AANLkTil_CQnqkq7fc033f84xKT2LKectWWeo72Cf1YQb@mail.gmail.com>
	<20100630141731.GA12774@erix.ericsson.se>
Message-ID: <AANLkTimF7M9gUC8Da6tDrctsCSjtXsX0VOwzI30xRdi1@mail.gmail.com>

On Wed, Jun 30, 2010 at 8:17 AM, Raimo Niskanen
<raimo+erlang-questions@REDACTED> wrote:
> On Wed, Jun 30, 2010 at 07:33:39AM -0600, Wes James wrote:
>> Mangus,
>>
>> Thanks! This is much better!
>>
>> has_query(A) ->
>> ? ? ? try
>> ? ? ? ? ? ? ? yaws_api:parse_query(A) /= []
>> ? ? ? catch
>> ? ? ? ? ? ? ? _:_ -> false
>> ? ? ? end.
>>
>> -wes
>
> This might be even clearer (separating the right and wrong cases):
>
> has_query(A) ->
> ? ?try yaws_api:parse_query(A) of
> ? ? ? ?[] -> false;
> ? ? ? ?_ -> true % Were you supposed to return true for this case?
> ? ?catch
> ? ? ? ?error:_ -> false % Only cathes runtime errors, not exit/1.
> ? ?end.
>


Thanks.  This works too.  Bottom line, is I want to show the default
search page even if the parse_query call throws an error.  Maybe
someone is trying to insert bad chars or such in to the URL to try to
reveal something or even hack the system, etc.

thx,

-wes

From ok@REDACTED  Thu Jul  1 06:04:49 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Thu, 1 Jul 2010 16:04:49 +1200
Subject: [erlang-questions] Re: Compare XML string
In-Reply-To: <4C29DBC5.8080903@nm.ru>
References: <AANLkTikGoNxQGU5ScKD4HEcjw6ByGhGxfgb7j7uVUrlQ@mail.gmail.com> <f4bc7b54-fcee-47e6-94f4-e07e6e276121@s9g2000yqd.googlegroups.com> <4C29DBC5.8080903@nm.ru>
Message-ID: <94DF6F13-2007-4393-AC1A-74BFDDD6ADDC@cs.otago.ac.nz>


On Jun 29, 2010, at 11:40 PM, Dmitry Belyaev wrote:

> First of all, what does author want to compare: plain strings or xml  
> documents?
>
> If documents (or parts of documents) then what about order of  
> attributes and child elements? Does it matter?

A structure-based XML application shouldn't care what the order
of attributes is.  (In particular, given that XML, like SGML
before it, allows defaulting of attributes, I don't believe there
is any definition anywhere of where the defaulted attributes would
go in any sequence.)  Here's what I'm getting at:

f% cat foo.xml
<!DOCTYPE foo [
  <!ELEMENT foo (bar,bar)>
  <!ELEMENT bar EMPTY>
  <!ATTLIST bar x CDATA "X" y CDATA "Y">
]>
<foo>
  <bar x="X"/>
  <bar y="Y"/>
</foo>

The two instances of <bar...> look different, but
after defaulting, they have the same values for all attributes:

f% xmls foo.xml | qe -hr
{document,[{root,"-"}],[
  {foo,[],[
   {bar,[{y,"Y"},{x,"X"}],[]},
   {bar,[{y,"Y"},{x,"X"}],[]}]}]}.

This tool-chain ends up putting attributes in reverse alphabetic
order.  (xmls puts them in alphabetic order after defaulting,
then qe, being rather lazy internally, reverses them.)
>
> <item attr1="value1" attr2="value2"/>
> <item attr2="value2" attr1="value1></item>
>
> Sand, do you count them identical?

Any sensible XML application other than an editor *must*.

>
> Dmitry Belyaev
>
>
> On 06/29/2010 03:32 PM, Steve Davis wrote:
>> Am I under-thinking this if I say:
>>
>> case GivenString of
>> ExpectedString ->  ok;
>> _ ->  error
>> end.
>>
>> ..or is the question really as simple as it sounds.
>>
>> /s
>>
>> On Jun 25, 1:43 am, Sand T<sand.softn...@REDACTED>  wrote:
>>
>>> Hi,
>>>
>>> I need to compare two given XML string to ensure that the two  
>>> strings
>>> are identical or not at runtime. Does anyone have any idea on how to
>>> do this in erlang?
>>>
>>> Following are some of the examples
>>> Given String
>>> <response type=\"progress\" im=\"IM\" login=\"ABC\"
>>> code=\"102\">Authentication Successful ...</response>
>>> Exp String:
>>> <response type=\"progress\" im=\"IM\" login=\"ABC\"
>>> code=\"102\">Authentication Successful ...</response>
>>>
>>> Eq 2:
>>> Given String
>>> <response type=\"progress\" im=\"IM\" login=\"ABC\"
>>> code=\"102\">Authentication Successful ...</response>
>>> <buddies im=\"IM\" login=\"ABC\"><buddy name=\"XYZ\" nickname=\"\"
>>> status=\"offline\" custom=\"Is offline\" group=\"Friends\"
>>> blocked=\"no\"/></buddies>
>>>
>>> Expected:
>>> <response type=\"progress\" im=\"IM\" login=\"ABC\">Authentication
>>> Successful ...</response>
>>> <buddies im=\"IM\" login=\"ABC\"><buddy name=\"XYZ\" nickname=\"\"
>>> status=\"online\" custom=\"Is offline\" group=\"Friends\"
>>> blocked=\"no\"/></buddies>
>>>
>>> Regards,
>>> Sandeep
>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> Seehttp://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED
>>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>


From antoine.koener@REDACTED  Thu Jul  1 14:18:33 2010
From: antoine.koener@REDACTED (Antoine Koener)
Date: Thu, 1 Jul 2010 14:18:33 +0200
Subject: [erlang-questions] binary expression with fixed and variable 
	fields
In-Reply-To: <201006291922003122229@its3.ch>
References: <201006291922003122229@its3.ch>
Message-ID: <AANLkTimuHSKdrwWa7mNm3XUDGwWRDzLharDn9I5f9bhK@mail.gmail.com>

On Tue, Jun 29, 2010 at 7:22 PM, info <info@REDACTED> wrote:

> Hi all,
> I have a string composed of several fixed and variable fields. I would like
> to parse this string as binary expression.
> I checked the example with an IP datagram (the variable fields are to the
> end ...):
>
>  <<field1:size1,field2:size2,field3:size3,field4:size4,field5:size5>>
>
> If the size3 of the field3 is variable,how to parse the string ?
>

Fields Size must be determined before the match or within the match.
see http://erlang.org/doc/programming_examples/bit_syntax.html#id2261909


>
> <<field1:size1,field2:size2,Rest/binary>>  but after ?
>
> If a field is empty, how to detect it ?
>

Use another binary expression.

case Bin of
  <<VersionWithField3>> ->
   ;
 <<VersionWithout>> ->
  ;
  _ -> % catch all others
    ok
end


> If a char (e.g comma) is between each field, is it always possible to use
> the binary syntax ?
>

Just use the "," notation:

<<field1:size1,",",field2:size2,",",Rest/binary>>

Long binary strings are used whenever the binary holds enough information
for itself,
when you need to "parse" and not "match" you may use smaller binary strings.

Taken from some kind of code of mine:

-define( UINT32(X), X:32/native-unsigned).
-define( UINT16(X), X:16/native-unsigned).

action(5522146, _Function, <<
?UINT32(Hwnd),
?UINT16(Size),
Title:Size/binary,
?UINT32(X),
?UINT32(Y),
?UINT32(Cx),
?UINT32(Cy)>>, Pid) ->

%io:format("~p: ~s, ~p ~p ~p~n", [?MODULE, Function, Pid, Hwnd, Title ]),

my 2 cents.

From bile@REDACTED  Thu Jul  1 17:32:10 2010
From: bile@REDACTED (bile@REDACTED)
Date: Thu, 1 Jul 2010 11:32:10 -0400
Subject: Pretty print terms from erl_call
Message-ID: <20100701113210.0b201349@otis>

I've been fooling around with erl_call and am wondering if there is any
simple way to get it to pretty print the string returned by the -a
call? Is the way the shell pretty prints documented anywhere?

From info@REDACTED  Thu Jul  1 18:49:08 2010
From: info@REDACTED (info)
Date: Thu, 1 Jul 2010 18:49:08 +0200
Subject: [erlang-questions] binary expression with fixed and variablefields
References: <201006291922003122229@its3.ch>,
 <AANLkTimuHSKdrwWa7mNm3XUDGwWRDzLharDn9I5f9bhK@mail.gmail.com>
Message-ID: <201007011849079531993@its3.ch>




On Tue, Jun 29, 2010 at 7:22 PM, info <info@REDACTED> wrote:

Hi all,
I have a string composed of several fixed and variable fields. I would like to parse this string as binary expression.
I checked the example with an IP datagram (the variable fields are to the end ...):

 <<field1:size1,field2:size2,field3:size3,field4:size4,field5:size5>>

If the size3 of the field3 is variable,how to parse the string ?



Fields Size must be determined before the match or within the match.
see http://erlang.org/doc/programming_examples/bit_syntax.html#id2261909

The general question is: shall I use the bit syntax to extract each field or shall I use the token method ?
After extraction with the bit syntax, each field will be integer. I must convert again in string if I want to compare with something. I don't see what I win or what I lost !
What is the more efficient in Erlang ? I read in this forum to evict the string syntax because of the "bad" representation of the char in erlang.


<<field1:size1,field2:size2,Rest/binary>>  but after ?

If a field is empty, how to detect it ?



Use another binary expression.


case Bin of
  <<VersionWithField3>> ->
   ;
 <<VersionWithout>> ->
  ;
  _ -> % catch all others  
    ok
end
How can I know if the field3 is empty? by the size of the full string. But if 2 fields are empty, it's impossible.
And if the field3 and the field4 are empty, you will have four versions in your case (2 power N) !

If a char (e.g comma) is between each field, is it always possible to use the binary syntax ?



Just use the "," notation:  


<<field1:size1,",",field2:size2,",",Rest/binary>>

What is "better" in Erlang: "," or _:8


Long binary strings are used whenever the binary holds enough information for itself,
when you need to "parse" and not "match" you may use smaller binary strings.


Taken from some kind of code of mine:


-define( UINT32(X), X:32/native-unsigned).
-define( UINT16(X), X:16/native-unsigned).


action(5522146, _Function, <<
?UINT32(Hwnd), 
?UINT16(Size),
Title:Size/binary,
?UINT32(X), 
?UINT32(Y), 
?UINT32(Cx),
?UINT32(Cy)>>, Pid) ->


%io:format("~p: ~s, ~p ~p ~p~n", [?MODULE, Function, Pid, Hwnd, Title ]), 


my 2 cents.

From rzezeski@REDACTED  Thu Jul  1 21:22:34 2010
From: rzezeski@REDACTED (Ryan Zezeski)
Date: Thu, 1 Jul 2010 15:22:34 -0400
Subject: Stream entity body in inets httpd
Message-ID: <AANLkTimh6N4foTl-vd35IlyH9FROTEkFCl0qfCN0M0vv@mail.gmail.com>

Is there any way to either get the entity body as a binary or stream the
entity body from an HTTP request to inets?  I'm working on an application
that needs to be able to accept a PUT request for CSVs over 160M in size.
 When I send the request to inets the Erlang VM quickly uses up all my free
memory (~5GB).  My guess this is because inets puts the entity body in a
list, rather than keeping it as a binary.  I spent some time looking through
the source code, but didn't see any way to change this behavior.  It looks
to be hardcoded.

-Ryan

From steven.charles.davis@REDACTED  Fri Jul  2 02:58:34 2010
From: steven.charles.davis@REDACTED (Steve Davis)
Date: Thu, 1 Jul 2010 17:58:34 -0700 (PDT)
Subject: binary expression with fixed and variablefields
In-Reply-To: <201007011849079531993@its3.ch>
References: <201006291922003122229@its3.ch>, <AANLkTimuHSKdrwWa7mNm3XUDGwWRDzLharDn9I5f9bhK@mail.gmail.com> 
	<201007011849079531993@its3.ch>
Message-ID: <bc52b757-b514-4186-a4da-29a743375b36@5g2000yqz.googlegroups.com>

On a related note, I find it curious that there's the following
limitation forcing you to manually calculate the size of an already
known binary:

1> <<"a", _/binary>> = <<"abc">>.
<<"abc">>
2> A = <<"a">>.
<<"a">>
3> ABC = <<"abc">>.
<<"abc">>
4> <<A, _/binary>> = ABC.
** exception error: no match of right hand side value <<"abc">>
5> Size = size(A).
1
6> <<A:Size/binary, _/binary>> = ABC.
<<"abc">>

...a minor inconvenience, but irritating.

Perhaps there's a reason that I don't immediately see why 4> isn't
valid?

/s

From rvirding@REDACTED  Fri Jul  2 03:13:51 2010
From: rvirding@REDACTED (Robert Virding)
Date: Fri, 2 Jul 2010 03:13:51 +0200
Subject: [erlang-questions] Re: binary expression with fixed and 
	variablefields
In-Reply-To: <bc52b757-b514-4186-a4da-29a743375b36@5g2000yqz.googlegroups.com>
References: <201006291922003122229@its3.ch> <AANLkTimuHSKdrwWa7mNm3XUDGwWRDzLharDn9I5f9bhK@mail.gmail.com> 
	<201007011849079531993@its3.ch> <bc52b757-b514-4186-a4da-29a743375b36@5g2000yqz.googlegroups.com>
Message-ID: <AANLkTimmzo9veoHM1PM7k2h18NWxAhSK6jdElHHR04GR@mail.gmail.com>

The main reason why 4> isn't valid is that the default type of a
binary segment is an integer. So by not qualifying A you are trying to
match an integer from ABC with the *binary* <<"a">>, which can never
match. That 1> works is because a string literal in a binary is
expanded into the sequence of bytes in the string. So in effect 1> is
equivalent to

<<$a,_/binary>> = <<$a,$b,$c>>.

Robert

On 2 July 2010 02:58, Steve Davis <steven.charles.davis@REDACTED> wrote:
> On a related note, I find it curious that there's the following
> limitation forcing you to manually calculate the size of an already
> known binary:
>
> 1> <<"a", _/binary>> = <<"abc">>.
> <<"abc">>
> 2> A = <<"a">>.
> <<"a">>
> 3> ABC = <<"abc">>.
> <<"abc">>
> 4> <<A, _/binary>> = ABC.
> ** exception error: no match of right hand side value <<"abc">>
> 5> Size = size(A).
> 1
> 6> <<A:Size/binary, _/binary>> = ABC.
> <<"abc">>
>
> ...a minor inconvenience, but irritating.
>
> Perhaps there's a reason that I don't immediately see why 4> isn't
> valid?
>
> /s
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From tanduy.vo@REDACTED  Fri Jul  2 06:21:17 2010
From: tanduy.vo@REDACTED (tanduy)
Date: Thu, 1 Jul 2010 21:21:17 -0700 (PDT)
Subject: Installing Module and Adding Path : Ibrowse
In-Reply-To: <AANLkTintX6jdsPpLRo9qFoIwFKYd_7jjhLFDemJX7o0Z@mail.gmail.com>
References: <AANLkTintX6jdsPpLRo9qFoIwFKYd_7jjhLFDemJX7o0Z@mail.gmail.com>
Message-ID: <40179f8f-7877-4e65-804a-4c39e3714a85@x24g2000pro.googlegroups.com>


Hi Ted Karmel.
If you copy & build ibrowse under this path: erl -noshell -eval
'io:format("~s/lib",[code:root_dir()])' -s init stop
You start erl anywhere that can load module ibrowse

Duy.

On Jun 29, 10:32?pm, Ted Karmel <ted.kar...@REDACTED> wrote:
> Sorry for the noob question.
>
> I am trying to install the ibrowse erlang module (http://wiki.github.com/cmullaparthi/ibrowse/ibrowse-api).
>
> I created a directory separate from the erlang lib one ( i.e.
> usr/local/lib/erlang/lib ?).
>
> I downloaded ibrowse to this folder and compiled ( make ) it successfully.
>
> I added this directory to the code path with the built in code module
> (http://www.erlang.org/doc/man/code.html).
>
> When I try using the ibrowse module from the erl command, it works
> when I am in the ibrowse directory and the ebin folder.
>
> However, whenever I am in another folder, I cannot call the ibrowse
> module. ?It is simply not recognized.
>
> Help.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> Seehttp://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED

From ulf.wiger@REDACTED  Fri Jul  2 12:44:19 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Fri, 02 Jul 2010 12:44:19 +0200
Subject: RFC: parse_trans for code generation
Message-ID: <4C2DC303.7060408@erlang-solutions.com>


I realize that quite the minority of list readers take an
interest in parse transforms. Nevertheless, I thought I'd
highlight a small addition to the parse_trans project to
assist code generation.

http://github.com/esl/parse_trans

(Note too the new location. The old repos still exists, but
I strongly recommend that you pull from the esl location.)

The parse_trans library has primarily offered various ways
to fold over code in various passes in order to collect
information and then make small transformations to code.

However, when generating significant amounts of code, you
tend to end up with tons of abstract code that looks pretty
horrible from a maintenance perspective (I've occasionally
thought about making an Abstract Form <-> XML translator and
calling it Executable XML - to be released on April 1, of course.)

To help things somewhat, I made a code generation parse transform,
called parse_trans_codegen. A small, highly contrived, example can
be found at

http://github.com/esl/parse_trans/blob/master/examples/ex_codegen.erl

Since it is small, I can include it here:

-module(ex_codegen).
-compile({parse_transform, parse_trans_codegen}).
-export([f/1, g/2, gen/2]).

f(Name) ->
     codegen:gen_function(
       Name,
       fun(1,2,3) ->
	      foo;
	  (A,B,C) ->
	      {A,B,C}
       end).

g(Name, V) ->
     codegen:gen_function(
       Name,
       fun(L) ->
	      member({'$var',V}, L)
       end).

gen(Name, X) ->
     codegen:gen_function(
       Name,
       fun(L) -> lists:member({'$var',X}, L) end).


The codegen:gen_function/2 function is just a pseudo
function that triggers the transformation. It takes as
first argument the name of the function being generated,
and as second argument an anonymous function whose body
defines the semantics of the generated function. A named
function is generated with the same clauses as the provided
fun. The {'$var',V} construct in g/2 is a trick to allow
value expansion at code generation time.

The arity of the generated function is derived from the
provided fun.

Using a utility function in parse_trans, we can inspect
the result of the compile-time transformation:

uwiger@REDACTED:~/ETC/git/parse_trans/examples$ erl -pa ../ebin
Erlang R13B04 (erts-5.7.5) [source] [rq:1] [async-threads:0] [hipe] 
[kernel-poll:false]

Eshell V5.7.5  (abort with ^G)
1> parse_trans:pp_beam("ex_codegen.beam").
-file("./ex_codegen.erl", 1).

-module(ex_codegen).

-export([f/1, g/2, gen/2]).

f(Name) ->
     {function, 9, Name, 3,
      [{clause, 11,
        [{integer, 11, 1}, {integer, 11, 2}, {integer, 11, 3}],
        [], [{atom, 12, foo}]},
       {clause, 13,
        [{var, 13, 'A'}, {var, 13, 'B'}, {var, 13, 'C'}], [],
        [{tuple, 14,
          [{var, 14, 'A'}, {var, 14, 'B'}, {var, 14, 'C'}]}]}]}.

g(Name, V) ->
     {function, 20, Name, 1,
      [{clause, 22, [{var, 22, 'L'}], [],
        [{call, 23, {atom, 23, member},
          [erl_parse:abstract(V, 23), {var, 23, 'L'}]}]}]}.

gen(Name, X) ->
     {function, 28, Name, 1,
      [{clause, 28, [{var, 28, 'L'}], [],
        [{call, 28,
          {remote, 28, {atom, 28, lists}, {atom, 28, member}},
          [erl_parse:abstract(X, 28), {var, 28, 'L'}]}]}]}.
ok

(The final 'ok' is the return value from the pretty-printing.)

We can call one of the functions:

2> ex_codegen:g(foo, bar).
{function,20,foo,1,
           [{clause,22,
                    [{var,22,'L'}],
                    [],
                    [{call,23,
                           {atom,23,member},
                           [{atom,23,bar},{var,23,'L'}]}]}]}

It is easier to see what happened if we pretty-print the
result:

2> ex_codegen:gen(contains_17, 17).
{function,28,contains_17,1,
           [{clause,28,
                    [{var,28,'L'}],
                    [],
                    [{call,28,
                           {remote,28,{atom,28,lists},{atom,28,member}},
                           [{integer,28,17},{var,28,'L'}]}]}]}
3> io:fwrite("~s~n", [erl_pp:form(v(2))]).
contains_17(L) ->
     lists:member(17, L).

ok

(Again, the trailing 'ok' is just the return value.)

The {'$var', V} construct allows us to dynamically insert
values into the code at generation time.

I hope some of you find it useful. Comments are welcome.
There is not much documentation - only a couple of paragraphs
in the edoc for parse_trans_codegen:parse_transform/2.

BR,
Ulf W
-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From serge@REDACTED  Fri Jul  2 17:45:55 2010
From: serge@REDACTED (Serge Aleynikov)
Date: Fri, 02 Jul 2010 11:45:55 -0400
Subject: type specification
Message-ID: <4C2E09B3.2050505@aleynikov.org>

Can user-defined type specification be imported from or referenced to 
another module?

E.g. if I have a function that returns date/time value in the same 
format as calendar:now_to_local_time/1 whose type t_datetime1970() is 
defined in the calendar module, what would the -spec of my function be:

-spec local_time() -> ???
local_time() ->
     calendar:now_to_local_time(now()).

From kostis@REDACTED  Fri Jul  2 18:41:31 2010
From: kostis@REDACTED (Kostis Sagonas)
Date: Fri, 02 Jul 2010 19:41:31 +0300
Subject: [erlang-questions] type specification
In-Reply-To: <4C2E09B3.2050505@aleynikov.org>
References: <4C2E09B3.2050505@aleynikov.org>
Message-ID: <4C2E16BB.8050506@cs.ntua.gr>

Serge Aleynikov wrote:
> Can user-defined type specification be imported from or referenced to 
> another module?
> 
> E.g. if I have a function that returns date/time value in the same 
> format as calendar:now_to_local_time/1 whose type t_datetime1970() is 
> defined in the calendar module, what would the -spec of my function be:
> 
> -spec local_time() -> ???
> local_time() ->
>     calendar:now_to_local_time(now()).

If the type is exported (cf. the new -export_type attribute) then what 
you want to write is as simple as:

   -spec local_time() -> calendar:t_datetime1970().

In this particular case, the t_datetime1970() is not exported, so you 
either need to clone it in your module or send a request to the module's 
maintainer to export this type.

Kostis

PS. Btw, I've just checked the 'calendar' manual page and the only types
     that it mentions there are date() and time(), which are also not
     exported by the module (and actually have slightly different names
     t_date() and t_time()).  IMO, they should be renamed and exported.
     It's not so clear to me whether datetime1970() should also be in the
     same category.

From kiszl@REDACTED  Fri Jul  2 19:30:21 2010
From: kiszl@REDACTED (Zoltan Lajos Kis)
Date: Fri, 02 Jul 2010 19:30:21 +0200
Subject: [erlang-questions] type specification
In-Reply-To: <4C2E16BB.8050506@cs.ntua.gr>
References: <4C2E09B3.2050505@aleynikov.org> <4C2E16BB.8050506@cs.ntua.gr>
Message-ID: <4C2E222D.7070000@tmit.bme.hu>

On 7/2/2010 6:41 PM, Kostis Sagonas wrote:
> Serge Aleynikov wrote:
>> Can user-defined type specification be imported from or referenced to 
>> another module?
>>
>> E.g. if I have a function that returns date/time value in the same 
>> format as calendar:now_to_local_time/1 whose type t_datetime1970() is 
>> defined in the calendar module, what would the -spec of my function be:
>>
>> -spec local_time() -> ???
>> local_time() ->
>>     calendar:now_to_local_time(now()).
>
> If the type is exported (cf. the new -export_type attribute) then what 
> you want to write is as simple as:
>
>   -spec local_time() -> calendar:t_datetime1970().
>
> In this particular case, the t_datetime1970() is not exported, so you 
> either need to clone it in your module or send a request to the 
> module's maintainer to export this type.
>
> Kostis
>

Could you explain how the new export_type attribute relates to the 
opaque attribute?

In R14A it seems that if I define an opaque type (without exporting it), 
and try to use it in another module, dialyzer emits an unknown type warning.
If I export the type the warning is not emitted, but the type is not 
treated as opaque anymore...

Thank you,
Zoltan.


From erlang@REDACTED  Fri Jul  2 23:05:10 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Fri, 2 Jul 2010 23:05:10 +0200
Subject: [erlang-questions] two simple escript questions
In-Reply-To: <AANLkTik5AfX-McrWQOJf_ZwFZFxQbxhJKisulw9mglol@mail.gmail.com>
References: <AANLkTik5AfX-McrWQOJf_ZwFZFxQbxhJKisulw9mglol@mail.gmail.com>
Message-ID: <AANLkTinwp4jshZUrfbDNwaY7AeW85ucktIbhVOFQxaqH@mail.gmail.com>

#!/usr/local/bin/escript
main(_) ->
    Name = io:get_line("What's your name?\n> "),
    io:format("Hello ~s!~n", [Name]).

erl -man io

is your friend

/Joe



On Tue, Jun 29, 2010 at 9:44 PM, Gonzalo <gonzalo@REDACTED> wrote:
> Hi all,
>
> I have two questions regarding the following simple erlang script:
>
>
> #!/opt/local/bin/escript
> main(_) -> {ok, Name} = io:read("What's your name?\n> "),
> ? ? ? ? ? io:format("Hello ~s!~n", [Name]).
>
> Execution:
>
> Denver:Erlang gonzalo$ ./hello
> What's your name?
>> gonzalo.
> Hello gonzalo!
>
> It works for a simple atom.
>
> 1. I would like to modify this script so I could type anything.
> Examples: gonzalo, jean paul, Gonzalo, Jean Paul, etc.
>
> 2. It seems that io:read() expects an expression ending with a dot (.)
> Is it possible to avoid this? Just pressing enter should work.
>
> Thanks for your tips.
> Gonzalo.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From info@REDACTED  Fri Jul  2 23:32:16 2010
From: info@REDACTED (info)
Date: Fri, 2 Jul 2010 23:32:16 +0200
Subject: bit syntax or tokens ?
Message-ID: <201007022332132816745@its3.ch>

Given a string S = <<"ABC,DE,FGH">>.
I do 
<<Alpha:24,_:8,Beta:16,_:8,Gamma:24>> = S.
and
Alpha. gives 4276803

How to find the string ABC from Alpha ?

The bix syntax seems to be better in Erlang but is it a good approach to extract string fields from a string  or is it better to use the tokens ?

John

From jesper.louis.andersen@REDACTED  Fri Jul  2 23:38:03 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Fri, 2 Jul 2010 23:38:03 +0200
Subject: [erlang-questions] bit syntax or tokens ?
In-Reply-To: <201007022332132816745@its3.ch>
References: <201007022332132816745@its3.ch>
Message-ID: <AANLkTildlh5lUYGgoE0WdIB2lrIqKL-TbvrNh07DnkC5@mail.gmail.com>

On Fri, Jul 2, 2010 at 11:32 PM, info <info@REDACTED> wrote:
> Given a string S = <<"ABC,DE,FGH">>.
> I do
> <<Alpha:24,_:8,Beta:16,_:8,Gamma:24>> = S.
> and
> Alpha. gives 4276803

This is an excellent case for the new R14A/EEP-31 binary module,
presumed I understand your question:

3> binary:split(<<"ABC,DE,FHG">>, <<",">>).
[<<"ABC">>,<<"DE,FHG">>]


-- 
J.

From rvirding@REDACTED  Sat Jul  3 00:06:10 2010
From: rvirding@REDACTED (Robert Virding)
Date: Sat, 3 Jul 2010 00:06:10 +0200
Subject: [erlang-questions] bit syntax or tokens ?
In-Reply-To: <AANLkTildlh5lUYGgoE0WdIB2lrIqKL-TbvrNh07DnkC5@mail.gmail.com>
References: <201007022332132816745@its3.ch> <AANLkTildlh5lUYGgoE0WdIB2lrIqKL-TbvrNh07DnkC5@mail.gmail.com>
Message-ID: <AANLkTiln7QAYFhS4Tu-B9p8b9ZsQB9X0sFJKVINopZXl@mail.gmail.com>

Another alternative is to do:

<<A:3/binary,_:8,B:2/binary,_:8,G/binary>> = S.

which will give binaries A, B and G. It is, however, a very static way
of doing it. Using the new binary module as Jesper suggests is much
more dynamic and adaptable. While you can put what you want into a
binary the bit syntax was never really designed for string fields,
especially not dynamic ones, as you can't search with it.

How much do you know about the substrings and what are you going to do
with them once you have got them? This can also influence how you
extract them.

Robert


On 2 July 2010 23:38, Jesper Louis Andersen
<jesper.louis.andersen@REDACTED> wrote:
> On Fri, Jul 2, 2010 at 11:32 PM, info <info@REDACTED> wrote:
>> Given a string S = <<"ABC,DE,FGH">>.
>> I do
>> <<Alpha:24,_:8,Beta:16,_:8,Gamma:24>> = S.
>> and
>> Alpha. gives 4276803
>
> This is an excellent case for the new R14A/EEP-31 binary module,
> presumed I understand your question:
>
> 3> binary:split(<<"ABC,DE,FHG">>, <<",">>).
> [<<"ABC">>,<<"DE,FHG">>]
>
>
> --
> J.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From vances@REDACTED  Sat Jul  3 00:28:36 2010
From: vances@REDACTED (Vance Shipley)
Date: Fri, 2 Jul 2010 18:28:36 -0400
Subject: Change node name in mnesia
In-Reply-To: <20100214031924.GM13976@h216-235-12-174.host.egate.net>
References: <20100214031924.GM13976@h216-235-12-174.host.egate.net>
Message-ID: <20100702222835.GC267@h216-235-12-169.host.egate.net>

Is it valid to have records in an mnesia table of this form:

  {log_header,dcl_log,"1.0","4.4.10",'foo@REDACTED',{1266,113437,587068}},

The tables seem to be working fine even though these entries are
there which obviously do not have the correct OID for the table.

What I'd like to understand is if I've broken the tables myself
or if this type of thing is valid and I should just deal with
them when traversing a table with mnesia:foldl/3.

	-Vance

On Sat, Feb 13, 2010 at 10:19:24PM -0500, Vance Shipley wrote:
}  I used the example in the Mnesia User's Guide to backup
}  and transform a database from a long node name to a short
}  one.  That all seemed to go smoothly enough but now I'm
}  noticing these strange records in my tables:
}  
}     {log_header,dcl_log,"1.0","4.4.10",'foo@REDACTED',{1266,113437,587068}},
}  
}  I discovered this using mnesia:foldl/3.  Is this normal
}  or have I messed things up?
}  
}  -- 
}  	-Vance
}  
}  ________________________________________________________________
}  erlang-questions (at) erlang.org mailing list.
}  See http://www.erlang.org/faq.html
}  To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED

-- 
	-Vance

From dgud@REDACTED  Sat Jul  3 09:09:31 2010
From: dgud@REDACTED (Dan Gudmundsson)
Date: Sat, 3 Jul 2010 09:09:31 +0200
Subject: [erlang-questions] Re: Change node name in mnesia
In-Reply-To: <20100702222835.GC267@h216-235-12-169.host.egate.net>
References: <20100214031924.GM13976@h216-235-12-174.host.egate.net>
	<20100702222835.GC267@h216-235-12-169.host.egate.net>
Message-ID: <AANLkTimox_subYsK1okfVg3U53CG2_WisT12342hhDza@mail.gmail.com>

Are you seeing those in the ets table?

They should not be in the table, they are what they say the  header of
a TABLE.DCL file.

Either you or I have some improvements to do :-)

/Dan

On Sat, Jul 3, 2010 at 12:28 AM, Vance Shipley <vances@REDACTED> wrote:
> Is it valid to have records in an mnesia table of this form:
>
> ?{log_header,dcl_log,"1.0","4.4.10",'foo@REDACTED',{1266,113437,587068}},
>
> The tables seem to be working fine even though these entries are
> there which obviously do not have the correct OID for the table.
>
> What I'd like to understand is if I've broken the tables myself
> or if this type of thing is valid and I should just deal with
> them when traversing a table with mnesia:foldl/3.
>
> ? ? ? ?-Vance
>
> On Sat, Feb 13, 2010 at 10:19:24PM -0500, Vance Shipley wrote:
> } ?I used the example in the Mnesia User's Guide to backup
> } ?and transform a database from a long node name to a short
> } ?one. ?That all seemed to go smoothly enough but now I'm
> } ?noticing these strange records in my tables:
> }
> } ? ? {log_header,dcl_log,"1.0","4.4.10",'foo@REDACTED',{1266,113437,587068}},
> }
> } ?I discovered this using mnesia:foldl/3. ?Is this normal
> } ?or have I messed things up?
> }
> } ?--
> } ? ? ? -Vance
> }
> } ?________________________________________________________________
> } ?erlang-questions (at) erlang.org mailing list.
> } ?See http://www.erlang.org/faq.html
> } ?To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
> --
> ? ? ? ?-Vance
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From kostis@REDACTED  Sat Jul  3 09:21:31 2010
From: kostis@REDACTED (Kostis Sagonas)
Date: Sat, 03 Jul 2010 10:21:31 +0300
Subject: [erlang-questions] type specification
In-Reply-To: <4C2E222D.7070000@tmit.bme.hu>
References: <4C2E09B3.2050505@aleynikov.org> <4C2E16BB.8050506@cs.ntua.gr> <4C2E222D.7070000@tmit.bme.hu>
Message-ID: <4C2EE4FB.5070104@cs.ntua.gr>

Zoltan Lajos Kis wrote:
> 
> Could you explain how the new export_type attribute relates to the 
> opaque attribute?

Declaring a type as opaque means that you want to keep the structure 
private to the defining module (which of course can manipulate the 
structure of such terms) and prevent other modules from doing operations 
to such a term that depends on its structure; dialyzer will warn you 
about such uses. Because the defining module can always manipulate the 
structure of such terms, it does not make sense to declare a type as 
opaque in some module and have it module-local (i.e., not exported).

Thus, an opaque type should always be exported.

> In R14A it seems that if I define an opaque type (without exporting it), 
> and try to use it in another module, dialyzer emits an unknown type 
> warning.

Yes, this is expected. You can not use remote types (types defined in 
some other module) that are not exported by the defining module.

> If I export the type the warning is not emitted, but the type is not 
> treated as opaque anymore...

Either I do not understand what you mean here, or I doubt this.  A small 
code example with the behavior you observe will help here (perhaps off 
list, if it is too big).

Kostis

From kiszl@REDACTED  Sat Jul  3 09:55:25 2010
From: kiszl@REDACTED (Zoltan Lajos Kis)
Date: Sat, 03 Jul 2010 09:55:25 +0200
Subject: [erlang-questions] type specification
In-Reply-To: <4C2EE4FB.5070104@cs.ntua.gr>
References: <4C2E09B3.2050505@aleynikov.org> <4C2E16BB.8050506@cs.ntua.gr> <4C2E222D.7070000@tmit.bme.hu> <4C2EE4FB.5070104@cs.ntua.gr>
Message-ID: <4C2EECED.7070601@tmit.bme.hu>

On 7/3/2010 9:21 AM, Kostis Sagonas wrote:
> Zoltan Lajos Kis wrote:
>>
>> Could you explain how the new export_type attribute relates to the 
>> opaque attribute?
>
> Declaring a type as opaque means that you want to keep the structure 
> private to the defining module (which of course can manipulate the 
> structure of such terms) and prevent other modules from doing 
> operations to such a term that depends on its structure; dialyzer will 
> warn you about such uses. Because the defining module can always 
> manipulate the structure of such terms, it does not make sense to 
> declare a type as opaque in some module and have it module-local 
> (i.e., not exported).
>
> Thus, an opaque type should always be exported.
>
>> In R14A it seems that if I define an opaque type (without exporting 
>> it), and try to use it in another module, dialyzer emits an unknown 
>> type warning.
>
> Yes, this is expected. You can not use remote types (types defined in 
> some other module) that are not exported by the defining module.
>
>> If I export the type the warning is not emitted, but the type is not 
>> treated as opaque anymore...
>
> Either I do not understand what you mean here, or I doubt this.  A 
> small code example with the behavior you observe will help here 
> (perhaps off list, if it is too big).
>
> Kostis

Shouldn't I be warned that b:f breaks the opaqueness of a:my_type() with 
the modules below?

Zoltan.
--------------------------------------------
-module(a).
-compile(export_all).

-opaque( my_type() :: {atom(), atom()} ).

-export_type([my_type/0]).

-spec( f(my_type()) -> atom() ).
f({A,_B}) -> A.
---------------------------------------------
-module(b).
-compile(export_all).

-spec( f(a:my_type()) -> atom() ).
f({A,_B}) -> A.
---------------------------------------------


From bgustavsson@REDACTED  Sat Jul  3 11:13:42 2010
From: bgustavsson@REDACTED (=?UTF-8?Q?Bj=C3=B6rn_Gustavsson?=)
Date: Sat, 3 Jul 2010 11:13:42 +0200
Subject: [erlang-questions] Stack space used by "body-recursive calls".
In-Reply-To: <A24A6A72-CFC0-480A-B81F-05C77DF71882@trifork.com>
References: <A24A6A72-CFC0-480A-B81F-05C77DF71882@trifork.com>
Message-ID: <AANLkTikspC74Y83rOm2uWr9P_bGpBwUFWRwTER60dfaU@mail.gmail.com>

On Wed, Jun 30, 2010 at 10:02 AM, Kresten Krab Thorup <krab@REDACTED> wrote:
> One of my challenges in Erjang is that list comprehensions end up chewing stack space. ?And today I got a glimpse of hope reading this:
>
> According to http://www.erlang.org/doc/efficiency_guide/myths.html
>
> In R12B and later releases, there is an optimization that will in many cases reduces the number of words used on the stack in body-recursive calls, so that a body-recursive list function and tail-recursive function that calls lists:reverse/1<../man/lists.html#reverse-1> at the end will use exactly the same amount of memory. lists:map/2, lists:filter/2, list comprehensions, and many other recursive functions now use the same amount of space as their tail-recursive equivalents.
>
> Can someone tell me, what exactly is the optimization that was done in R12B? It must be something in the runtime system that recognizes these conditions and does something smart; I'd love to be able to be equally smart.

No, it's a compiler optimization - stack trimming. List comprehensions and
other body recursive calls used to eat even more stack space before R12.
(The only support that was added to the run-time system was the trim/2
instruction to do the actual stack trimming.)

-- 
Bj?rn Gustavsson, Erlang/OTP, Ericsson AB

From info@REDACTED  Sat Jul  3 11:56:45 2010
From: info@REDACTED (info)
Date: Sat, 3 Jul 2010 11:56:45 +0200
Subject: [erlang-questions] bit syntax or tokens ?
References: <201007022332132816745@its3.ch>,
 <AANLkTildlh5lUYGgoE0WdIB2lrIqKL-TbvrNh07DnkC5@mail.gmail.com>,
 <AANLkTiln7QAYFhS4Tu-B9p8b9ZsQB9X0sFJKVINopZXl@mail.gmail.com>
Message-ID: <201007031156453128795@its3.ch>

Thank you Robert,
Once I have got them, I will mainly compare with string data or make calculation.
if A == "ABC" -> ...
Sometimes I want A as a string, sometimes A as integer !!
I try to stay with the bit syntax "as long as possible" but I don't know if it's a good approach !
John


Another alternative is to do:

< <A:3/binary,_:8,B:2/binary,_:8,G/binary > > = S.

which will give binaries A, B and G. It is, however, a very static way
of doing it. Using the new binary module as Jesper suggests is much
more dynamic and adaptable. While you can put what you want into a
binary the bit syntax was never really designed for string fields,
especially not dynamic ones, as you can't search with it.

How much do you know about the substrings and what are you going to do
with them once you have got them? This can also influence how you
extract them.

Robert


On 2 July 2010 23:38, Jesper Louis Andersen
<jesper.louis.andersen@REDACTED > wrote:
> On Fri, Jul 2, 2010 at 11:32 PM, info  <info@REDACTED > wrote:
> > Given a string S =  < <"ABC,DE,FGH" > >.
> > I do
> >  < <Alpha:24,_:8,Beta:16,_:8,Gamma:24 > > = S.
> > and
> > Alpha. gives 4276803
>
> This is an excellent case for the new R14A/EEP-31 binary module,
> presumed I understand your question:
>
> 3 > binary:split( < <"ABC,DE,FHG" > >,  < <"," > >).
> [ < <"ABC" > >, < <"DE,FHG" > >]
>
>
> --
> J.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From jesper.louis.andersen@REDACTED  Sat Jul  3 16:55:18 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Sat, 3 Jul 2010 16:55:18 +0200
Subject: [erlang-questions] bit syntax or tokens ?
In-Reply-To: <201007031156453128795@its3.ch>
References: <201007022332132816745@its3.ch> <AANLkTildlh5lUYGgoE0WdIB2lrIqKL-TbvrNh07DnkC5@mail.gmail.com> 
	<AANLkTiln7QAYFhS4Tu-B9p8b9ZsQB9X0sFJKVINopZXl@mail.gmail.com> 
	<201007031156453128795@its3.ch>
Message-ID: <AANLkTinFWiwOxDIhtccia1as6zyOQ9TASmXvI1EcwCpu@mail.gmail.com>

On Sat, Jul 3, 2010 at 11:56 AM, info <info@REDACTED> wrote:
> Thank you Robert,
> Once I have got them, I will mainly compare with string data or make calculation.
> if A == "ABC" -> ...
> Sometimes I want A as a string, sometimes A as integer !!

One way to achieve this is the decode the binary as both a string and
an integer, and then lug both around at the same time.

> I try to stay with the bit syntax "as long as possible" but I don't know if it's a good approach !

My guess is you wont win much by doing this. Of course, the string is
taking up some space, but lugging it around is still just a
pointer-pass. I wouldn't worry too much about it until it ends up
being a bottleneck.

-- 
J.

From zeno490@REDACTED  Sat Jul  3 17:58:26 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Sat, 3 Jul 2010 11:58:26 -0400
Subject: escript os:cmd behavior different from erl or command line
Message-ID: <AANLkTimY90AI_a1SNlKQxwoWXYR4WEQQEgxQ0I2NPWKv@mail.gmail.com>

Hi,
I am attempting to run 'make' using os:cmd("make"). from an escript.
The command works fine if I run it from the erl interpreter (or from the
command like) but not from an escript.
>From the escript, (i'm building mochiweb) for each beam, i'll get an error
however the beam still gets created and in fact, using make -k seems to
force it to work.
Errors are like this:

nicholas@REDACTED:~/projects/mochiweb-dev$ ./test
(cd src;make all)
make[1]: Entering directory `/home/nicholas/projects/mochiweb-dev/src'
erlc -W -I ../include  +debug_info -o ../ebin mochifmt_records.erl
File has no extension: /home/nicholas/projects/mochiweb-dev/src/!
make[1]: *** [../ebin/mochifmt_records.beam] Error 1
make[1]: Leaving directory `/home/nicholas/projects/mochiweb-dev/src'
make: *** [all] Error 2

Where test is an escript like so:
#!/usr/bin/env escript
%% -*- erlang -*-
%%!

main(_Args) ->
    Result = os:cmd("make"),
    io:format("~s~n", [Result]),
    ok.

I'm not a make fan/expert but as far as I can tell, the mochiweb make files
are looking good.
I'm using erlang R13B01 on ubuntu 9.10 and mochiweb is the head I grabbed
earlier today via the download source button.

Thanks

From prikrutil@REDACTED  Sat Jul  3 18:45:25 2010
From: prikrutil@REDACTED (Sergey Samokhin)
Date: Sat, 3 Jul 2010 20:45:25 +0400
Subject: [erlang-questions] escript os:cmd behavior different from erl or 
	command line
In-Reply-To: <AANLkTimY90AI_a1SNlKQxwoWXYR4WEQQEgxQ0I2NPWKv@mail.gmail.com>
References: <AANLkTimY90AI_a1SNlKQxwoWXYR4WEQQEgxQ0I2NPWKv@mail.gmail.com>
Message-ID: <AANLkTimxLm8hDNY7Uc3AXMxxcuqRcUMvy6AWZgGoMOqH@mail.gmail.com>

Hello, Nicholas.

This bug has been fixed in R13B02.

Upgrade to R13B02 or delete

%%!

from your escript.

Answer to my bug report:
http://www.erlang.org/cgi-bin/ezmlm-cgi?2:msp:1460:ihedkfpokaibbannbafi

-- 
Sergey Samokhin

From zeno490@REDACTED  Sat Jul  3 19:14:21 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Sat, 3 Jul 2010 13:14:21 -0400
Subject: [erlang-questions] escript os:cmd behavior different from erl or 
	command line
In-Reply-To: <AANLkTimxLm8hDNY7Uc3AXMxxcuqRcUMvy6AWZgGoMOqH@mail.gmail.com>
References: <AANLkTimY90AI_a1SNlKQxwoWXYR4WEQQEgxQ0I2NPWKv@mail.gmail.com>
	<AANLkTimxLm8hDNY7Uc3AXMxxcuqRcUMvy6AWZgGoMOqH@mail.gmail.com>
Message-ID: <AANLkTimsBhPtROJFvN53e-ACYd3cRp7gPGtkQA1x2VSC@mail.gmail.com>

Indeed that fixed it, thanks!

On Sat, Jul 3, 2010 at 12:45 PM, Sergey Samokhin <prikrutil@REDACTED>wrote:

> Hello, Nicholas.
>
> This bug has been fixed in R13B02.
>
> Upgrade to R13B02 or delete
>
> %%!
>
> from your escript.
>
> Answer to my bug report:
> http://www.erlang.org/cgi-bin/ezmlm-cgi?2:msp:1460:ihedkfpokaibbannbafi
>
> --
> Sergey Samokhin
>

From gonzalo@REDACTED  Sun Jul  4 01:06:36 2010
From: gonzalo@REDACTED (Gonzalo)
Date: Sun, 4 Jul 2010 01:06:36 +0200
Subject: [erlang-questions] two simple escript questions
In-Reply-To: <AANLkTinwp4jshZUrfbDNwaY7AeW85ucktIbhVOFQxaqH@mail.gmail.com>
References: <AANLkTik5AfX-McrWQOJf_ZwFZFxQbxhJKisulw9mglol@mail.gmail.com>
	<AANLkTinwp4jshZUrfbDNwaY7AeW85ucktIbhVOFQxaqH@mail.gmail.com>
Message-ID: <AANLkTilVQN8a2CjsQmEZG-K_uovf7aAdaG_DFYETKu94@mail.gmail.com>

Cool!
Thanks for the tip Joe!

By the way, it's a pleasure to read your book "Programming Erlang"
(Pragmatic Programmers). It's very well written.

Regards.
Gonzalo.

From joaohf@REDACTED  Sun Jul  4 02:02:25 2010
From: joaohf@REDACTED (=?UTF-8?Q?Jo=C3=A3o_Henrique_Freitas?=)
Date: Sat, 3 Jul 2010 21:02:25 -0300
Subject: Trying to change things
Message-ID: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>

Hello,

I am working on a place wich uses the CHILL language programming to
develop a huge telecom system. We use others languages too like C and
C++. But CHILL is the largest code base.

I staring to learning Erlang about six months ago and in the last
three months I spent a lot of energies trying persuade developers to
change from CHILL/C/C++ to Erlang.

But is hard change things. Anybody have some experience with these situation?

My boss question me about 'Who is using Erlang?' and I am trying to
found some in my country (Brazil).

Now I can't waiting more and start a internal project to interfacing
with CHILL/C/C++ old base and Erlang.

Thanks

-- 
-----------------------------------------------------------
Jo?o Henrique Freitas - joaohf_at_gmail.com
Campinas-SP-Brasil
BSD051283
LPI 1
http://www.joaohfreitas.eti.br

From bernie@REDACTED  Sun Jul  4 02:50:04 2010
From: bernie@REDACTED (Bernard Duggan)
Date: Sun, 04 Jul 2010 10:50:04 +1000
Subject: [erlang-questions] Trying to change things
In-Reply-To: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
References: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
Message-ID: <4C2FDABC.2040407@m5net.com>

 Hi Jo?o,

On 4/07/2010 10:02 AM, Jo?o Henrique Freitas wrote:
> Hello,
>
> I am working on a place wich uses the CHILL language programming to
> develop a huge telecom system. We use others languages too like C and
> C++. But CHILL is the largest code base.
We were in almost exactly the same situation as you a couple of years
ago, minus the CHILL - we were just using C/C++.
> I staring to learning Erlang about six months ago and in the last
> three months I spent a lot of energies trying persuade developers to
> change from CHILL/C/C++ to Erlang.
We did that when we first discovered Erlang too - doing that without a
lot of stuff to back you up (see below) is almost certainly doomed to
failure.
> But is hard change things. Anybody have some experience with these situation?
Yes, indeed I do :)  I'm not going to proffer what I'm saying as general
advice, but it's what allowed us some progress in our particular
situation.  Here's what we did:

* Start, in your "spare time", to write something in Erlang that's going
to be useful but doesn't exist yet because "we'll get to it later,,,when
we have time" :)  (Make sure you treat this as a learning experience -
you /will/ look back at this code in a couple of years and marvel at how
terrible it is, I promise you :)).  In our case, one of the biggest
problems we had was that we had no good way to test how the system would
behave when we plugged 3000 phones into it, because we had neither 3000
phones nor the 3000 QA guys to run them :)  Erlang's concurrent nature
made it a perfect fit for this kind of role - acting exactly like a
whole pile of phones.  After a few months we suddenly had a tool that
both allowed us to do something really useful and showed off Erlang.

* Make sure everyone knows how awesome this is, and that they know that
it's awesome, at least partly, because it's in Erlang (and also,
naturally, because /you/ wrote it :)).

* Hopefully, people will start asking "why doesn't it do X?" (though
they'll rarely marvel at how something useful sprung up without them
having to do anything or even ask for it - it's all about what it
/doesn't/ do).  Once again, you can show how nice and easy Erlang is to
modify by adding X.  But make sure you /show/ them how easy it is to
add.  Maybe they might want to add the next feature themselves (because
you're really busy right now...)?  Hey look - you have another person
writing Erlang :)

* Make sure you read up on all the great stuff Erlang can give you -
especially the reliability and "safe crashing" aspects.  Telco people,
especially, /love/ reliability for obvious reasons.  We have a process
where one single bad pointer can take down 5000 phones for 20 seconds -
imagine how aweomse it sounds if a bug in your code will, in all but the
worst possible cases, take down only one or two!

* This step is where, I think, we got a bit lucky - we started actively
agitating to write new bits of the core code in Erlang.  Depeding on
your system, that's probably going to have a high startup cost in terms
of writing a layer to interact with the legacy code.  Somehow we
convinced them it was, in fact, the "way forward", but we didn't have
time to convert anything that we currently had (fair enough - it was all
"working" okay).  But then we got another lucky break when we were asked
to write a whole new module for the existing core system, and the job
was given to the two biggest Erlang users :)

* This time, we didn't try to sneak it "under the radar" - we said we
wanted to do it in Erlang, said there would be a certain cost to getting
the initial interface layer written, but also made it clear that we were
totally convinced it would pay off, even for this single module.  Based
in no small part on our earlier success with the testing system, we got
the go-ahead.

* The only other suggestion I can give is, if you get to that stage,
take as much time as you can to make sure you get the first serious bit
of Erlang stuff "right".  If you still have nay-sayers, they will be
looking for any little thing that goes wrong as a way of saying "see? 
Told you Erlang was rubbish - we should be sticking with good-ole
reliable C++".  Never mind that the C++ stuff crashed twice a day when
they first coded it :)

Like I said, that's just our story - it may or may not be any use to you.
> My boss question me about 'Who is using Erlang?' and I am trying to
> found some in my country (Brazil).
Can't help you with that one, sorry (not for Brazil, anyway).  What I
/would/ say is that it's entirely typical of "management" to take the
"well if it's so great, why isn't everyone else using it?" attitude. 
I'm sure it's self-evident to everyone on this list why that very
question itself is wrong, but it's the job of management not to screw
up.  If they have something that is seen to be working (for some
definition of "working"), the choice they see is between a "zero risk"
option of changing nothing or a risky option that some guy is telling
them will make things better.  It's always the easier choice to stick
with a known quantity.  I'm not meaning this as some kind of
"anti-management-they're-all-morons" rant - they have a different
perspective on things and I can totally understand their reluctance to
move away from a known quantity.
> Now I can't waiting more and start a internal project to interfacing
> with CHILL/C/C++ old base and Erlang.
Good luck!  Let us know how you get on.

B

From kenji.rikitake@REDACTED  Sun Jul  4 09:32:01 2010
From: kenji.rikitake@REDACTED (Kenji Rikitake)
Date: Sun, 4 Jul 2010 16:32:01 +0900
Subject: native Erlang version of SFMT PRNG
Message-ID: <20100704073201.GA37621@k2r.org>

A crude pure Erlang version of SFMT
(SIMD-oriented Fast Mersenne Twister) PRNG:
http://github.com/jj1bdx/sfmt-erlang

Note: this code is still ~300 times slower than the C code of SFMT
even when HiPE enabled on Erlang/OTP R14A at FreeBSD 7.3-RELEASE x86;
a NIF set will boost the speed.  I've already dissected the original
SFMT code for a thread-safe implementation at:
http://github.com/jj1bdx/sfmt-extstate

Kenji Rikitake
(well, if nobody does something for me, I have to do it anyway :))

In the message <20100530075320.GA29981@REDACTED>
dated Sun, May 30, 2010 at 04:52:56PM +0900,
Kenji Rikitake <kenji.rikitake@REDACTED> writes:
> Anybody has implemented a NIF or port version of Mersenne Twister or SFMT?
> http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html
> 
> (Mersenne Twister has been incorporated as the default RNG for Python
> and R, so far as I know.)

From torben.lehoff@REDACTED  Sun Jul  4 16:55:51 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Sun, 4 Jul 2010 16:55:51 +0200
Subject: [erlang-questions] Trying to change things
In-Reply-To: <4C2FDABC.2040407@m5net.com>
References: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
	<4C2FDABC.2040407@m5net.com>
Message-ID: <AANLkTilrXzQIp9eZCeBUSg3OHdSYXmBlpVwa4CFhEHRr@mail.gmail.com>

Jo?o,

I second many of Bernard's observations - see
http://erlang-factory.com/conference/2008LondonErlangeXchange/speakers/NicholasGunderfor
our personal war story.
See the slides and come back with additional questions - I have some hidden
slides and notes I can dig out for you.

Cheers,
Torben

2010/7/4 Bernard Duggan <bernie@REDACTED>

>  Hi Jo?o,
>
> On 4/07/2010 10:02 AM, Jo?o Henrique Freitas wrote:
> > Hello,
> >
> > I am working on a place wich uses the CHILL language programming to
> > develop a huge telecom system. We use others languages too like C and
> > C++. But CHILL is the largest code base.
> We were in almost exactly the same situation as you a couple of years
> ago, minus the CHILL - we were just using C/C++.
> > I staring to learning Erlang about six months ago and in the last
> > three months I spent a lot of energies trying persuade developers to
> > change from CHILL/C/C++ to Erlang.
> We did that when we first discovered Erlang too - doing that without a
> lot of stuff to back you up (see below) is almost certainly doomed to
> failure.
> > But is hard change things. Anybody have some experience with these
> situation?
> Yes, indeed I do :)  I'm not going to proffer what I'm saying as general
> advice, but it's what allowed us some progress in our particular
> situation.  Here's what we did:
>
> * Start, in your "spare time", to write something in Erlang that's going
> to be useful but doesn't exist yet because "we'll get to it later,,,when
> we have time" :)  (Make sure you treat this as a learning experience -
> you /will/ look back at this code in a couple of years and marvel at how
> terrible it is, I promise you :)).  In our case, one of the biggest
> problems we had was that we had no good way to test how the system would
> behave when we plugged 3000 phones into it, because we had neither 3000
> phones nor the 3000 QA guys to run them :)  Erlang's concurrent nature
> made it a perfect fit for this kind of role - acting exactly like a
> whole pile of phones.  After a few months we suddenly had a tool that
> both allowed us to do something really useful and showed off Erlang.
>
> * Make sure everyone knows how awesome this is, and that they know that
> it's awesome, at least partly, because it's in Erlang (and also,
> naturally, because /you/ wrote it :)).
>
> * Hopefully, people will start asking "why doesn't it do X?" (though
> they'll rarely marvel at how something useful sprung up without them
> having to do anything or even ask for it - it's all about what it
> /doesn't/ do).  Once again, you can show how nice and easy Erlang is to
> modify by adding X.  But make sure you /show/ them how easy it is to
> add.  Maybe they might want to add the next feature themselves (because
> you're really busy right now...)?  Hey look - you have another person
> writing Erlang :)
>
> * Make sure you read up on all the great stuff Erlang can give you -
> especially the reliability and "safe crashing" aspects.  Telco people,
> especially, /love/ reliability for obvious reasons.  We have a process
> where one single bad pointer can take down 5000 phones for 20 seconds -
> imagine how aweomse it sounds if a bug in your code will, in all but the
> worst possible cases, take down only one or two!
>
> * This step is where, I think, we got a bit lucky - we started actively
> agitating to write new bits of the core code in Erlang.  Depeding on
> your system, that's probably going to have a high startup cost in terms
> of writing a layer to interact with the legacy code.  Somehow we
> convinced them it was, in fact, the "way forward", but we didn't have
> time to convert anything that we currently had (fair enough - it was all
> "working" okay).  But then we got another lucky break when we were asked
> to write a whole new module for the existing core system, and the job
> was given to the two biggest Erlang users :)
>
> * This time, we didn't try to sneak it "under the radar" - we said we
> wanted to do it in Erlang, said there would be a certain cost to getting
> the initial interface layer written, but also made it clear that we were
> totally convinced it would pay off, even for this single module.  Based
> in no small part on our earlier success with the testing system, we got
> the go-ahead.
>
> * The only other suggestion I can give is, if you get to that stage,
> take as much time as you can to make sure you get the first serious bit
> of Erlang stuff "right".  If you still have nay-sayers, they will be
> looking for any little thing that goes wrong as a way of saying "see?
> Told you Erlang was rubbish - we should be sticking with good-ole
> reliable C++".  Never mind that the C++ stuff crashed twice a day when
> they first coded it :)
>
> Like I said, that's just our story - it may or may not be any use to you.
> > My boss question me about 'Who is using Erlang?' and I am trying to
> > found some in my country (Brazil).
> Can't help you with that one, sorry (not for Brazil, anyway).  What I
> /would/ say is that it's entirely typical of "management" to take the
> "well if it's so great, why isn't everyone else using it?" attitude.
> I'm sure it's self-evident to everyone on this list why that very
> question itself is wrong, but it's the job of management not to screw
> up.  If they have something that is seen to be working (for some
> definition of "working"), the choice they see is between a "zero risk"
> option of changing nothing or a risky option that some guy is telling
> them will make things better.  It's always the easier choice to stick
> with a known quantity.  I'm not meaning this as some kind of
> "anti-management-they're-all-morons" rant - they have a different
> perspective on things and I can totally understand their reluctance to
> move away from a known quantity.
> > Now I can't waiting more and start a internal project to interfacing
> > with CHILL/C/C++ old base and Erlang.
> Good luck!  Let us know how you get on.
>
> B
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>


-- 
http://www.linkedin.com/in/torbenhoffmann

From g9414002.pccu.edu.tw@REDACTED  Sun Jul  4 17:04:37 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Sun, 4 Jul 2010 23:04:37 +0800
Subject: [erlang-questions] Trying to change things
In-Reply-To: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
References: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
Message-ID: <AANLkTilTsmqJivGnnRUMFsQYzJp9Qb2QKg794lJFgwJc@mail.gmail.com>

2010/7/4 Jo?o Henrique Freitas <joaohf@REDACTED>

> I am working on a place wich uses the CHILL language programming to
> develop a huge telecom system. We use others languages too like C and
> C++. But CHILL is the largest code base.
>
> I staring to learning Erlang about six months ago and in the last
> three months I spent a lot of energies trying persuade developers to
> change from CHILL/C/C++ to Erlang.
>
> But is hard change things. Anybody have some experience with these
> situation?
>
> My boss question me about 'Who is using Erlang?' and I am trying to
> found some in my country (Brazil).
>
> Now I can't waiting more and start a internal project to interfacing
> with CHILL/C/C++ old base and Erlang.
>
>
It a cultural and religious problems. And it's not easy to vanquish all
users
of other languages. They used CHILL, C, and C++. Do you know about
how much they used them and enjoyed benefits of them? And how long
have you been in the firm is another factor.

If you have to replace original things with others, you have to give
something
with more benefits than the older one. You must give something that they
can try and done.

I'm in Taiwan, and there's no Erlang jobs and cases here. I'm seeking
opportunities for showing and promoting Erlang. Writing a book may be
a way. In my firm, unfortunately, they immersed in Microsoft solutions.
It's not bad, but it seems no way left for Erlang. :$

And I'm figuring which kind of application may be a start for Erlang.
Web development solutions? I'm not sure.

From kenji.rikitake@REDACTED  Mon Jul  5 07:17:54 2010
From: kenji.rikitake@REDACTED (Kenji Rikitake)
Date: Mon, 5 Jul 2010 14:17:54 +0900
Subject: revised R14A FreeBSD unofficial port Re: [erlang-questions] R14A
	FreeBSD unofficial port
In-Reply-To: <20100620042450.GA28253@k2r.org>
References: <20100620042450.GA28253@k2r.org>
Message-ID: <20100705051754.GA74549@k2r.org>

http://www.ne.jp/asahi/bdx/info/software/erlang-r14a,2-20100705.tar.gz

This tar.gz archive includes an unofficial port of
Erlang R14A for FreeBSD (lang/erlang, erlang-r14a,2_1)

Note 1: R13A port hasn't been released officially, so
        I expect R14A port won't be released officially either.

Note 2: Java functionality untested.

Note 3: Compilation/installation ested on FreeBSD 7.3-RELEASE i386.

Note 4: a patch added 
        to fix inet_drv to detect passive mode UDP errors for SCTP builds
http://www.erlang.org/cgi-bin/ezmlm-cgi?3:mss:1195:201006:ljbebjdglkaipibfaoaf
http://github.com/RaimoNiskanen/otp/commit/5615d7ac85e94ec718a2acdc9e77381f9109a64c

Regards,
Kenji Rikitake

From info@REDACTED  Mon Jul  5 11:01:24 2010
From: info@REDACTED (info)
Date: Mon, 5 Jul 2010 11:01:24 +0200
Subject: embedded timeouts
Message-ID: <201007051101243128942@its3.ch>

Hi all,
Why the first timeout never happens ?
How must be structured this code in order to have two timeouts ?

init(Timeout)->
   receive
     ...
     loop(),
     after Timeout ->
     ...
   end.

loop()->
   ...
   send(Message),
   receive after 1000 -> 0 end
loop().

From ulf.wiger@REDACTED  Mon Jul  5 11:22:40 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Mon, 05 Jul 2010 11:22:40 +0200
Subject: [erlang-questions] embedded timeouts
In-Reply-To: <201007051101243128942@its3.ch>
References: <201007051101243128942@its3.ch>
Message-ID: <4C31A460.8000308@erlang-solutions.com>

info wrote:
> Hi all,
> Why the first timeout never happens ?

Does the function in init/1 receive a message?
If it does, and loop/1 is called, it is no longer inside
the receive clause, and the 'after' clause will not
execute (it simply means, do this if no message has arrived
within Timeout milliseconds).

If no message is sent to the receive clause in init/1,
loop() will never be called.

BR,
Ulf W

> How must be structured this code in order to have two timeouts ?
> 
> init(Timeout)->
>    receive
>      ...
>      loop(),
>      after Timeout ->
>      ...
>    end.
> 
> loop()->
>    ...
>    send(Message),
>    receive after 1000 -> 0 end
> loop().
> 


-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From marc@REDACTED  Mon Jul  5 11:55:41 2010
From: marc@REDACTED (Marc Worrell)
Date: Mon, 5 Jul 2010 11:55:41 +0200
Subject: Looking for an Erlang developer
Message-ID: <5BEFD130-1A15-4CE3-B2C5-2497A24492D1@worrell.nl>

We are looking for an Erlang programmer and found that it is quite difficult to find someone.  We also found that the available positions are spread out over many websites.  Which makes it hard to find interesting positions for those that are looking for Erlang work.

So we made a little site ( http://totally-erlang.com/ ) to quickly (and freely) publish any Erlang positions.

The first thing we need now is other people joining in so if you know anybody that needs to post a job ? I would appreciate it if you pass it on!

Kind Regards,

Marc Worrell

From rapsey@REDACTED  Mon Jul  5 12:21:03 2010
From: rapsey@REDACTED (Rapsey)
Date: Mon, 5 Jul 2010 12:21:03 +0200
Subject: [Erlyaws-list] Write rendered EHTML to file
In-Reply-To: <AANLkTil9oGZBwTHn2bEZ2CZ8ZOvv0DrUzwYk2uBkwosj@mail.gmail.com>
References: <AANLkTil9oGZBwTHn2bEZ2CZ8ZOvv0DrUzwYk2uBkwosj@mail.gmail.com>
Message-ID: <AANLkTilcLc23MPuH9MBWBgX62iGjXk4sVJLJfDIAG9bb@mail.gmail.com>

Call the ehtml functions in yaws_api directly to convert ehtml to iolist.
yaws_api:ehtml_expand(EHTML) should be the right one I think.


Sergej

On Mon, Jul 5, 2010 at 11:58 AM, Branko Vukelic <bg.branko@REDACTED> wrote:

> Hi,
>
> Is there a way to write rendered EHTML to a file instead of returning it?
>
> What I'm trying to do is to make a appmod for generating static HTML
> pages based on user input that will be placed in a directory that is
> served as a regular static site.
>
> Thanks,
>
> --
> Branko Vukeli?
>
> bg.branko@REDACTED
> studio@REDACTED
>
> Check out my blog: http://www.brankovukelic.com/
> Check out my portfolio: http://www.flickr.com/photos/foxbunny/
> Registered Linux user #438078 (http://counter.li.org/)
> I hang out on identi.ca: http://identi.ca/foxbunny
>
> Gimp Brushmakers Guild
> http://bit.ly/gbg-group
>
>
> ------------------------------------------------------------------------------
> This SF.net email is sponsored by Sprint
> What will you do first with EVO, the first 4G phone?
> Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first
> _______________________________________________
> Erlyaws-list mailing list
> Erlyaws-list@REDACTED
> https://lists.sourceforge.net/lists/listinfo/erlyaws-list
>

From e_d_k@REDACTED  Mon Jul  5 14:21:11 2010
From: e_d_k@REDACTED (Ed Keith)
Date: Mon, 5 Jul 2010 05:21:11 -0700 (PDT)
Subject: [erlang-questions] Looking for an Erlang developer
In-Reply-To: <5BEFD130-1A15-4CE3-B2C5-2497A24492D1@worrell.nl>
Message-ID: <812947.17334.qm@web120510.mail.ne1.yahoo.com>

It might be a good idea to also allow people looking for Erlang Jobs to post resumes.

  -EdK

Ed Keith
e_d_k@REDACTED

Blog: edkeith.blogspot.com


--- On Mon, 7/5/10, Marc Worrell <marc@REDACTED> wrote:

> From: Marc Worrell <marc@REDACTED>
> Subject: [erlang-questions] Looking for an Erlang developer
> To: erlang-questions@REDACTED
> Date: Monday, July 5, 2010, 5:55 AM
> We are looking for an Erlang
> programmer and found that it is quite difficult to find
> someone.? We also found that the available positions
> are spread out over many websites.? Which makes it hard
> to find interesting positions for those that are looking for
> Erlang work.
> 
> So we made a little site ( http://totally-erlang.com/ ) to quickly (and freely)
> publish any Erlang positions.
> 
> The first thing we need now is other people joining in so
> if you know anybody that needs to post a job ? I would
> appreciate it if you pass it on!
> 
> Kind Regards,
> 
> Marc Worrell


      

From info@REDACTED  Mon Jul  5 15:33:48 2010
From: info@REDACTED (info)
Date: Mon, 5 Jul 2010 15:33:48 +0200
Subject: [erlang-questions] embedded timeouts
References: <201007051101243128942@its3.ch>,
 <4C31A460.8000308@erlang-solutions.com>
Message-ID: <201007051533476090057@its3.ch>

The problem is that the "after Timeout" closure is never called. The loop never stops !
John

info wrote:
> Hi all,
> Why the first timeout never happens ?

Does the function in init/1 receive a message?
If it does, and loop/1 is called, it is no longer inside
the receive clause, and the 'after' clause will not
execute (it simply means, do this if no message has arrived
within Timeout milliseconds).

If no message is sent to the receive clause in init/1,
loop() will never be called.

BR,
Ulf W

> How must be structured this code in order to have two timeouts ?
> 
> init(Timeout)- >
>    receive
>      ...
>      loop(),
>      after Timeout - >
>      ...
>    end.
> 
> loop()- >
>    ...
>    send(Message),
>    receive after 1000 - > 0 end
> loop().
> 


-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From bartlomiej@REDACTED  Mon Jul  5 15:37:49 2010
From: bartlomiej@REDACTED (=?utf-8?Q?Bart=C5=82omiej_Puzo=C5=84?=)
Date: Mon, 5 Jul 2010 13:37:49 +0000 (GMT)
Subject: [erlang-questions] embedded timeouts
In-Reply-To: <201007051533476090057@its3.ch>
Message-ID: <871634171.568481278337069585.JavaMail.root@zimbra>

Yes, it is an intended behaviour. The receive's "after" closure applies if and only if there is no message to match
for the receive construct within a given amount of time.


----- "info" <info@REDACTED> escribi?:

> The problem is that the "after Timeout" closure is never called. The
> loop never stops !
> John
> 
> info wrote:
> > Hi all,
> > Why the first timeout never happens ?
> 
> Does the function in init/1 receive a message?
> If it does, and loop/1 is called, it is no longer inside
> the receive clause, and the 'after' clause will not
> execute (it simply means, do this if no message has arrived
> within Timeout milliseconds).
> 
> If no message is sent to the receive clause in init/1,
> loop() will never be called.
> 
> BR,
> Ulf W
> 
> > How must be structured this code in order to have two timeouts ?
> > 
> > init(Timeout)- >
> >    receive
> >      ...
> >      loop(),
> >      after Timeout - >
> >      ...
> >    end.
> > 
> > loop()- >
> >    ...
> >    send(Message),
> >    receive after 1000 - > 0 end
> > loop().
> > 
> 
> 
> -- 
> Ulf Wiger
> CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
> http://www.erlang-solutions.com

-- 
Bart?omiej Puzo?
Erlang Solutions
bartlomiej.puzon@REDACTED

From juanjo@REDACTED  Mon Jul  5 17:57:47 2010
From: juanjo@REDACTED (Juan Jose Comellas)
Date: Mon, 5 Jul 2010 12:57:47 -0300
Subject: [erlang-questions] Trying to change things
In-Reply-To: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
References: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
Message-ID: <AANLkTinZ2IhC6094Cx88vPVJhHXBbyOEfOKFuV24lsMS@mail.gmail.com>

Jo?o, we successfully migrated a client's distributed telecom system (about
50K users) from Java/C/C++ to Erlang/C a few years ago. The new system's
been in production for a little less than a year and it took about 1.5 years
to rewrite it and achieve feature parity (and more) with the original
system. Nowadays, the new system can probably handle 10x the load of the
original one per server. There were improvements in the architecture, of
course, but switching to Erlang was one of the main reasons for the
project's success and the performance improvements.

About 3 years ago, we were reaching the limits of the old system, so we
asked the client to let us dedicate 2 developers to creating some prototypes
for a new version of the system. We created 3 prototypes: one in Java; one
in a mixture of JavaScript and a C core; and the other one in Erlang. The
Erlang prototype was the last one we did, and even before finishing it, it
was clear that it was the way to go. The JavaScript version was discarded
because it lacked certain key functionality that was really very difficult
to add. For the Java prototype we'd spent weeks trying to transparently
distribute calls among servers, to support hot code loading and to achieve a
level of fault-tolerance that would allow us to avoid dropping calls in case
of exceptions/errors in our own code. We made it work, but when compared to
what Erlang gave us for free our own code was much less resilient and much
more complex. It was clear at that point that continuing using Java for this
was harming us more than helping us. We talked to the client, showed them
the code and how simpler it was to solve our problem in Erlang and convinced
them to switch.

Erlang has its own set of problems, but they are mostly due to its weirdness
when coming from an imperative background and to its lack of market
penetration. We are in Buenos Aires, Argentina (not that far from you and
sharing your pain in the World Cup), and finding Erlang developers at the
time was a bit problematic. In our case, we didn't have any previous
experience with Erlang, other than using ejabberd for other projects, so we
had to learn it by ourselves and then had to retrain our Java developers. It
took at least a month to get them to the point where they could start
working on "real" code.

I have no regrets regarding the decision, but you will need the people
responsible for making the decision to trust you enough to commit to it.
Nowadays the decision should be simpler because there are some great books
and opensource libraries around. There are also several success stories from
big companies that have helped gather more mindshare.

So, good luck with this and don't hesitate to contact me if I can be of any
help.


2010/7/3 Jo?o Henrique Freitas <joaohf@REDACTED>

> Hello,
>
> I am working on a place wich uses the CHILL language programming to
> develop a huge telecom system. We use others languages too like C and
> C++. But CHILL is the largest code base.
>
> I staring to learning Erlang about six months ago and in the last
> three months I spent a lot of energies trying persuade developers to
> change from CHILL/C/C++ to Erlang.
>
> But is hard change things. Anybody have some experience with these
> situation?
>
> My boss question me about 'Who is using Erlang?' and I am trying to
> found some in my country (Brazil).
>
> Now I can't waiting more and start a internal project to interfacing
> with CHILL/C/C++ old base and Erlang.
>
> Thanks
>
> --
> -----------------------------------------------------------
> Jo?o Henrique Freitas - joaohf_at_gmail.com
> Campinas-SP-Brasil
> BSD051283
> LPI 1
> http://www.joaohfreitas.eti.br
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From max.lapshin@REDACTED  Mon Jul  5 22:36:11 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Tue, 6 Jul 2010 00:36:11 +0400
Subject: Segmentation fault in crypto:dh_generate_key R13B4
Message-ID: <AANLkTilbwtMtLdMDNDfyvOtjnlZCTlnifhNZc5jhK5xN@mail.gmail.com>

Erlang R13B4, OS X 10.6, erlang build from homebrew


otool -L /usr/local/lib/erlang/lib/crypto-1.6.4/priv/lib/crypto_drv.so
/usr/local/lib/erlang/lib/crypto-1.6.4/priv/lib/crypto_drv.so:
	/usr/lib/libcrypto.0.9.8.dylib (compatibility version 0.9.8, current
version 0.9.8)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
version 125.0.0)


Starting attached file leads to Segmentation Fault:


maxbp:erlyvideo max$ ./dh_check.erl
Segmentation fault

What should I do more to fix this problem?
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From jesper.louis.andersen@REDACTED  Tue Jul  6 00:01:55 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Tue, 6 Jul 2010 00:01:55 +0200
Subject: ANN: etorrent v1.0.0
Message-ID: <AANLkTikv3c93BuqH8lUTgMkYJDfqWv3p8rOJ1k_zXDpS@mail.gmail.com>

(Apologies if there is another list taking software release announcements)

I am happy to announce etorrent v1.0.0 to the masses. Etorrent is a
bittorrent client
written in Erlang, relying on concurrency to get the job done.
Etorrent is a fully functional bittorrent client for the base
protocol, although it needs some work to support all extensions to the
protocol. This is the first release in about 2 years on the project.
Overall this version of the client is the first one which is not
simply a tech-preview. It can actually be used as a client on a daily
basis if one wants.

Code and downloads are available from the Github page:

http://github.com/jlouis/etorrent

Building requires rebar, although it should be fairly easy to call
emake by yourself if wanted.

  Highlights:

  (Tuncer Ayaz): Estimate the ETA of torrents. Guess at when they are done.

  When processes are stopping, correctly clean up ETS tables. The solution we
  use is to place monitors on key processes. Bookkeeping processes then act on
  'DOWN' messages and remove ETS entries again.

  All module-exported functions now have edoc tags and -spec entries.

  We now use rebar for building the application. To come is a standalone-node
  provisioning. For now the 'run' makefile target is to be used. Also adapt the
  file layout mandated by rebar.

  Adaptive active/passive sockets. When a peer is slow, we manage the socket
  ourselves. This gives fine granularity of its speed. When the peer socket
  jumps above a high watermark, it is made active, pushing the overhead to the
  C-layer of the VM.

  Use an LRU-replacement scheme on open files. Limit the number of open files
  to 128 at once. This enables torrents with more than 1024 - OPEN_SOCKETS
  files to be downloaded.

  Add a WebUI. The inets server provides a simple RPC-service for a primarily
  Javascript-enabled web-frontend. It can only display the basic overview at
  the moment, but it should be easy to extend with new functionality.

  Numerous additional code cleanups here and there. It should be even easier to
  read and understand now.

  Make GitHub the official repository place:

    http://github.com/jlouis/etorrent

  Use http://github.com/jlouis/etorrent/issues for issues. Issues can be voted
  on, so if one prefers one thing over the other, don't hesitate to hint me :)


-- 
J.

From ci.johnpaul87@REDACTED  Tue Jul  6 05:53:25 2010
From: ci.johnpaul87@REDACTED (johnpaul ci)
Date: Mon, 5 Jul 2010 23:53:25 -0400
Subject: Fwd: error in crypo module
Message-ID: <AANLkTik19pGb8lhoGFD4fHJsX78bz6OnjFrU5Ko4XQn-@mail.gmail.com>

---------- Forwarded message ----------
From: johnpaul ci <ci.johnpaul87@REDACTED>
Date: Mon, 5 Jul 2010 00:53:41 -0400
Subject: Re: ex11 usage
To: Joe Armstrong <erlang@REDACTED>

Hello


This time I am sending you another errot encountered when using the
crypto moduke in erlang. I have installed the package erlang-crypto
and some its functions are working well. The following errors occured
when tried to run the functions of DES encryption.

3>Key = <<16#01,16#23,16#45,16#67,16#89,16#ab,16#cd,16#ef>>.
<<1,35,69,103,137,171,205,239>>
4> IVec = <<16#12,16#34,16#56,16#78,16#90,16#ab,16#cd,16#ef>>.
<<18,52,86,120,144,171,205,239>>
5> P = "Now is the time for all ".
"Now is the time for all "
6> C = crypto:des_cbc_encrypt(Key, IVec, P).
** exception error: bad argument
     in function  port_control/3
        called as port_control(crypto_drv02,13,
                               [<<1,35,69,103,137,171,205,239>>,
                                <<18,52,86,120,144,171,205,239>>,
                                "Now is the time for all "])
     in call from crypto:control/2


How can this be rectified.

Thankyou

From kenji.rikitake@REDACTED  Tue Jul  6 06:42:51 2010
From: kenji.rikitake@REDACTED (Kenji Rikitake)
Date: Tue, 6 Jul 2010 13:42:51 +0900
Subject: [erlang-questions] Fwd: error in crypo module
In-Reply-To: <AANLkTik19pGb8lhoGFD4fHJsX78bz6OnjFrU5Ko4XQn-@mail.gmail.com>
References: <AANLkTik19pGb8lhoGFD4fHJsX78bz6OnjFrU5Ko4XQn-@mail.gmail.com>
Message-ID: <20100706044251.GA9836@k2r.org>

Which version of Erlang are you using?
In R13B04 and before (inclusive), you need to do
crypto:start()
before using the crypto module functions.
In R14A, you don't have to.

Here it's like this:
-- begin --
Erlang R14A (erts-5.8) [source] [smp:2:2] [rq:2] [async-threads:0] [hipe] [kernel-poll:false]

Eshell V5.8  (abort with ^G)
1> Key = <<16#01,16#23,16#45,16#67,16#89,16#ab,16#cd,16#ef>>.
<<1,35,69,103,137,171,205,239>>
2> IVec = <<16#12,16#34,16#56,16#78,16#90,16#ab,16#cd,16#ef>>.
<<18,52,86,120,144,171,205,239>>
3> P = "Now is the time for all ".
"Now is the time for all "
4> length(P).
24
5> C = crypto:des_cbc_encrypt(Key, IVec, P).
<<229,199,205,222,135,43,242,124,67,233,52,0,140,56,156,
  15,104,55,136,73,154,124,5,246>>
6> P2 = crypto:des_cbc_decrypt(Key, IVec, C).
<<"Now is the time for all ">>

10> P3 = erlang:binary_to_list(P2).
"Now is the time for all "
11> P3 =:= P.
true
-- end --

Kenji Rikitake

In the message <AANLkTik19pGb8lhoGFD4fHJsX78bz6OnjFrU5Ko4XQn-@REDACTED>
dated Mon, Jul 05, 2010 at 11:53:01PM -0400,
johnpaul ci <ci.johnpaul87@REDACTED> writes:

> 3>Key = <<16#01,16#23,16#45,16#67,16#89,16#ab,16#cd,16#ef>>.
> <<1,35,69,103,137,171,205,239>>
> 4> IVec = <<16#12,16#34,16#56,16#78,16#90,16#ab,16#cd,16#ef>>.
> <<18,52,86,120,144,171,205,239>>
> 5> P = "Now is the time for all ".
> "Now is the time for all "
> 6> C = crypto:des_cbc_encrypt(Key, IVec, P).
> ** exception error: bad argument
>      in function  port_control/3
>         called as port_control(crypto_drv02,13,
>                                [<<1,35,69,103,137,171,205,239>>,
>                                 <<18,52,86,120,144,171,205,239>>,
>                                 "Now is the time for all "])
>      in call from crypto:control/2

From kenji.rikitake@REDACTED  Tue Jul  6 06:51:28 2010
From: kenji.rikitake@REDACTED (Kenji Rikitake)
Date: Tue, 6 Jul 2010 13:51:28 +0900
Subject: Tokyo Erlang Workshop #5: Friday 27-AUG-2010 8pm-10pm(JST) at
	Oracle Aoyama Center
Message-ID: <20100706045128.GB9836@k2r.org>

Tokyo Erlang Workshop #5 will be held on
Friday, August 27, 2010 8pm-10pm JST at
Oracle Aoyama Center (near Tokyo Metro Gaien-Mae station)
Location map in Japanese:
http://www.oracle.co.jp/aoyamacenter/

Presentations are mostly given in Japanese but English-speaking
participants are also welcome.

Program details TBD.
(Gemini Mobile Technology Japan will make a presentation about the
Hibari KVS, in English.  Details may be changed later.)

Contact
Masahito Ikuta <cooldaemon@REDACTED>
for the further details.

Regards,
Kenji Rikitake

From michael.eugene.turner@REDACTED  Tue Jul  6 09:50:08 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Tue, 6 Jul 2010 16:50:08 +0900
Subject: [erlang-questions] Trying to change things
In-Reply-To: <AANLkTinApQbJ4LO8Nw4wq90nxoqtUrTopCfXp3Y_dYj3@mail.gmail.com>
References: <AANLkTilxSj8EGToIYxLETSc1tTy_UnWVZp3vuvGORTd9@mail.gmail.com>
	<AANLkTinApQbJ4LO8Nw4wq90nxoqtUrTopCfXp3Y_dYj3@mail.gmail.com>
Message-ID: <AANLkTikgO3wPuFeVPG-f_LiQ8ymdEJQiuWJnwKc9TY6a@mail.gmail.com>

In private e-mail, I wrote, in part:

2010/7/5 Michael Turner <michael.eugene.turner@REDACTED>

> "CHILL is unusual in that it supports two forms of declaration syntax, one
> based on Cobol <http://en.wikipedia.org/wiki/Cobol> and the other on PL/1<http://en.wikipedia.org/wiki/PL/1>."
>  (Wikipedia)
>
> My heart goes out to you. ;-)
>
> You're fighting the inertia of legacy code.  However, the inertia of a
> legacy can cut both ways.  Erlang itself has benefited by the same social
> and institutional inertia you describe.  Erlang survived in part because
> open-sourcing helped circumvent the *formal* objection that -- contrary to a
> recent policy in the late 90s at Ericsson -- it was not independently
> supported.  Realistically, however, Erlang was foundational in a successful
> product.  It takes a long time to get rid of something like that, even if
> you should.  Erlang is an open-sourced legacy, luckily with real legs,
> crossing seas.
>

It occurs to me now that, both in my joke and in the rest of my comments,
there's an underlying message: politically, it seldom hurts to show due
respect for why people have done things a certain way in the past.  If your
company uses CHILL, it probably made sense at one time, and might even make
a lot of sense now.

Take CHILL'S PL/1 and COBOL declaration syntax (please!).  I can see why it
might be important, even now.

Telecom is concurrent-event-intensive, so Erlang is a good match.  However,
with these events, we're not talking about UDP packets, which you can toss
on the floor without much worry.  No, many, if not most, of certain major
classes of events also represent *billing opportunities*, or they at least
relate to billing opportunities in some way that has bottom-line impact for
the telco.

Billing is often done on legacy systems, in COBOL.  Yes, still!  The COBOL
billing code is often hosted on IBM mainframes -- yes, still!  The systems
programming language for those mainframes might still be predominantly PL/1
-- yes, still!  And ultimately, the telecom switches have to be integrated
with the business systems, because nobody's going type all that stuff in
from switch log printouts.  There's not enough paper in the world anyway, to
print it all out.

If CHILL uses PL/1 and COBOL declaration syntax, that might be ugly, but
from a global systems configuration perspective, and from a source code
management perspective, using that syntax might also exceedingly practical.
 It means the CHILL code that runs the switch, the PL/1 code that talks
directly to the switch, and the COBOL code that talks to the PL/1 code, can
*all* share header files.

Now, these facts might actually be irrelevant in your context, in the year
2010.  Maybe your company's business apps are now all written in Java.  But
what if it isn't irrelevant?  What if it's, in fact, mission-critical? Then
writing something in Erlang that can understand PL/1 and COBOL declaration
syntax (don't try Erlang parse transforms at home, at least not at this
stage) would speak very clearly to management, in your favor.  It shows you
can nod toward the necessities of the past while looking toward the future.
 It would be especially cool if you could use Erlang bitstring features to
adhere to any binary (and, where character-oriented, possibly EBCDIC-based)
protocols.


Here's another sales technique that can work.  (If you aren't good at
selling technical ideas to technical people, and then to managers above
them, find somebody in your workplace who is, and convert them to Erlang
ideas the best you can.)

Give a presentation and get the nod of approval for Erlang from the
*smartest* person in your shop, whether they have any real authority or not.

Then teach some Erlang to the person in your shop who is generally regarded
as the slowest.  (Be careful here: the real problem with this person might
be only that they aren't very motivated, because they've gotten bored with
programming.  And if you're lucky, Erlang exposure could change that.)

You now have two very persuasive arguments in your favor:

(1) The endorsement of the brightest.

(2) A defense against the following (very common) management objection to
adopting new technology, "Well, sure, our smartest programmer is probably
right when he agrees with you that [technology X] very powerful and useful.
 For really smart people, maybe [technology X] makes sense.  But we have to
hire -- and make use of -- relatively average programmers as well.
 [Technology X] is probably over their heads."  Running code in Erlang
written by your resident "relatively average" programmer closes the deal.
 Just be careful how you say this.

-michael turner

From schramm.ingo@REDACTED  Tue Jul  6 10:05:31 2010
From: schramm.ingo@REDACTED (ingo.schramm)
Date: Tue, 6 Jul 2010 01:05:31 -0700 (PDT)
Subject: Erlang: Who uses it for games?
Message-ID: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>

Does somebody ever used Erlang to program game servers? Is there any
real live industrial game solution written in Erlang?

I need to know this for some evangelization :)

Cheers,
Ingo

From pguyot@REDACTED  Tue Jul  6 10:12:36 2010
From: pguyot@REDACTED (Paul Guyot)
Date: Tue, 6 Jul 2010 10:12:36 +0200
Subject: Segmentation fault in crypto:dh_generate_key R13B4
In-Reply-To: <1278402610.30818.ezmlm@erlang.org>
References: <1278402610.30818.ezmlm@erlang.org>
Message-ID: <74E5A8FE-C6D6-4697-8E8D-FBAFF80119B8@kallisys.net>


Le 6 juil. 2010 ? 09:50, erlang-questions-digest-help@REDACTED a ?crit :

> De : Max Lapshin <max.lapshin@REDACTED>
> Date : 5 juillet 2010 22:36:11 HAEC
> ? : Erlang-Questions Questions <erlang-questions@REDACTED>
> Objet : Segmentation fault in crypto:dh_generate_key R13B4
> 
> 
> Erlang R13B4, OS X 10.6, erlang build from homebrew
> 
> 
> otool -L /usr/local/lib/erlang/lib/crypto-1.6.4/priv/lib/crypto_drv.so
> /usr/local/lib/erlang/lib/crypto-1.6.4/priv/lib/crypto_drv.so:
> 	/usr/lib/libcrypto.0.9.8.dylib (compatibility version 0.9.8, current
> version 0.9.8)
> 	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
> version 125.0.0)
> 
> 
> Starting attached file leads to Segmentation Fault:
> 
> 
> maxbp:erlyvideo max$ ./dh_check.erl
> Segmentation fault
> 
> What should I do more to fix this problem?
> <dh_check.erl>

As of R14A, crypto has been rewritten and is now based on NIF instead of relying on a linked-in driver. While this doesn't excuse the seg fault, I believe there is a bug in your code:

  DH_P = <<16#ff, 16#ff, 16#ff, 16#ff, 16#ff,
            		16#ff, 16#ff, 16#ff, 16#c9, 16#0f, 16#da, 16#a2, 16#21,
            		16#68, 16#c2, 16#34, 16#c4, 16#c6, 16#62, 16#8b, 16#80,
            		16#dc, 16#1c, 16#d1, 16#29, 16#02, 16#4e, 16#08, 16#8a,
            		16#67, 16#cc, 16#74, 16#02, 16#0b, 16#be, 16#a6, 16#3b,
            		16#13, 16#9b, 16#22, 16#51, 16#4a, 16#08, 16#79, 16#8e,
            		16#34, 16#04, 16#dd, 16#ef, 16#95, 16#19, 16#b3, 16#cd,
            		16#3a, 16#43, 16#1b, 16#30, 16#2b, 16#0a, 16#6d, 16#f2,
            		16#5f, 16#14, 16#37, 16#4f, 16#e1, 16#35, 16#6d, 16#6d,
            		16#51, 16#c2, 16#45, 16#e4, 16#85, 16#b5, 16#76, 16#62,
            		16#5e, 16#7e, 16#c6, 16#f4, 16#4c, 16#42, 16#e9, 16#a6,
            		16#37, 16#ed, 16#6b, 16#0b, 16#ff, 16#5c, 16#b6, 16#f4,
            		16#06, 16#b7, 16#ed, 16#ee, 16#38, 16#6b, 16#fb, 16#5a,
            		16#89, 16#9f, 16#a5, 16#ae, 16#9f, 16#24, 16#11, 16#7c,
            		16#4b, 16#1f, 16#e6, 16#49, 16#28, 16#66, 16#51, 16#ec,
            		16#e6, 16#53, 16#81, 16#ff, 16#ff, 16#ff, 16#ff, 16#ff,
            		16#ff, 16#ff, 16#ff>>,
  DH_G = 2,
  crypto:dh_generate_key([DH_P, DH_G]).

You pass a binary which is not a mpint() and an integer to crypto:dh_generate_key/1.
You should call crypto:mpint/1 instead, e.g.:

  DH_P = crypto:mpint(16#ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024e088a67cc74020bbea63b139b22514a08798e3404ddef9519b3cd3a431b302b0a6df25f14374fe1356d6d51c245e485b576625e7ec6f44c42e9a637ed6b0bff5cb6f406b7edee386bfb5a899fa5ae9f24117c4b1fe649286651ece65381ffffffffffffffff),
  DH_G = crypto:mpint(2),
  crypto:dh_generate_key([DH_P, DH_G]).
  
Paul
-- 
Semiocast                    http://semiocast.com/
+33.175000290 - 62 bis rue Gay-Lussac, 75005 Paris


From max.lapshin@REDACTED  Tue Jul  6 10:16:26 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Tue, 6 Jul 2010 12:16:26 +0400
Subject: [erlang-questions] Re: Segmentation fault in crypto:dh_generate_key 
	R13B4
In-Reply-To: <74E5A8FE-C6D6-4697-8E8D-FBAFF80119B8@kallisys.net>
References: <1278402610.30818.ezmlm@erlang.org>
	<74E5A8FE-C6D6-4697-8E8D-FBAFF80119B8@kallisys.net>
Message-ID: <AANLkTiklv9O08BFT9aP96ay8C1IrVDahP9AImEgPBOXS@mail.gmail.com>

You've seen my code in attached file. It produces segmentation fault,
so it doesn't matter, whether it is bug in my code or not.
Under no circumstances erlang linked-in driver should generate segfault.

However, if it is rewritten, I will check under R14A and tell about my
experience.

From rapsey@REDACTED  Tue Jul  6 10:32:18 2010
From: rapsey@REDACTED (Rapsey)
Date: Tue, 6 Jul 2010 10:32:18 +0200
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
Message-ID: <AANLkTimZhKdqYzLaROwfkHnFyBoSFal5hUK9L45KH4Zf@mail.gmail.com>

There are a number of hits on google if you search for erlang and mmo


Sergej


On Tue, Jul 6, 2010 at 10:05 AM, ingo.schramm
<schramm.ingo@REDACTED>wrote:

> Does somebody ever used Erlang to program game servers? Is there any
> real live industrial game solution written in Erlang?
>
> I need to know this for some evangelization :)
>
> Cheers,
> Ingo
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From pguyot@REDACTED  Tue Jul  6 10:33:51 2010
From: pguyot@REDACTED (Paul Guyot)
Date: Tue, 6 Jul 2010 10:33:51 +0200
Subject: [erlang-questions] Re: Segmentation fault in crypto:dh_generate_key R13B4
In-Reply-To: <AANLkTiklv9O08BFT9aP96ay8C1IrVDahP9AImEgPBOXS@mail.gmail.com>
References: <1278402610.30818.ezmlm@erlang.org> <74E5A8FE-C6D6-4697-8E8D-FBAFF80119B8@kallisys.net> <AANLkTiklv9O08BFT9aP96ay8C1IrVDahP9AImEgPBOXS@mail.gmail.com>
Message-ID: <2B4B8C20-54D8-4089-ABBD-602B28D93172@kallisys.net>


Le 6 juil. 2010 ? 10:16, Max Lapshin a ?crit :

> You've seen my code in attached file. It produces segmentation fault,
> so it doesn't matter, whether it is bug in my code or not.
> Under no circumstances erlang linked-in driver should generate segfault.

I agree.

> However, if it is rewritten, I will check under R14A and tell about my
> experience.

For the record, the original code does not segfault with crypto 2.0 (R14A).

Regards,

Paul
-- 
Semiocast                    http://semiocast.com/
+33.175000290 - 62 bis rue Gay-Lussac, 75005 Paris


From gleber.p@REDACTED  Tue Jul  6 12:43:39 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Tue, 6 Jul 2010 12:43:39 +0200
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <AANLkTimZhKdqYzLaROwfkHnFyBoSFal5hUK9L45KH4Zf@mail.gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com> 
	<AANLkTimZhKdqYzLaROwfkHnFyBoSFal5hUK9L45KH4Zf@mail.gmail.com>
Message-ID: <AANLkTimAo46qEsMqAR55xLbK_DJEl3UorYB_L6AS2bSj@mail.gmail.com>

Vendetta Online (an Eve-like MMO game) is known to be at least
partially written in Erlang

On Tue, Jul 6, 2010 at 10:32, Rapsey <rapsey@REDACTED> wrote:
> There are a number of hits on google if you search for erlang and mmo
>
>
> Sergej
>
>
> On Tue, Jul 6, 2010 at 10:05 AM, ingo.schramm
> <schramm.ingo@REDACTED>wrote:
>
>> Does somebody ever used Erlang to program game servers? Is there any
>> real live industrial game solution written in Erlang?
>>
>> I need to know this for some evangelization :)
>>
>> Cheers,
>> Ingo
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>

From marc@REDACTED  Tue Jul  6 13:19:34 2010
From: marc@REDACTED (Marc Worrell)
Date: Tue, 6 Jul 2010 13:19:34 +0200
Subject: [erlang-questions] Looking for an Erlang developer
In-Reply-To: <812947.17334.qm@web120510.mail.ne1.yahoo.com>
References: <812947.17334.qm@web120510.mail.ne1.yahoo.com>
Message-ID: <B2C78CFC-A7CA-4198-BA35-3413D23EE463@worrell.nl>

Hi Ed,

Thanks for the suggestion, I will look into it and see if we can add this.

Best,  Marc



On Jul 5, 2010, at 14:21 , Ed Keith wrote:

> It might be a good idea to also allow people looking for Erlang Jobs to post resumes.
> 
>  -EdK
> 
> Ed Keith
> e_d_k@REDACTED
> 
> Blog: edkeith.blogspot.com
> 
> 
> --- On Mon, 7/5/10, Marc Worrell <marc@REDACTED> wrote:
> 
>> From: Marc Worrell <marc@REDACTED>
>> Subject: [erlang-questions] Looking for an Erlang developer
>> To: erlang-questions@REDACTED
>> Date: Monday, July 5, 2010, 5:55 AM
>> We are looking for an Erlang
>> programmer and found that it is quite difficult to find
>> someone.  We also found that the available positions
>> are spread out over many websites.  Which makes it hard
>> to find interesting positions for those that are looking for
>> Erlang work.
>> 
>> So we made a little site ( http://totally-erlang.com/ ) to quickly (and freely)
>> publish any Erlang positions.
>> 
>> The first thing we need now is other people joining in so
>> if you know anybody that needs to post a job ? I would
>> appreciate it if you pass it on!
>> 
>> Kind Regards,
>> 
>> Marc Worrell
> 
> 
> 


From luismarianoguerra@REDACTED  Tue Jul  6 14:09:15 2010
From: luismarianoguerra@REDACTED (Mariano Guerra)
Date: Tue, 6 Jul 2010 09:09:15 -0300
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
Message-ID: <AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com>

On Tue, Jul 6, 2010 at 5:05 AM, ingo.schramm
<schramm.ingo@REDACTED> wrote:
> Does somebody ever used Erlang to program game servers? Is there any
> real live industrial game solution written in Erlang?
>
> I need to know this for some evangelization :)

openpoker is written in erlang

http://www.devmaster.net/articles/mmo-scalable-server/
http://github.com/wagerlabs/openpoker

From bpaquet@REDACTED  Tue Jul  6 17:53:05 2010
From: bpaquet@REDACTED (Bertrand Paquet)
Date: Tue, 6 Jul 2010 17:53:05 +0200
Subject: Slave node and open file
Message-ID: <AANLkTim445rk88N0WNUQrr8q1CVqwY9m6eqPWFH_1A1A@mail.gmail.com>

Hi,

I have the following problem :

1) On master node, I start a remote erlang node with slave:start
command, using ssh
2) I spawn a process in this node
3) In the spawned process, I run inet:gethostname() command, which
give me the remote hostname -> OK
4) In the spawned process, I open /proc/sys/kernel/hostname : I get
the local hostname -> It's not that I want

Do you know :
- if this comportement is normal : a remote node started with
slave:start, which use file:open command access to master node
filesystem ?
- if there is a solution to access to the remote node file system ?

Thank you for your help.

Regards,

Bertrand

From max.lapshin@REDACTED  Tue Jul  6 19:51:44 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Tue, 6 Jul 2010 21:51:44 +0400
Subject: [erlang-questions] Slave node and open file
In-Reply-To: <AANLkTim445rk88N0WNUQrr8q1CVqwY9m6eqPWFH_1A1A@mail.gmail.com>
References: <AANLkTim445rk88N0WNUQrr8q1CVqwY9m6eqPWFH_1A1A@mail.gmail.com>
Message-ID: <AANLkTilkw4OGHDCOOdbe_UbJ8m2jOjW2eq_WG4N8fe2s@mail.gmail.com>

rpc:call ?

From zeno490@REDACTED  Tue Jul  6 21:02:30 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Tue, 6 Jul 2010 15:02:30 -0400
Subject: [erlang-questions] Slave node and open file
In-Reply-To: <AANLkTilkw4OGHDCOOdbe_UbJ8m2jOjW2eq_WG4N8fe2s@mail.gmail.com>
References: <AANLkTim445rk88N0WNUQrr8q1CVqwY9m6eqPWFH_1A1A@mail.gmail.com>
	<AANLkTilkw4OGHDCOOdbe_UbJ8m2jOjW2eq_WG4N8fe2s@mail.gmail.com>
Message-ID: <AANLkTilF1uB2m4sAlDS_bqEr-MoTLAtxtD_vrNwMlJL_@mail.gmail.com>

Unless I am mistaken, the erlang master/slave modules are designed such that
all IO (perhaps only file system IO) on the slave is redirected to the
master. This allows slaves to read/write to the master while doing the heavy
lifting on the remote cpu.
I'm not sure if you can access the slave's file system that way.

On Tue, Jul 6, 2010 at 1:51 PM, Max Lapshin <max.lapshin@REDACTED> wrote:

> rpc:call ?
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From bpaquet@REDACTED  Wed Jul  7 08:37:09 2010
From: bpaquet@REDACTED (Bertrand Paquet)
Date: Wed, 7 Jul 2010 08:37:09 +0200
Subject: [erlang-questions] Slave node and open file
In-Reply-To: <AANLkTilF1uB2m4sAlDS_bqEr-MoTLAtxtD_vrNwMlJL_@mail.gmail.com>
References: <AANLkTim445rk88N0WNUQrr8q1CVqwY9m6eqPWFH_1A1A@mail.gmail.com>
	<AANLkTilkw4OGHDCOOdbe_UbJ8m2jOjW2eq_WG4N8fe2s@mail.gmail.com>
	<AANLkTilF1uB2m4sAlDS_bqEr-MoTLAtxtD_vrNwMlJL_@mail.gmail.com>
Message-ID: <AANLkTimLrT34DXB8Gf6KlcnplaP2inZLC4mvDkt8mAog@mail.gmail.com>

On Tue, Jul 6, 2010 at 21:02, Nicholas Frechette <zeno490@REDACTED> wrote:
> Unless I am mistaken, the erlang master/slave modules are designed such that
> all IO (perhaps only file system IO) on the slave is redirected to the
> master. This allows slaves to read/write to the master while doing the heavy
> lifting on the remote cpu.
> I'm not sure if you can access the slave's file system that way.

Network IOs are not redirected, but stdout and file IO seems to be :-)

Do you know a solution to have the same function as slave:start,
without redirection ?
- start a remote node using rsh
- stop remote nodes when killing master

Actually, I do that with os:cmd("ssh remote erl ..."), but it's not
very clean. And the remote erlang vm is not killed when I kill the
master.

Regards,

Bertrand

From kenji.rikitake@REDACTED  Wed Jul  7 08:46:32 2010
From: kenji.rikitake@REDACTED (Kenji Rikitake)
Date: Wed, 7 Jul 2010 15:46:32 +0900
Subject: [erlang-questions] Tokyo Erlang Workshop #5: Friday
	27-AUG-2010 8pm-10pm(JST) at Oracle Aoyama Center
In-Reply-To: <20100706045128.GB9836@k2r.org>
References: <20100706045128.GB9836@k2r.org>
Message-ID: <20100707064632.GA34594@k2r.org>

Reservation site for Tokyo Erlang Workshop #5 now available:
http://atnd.org/events/6270
(in Japanese)

FYI
Kenji Rikitake

In the message <20100706045128.GB9836@REDACTED>
dated Tue, Jul 06, 2010 at 01:51:04PM +0900,
Kenji Rikitake <kenji.rikitake@REDACTED> writes:
> Date: Tue, 6 Jul 2010 13:51:28 +0900
> From: Kenji Rikitake <kenji.rikitake@REDACTED>
> Subject: [erlang-questions] Tokyo Erlang Workshop #5: Friday 27-AUG-2010 8pm-10pm(JST) at
> 	Oracle Aoyama Center
> To: erlang-questions <erlang-questions@REDACTED>
> 
> Tokyo Erlang Workshop #5 will be held on
> Friday, August 27, 2010 8pm-10pm JST at
> Oracle Aoyama Center (near Tokyo Metro Gaien-Mae station)
> Location map in Japanese:
> http://www.oracle.co.jp/aoyamacenter/
> 
> Presentations are mostly given in Japanese but English-speaking
> participants are also welcome.
> 
> Program details TBD.
> (Gemini Mobile Technology Japan will make a presentation about the
> Hibari KVS, in English.  Details may be changed later.)
> 
> Contact
> Masahito Ikuta <cooldaemon@REDACTED>
> for the further details.
> 
> Regards,
> Kenji Rikitake

From therevoltingx@REDACTED  Wed Jul  7 10:44:24 2010
From: therevoltingx@REDACTED (Miguel Morales)
Date: Wed, 7 Jul 2010 01:44:24 -0700
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
	<AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com>
Message-ID: <AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com>

I'm developing a mobile 2D multiplayer rpg, although it's not open
source you can find my dev blog here:
http://developingthedream.blogspot.com/

I use it alongside rabbitmq and a use the whole 'eveything is a process' method.
Although I haven't released it and scaled it yet, I hope it'll scale
will.  That is if the game needs to.
Some of the links posted are interesting, you'll also get a lot of
hits if you google 'erlang mmo'

It was interesting implementing things like game loops, pathfinding,
chat, etc.  Erlang so far has been a good choice.

(err, sorry, I'm used to using the android-dev list, forgot to hit reply-all)


On Tue, Jul 6, 2010 at 5:09 AM, Mariano Guerra
<luismarianoguerra@REDACTED> wrote:
> On Tue, Jul 6, 2010 at 5:05 AM, ingo.schramm
> <schramm.ingo@REDACTED> wrote:
>> Does somebody ever used Erlang to program game servers? Is there any
>> real live industrial game solution written in Erlang?
>>
>> I need to know this for some evangelization :)
>
> openpoker is written in erlang
>
> http://www.devmaster.net/articles/mmo-scalable-server/
> http://github.com/wagerlabs/openpoker
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
http://developingthedream.blogspot.com/,
http://diastrofunk.com,
http://www.youtube.com/user/revoltingx, ~Isaiah 55:8-9

From kostis@REDACTED  Wed Jul  7 11:34:56 2010
From: kostis@REDACTED (Kostis Sagonas)
Date: Wed, 07 Jul 2010 12:34:56 +0300
Subject: [erlang-questions] type specification
In-Reply-To: <4C2EECED.7070601@tmit.bme.hu>
References: <4C2E09B3.2050505@aleynikov.org> <4C2E16BB.8050506@cs.ntua.gr> <4C2E222D.7070000@tmit.bme.hu> <4C2EE4FB.5070104@cs.ntua.gr> <4C2EECED.7070601@tmit.bme.hu>
Message-ID: <4C344A40.2030102@cs.ntua.gr>

Zoltan Lajos Kis wrote:
> Shouldn't I be warned that b:f breaks the opaqueness of a:my_type() with 
> the modules below?

Well, first of all there is no such should as far as dialyzer is 
concerned. The only property that dialyzer guarantees is that it will 
never produce a warning that is not a discrepancy. Dialyzer has nowhere 
mentioned that it will identify all discrepancies in your program. 
There is a fundamental reason why this is so: so that it guarantees that 
it will never produce a warning that is not a discrepancy ;-)

This property aside, the reason why currently you get no such warning is 
that there is no information flow between the module defining the opaque 
data type and the module where the data type is used. (In fact, in your 
example, the module defining the opaque data type does not really 
construct any such term.) Write in module 'a' a function that constructs 
an opaque term, i.e.

-spec new() -> my_type()
new() -> {foo, bar}.

and use this in module 'b' as follows:

use() ->
    T = a:new(),
    f(T).

and you will get a warning.  I hope it is clear what's happening.

> --------------------------------------------
> -module(a).
> -compile(export_all).
> 
> -opaque( my_type() :: {atom(), atom()} ).
> 
> -export_type([my_type/0]).
> 
> -spec( f(my_type()) -> atom() ).
> f({A,_B}) -> A.
> ---------------------------------------------
> -module(b).
> -compile(export_all).
> 
> -spec( f(a:my_type()) -> atom() ).
> f({A,_B}) -> A.
> ---------------------------------------------

Now, having written all the above, in the current development version of 
dialyzer we have made, long before your mail, an important enhancement 
to the analysis that it will allow you to get the warning you desire. 
Indeed, I get:

b.erl:5: Function f/1 has no local return
b.erl:5: The attempt to match a term of type a:my_type() against the 
pattern {A, _B} breaks the opaqueness of the term


Stay tuned for R14B!

Kostis

From zeno490@REDACTED  Wed Jul  7 15:59:12 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Wed, 7 Jul 2010 09:59:12 -0400
Subject: [erlang-questions] Slave node and open file
In-Reply-To: <AANLkTimLrT34DXB8Gf6KlcnplaP2inZLC4mvDkt8mAog@mail.gmail.com>
References: <AANLkTim445rk88N0WNUQrr8q1CVqwY9m6eqPWFH_1A1A@mail.gmail.com>
	<AANLkTilkw4OGHDCOOdbe_UbJ8m2jOjW2eq_WG4N8fe2s@mail.gmail.com>
	<AANLkTilF1uB2m4sAlDS_bqEr-MoTLAtxtD_vrNwMlJL_@mail.gmail.com>
	<AANLkTimLrT34DXB8Gf6KlcnplaP2inZLC4mvDkt8mAog@mail.gmail.com>
Message-ID: <AANLkTin821lYIBlnhJfijE4Xw2-cVmlpD_bFcCGKVvwE@mail.gmail.com>

Couldn't you connect the slave to the master and link against say, the
supervisor process of the master? If the node goes down or shuts down, won't
that take down the slave as well?
You could even do all that from the master node via rpc module (ie: fork
slave node with name 'foo', use rpc to fork a process that links both the
process on the master that simply kills the slave node when it receives the
node down message).
You can even send the code from the master such that it doesn't need to be
where the slave is started.
Unless there is a cleaner way to do it, that's probably how I would hack it
up if I had to.

On Wed, Jul 7, 2010 at 2:37 AM, Bertrand Paquet <bpaquet@REDACTED> wrote:

> On Tue, Jul 6, 2010 at 21:02, Nicholas Frechette <zeno490@REDACTED>
> wrote:
> > Unless I am mistaken, the erlang master/slave modules are designed such
> that
> > all IO (perhaps only file system IO) on the slave is redirected to the
> > master. This allows slaves to read/write to the master while doing the
> heavy
> > lifting on the remote cpu.
> > I'm not sure if you can access the slave's file system that way.
>
> Network IOs are not redirected, but stdout and file IO seems to be :-)
>
> Do you know a solution to have the same function as slave:start,
> without redirection ?
> - start a remote node using rsh
> - stop remote nodes when killing master
>
> Actually, I do that with os:cmd("ssh remote erl ..."), but it's not
> very clean. And the remote erlang vm is not killed when I kill the
> master.
>
> Regards,
>
> Bertrand
>

From mjtruog@REDACTED  Wed Jul  7 16:36:03 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Wed, 07 Jul 2010 07:36:03 -0700
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>	<AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com> <AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com>
Message-ID: <4C3490D3.1030108@gmail.com>

The biggest seems to be Vendetta Online
http://www.vendetta-online.com/

Their engine is being sold/licensed here
http://www.guildsoftware.com/naos/

However, the Erlang piece seems to be mainly for NPC actors (ships (?))
and the AI associated with them... but that is just speculation after
reading their development blog a year or two ago (I think that is when
it went into production).  They call it the "/Kourier"/ system.

Here is a paper on the topic
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.73.5033

For a normal MMO you would probably need a few NIFs to make everything
as efficient as possible but its scalability should surpass other
language implementations (with less lines of code and less complexity).


Miguel Morales wrote:
> I'm developing a mobile 2D multiplayer rpg, although it's not open
> source you can find my dev blog here:
> http://developingthedream.blogspot.com/
>
> I use it alongside rabbitmq and a use the whole 'eveything is a process' method.
> Although I haven't released it and scaled it yet, I hope it'll scale
> will.  That is if the game needs to.
> Some of the links posted are interesting, you'll also get a lot of
> hits if you google 'erlang mmo'
>
> It was interesting implementing things like game loops, pathfinding,
> chat, etc.  Erlang so far has been a good choice.
>
> (err, sorry, I'm used to using the android-dev list, forgot to hit reply-all)
>
>
> On Tue, Jul 6, 2010 at 5:09 AM, Mariano Guerra
> <luismarianoguerra@REDACTED> wrote:
>   
>> On Tue, Jul 6, 2010 at 5:05 AM, ingo.schramm
>> <schramm.ingo@REDACTED> wrote:
>>     
>>> Does somebody ever used Erlang to program game servers? Is there any
>>> real live industrial game solution written in Erlang?
>>>
>>> I need to know this for some evangelization :)
>>>       
>> openpoker is written in erlang
>>
>> http://www.devmaster.net/articles/mmo-scalable-server/
>> http://github.com/wagerlabs/openpoker
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>>     
>
>
>
>   


From zeno490@REDACTED  Wed Jul  7 18:27:16 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Wed, 7 Jul 2010 12:27:16 -0400
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <4C3490D3.1030108@gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
	<AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com>
	<AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com>
	<4C3490D3.1030108@gmail.com>
Message-ID: <AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com>

For an MMO backend, erlang could be decent. Depending on how many external
libraries you use or rather how many native libraries you need to interface
with, it might not be too bad.
No reason I can think of why you couldn't.
For a regular game or for an MMO client however, I'm not so sure. For those,
something like C# might be a better fit (easy to interface with C++, native
or managed). As far as consoles go, I could see erlang running on a 360
fine, using all cores but not so much on a Wii (where you too often need to
hand optimize code which will require C++/assembly) and not so much on the
PS3 where you may get a hard time using the SPUs from erlang (as I'm
guessing the VM won't run on them out of the box and you might have to spend
considerable time to get erlang processes to run on SPUs (feasible I'm
sure)).

You'll definitely need a large number of NIFs for allocating memory aligned
binaries for all that data you need to process with SIMD instructions and
all kind of other stuff too. Games where performance isn't a huge bottleneck
or where is it easy to parallelize would be a good fit for erlang, such as
the poker game mentioned.
I could see a small company willing to invest in building their core tech in
erlang but I doubt we'll see any big ones change any time soon. For them, it
would make more business sense to build support applications with it (such
as online presence stuff, debugging tools, test tools, data/code build
tools, etc.), things you mostly access through a network or are distributed
in nature.

The truth is that most game programmers out there are fundamentally
imperative programmers. I work in the industry and frankly, I haven't met
many programmers that have used functional p. languages beyond a few simple
scripts or that have even played with them in the past. Most of them come
from a C/C++ background and as such, if you are a company looking to hire
talent and experience, you'll need to offer work in something they are
familiar with. This is mainly why a language like C# has more chances of
succeeding, if only because of the familiar syntax. I do believe the code
quality would be higher if more of it was written in a functional language
but I can't picture seeing it happening very fast. I do know of some studios
using LISP variants and I also know they have a hard time hiring programmers
(mostly hire seniors with functional p. experience and game experience,
which is not so common).

Also keep in mind a substantial portion of the companies out there making
video games are essentially microsoft shops. They run windows, use visual
studio, etc. That means they have support directly from microsoft for all
their products (compilers, linkers, sdks, etc.). There is a huge incentive
to use microsoft products for them in development so even when an
opportunity arises where they could build an application, they will often
opt for C++ or C# (or a mix of both) because of that fact and the one
mentioned above where that is where most of their talent pool lies. As such,
for anyone part of such a project, it'll be an uphill battle. The state of
things is unlikely to change anytime soon seeing three of the four biggest
markets are PC gaming, console gaming (360 SDK pretty much requires
windows/vs) and web based games (flash dev tools are mostly for windows, so
is silverlight (who uses java anymore on the web anyway?)) The fourth being
mobile games. (Mac/linux gaming omitted, while it is slowly picking up
recently (specially noticeable with Stream), it isn't very big yet)

For erlang to make more headway into games, I believe they would need to
make it easier to integrate into existing applications. It is fairly
straightforward to integrate python, lisp, lua or even javascript into an
existing application but I'm not sure I could say the same of erlang. Being
easy to embed would be a great first step, allowing progressive transition
from C++ into erlang (for PC at least). To use erlang on consoles, you'll
need a beam to native compiler for sure as some consoles do not allow
interpreted code to execute (ie: PS3, applies to mobile devices as well such
as the iPhone/iPad). Even if it were for just a subset of erlang, an LLVM
frontend could achieve that with backends for different target
architectures. Thankfully the current generation of consoles is all powerpc
based so that might not be that much work.

I for one would love to see erlang used more in games as well as their
supporting applications :)

2cents
Nicholas

On Wed, Jul 7, 2010 at 10:36 AM, Michael Truog <mjtruog@REDACTED> wrote:

> The biggest seems to be Vendetta Online
> http://www.vendetta-online.com/
>
> Their engine is being sold/licensed here
> http://www.guildsoftware.com/naos/
>
> However, the Erlang piece seems to be mainly for NPC actors (ships (?))
> and the AI associated with them... but that is just speculation after
> reading their development blog a year or two ago (I think that is when
> it went into production).  They call it the "/Kourier"/ system.
>
> Here is a paper on the topic
> http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.73.5033
>
> For a normal MMO you would probably need a few NIFs to make everything
> as efficient as possible but its scalability should surpass other
> language implementations (with less lines of code and less complexity).
>
>
> Miguel Morales wrote:
> > I'm developing a mobile 2D multiplayer rpg, although it's not open
> > source you can find my dev blog here:
> > http://developingthedream.blogspot.com/
> >
> > I use it alongside rabbitmq and a use the whole 'eveything is a process'
> method.
> > Although I haven't released it and scaled it yet, I hope it'll scale
> > will.  That is if the game needs to.
> > Some of the links posted are interesting, you'll also get a lot of
> > hits if you google 'erlang mmo'
> >
> > It was interesting implementing things like game loops, pathfinding,
> > chat, etc.  Erlang so far has been a good choice.
> >
> > (err, sorry, I'm used to using the android-dev list, forgot to hit
> reply-all)
> >
> >
> > On Tue, Jul 6, 2010 at 5:09 AM, Mariano Guerra
> > <luismarianoguerra@REDACTED> wrote:
> >
> >> On Tue, Jul 6, 2010 at 5:05 AM, ingo.schramm
> >> <schramm.ingo@REDACTED> wrote:
> >>
> >>> Does somebody ever used Erlang to program game servers? Is there any
> >>> real live industrial game solution written in Erlang?
> >>>
> >>> I need to know this for some evangelization :)
> >>>
> >> openpoker is written in erlang
> >>
> >> http://www.devmaster.net/articles/mmo-scalable-server/
> >> http://github.com/wagerlabs/openpoker
> >>
> >> ________________________________________________________________
> >> erlang-questions (at) erlang.org mailing list.
> >> See http://www.erlang.org/faq.html
> >> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >>
> >>
> >>
> >
> >
> >
> >
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From anton.krasovsky@REDACTED  Wed Jul  7 23:59:50 2010
From: anton.krasovsky@REDACTED (Anton Krasovsky)
Date: Wed, 7 Jul 2010 22:59:50 +0100
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
Message-ID: <AANLkTinIP5y6uTj7spKUASz0ShWTo1NK_tYuYRcLGjwU@mail.gmail.com>

http://www.demonware.net/  who are owned by Activision/Blizzard are
using Erlang.

Anton

On Tue, Jul 6, 2010 at 9:05 AM, ingo.schramm
<schramm.ingo@REDACTED> wrote:
> Does somebody ever used Erlang to program game servers? Is there any
> real live industrial game solution written in Erlang?
>
> I need to know this for some evangelization :)
>
> Cheers,
> Ingo
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From ok@REDACTED  Thu Jul  8 02:05:24 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Thu, 8 Jul 2010 12:05:24 +1200
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com> <AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com> <AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com> <4C3490D3.1030108@gmail.com> <AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com>
Message-ID: <7DC4E578-DDDA-47BA-BE09-1733A209799E@cs.otago.ac.nz>


On Jul 8, 2010, at 4:27 AM, Nicholas Frechette wrote:
> hand optimize code which will require C++/assembly) and not so much  
> on the
> PS3 where you may get a hard time using the SPUs from erlang (as I'm
> guessing the VM won't run on them out of the box and you might have  
> to spend
> considerable time to get erlang processes to run on SPUs (feasible I'm
> sure)).

It's not clear that it _is_ feasible in any interesting sense.
The SPUs are essentially numeric vector engines.  They have 128
registers, each 128 bits wide; loads are only 128 bits (16 bytes)
and stores are only 128 bits (16 bytes).  Memory is byte addressed
and addresses are 32 bits, but the 2009 manual talks about 256 kB.

One could imagine SPU _nodes_ doing vector crunching that Erlang
processes running on the PPU communicated with as if Erlang.  But
Erlang would not be the language of choice for programming SPUs.
(An APL dialect would be ideal, or Fortran 95.)



From dangud@REDACTED  Thu Jul  8 09:44:07 2010
From: dangud@REDACTED (Dan Gudmundsson)
Date: Thu, 8 Jul 2010 09:44:07 +0200
Subject: [erlang-questions] Re: On Windows XP (SP2): wx broken
In-Reply-To: <aeb6a06d1003041848k7e8a4d11h3b04cffa812ea3a@mail.gmail.com>
References: <aeb6a06d1003012305m62020dd1t7f11146db72a8ea9@mail.gmail.com>
	<9C6B96B5-37FA-4CF6-A7D3-663736CEE916@gmail.com>
	<69869ad8-a27a-48e6-8835-8303a87ed40d@g11g2000yqe.googlegroups.com>
	<93df43b61003032220m5b4d396dn4aca92270134d795@mail.gmail.com>
	<aeb6a06d1003041848k7e8a4d11h3b04cffa812ea3a@mail.gmail.com>
Message-ID: <AANLkTingr_hHSs0MXhC9mRGuvedjcWM1vYBYabtoxCC4@mail.gmail.com>

Have you with this problem tried R14A, is it working now?

I found that we had upgraded Visual Studio without recompiling
wxWidgets DLL's causing the
wx-driver to be dependent on two different versions of the runtime DLL,
where only the latest where installed with erlang.

Thanks for locating it.

/Dan

On Fri, Mar 5, 2010 at 4:48 AM, MapAndFold <mapandfold@REDACTED> wrote:
> I have a Intel Core 2, SMP is enabled, and I am using werl.
>
> Erlang R13B04 (erts-5.7.5) [smp:2:2] [rq:2] [async-threads:0]
>
> Eshell V5.7.5 ?(abort with ^G)
> 1> wx:demo().
>
> Then, a memory access error occurred, and werl aborted.
>
> ---------------------------
> werl.exe - Application Error
> ---------------------------
> The instruction at "0x7c911948" referenced memory at "0x00000000". The
> memory could not be "read".
>
> On Thu, Mar 4, 2010 at 2:20 PM, Dan Gudmundsson <dangud@REDACTED> wrote:
>> Are you running it from werl?
>>
>> erl and wxwidgets seems to be fighting for stdio, so it needs to be run from
>> werl or erl -detached -s wx demo
>>
>> /Dan
>>
>> On Thu, Mar 4, 2010 at 7:01 AM, Steve Davis
>> <steven.charles.davis@REDACTED> wrote:
>>
>

From schramm.ingo@REDACTED  Thu Jul  8 09:54:16 2010
From: schramm.ingo@REDACTED (ingo.schramm)
Date: Thu, 8 Jul 2010 00:54:16 -0700 (PDT)
Subject: Erlang: Who uses it for games?
In-Reply-To: <7DC4E578-DDDA-47BA-BE09-1733A209799E@cs.otago.ac.nz>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com> 
	<AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com> 
	<AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com> 
	<4C3490D3.1030108@gmail.com> <AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com> 
	<7DC4E578-DDDA-47BA-BE09-1733A209799E@cs.otago.ac.nz>
Message-ID: <95f43ac3-f279-4990-b4eb-c90fef53192e@r27g2000yqb.googlegroups.com>

Great! So many Erlang gamers out there!

Somebody told me, a Battlestar Galactica browser game is backed up by
an Erlang engine.

On Jul 8, 2:05?am, "Richard O'Keefe" <o...@REDACTED> wrote:
> On Jul 8, 2010, at 4:27 AM, Nicholas Frechette wrote:
>
> > hand optimize code which will require C++/assembly) and not so much ?
> > on the
> > PS3 where you may get a hard time using the SPUs from erlang (as I'm
> > guessing the VM won't run on them out of the box and you might have ?
> > to spend
> > considerable time to get erlang processes to run on SPUs (feasible I'm
> > sure)).
>
> It's not clear that it _is_ feasible in any interesting sense.
> The SPUs are essentially numeric vector engines. ?They have 128
> registers, each 128 bits wide; loads are only 128 bits (16 bytes)
> and stores are only 128 bits (16 bytes). ?Memory is byte addressed
> and addresses are 32 bits, but the 2009 manual talks about 256 kB.
>
> One could imagine SPU _nodes_ doing vector crunching that Erlang
> processes running on the PPU communicated with as if Erlang. ?But
> Erlang would not be the language of choice for programming SPUs.
> (An APL dialect would be ideal, or Fortran 95.)
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> Seehttp://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED

From 8mayday@REDACTED  Thu Jul  8 11:57:46 2010
From: 8mayday@REDACTED (Andrey Popp)
Date: Thu, 8 Jul 2010 13:57:46 +0400
Subject: Possible leak in inets httpc.
Message-ID: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com>

Hello,

I have application that makes huge number of HTTP requests with httpc
and I have spotted that `httpc_manager__handler_db` ETS table growing
in size and doesn't clean up. That is the example records from this
table (ets:i(httpc_manager__handler_db)):

<1   > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
<2   > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
<3   > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
<4   > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
<5   > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}

and processes with handler pids are no longer alive. Also, note that I
have no timeout setting in my http:request HTTPOptions, but I think
inets should not leak even in that case.

Thanks.

-- 
Andrey Popp

phone: +7 911 740 24 91
e-mail: 8mayday@REDACTED

From michael.eugene.turner@REDACTED  Thu Jul  8 12:10:45 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Thu, 8 Jul 2010 19:10:45 +0900
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
Message-ID: <AANLkTilG1SBnuH3voAMcgkkFATmHgnVR4O_KBSV589RK@mail.gmail.com>

Though James Hague has mainly talked about client-side game programming, and
mostly separately from Erlang topics, his writings are on both Erlang and
games is fascinating, and even where there's no clear overlap, they perhaps
be a source of insights on this topic.  Besides which, reading him on these
subjects leads you compulsively onto other programming topics he's covered,
and before you know it, you've eaten the *whole bag* of potato chips ;-)

  *http://tinyurl.com/26dthru*
*
*
-michael turner

On Tue, Jul 6, 2010 at 5:05 PM, ingo.schramm <schramm.ingo@REDACTED>wrote:

> Does somebody ever used Erlang to program game servers? Is there any
> real live industrial game solution written in Erlang?
>
> I need to know this for some evangelization :)
>
> Cheers,
> Ingo
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From 8mayday@REDACTED  Thu Jul  8 12:12:07 2010
From: 8mayday@REDACTED (Andrey Popp)
Date: Thu, 8 Jul 2010 14:12:07 +0400
Subject: Possible leak in inets httpc.
In-Reply-To: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com>
Message-ID: <AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com>

It seems it has been fixed with [1] in inets-5.3.2. Sorry.

[1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49

On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
> Hello,
>
> I have application that makes huge number of HTTP requests with httpc
> and I have spotted that `httpc_manager__handler_db` ETS table growing
> in size and doesn't clean up. That is the example records from this
> table (ets:i(httpc_manager__handler_db)):
>
> <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
> <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
> <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
> <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
> <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
>
> and processes with handler pids are no longer alive. Also, note that I
> have no timeout setting in my http:request HTTPOptions, but I think
> inets should not leak even in that case.
>
> Thanks.
>
> --
> Andrey Popp
>
> phone: +7 911 740 24 91
> e-mail: 8mayday@REDACTED
>



-- 
Andrey Popp

phone: +7 911 740 24 91
e-mail: 8mayday@REDACTED

From michael.eugene.turner@REDACTED  Thu Jul  8 12:47:05 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Thu, 8 Jul 2010 19:47:05 +0900
Subject: Something like csh "source" command in Erlang shell?
Message-ID: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>

Is there some way to read in a bunch of Erlang shell commands as if they'd
been typed in?  I'm thinking of something like the "source" command in csh.

OK: why?  That's a reasonable question.

The reason I want this: I started into a tutorial for wx that was very
command-line intensive, showing how you call wx to put up a window, put a
menu in that window, put an item in that menu, etc., just by issuing
commands in the shell.  I was quite delighted to see that Erlang is almost
like Tcl/Tk's tclsh in this respect.  Perhaps it's an under-appreciated
feature of graphics programming for Erlang.

If you don't mind stuffing a lot of callbacks into fun-valued variables, you
can actually bring up a whole little GUI through which you can actually do
stuff, just by typing commands into the Erlang shell.

But then if you q() out, it all goes away.

What I'd like to do here is to tell the tutorial reader to copy-paste the
commands of interest to a file, one that can be read back in as a series of
commands, not only to rebuild the GUI being assembled interactively, but
also to reestablish  --*in the Erlang shell session* -- the variable
bindings made by the commands.  Eventually, of course, you want the reader
of the tutorial to either throw all that out or package it more cleanly in a
module, before continuing.  In the meantime, though, it would give them a
way to "pick up where they left off" in an ongoing command line dialogue, by
reading in all the commands they wanted to keep, in the order they issued
them.  Not to mention that having all the commands of interest, in order,
batched in a text file, makes for easier review.  I think for learning even
the rudiments of something as sprawling as wx, this approach, "today's
commands after re-reading, then re-using, yesterday's", would be helpful.

Is there something like this in the Erlang shell, either undocumented or so
under-documented that I keep missing it?

-michael turner

From attila.r.nohl@REDACTED  Thu Jul  8 14:11:14 2010
From: attila.r.nohl@REDACTED (Attila Rajmund Nohl)
Date: Thu, 8 Jul 2010 14:11:14 +0200
Subject: [erlang-questions] Something like csh "source" command in Erlang 
	shell?
In-Reply-To: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>
References: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>
Message-ID: <AANLkTinJbZ8enwYAqnVrJxUgIk8lQyl2YMWPtuLojLAB@mail.gmail.com>

2010/7/8, Michael Turner <michael.eugene.turner@REDACTED>:
> Is there some way to read in a bunch of Erlang shell commands as if they'd
> been typed in?  I'm thinking of something like the "source" command in csh.

file:eval/1 isn't what you want?

From james.hague@REDACTED  Thu Jul  8 15:24:26 2010
From: james.hague@REDACTED (James Hague)
Date: Thu, 8 Jul 2010 08:24:26 -0500
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
	<AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com>
	<AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com>
	<4C3490D3.1030108@gmail.com>
	<AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com>
Message-ID: <AANLkTikzabtbeAGW_CqUP81IOGXBeubb9ygkUrpzMcar@mail.gmail.com>

>To use erlang on consoles, you'll
>need a beam to native compiler for sure as some consoles do not allow
>interpreted code to execute (ie: PS3, applies to mobile devices as well
such
>as the iPhone/iPad).

Not true about the PS3. Using Lua as a scripting language is common. (It's
also used in iPhone games.)

A bigger problem is that BEAM relies on gcc extensions for speed, so you
have to take the hit if you're using platform where a specific C compiler is
mandated.

From mixolyde@REDACTED  Thu Jul  8 15:34:29 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Thu, 8 Jul 2010 09:34:29 -0400
Subject: Nested Record Pattern Matching in R14A
Message-ID: <AANLkTiln5veifvt43lnZgcacXC3aFDT_QtZDVtuCjqQz@mail.gmail.com>

I converted a small search algorithm project to use the new nested
record syntax in R14A.
My records are:
-record(state, {yard_state}).
-record(solution_state, {state = #state{}, moves, depth}).
-record(astar_solution_state, {solution_state = #solution_state{}, fvalue}).

I was able to use a line like this to access a field in the nested record:
Astar_Solution_State#astar_solution_state.solution_state#solution_state.state

Based on the example in the reference manual, I thought the pattern
for matching the state field would be:

function_call(#astar_solution_state.solution_state#solution_state{state
= State})

However, that gave me "illegal pattern" errors, and after a bit of
fiddling, I got this to work:
#astar_solution_state{solution_state = #solution_state{state = State}}

Is this intended? Or a bug?

-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From ulf.wiger@REDACTED  Thu Jul  8 15:34:36 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Thu, 08 Jul 2010 15:34:36 +0200
Subject: [erlang-questions] Something like csh "source" command in Erlang
 shell?
In-Reply-To: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>
References: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>
Message-ID: <4C35D3EC.8050807@erlang-solutions.com>


I don't think that can be done out of the box. Some assembly
is certainly required.

I wrote a small code snippet to allow saving the shell history
to a file in a format that can be handled by file:eval/1 or
file:script/1 (the difference between the two is that the latter
returns the result of the last expression, while file:eval/1
only returns 'ok').

http://gist.github.com/468003

The code doesn't bother checking whether the commands were
successful before saving, but this could be added.

How to restore the bindings in the shell would be another
challenge. I've not looked into whether it can be done without
hacking the evaluator.

BR,
Ulf W
-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From mononcqc@REDACTED  Thu Jul  8 15:46:15 2010
From: mononcqc@REDACTED (Fred Hebert)
Date: Thu, 8 Jul 2010 09:46:15 -0400
Subject: gen_event init and global names.
Message-ID: <AANLkTinNOLWr-60dCzFZjNXzzQRVKE5HxzMUs4YbH7WS@mail.gmail.com>

I'm working on Chut <http://bitbucket.org/ferd/chut> (reading the app's
design might be useful), trying to add type specs to my program when I found
I were breaking contracts with the gen_event:start_link/1 and
gen_fsm:start_link/3 functions.

I prototyped my application using the global module directly to register my
processes (I need name distribution), which accepts any term for a name (I
use {atom(), term()}). However, I later on moved it all to a supervision
tree and consequently moved the registration of the processes to the
gen_event and gen_fsm mechanisms, using {global, Name}. This, as expected,
creates a problem because:

   1. the contract is broken - {global, {atom(), term()}} =/= {global,
   atom()}.
   2. I can no longer pass conflict-resolving functions to the global module
   as the OTP behaviors take no argument for that.

So to get the functionality back and respect types, I decided to move in the
global registration to gen_fsm's init function. I'd just pass the supervisor
the name info needed, which would then pass it to gen_fsm:start_link/3,
which would in turn call Mod:init/1 with the right info for it to register
itself. This would work well, without any big apparent problem.

However, this won't hold with the gen_event because there isn't any way to
have an init function running in there without having a handler. I also
can't add a handler without naming the process because I have no direct
access to the Pid. Things go a bit like this:  <some user process> -->
top-level supervisor:add_child --> user_supervisor:start_link -->
my_gen_event:start_link.

I'm a bit lost with it all. The only solution I've found that would work and
be easy to implement would be to use the user_supervisor to find the
gen_event (with supervisor:which_children), then add an event handler whose
role is to do the registration in its own init/1 function.

Does anyone else have a better idea? Ideally I'd like not to change my app's
architecture too much given it fits pretty much every requirements I had
already, except for the type contracts.

From lfredlund@REDACTED  Thu Jul  8 16:14:38 2010
From: lfredlund@REDACTED (=?ISO-8859-1?Q?Lars-=C5ke_Fredlund?=)
Date: Thu, 08 Jul 2010 16:14:38 +0200
Subject: [erlang-questions] Something like csh "source" command in Erlang
 	shell?
In-Reply-To: <AANLkTinJbZ8enwYAqnVrJxUgIk8lQyl2YMWPtuLojLAB@mail.gmail.com>
References: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com> <AANLkTinJbZ8enwYAqnVrJxUgIk8lQyl2YMWPtuLojLAB@mail.gmail.com>
Message-ID: <4C35DD4E.6060809@fi.upm.es>

On 07/08/2010 02:11 PM, Attila Rajmund Nohl wrote:
> 2010/7/8, Michael Turner<michael.eugene.turner@REDACTED>:
>    
>> Is there some way to read in a bunch of Erlang shell commands as if they'd
>> been typed in?  I'm thinking of something like the "source" command in csh.
>>      
> file:eval/1 isn't what you want?
>    
Does file:eval really permit executing normal shell commands?
That is, reading record definitions using rr("record.hrl") for instance?

I too would be very happy to have a source command functionality for the 
shell.

Preferably the "source command" would be a normal function rather than a 
shell command so that one could automatically read in a number of 
definitions when Erlang starts without typing anything.







From mats.westin@REDACTED  Thu Jul  8 16:30:13 2010
From: mats.westin@REDACTED (Mats)
Date: Thu, 8 Jul 2010 16:30:13 +0200
Subject: [erlang-questions] Something like csh "source" command in Erlang 
	shell?
In-Reply-To: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>
References: <AANLkTikr5WJu3bdUxpNCRX2ERFs7GHTo-s9SnDQPDaK8@mail.gmail.com>
Message-ID: <AANLkTint80upNTjsYWIngBp1xn1QzZ8C5EOMXi7U6lh2@mail.gmail.com>

Screen can receive text as if you were typing it.

Start erlang inside screen with:
screen -S erl_screen erl

Send a file:
screen -S erl_screen -p 0 -X stuff "`cat hist_erl`"

A cr with:
screen -S erl_screen -p 0 -X stuff $'\n'

Quit your session with:
screen -S erl_screen -p 0 -X quit


On Thu, Jul 8, 2010 at 12:47 PM, Michael Turner <
michael.eugene.turner@REDACTED> wrote:

> Is there some way to read in a bunch of Erlang shell commands as if they'd
> been typed in?  I'm thinking of something like the "source" command in csh.
>
> OK: why?  That's a reasonable question.
>
> The reason I want this: I started into a tutorial for wx that was very
> command-line intensive, showing how you call wx to put up a window, put a
> menu in that window, put an item in that menu, etc., just by issuing
> commands in the shell.  I was quite delighted to see that Erlang is almost
> like Tcl/Tk's tclsh in this respect.  Perhaps it's an under-appreciated
> feature of graphics programming for Erlang.
>
> If you don't mind stuffing a lot of callbacks into fun-valued variables,
> you
> can actually bring up a whole little GUI through which you can actually do
> stuff, just by typing commands into the Erlang shell.
>
> But then if you q() out, it all goes away.
>
> What I'd like to do here is to tell the tutorial reader to copy-paste the
> commands of interest to a file, one that can be read back in as a series of
> commands, not only to rebuild the GUI being assembled interactively, but
> also to reestablish  --*in the Erlang shell session* -- the variable
> bindings made by the commands.  Eventually, of course, you want the reader
> of the tutorial to either throw all that out or package it more cleanly in
> a
> module, before continuing.  In the meantime, though, it would give them a
> way to "pick up where they left off" in an ongoing command line dialogue,
> by
> reading in all the commands they wanted to keep, in the order they issued
> them.  Not to mention that having all the commands of interest, in order,
> batched in a text file, makes for easier review.  I think for learning even
> the rudiments of something as sprawling as wx, this approach, "today's
> commands after re-reading, then re-using, yesterday's", would be helpful.
>
> Is there something like this in the Erlang shell, either undocumented or so
> under-documented that I keep missing it?
>
> -michael turner
>

From zeno490@REDACTED  Thu Jul  8 16:47:29 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Thu, 8 Jul 2010 10:47:29 -0400
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <7DC4E578-DDDA-47BA-BE09-1733A209799E@cs.otago.ac.nz>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
	<AANLkTim7FEjIQQZd0JZrrbIsNEGF6azYOKJFmk16e3zB@mail.gmail.com>
	<AANLkTilJ0Qg2Wyd7H3jEu1b83-JSpTvoKhXaNPHE_qXM@mail.gmail.com>
	<4C3490D3.1030108@gmail.com>
	<AANLkTilwQ_tnx-Bm2wzx4IZisqz-kn-F0u1qB0ftiBkp@mail.gmail.com>
	<7DC4E578-DDDA-47BA-BE09-1733A209799E@cs.otago.ac.nz>
Message-ID: <AANLkTilJYaGHbfKCGF8aySu0hWZ89Jo28ve8Dhul4Gyy@mail.gmail.com>

While yes the SPUs are mainly for vector processing, imo, they could be
suited quite well in practice for erlang processes.
256kb is total space they have for code/data as such would be great for
small processes. Erlang processes already have all their data immutable
meaning this would imply little need to dma info in/out of spus. While not
designed for it, the SPUs can still be used for general processing and in
fact, it is better to use them with something they aren't so good at rather
than not use them at all. You'll find that a large number of ps3 games, even
today make use of less than 75% of the SPUs.

Since most erlang applications are already message passing based, the
processes need not share their memory with each other. Obviously, the size
being the key factor here, one would still have to fit the code in <150kb to
be able to do much with the processes. For long lists processing or large
binaries, one might be able to do double buffering (or tripple) and still
keep decent speeds. This could be done in erlang with minimal nif support,
see below.

I'd see it like this: you'd spawn a process, you'd mark it as being "spu
friendly" so that the spus can find it when they look for the next process
to execute. SPUs would then dma the code & process data and run it and then
move on to the next process. For long running processes, one could
artificially "yield" to allow the spu to run another task before returning
to it, something like a yield() nif. Obviously, only a subset of erlang
would run out of the box, as things like io/kernel stuff would require
message passing with a process on the PPU to execute them. I could see
number crunching processes having a partner process on the PPU who's job
would be to partition/segment the data and feed it to the SPU process on
demand. The spu process could then do something like:

%% Process data in 50kb chunks, or perhaps less
loop(SomeData, CurrPos) ->
PPUPartner ! {send_next, CurrPos}, %% DMAed and sent to the PPU partner
process executing on the PPU, might not be needed if the partner process
just splits everything up front and queues all the processing messages or
keeps track via the 'processed' message and keeps the queue full or at a
decent size
process current pos. stuff here, part 1... %% This doesn't have to be simd
stuff, but very well could be (using NIFs)
begin_receive_msgs(), %% NIF to start dma of messages, this would start
streaming in the next data chunk, optional, only there to reduce latency
from blocking receive statement which has to dma any new messages and wait
for their data
process current pos. stuff here, part 2...
PPUPartner ! {processed, CurrPos, Result}, %% Sends the result calculated
back to the ppu partner process to gather them back, come to think of it,
this pattern is similar to map-reduce
receive {data, Data, Pos} -> loop(Data, Pos), done -> ok end.

When the process ends execution, run GC if needed, wait for all pending DMAs
to finish and grab the next one. On the PPU side, the partner process mostly
idles waiting for the SPU to be done with the data and request more or send
back results. It would do simple operations like appending the result to the
head of a list for max performance then at the end, simple run a
lists:reverse (as done traditionally anyway) or for long lists, run that
operation on the SPUs as well (lists:spu_reverse?). 1 PPU partner process
could easily split work among several SPU processes, feeding them and
gathering/sorting their results.

Anyhow, sorry for the lengthy train of thoughts. It is a shame now that the
PS3 is no longer supporting the "other OS" option otherwise I would love to
experiment with something like this. Then again, it appears IBM will no
longer develop new cell processors in the future so this effort might be
moot. (I think they are stopping at something like 2 ppu hyper threaded
cores (4 virtual cores) and 32 spu cores per chip? alas I forgot the
details) I'm also not sure if the other os option allowed the OS to access
to the spus in the first place as if I remember correctly, a number of
things are "turned off" and inaccessible so mostly all of this talk is
speculation :).

2cents :)
Nicholas

On Wed, Jul 7, 2010 at 8:05 PM, Richard O'Keefe <ok@REDACTED> wrote:

>
> On Jul 8, 2010, at 4:27 AM, Nicholas Frechette wrote:
>
>> hand optimize code which will require C++/assembly) and not so much on the
>> PS3 where you may get a hard time using the SPUs from erlang (as I'm
>> guessing the VM won't run on them out of the box and you might have to
>> spend
>> considerable time to get erlang processes to run on SPUs (feasible I'm
>> sure)).
>>
>
> It's not clear that it _is_ feasible in any interesting sense.
> The SPUs are essentially numeric vector engines.  They have 128
> registers, each 128 bits wide; loads are only 128 bits (16 bytes)
> and stores are only 128 bits (16 bytes).  Memory is byte addressed
> and addresses are 32 bits, but the 2009 manual talks about 256 kB.
>
> One could imagine SPU _nodes_ doing vector crunching that Erlang
> processes running on the PPU communicated with as if Erlang.  But
> Erlang would not be the language of choice for programming SPUs.
> (An APL dialect would be ideal, or Fortran 95.)
>
>
>

From erlangy@REDACTED  Thu Jul  8 17:00:31 2010
From: erlangy@REDACTED (Michael McDaniel)
Date: Thu, 8 Jul 2010 08:00:31 -0700
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <AANLkTilG1SBnuH3voAMcgkkFATmHgnVR4O_KBSV589RK@mail.gmail.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com> <AANLkTilG1SBnuH3voAMcgkkFATmHgnVR4O_KBSV589RK@mail.gmail.com>
Message-ID: <20100708150030.GT30357@delora.autosys.us>

On Thu, Jul 08, 2010 at 07:10:45PM +0900, Michael Turner wrote:
> Though James Hague has mainly talked about client-side game programming, and
> mostly separately from Erlang topics, his writings are on both Erlang and
> games is fascinating, and even where there's no clear overlap, they perhaps
> be a source of insights on this topic.  Besides which, reading him on these
> subjects leads you compulsively onto other programming topics he's covered,
> and before you know it, you've eaten the *whole bag* of potato chips ;-)
> 
>   *http://tinyurl.com/26dthru*
> *
> *
> -michael turner
> 
> On Tue, Jul 6, 2010 at 5:05 PM, ingo.schramm <schramm.ingo@REDACTED>wrote:
> 
> > Does somebody ever used Erlang to program game servers? Is there any
> > real live industrial game solution written in Erlang?
> >
> > I need to know this for some evangelization :)
> >
> > Cheers,
> > Ingo
> >
________________________________________________________________

 This is the article by James that introduced me to Erlang ...

    http://www.dadgum.com/james/performance.html

   (see also  http://prog21.dadgum.com/11.html)

 I think I stumbled upon the original performance article
 in early 2005 and investigated Erlang at that time.

 I was fairly burnt out on computers and especially software
 (after about 30 years of computers, last 20 of which were
 software).  I was on a multi-month (year?) hiatus from
 software/systems creation in any form.

 Then I stumbled upon James's article and actually got excited
 about software again!  James introduced me to a tool, Erlang,
 that didn't get in my way, but actually, in a major way,
 facilitated my end results.  And provided some income and 
 lots of fun (still).

 James, I doubt I ever said so until now, so *"Thank you"* for
 the original performance article and introduction to Erlang.
 (I have told the OTP team *Thank you* for Erlang, and do so
  again here).

~M

-- 
Michael McDaniel
Portland, Oregon, USA
http://trip.autosys.us
http://edids.org


From michael.eugene.turner@REDACTED  Thu Jul  8 17:29:11 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Fri, 9 Jul 2010 00:29:11 +0900
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <20100708150030.GT30357@delora.autosys.us>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
	<AANLkTilG1SBnuH3voAMcgkkFATmHgnVR4O_KBSV589RK@mail.gmail.com>
	<20100708150030.GT30357@delora.autosys.us>
Message-ID: <AANLkTin04xDMFD3Ay4rD0mGTsJq16cLKFbZoMcDnimJc@mail.gmail.com>

Very O/T here, but ... I think the main reason I left three (or was it four)
grammatical errors in my plug for Hague's blog is that I was trying to write
as well as he does.  I shouldn't try.  Not that he needs *another* one for
me, after what Michael McDaniel just wrote.  Joe Armstrong says we need more
books.  I'm starting a "Draft James Hague" movement: write a book.  I'll buy
it even if he just ends up just *pretending* it's about Erlang. Better yet,
team up with Nicholas Frechette to write Erlang for GPU Programming, or
something similarly unlikely.

-michael turner

On Fri, Jul 9, 2010 at 12:00 AM, Michael McDaniel <erlangy@REDACTED>wrote:

> On Thu, Jul 08, 2010 at 07:10:45PM +0900, Michael Turner wrote:
> > Though James Hague has mainly talked about client-side game programming,
> and
> > mostly separately from Erlang topics, his writings are on both Erlang and
> > games is fascinating, and even where there's no clear overlap, they
> perhaps
> > be a source of insights on this topic.  Besides which, reading him on
> these
> > subjects leads you compulsively onto other programming topics he's
> covered,
> > and before you know it, you've eaten the *whole bag* of potato chips ;-)
> >
> >   *http://tinyurl.com/26dthru*
> > *
> > *
> > -michael turner
> >
> > On Tue, Jul 6, 2010 at 5:05 PM, ingo.schramm <
> schramm.ingo@REDACTED>wrote:
> >
> > > Does somebody ever used Erlang to program game servers? Is there any
> > > real live industrial game solution written in Erlang?
> > >
> > > I need to know this for some evangelization :)
> > >
> > > Cheers,
> > > Ingo
> > >
> ________________________________________________________________
>
>  This is the article by James that introduced me to Erlang ...
>
>    http://www.dadgum.com/james/performance.html
>
>   (see also  http://prog21.dadgum.com/11.html)
>
>  I think I stumbled upon the original performance article
>  in early 2005 and investigated Erlang at that time.
>
>  I was fairly burnt out on computers and especially software
>  (after about 30 years of computers, last 20 of which were
>  software).  I was on a multi-month (year?) hiatus from
>  software/systems creation in any form.
>
>  Then I stumbled upon James's article and actually got excited
>  about software again!  James introduced me to a tool, Erlang,
>  that didn't get in my way, but actually, in a major way,
>  facilitated my end results.  And provided some income and
>  lots of fun (still).
>
>  James, I doubt I ever said so until now, so *"Thank you"* for
>  the original performance article and introduction to Erlang.
>  (I have told the OTP team *Thank you* for Erlang, and do so
>  again here).
>
> ~M
>
> --
> Michael McDaniel
> Portland, Oregon, USA
> http://trip.autosys.us
> http://edids.org
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From hd2010@REDACTED  Thu Jul  8 18:22:10 2010
From: hd2010@REDACTED (Henning Diedrich)
Date: Thu, 08 Jul 2010 18:22:10 +0200
Subject: [erlang-questions] Erlang: Who uses it for games?
In-Reply-To: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com>
Message-ID: <4C35FB32.2080705@eonblast.com>

Hi Ingo,

we are currently developing an experimental browser game server in 
Erlang, with game logic embedded in Lua.

Henning

ingo.schramm wrote:
> Does somebody ever used Erlang to program game servers? Is there any
> real live industrial game solution written in Erlang?
>
> I need to know this for some evangelization :)
>
> Cheers,
> Ingo
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>
>   


From anthonym@REDACTED  Thu Jul  8 22:13:41 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Thu, 8 Jul 2010 13:13:41 -0700
Subject: [erlang-questions] Re: Possible leak in inets httpc.
In-Reply-To: <AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com> <AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com>
Message-ID: <20100708201341.GB9969@alumni.caltech.edu>

Hi, anyone know if its safe to backport this fix to R13B04?  I'm in the process
of deploying R13B04 as an upgrade from R12B05 and since I make heavy use of
httpc this will bite me.  Ideally, I can just grab the appropriate files from
git and plop them into my R13B04 when I build an rpm (of course I need to
remember enough git to do that :) ), so wondering if it's possible or if
there are deps outside of the inets directory which matter?

Thanks,

-Anthony

On Thu, Jul 08, 2010 at 02:12:07PM +0400, Andrey Popp wrote:
> It seems it has been fixed with [1] in inets-5.3.2. Sorry.
> 
> [1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
> 
> On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
> > Hello,
> >
> > I have application that makes huge number of HTTP requests with httpc
> > and I have spotted that `httpc_manager__handler_db` ETS table growing
> > in size and doesn't clean up. That is the example records from this
> > table (ets:i(httpc_manager__handler_db)):
> >
> > <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
> > <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
> > <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
> > <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
> > <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
> >
> > and processes with handler pids are no longer alive. Also, note that I
> > have no timeout setting in my http:request HTTPOptions, but I think
> > inets should not leak even in that case.
> >
> > Thanks.
> >
> > --
> > Andrey Popp
> >
> > phone: +7 911 740 24 91
> > e-mail: 8mayday@REDACTED
> >
> 
> 
> 
> -- 
> Andrey Popp
> 
> phone: +7 911 740 24 91
> e-mail: 8mayday@REDACTED
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From anthonym@REDACTED  Thu Jul  8 23:34:10 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Thu, 8 Jul 2010 14:34:10 -0700
Subject: [erlang-questions] Re: Possible leak in inets httpc.
In-Reply-To: <20100708201341.GB9969@alumni.caltech.edu>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com> <AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com> <20100708201341.GB9969@alumni.caltech.edu>
Message-ID: <20100708213410.GC9969@alumni.caltech.edu>

Well, looks like the answer is yes and no.  I was able to get a patch
which applied cleanly, however, the problem does not appear to be fixed.
The ets table still fills up with every request that times out
(I unfortunately don't have a standalone test, but I've tested
repeatedly and it always seem to get an extra entry for every request
that times out).

This is sort of a show stopper for me upgrading, so I'll be trying to
figure out a fix, but if anyone more familiar with the code wants to
help me out, it would be appreciated.

Thanks,

-Anthony

On Thu, Jul 08, 2010 at 01:13:41PM -0700, Anthony Molinaro wrote:
> Hi, anyone know if its safe to backport this fix to R13B04?  I'm in the process
> of deploying R13B04 as an upgrade from R12B05 and since I make heavy use of
> httpc this will bite me.  Ideally, I can just grab the appropriate files from
> git and plop them into my R13B04 when I build an rpm (of course I need to
> remember enough git to do that :) ), so wondering if it's possible or if
> there are deps outside of the inets directory which matter?
> 
> Thanks,
> 
> -Anthony
> 
> On Thu, Jul 08, 2010 at 02:12:07PM +0400, Andrey Popp wrote:
> > It seems it has been fixed with [1] in inets-5.3.2. Sorry.
> > 
> > [1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
> > 
> > On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
> > > Hello,
> > >
> > > I have application that makes huge number of HTTP requests with httpc
> > > and I have spotted that `httpc_manager__handler_db` ETS table growing
> > > in size and doesn't clean up. That is the example records from this
> > > table (ets:i(httpc_manager__handler_db)):
> > >
> > > <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
> > > <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
> > > <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
> > > <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
> > > <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
> > >
> > > and processes with handler pids are no longer alive. Also, note that I
> > > have no timeout setting in my http:request HTTPOptions, but I think
> > > inets should not leak even in that case.
> > >
> > > Thanks.
> > >
> > > --
> > > Andrey Popp
> > >
> > > phone: +7 911 740 24 91
> > > e-mail: 8mayday@REDACTED
> > >
> > 
> > 
> > 
> > -- 
> > Andrey Popp
> > 
> > phone: +7 911 740 24 91
> > e-mail: 8mayday@REDACTED
> > 
> > ________________________________________________________________
> > erlang-questions (at) erlang.org mailing list.
> > See http://www.erlang.org/faq.html
> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> > 
> 
> -- 
> ------------------------------------------------------------------------
> Anthony Molinaro                           <anthonym@REDACTED>

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From mapandfold@REDACTED  Fri Jul  9 03:54:56 2010
From: mapandfold@REDACTED (MapAndFold)
Date: Fri, 9 Jul 2010 09:54:56 +0800
Subject: [erlang-questions] Re: On Windows XP (SP2): wx broken
In-Reply-To: <AANLkTingr_hHSs0MXhC9mRGuvedjcWM1vYBYabtoxCC4@mail.gmail.com>
References: <aeb6a06d1003012305m62020dd1t7f11146db72a8ea9@mail.gmail.com>
	<9C6B96B5-37FA-4CF6-A7D3-663736CEE916@gmail.com>
	<69869ad8-a27a-48e6-8835-8303a87ed40d@g11g2000yqe.googlegroups.com>
	<93df43b61003032220m5b4d396dn4aca92270134d795@mail.gmail.com>
	<aeb6a06d1003041848k7e8a4d11h3b04cffa812ea3a@mail.gmail.com>
	<AANLkTingr_hHSs0MXhC9mRGuvedjcWM1vYBYabtoxCC4@mail.gmail.com>
Message-ID: <AANLkTimwf8xVDhqglTw926VggJnX7l0EA5i9WvaXkZKG@mail.gmail.com>

Yeah, I have tried again on R14A, and it is *almost* OK now.

But, another problem occurs:

Opening the sudoku demo, drag to resize the window, then things crash
with this message.

---------------------------------------------------------------------------------
---------------------------
Sudoku: werl.exe - Application Error
---------------------------
The instruction at "0x02292376" referenced memory at "0x00000010". The
memory could not be "read".
---------------------------------------------------------------------------------

My guest is that it seems to be related to the painting procedure of
the window. My little app which draws some graphics is also easy to
crash when resizing the window, while in wx:demo(), most of the
examples are OK (graphicsContext is easy to crash).

On Thu, Jul 8, 2010 at 3:44 PM, Dan Gudmundsson <dangud@REDACTED> wrote:
> Have you with this problem tried R14A, is it working now?
>
> I found that we had upgraded Visual Studio without recompiling
> wxWidgets DLL's causing the
> wx-driver to be dependent on two different versions of the runtime DLL,
> where only the latest where installed with erlang.
>
> Thanks for locating it.
>
> /Dan
>

From rvg@REDACTED  Fri Jul  9 07:32:38 2010
From: rvg@REDACTED (Rudolph van Graan)
Date: Fri, 9 Jul 2010 07:32:38 +0200
Subject: ORBER and support for valuetype
Message-ID: <4B63B58C-7D06-42EE-84F6-72EBA2480481@patternmatched.com>

Hi,

Does anyone know if there is an upcoming version of ORBER that will an implementation of the CORBA valuetype semantics that will allow one to do this:

valuetype Base {
  long    some_data;
};

valuetype  Derived : Base {
  long    more_data;
};

Thanks,

Rudolph van Graan

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From 8mayday@REDACTED  Fri Jul  9 08:12:37 2010
From: 8mayday@REDACTED (Andrey Popp)
Date: Fri, 9 Jul 2010 10:12:37 +0400
Subject: [erlang-questions] Re: Possible leak in inets httpc.
In-Reply-To: <20100708213410.GC9969@alumni.caltech.edu>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com> 
	<AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com> 
	<20100708201341.GB9969@alumni.caltech.edu> <20100708213410.GC9969@alumni.caltech.edu>
Message-ID: <AANLkTiluo6r8ehcdcCFrhrcKsaTtku3OOuOumQ3sJsVD@mail.gmail.com>

We have updated to R14 (thanks to deb packages in debian squeeze
repository) and all seems to be ok for now.

On Fri, Jul 9, 2010 at 1:34 AM, Anthony Molinaro
<anthonym@REDACTED> wrote:
> Well, looks like the answer is yes and no. ?I was able to get a patch
> which applied cleanly, however, the problem does not appear to be fixed.
> The ets table still fills up with every request that times out
> (I unfortunately don't have a standalone test, but I've tested
> repeatedly and it always seem to get an extra entry for every request
> that times out).
>
> This is sort of a show stopper for me upgrading, so I'll be trying to
> figure out a fix, but if anyone more familiar with the code wants to
> help me out, it would be appreciated.
>
> Thanks,
>
> -Anthony
>
> On Thu, Jul 08, 2010 at 01:13:41PM -0700, Anthony Molinaro wrote:
>> Hi, anyone know if its safe to backport this fix to R13B04? ?I'm in the process
>> of deploying R13B04 as an upgrade from R12B05 and since I make heavy use of
>> httpc this will bite me. ?Ideally, I can just grab the appropriate files from
>> git and plop them into my R13B04 when I build an rpm (of course I need to
>> remember enough git to do that :) ), so wondering if it's possible or if
>> there are deps outside of the inets directory which matter?
>>
>> Thanks,
>>
>> -Anthony
>>
>> On Thu, Jul 08, 2010 at 02:12:07PM +0400, Andrey Popp wrote:
>> > It seems it has been fixed with [1] in inets-5.3.2. Sorry.
>> >
>> > [1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
>> >
>> > On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
>> > > Hello,
>> > >
>> > > I have application that makes huge number of HTTP requests with httpc
>> > > and I have spotted that `httpc_manager__handler_db` ETS table growing
>> > > in size and doesn't clean up. That is the example records from this
>> > > table (ets:i(httpc_manager__handler_db)):
>> > >
>> > > <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
>> > > <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
>> > > <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
>> > > <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
>> > > <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
>> > >
>> > > and processes with handler pids are no longer alive. Also, note that I
>> > > have no timeout setting in my http:request HTTPOptions, but I think
>> > > inets should not leak even in that case.
>> > >
>> > > Thanks.
>> > >
>> > > --
>> > > Andrey Popp
>> > >
>> > > phone: +7 911 740 24 91
>> > > e-mail: 8mayday@REDACTED
>> > >
>> >
>> >
>> >
>> > --
>> > Andrey Popp
>> >
>> > phone: +7 911 740 24 91
>> > e-mail: 8mayday@REDACTED
>> >
>> > ________________________________________________________________
>> > erlang-questions (at) erlang.org mailing list.
>> > See http://www.erlang.org/faq.html
>> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>> >
>>
>> --
>> ------------------------------------------------------------------------
>> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
>
> --
> ------------------------------------------------------------------------
> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
Andrey Popp

phone: +7 911 740 24 91
e-mail: 8mayday@REDACTED

From schramm.ingo@REDACTED  Fri Jul  9 09:43:30 2010
From: schramm.ingo@REDACTED (ingo.schramm)
Date: Fri, 9 Jul 2010 00:43:30 -0700 (PDT)
Subject: Erlang: Who uses it for games?
In-Reply-To: <20100708150030.GT30357@delora.autosys.us>
References: <c6dcbad9-144f-4f22-ad37-b7793a4ec6a1@w31g2000yqb.googlegroups.com> 
	<AANLkTilG1SBnuH3voAMcgkkFATmHgnVR4O_KBSV589RK@mail.gmail.com> 
	<20100708150030.GT30357@delora.autosys.us>
Message-ID: <2861ca59-2583-43d0-914b-4c6bcff91436@k39g2000yqd.googlegroups.com>

Hey Michael, I just have 20 years of computers and software but some
10-15 of the Internet with all those crappy quickies of time to market
stuff and only Erlang saved me to still believe in the possibility of
well crafted software :)

On Jul 8, 5:00?pm, Michael McDaniel <erla...@REDACTED> wrote:
>
> ?This is the article by James that introduced me to Erlang ...
>
> ? ?http://www.dadgum.com/james/performance.html
>
> ? ?(see also ?http://prog21.dadgum.com/11.html)
>
> ?I think I stumbled upon the original performance article
> ?in early 2005 and investigated Erlang at that time.
>
> ?I was fairly burnt out on computers and especially software
> ?(after about 30 years of computers, last 20 of which were
> ?software). ?I was on a multi-month (year?) hiatus from
> ?software/systems creation in any form.
>
> ?Then I stumbled upon James's article and actually got excited
> ?about software again! ?James introduced me to a tool, Erlang,
> ?that didn't get in my way, but actually, in a major way,
> ?facilitated my end results. ?And provided some income and
> ?lots of fun (still).
>
> ?James, I doubt I ever said so until now, so *"Thank you"* for
> ?the original performance article and introduction to Erlang.
> ?(I have told the OTP team *Thank you* for Erlang, and do so
> ? again here).
>
> ~M
>
> --
> Michael McDaniel
> Portland, Oregon, USAhttp://trip.autosys.ushttp://edids.org
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> Seehttp://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED

From antoine.koener@REDACTED  Fri Jul  9 12:07:28 2010
From: antoine.koener@REDACTED (Antoine Koener)
Date: Fri, 9 Jul 2010 12:07:28 +0200
Subject: [erlang-questions] Re: On Windows XP (SP2): wx broken
In-Reply-To: <AANLkTimwf8xVDhqglTw926VggJnX7l0EA5i9WvaXkZKG@mail.gmail.com>
References: <aeb6a06d1003012305m62020dd1t7f11146db72a8ea9@mail.gmail.com>
	<9C6B96B5-37FA-4CF6-A7D3-663736CEE916@gmail.com>
	<69869ad8-a27a-48e6-8835-8303a87ed40d@g11g2000yqe.googlegroups.com>
	<93df43b61003032220m5b4d396dn4aca92270134d795@mail.gmail.com>
	<aeb6a06d1003041848k7e8a4d11h3b04cffa812ea3a@mail.gmail.com>
	<AANLkTingr_hHSs0MXhC9mRGuvedjcWM1vYBYabtoxCC4@mail.gmail.com>
	<AANLkTimwf8xVDhqglTw926VggJnX7l0EA5i9WvaXkZKG@mail.gmail.com>
Message-ID: <AANLkTin4pkTu2uo4d-dznl4uQrrH6mM20TskuktYVk6U@mail.gmail.com>

On Fri, Jul 9, 2010 at 3:54 AM, MapAndFold <mapandfold@REDACTED> wrote:

> Yeah, I have tried again on R14A, and it is *almost* OK now.
>
> But, another problem occurs:
>
> Opening the sudoku demo, drag to resize the window, then things crash
> with this message.
>
>
While your talking about the sudoku application, it's worth saying that it
takes 100% CPU.
Don't know if it's wx related but for my point of view it's a complete
failure.
UI must not take too much cpu (I'm not talking about games...)

Note that I know that this sudoku thing is only a proof of concept, and it
is not designed as
a top quality game, but this don't encourage myself to rely heavily on
wx/erlang :/


>
> ---------------------------------------------------------------------------------
> ---------------------------
> Sudoku: werl.exe - Application Error
> ---------------------------
> The instruction at "0x02292376" referenced memory at "0x00000010". The
> memory could not be "read".
>
> ---------------------------------------------------------------------------------
>
> My guest is that it seems to be related to the painting procedure of
> the window. My little app which draws some graphics is also easy to
> crash when resizing the window, while in wx:demo(), most of the
> examples are OK (graphicsContext is easy to crash).
>
> On Thu, Jul 8, 2010 at 3:44 PM, Dan Gudmundsson <dangud@REDACTED> wrote:
> > Have you with this problem tried R14A, is it working now?
> >
> > I found that we had upgraded Visual Studio without recompiling
> > wxWidgets DLL's causing the
> > wx-driver to be dependent on two different versions of the runtime DLL,
> > where only the latest where installed with erlang.
> >
> > Thanks for locating it.
> >
> > /Dan
> >
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From bomicael@REDACTED  Fri Jul  9 12:12:13 2010
From: bomicael@REDACTED (Micael Karlberg)
Date: Fri, 9 Jul 2010 12:12:13 +0200
Subject: [erlang-questions] Re: Possible leak in inets httpc.
In-Reply-To: <AANLkTiluo6r8ehcdcCFrhrcKsaTtku3OOuOumQ3sJsVD@mail.gmail.com>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com>
	<AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com>
	<20100708201341.GB9969@alumni.caltech.edu>
	<20100708213410.GC9969@alumni.caltech.edu>
	<AANLkTiluo6r8ehcdcCFrhrcKsaTtku3OOuOumQ3sJsVD@mail.gmail.com>
Message-ID: <AANLkTimA8WAaN_VXAFjktbWbCDvmEAZCRPxmlvR5u9zY@mail.gmail.com>

This problem was fixed in inets-5.3.2. The fix was reported by Lev Walkin:

http://www.erlang.org/cgi-bin/ezmlm-cgi/2/1766

Unfortunately, github was not updated in one commit, but in several, here
are some of them:

http://github.com/erlang/otp/commit/4b87b22ce97abf2759eb551222a862e17c5f4dcb
http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49

So you have to do a bit of cut-and-paste. The last version of inets in
R13B was 5.3.3,
but I don't know if that made it into github.

Regards,
    /BMK

On Fri, Jul 9, 2010 at 8:12 AM, Andrey Popp <8mayday@REDACTED> wrote:
> We have updated to R14 (thanks to deb packages in debian squeeze
> repository) and all seems to be ok for now.
>
> On Fri, Jul 9, 2010 at 1:34 AM, Anthony Molinaro
> <anthonym@REDACTED> wrote:
>> Well, looks like the answer is yes and no. ?I was able to get a patch
>> which applied cleanly, however, the problem does not appear to be fixed.
>> The ets table still fills up with every request that times out
>> (I unfortunately don't have a standalone test, but I've tested
>> repeatedly and it always seem to get an extra entry for every request
>> that times out).
>>
>> This is sort of a show stopper for me upgrading, so I'll be trying to
>> figure out a fix, but if anyone more familiar with the code wants to
>> help me out, it would be appreciated.
>>
>> Thanks,
>>
>> -Anthony
>>
>> On Thu, Jul 08, 2010 at 01:13:41PM -0700, Anthony Molinaro wrote:
>>> Hi, anyone know if its safe to backport this fix to R13B04? ?I'm in the process
>>> of deploying R13B04 as an upgrade from R12B05 and since I make heavy use of
>>> httpc this will bite me. ?Ideally, I can just grab the appropriate files from
>>> git and plop them into my R13B04 when I build an rpm (of course I need to
>>> remember enough git to do that :) ), so wondering if it's possible or if
>>> there are deps outside of the inets directory which matter?
>>>
>>> Thanks,
>>>
>>> -Anthony
>>>
>>> On Thu, Jul 08, 2010 at 02:12:07PM +0400, Andrey Popp wrote:
>>> > It seems it has been fixed with [1] in inets-5.3.2. Sorry.
>>> >
>>> > [1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
>>> >
>>> > On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
>>> > > Hello,
>>> > >
>>> > > I have application that makes huge number of HTTP requests with httpc
>>> > > and I have spotted that `httpc_manager__handler_db` ETS table growing
>>> > > in size and doesn't clean up. That is the example records from this
>>> > > table (ets:i(httpc_manager__handler_db)):
>>> > >
>>> > > <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
>>> > > <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
>>> > > <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
>>> > > <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
>>> > > <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
>>> > >
>>> > > and processes with handler pids are no longer alive. Also, note that I
>>> > > have no timeout setting in my http:request HTTPOptions, but I think
>>> > > inets should not leak even in that case.
>>> > >
>>> > > Thanks.
>>> > >
>>> > > --
>>> > > Andrey Popp
>>> > >
>>> > > phone: +7 911 740 24 91
>>> > > e-mail: 8mayday@REDACTED
>>> > >
>>> >
>>> >
>>> >
>>> > --
>>> > Andrey Popp
>>> >
>>> > phone: +7 911 740 24 91
>>> > e-mail: 8mayday@REDACTED
>>> >
>>> > ________________________________________________________________
>>> > erlang-questions (at) erlang.org mailing list.
>>> > See http://www.erlang.org/faq.html
>>> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>> >
>>>
>>> --
>>> ------------------------------------------------------------------------
>>> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
>>
>> --
>> ------------------------------------------------------------------------
>> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>
>
>
> --
> Andrey Popp
>
> phone: +7 911 740 24 91
> e-mail: 8mayday@REDACTED
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From dangud@REDACTED  Fri Jul  9 12:25:48 2010
From: dangud@REDACTED (Dan Gudmundsson)
Date: Fri, 9 Jul 2010 12:25:48 +0200
Subject: [erlang-questions] Re: On Windows XP (SP2): wx broken
In-Reply-To: <AANLkTin4pkTu2uo4d-dznl4uQrrH6mM20TskuktYVk6U@mail.gmail.com>
References: <aeb6a06d1003012305m62020dd1t7f11146db72a8ea9@mail.gmail.com>
	<9C6B96B5-37FA-4CF6-A7D3-663736CEE916@gmail.com>
	<69869ad8-a27a-48e6-8835-8303a87ed40d@g11g2000yqe.googlegroups.com>
	<93df43b61003032220m5b4d396dn4aca92270134d795@mail.gmail.com>
	<aeb6a06d1003041848k7e8a4d11h3b04cffa812ea3a@mail.gmail.com>
	<AANLkTingr_hHSs0MXhC9mRGuvedjcWM1vYBYabtoxCC4@mail.gmail.com>
	<AANLkTimwf8xVDhqglTw926VggJnX7l0EA5i9WvaXkZKG@mail.gmail.com>
	<AANLkTin4pkTu2uo4d-dznl4uQrrH6mM20TskuktYVk6U@mail.gmail.com>
Message-ID: <AANLkTimynKiCnyEeRGRfWFW_S-lTnFgDnNXCNVwTc9Is@mail.gmail.com>

On Fri, Jul 9, 2010 at 12:07 PM, Antoine Koener
<antoine.koener@REDACTED> wrote:
> On Fri, Jul 9, 2010 at 3:54 AM, MapAndFold <mapandfold@REDACTED> wrote:
>>
>> Yeah, I have tried again on R14A, and it is *almost* OK now.
>>
>> But, another problem occurs:
>>
>> Opening the sudoku demo, drag to resize the window, then things crash
>> with this message.
>>
>
Thanks for the input, I need to see if I can repeat that.

> While your talking about the sudoku application, it's worth saying that it
> takes 100% CPU.
> Don't know if it's wx related but for my point of view it's a complete
> failure.
> UI must not take too much cpu (I'm not talking about games...)
> Note that I know that this sudoku thing is only a proof of concept, and it
> is not designed as
> a top quality game, but this don't encourage myself to rely heavily on
> wx/erlang :/

:-)

It's not the gui that takes 100% cpu, the game generates new boards in
the background for a while.
Generating boards (at least in my implementation) takes some cpu.
You know in erlang you can spawn processes to do work while waiting
for user input. :-)
But if you wait some time it will have generated 5 boards and it will
slow down.

/Dan

From nick@REDACTED  Fri Jul  9 12:35:26 2010
From: nick@REDACTED (Niclas Eklund)
Date: Fri, 9 Jul 2010 12:35:26 +0200 (CEST)
Subject: [erlang-questions] ORBER and support for valuetype
In-Reply-To: <4B63B58C-7D06-42EE-84F6-72EBA2480481@patternmatched.com>
References: <4B63B58C-7D06-42EE-84F6-72EBA2480481@patternmatched.com>
Message-ID: <Pine.LNX.4.64.1007091233020.4846@mallor.du.uab.ericsson.se>


Hello!

Currently there are no plans for adding IDL-support for valuetype in IC 
and Orber.

Best Regards,

Niclas @ Erlang/OTP


On Fri, 9 Jul 2010, Rudolph van Graan wrote:

> Hi,
>
> Does anyone know if there is an upcoming version of ORBER that will an 
> implementation of the CORBA valuetype semantics that will allow one to 
> do this:
>
> valuetype Base {
>  long    some_data;
> };
>
> valuetype  Derived : Base {
>  long    more_data;
> };
>
> Thanks,
>
> Rudolph van Graan
>
>



From anthonym@REDACTED  Fri Jul  9 18:26:48 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Fri, 9 Jul 2010 09:26:48 -0700
Subject: [erlang-questions] Re: Possible leak in inets httpc.
In-Reply-To: <AANLkTimA8WAaN_VXAFjktbWbCDvmEAZCRPxmlvR5u9zY@mail.gmail.com>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com> <AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com> <20100708201341.GB9969@alumni.caltech.edu> <20100708213410.GC9969@alumni.caltech.edu> <AANLkTiluo6r8ehcdcCFrhrcKsaTtku3OOuOumQ3sJsVD@mail.gmail.com> <AANLkTimA8WAaN_VXAFjktbWbCDvmEAZCRPxmlvR5u9zY@mail.gmail.com>
Message-ID: <20100709162648.GB18058@alumni.caltech.edu>

Yeah, I managed to get the entire set of patches, basically used

git diff 201ccdd08bd2a591fe1e348a9a1df3d94a3606e4 141ff3c087ca856d21d0 lib/inets

Which seemed to get them all.  However, I still see memory leaked

Erlang R13B04 (erts-5.7.5) [source] [64-bit] [smp:2:2] [rq:2] [async-threads:0]
[kernel-poll:false]

Eshell V5.7.5  (abort with ^G)
1> inets:start().
ok
2> ets:i().
...
 16402           httpc_manager__session_cookie_db bag   0      316      httpc_manager
 httpc_manager__handler_db httpc_manager__handler_db set   0      316      httpc_manager
 httpc_manager__session_db httpc_manager__session_db set   0      316      httpc_manager
...
3> http:request (post, { "http://www.example.com", [], "application/octet-stream", <<"hello">>}, [{connect_timeout, 100},{timeout, 10}], [{body_format, binary} ]).
{error,timeout}
4> ets:i().
...
 16402           httpc_manager__session_cookie_db bag   0      316      httpc_manager
 httpc_manager__handler_db httpc_manager__handler_db set   1      333      httpc_manager
 httpc_manager__session_db httpc_manager__session_db set   0      316      httpc_manager
...
5> ets:i(httpc_manager__handler_db).
<1   > {handler_info,#Ref<0.0.0.142>,undefined,<0.60.0>,<0.33.0>,operational}

6> m(inets).
Module inets compiled: Date: July 8 2010, Time: 06.45
Compiler options:  [{d,'SERVER_SOFTWARE',"inets/5.3.3"},
                    {cwd,"/home/molinaro/projects/work/vendor/erlang/R13B04/rpmbuild/BUILD/otp_src_R13B04/lib/inets/src/inets_app"},
                    {outdir,"/home/molinaro/projects/work/vendor/erlang/R13B04/rpmbuild/BUILD/otp_src_R13B04/lib/inets/src/inets_app/../../ebin"},
                    {attribute,insert,app_vsn,"inets-5.3.3"},
                    {parse_transform,sys_pre_attributes},
                    debug_info]
Object file: /usr/lib64/erlang/lib/inets-5.3.3/ebin/inets.beam
...

So it seems if you connect but then timeout you leak some memory even with
5.3.3.  I've not tried 5.4 which is in dev but the only changes there seem
to be related to ssl...

Can anyone else confirm this is still broken?

-Anthony

On Fri, Jul 09, 2010 at 12:12:13PM +0200, Micael Karlberg wrote:
> This problem was fixed in inets-5.3.2. The fix was reported by Lev Walkin:
> 
> http://www.erlang.org/cgi-bin/ezmlm-cgi/2/1766
> 
> Unfortunately, github was not updated in one commit, but in several, here
> are some of them:
> 
> http://github.com/erlang/otp/commit/4b87b22ce97abf2759eb551222a862e17c5f4dcb
> http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
> 
> So you have to do a bit of cut-and-paste. The last version of inets in
> R13B was 5.3.3,
> but I don't know if that made it into github.
> 
> Regards,
>     /BMK
> 
> On Fri, Jul 9, 2010 at 8:12 AM, Andrey Popp <8mayday@REDACTED> wrote:
> > We have updated to R14 (thanks to deb packages in debian squeeze
> > repository) and all seems to be ok for now.
> >
> > On Fri, Jul 9, 2010 at 1:34 AM, Anthony Molinaro
> > <anthonym@REDACTED> wrote:
> >> Well, looks like the answer is yes and no. ?I was able to get a patch
> >> which applied cleanly, however, the problem does not appear to be fixed.
> >> The ets table still fills up with every request that times out
> >> (I unfortunately don't have a standalone test, but I've tested
> >> repeatedly and it always seem to get an extra entry for every request
> >> that times out).
> >>
> >> This is sort of a show stopper for me upgrading, so I'll be trying to
> >> figure out a fix, but if anyone more familiar with the code wants to
> >> help me out, it would be appreciated.
> >>
> >> Thanks,
> >>
> >> -Anthony
> >>
> >> On Thu, Jul 08, 2010 at 01:13:41PM -0700, Anthony Molinaro wrote:
> >>> Hi, anyone know if its safe to backport this fix to R13B04? ?I'm in the process
> >>> of deploying R13B04 as an upgrade from R12B05 and since I make heavy use of
> >>> httpc this will bite me. ?Ideally, I can just grab the appropriate files from
> >>> git and plop them into my R13B04 when I build an rpm (of course I need to
> >>> remember enough git to do that :) ), so wondering if it's possible or if
> >>> there are deps outside of the inets directory which matter?
> >>>
> >>> Thanks,
> >>>
> >>> -Anthony
> >>>
> >>> On Thu, Jul 08, 2010 at 02:12:07PM +0400, Andrey Popp wrote:
> >>> > It seems it has been fixed with [1] in inets-5.3.2. Sorry.
> >>> >
> >>> > [1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
> >>> >
> >>> > On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
> >>> > > Hello,
> >>> > >
> >>> > > I have application that makes huge number of HTTP requests with httpc
> >>> > > and I have spotted that `httpc_manager__handler_db` ETS table growing
> >>> > > in size and doesn't clean up. That is the example records from this
> >>> > > table (ets:i(httpc_manager__handler_db)):
> >>> > >
> >>> > > <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
> >>> > > <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
> >>> > > <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
> >>> > > <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
> >>> > > <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
> >>> > >
> >>> > > and processes with handler pids are no longer alive. Also, note that I
> >>> > > have no timeout setting in my http:request HTTPOptions, but I think
> >>> > > inets should not leak even in that case.
> >>> > >
> >>> > > Thanks.
> >>> > >
> >>> > > --
> >>> > > Andrey Popp
> >>> > >
> >>> > > phone: +7 911 740 24 91
> >>> > > e-mail: 8mayday@REDACTED
> >>> > >
> >>> >
> >>> >
> >>> >
> >>> > --
> >>> > Andrey Popp
> >>> >
> >>> > phone: +7 911 740 24 91
> >>> > e-mail: 8mayday@REDACTED
> >>> >
> >>> > ________________________________________________________________
> >>> > erlang-questions (at) erlang.org mailing list.
> >>> > See http://www.erlang.org/faq.html
> >>> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >>> >
> >>>
> >>> --
> >>> ------------------------------------------------------------------------
> >>> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
> >>
> >> --
> >> ------------------------------------------------------------------------
> >> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
> >>
> >> ________________________________________________________________
> >> erlang-questions (at) erlang.org mailing list.
> >> See http://www.erlang.org/faq.html
> >> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >>
> >>
> >
> >
> >
> > --
> > Andrey Popp
> >
> > phone: +7 911 740 24 91
> > e-mail: 8mayday@REDACTED
> >
> > ________________________________________________________________
> > erlang-questions (at) erlang.org mailing list.
> > See http://www.erlang.org/faq.html
> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >
> >
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From boris.muehmer@REDACTED  Fri Jul  9 19:55:46 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Fri, 9 Jul 2010 19:55:46 +0200
Subject: Let's start a project for a (MMO-)Game in Erlang... (inspired by 
	"Erlang: Who uses it for games?")
Message-ID: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>

It looks like some people are interested in Erlang game programming.
On the other hand getting started in Erlang and OTP isn't too easy.
Especially for people with a strong C/C++/C#/Java/etc background.

Inspired by the "Erlang: Who uses it for games?" thread I thought about
starting a community project to implement a MMO game in Erlang/OTP.
The goal would be to collect some "best-practices" for different tasks.

Actually I am more interested in the server side than how to implement
a top-notch-state-of-the-art client. Also I think Erlang is more suited
for the server side. But I am also interested in how to interface the
"server-side erlang" using a (C/C++, Java, Python) cross-plattform
client (using wxWidget or Qt as a base and OpenGL for graphics).

What I would like to see are reponses from other people who may also
be interested in such a project. Not only beginners with Erlang/OTP,
but also (or especially) experienced people to guide and support the
others. And most of all, to have some fun practising Erlang.

Well, what do You think about it?

Best regards,
Boris

From dale@REDACTED  Fri Jul  9 20:10:04 2010
From: dale@REDACTED (Dale Harvey)
Date: Fri, 9 Jul 2010 19:10:04 +0100
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
Message-ID: <AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>

On 9 July 2010 18:55, Boris M?hmer <boris.muehmer@REDACTED> wrote:

> It looks like some people are interested in Erlang game programming.
> On the other hand getting started in Erlang and OTP isn't too easy.
> Especially for people with a strong C/C++/C#/Java/etc background.
>
> Inspired by the "Erlang: Who uses it for games?" thread I thought about
> starting a community project to implement a MMO game in Erlang/OTP.
> The goal would be to collect some "best-practices" for different tasks.
>
> Actually I am more interested in the server side than how to implement
> a top-notch-state-of-the-art client. Also I think Erlang is more suited
> for the server side. But I am also interested in how to interface the
> "server-side erlang" using a (C/C++, Java, Python) cross-plattform
> client (using wxWidget or Qt as a base and OpenGL for graphics).
>
>
I would completely recommend using a web front end, depending on the type of
graphics involved dom / canvas / svg or webgl can be used for rendering, and
comet or websockets for communication.

erlang has long missed the boat on becoming a strong platform for building
cross platform desktop clients, and considering how well suited it is for
writing the server components of a web application I would suggest sticking
to its strengths.

(I would love to keep updates, and while I would love to contribute, the
chances are I will be too busy, no harm in bugging me if you are looking for
a web frontend though)


> What I would like to see are reponses from other people who may also
> be interested in such a project. Not only beginners with Erlang/OTP,
> but also (or especially) experienced people to guide and support the
> others. And most of all, to have some fun practising Erlang.
>
> Well, what do You think about it?
>
> Best regards,
> Boris
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From therevoltingx@REDACTED  Fri Jul  9 21:33:46 2010
From: therevoltingx@REDACTED (Miguel Morales)
Date: Fri, 9 Jul 2010 12:33:46 -0700
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
Message-ID: <AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>

It would be feasible to do the client side using wxWidgets and/or esdl.
However, I think having a web frontend is the way to go.
I'm too busy on my own project to help, how about perhaps contributing
to existing mmorpg engines such as: http://www.next-gen.cc/
There goes a lot into making a game, not just programming.  A lot of
art is needed, plus people to design characters and story lines.  One
would have to think carefully as to what type of mmorpg to make before
even getting started.

On Fri, Jul 9, 2010 at 11:10 AM, Dale Harvey <dale@REDACTED> wrote:
> On 9 July 2010 18:55, Boris M?hmer <boris.muehmer@REDACTED> wrote:
>
>> It looks like some people are interested in Erlang game programming.
>> On the other hand getting started in Erlang and OTP isn't too easy.
>> Especially for people with a strong C/C++/C#/Java/etc background.
>>
>> Inspired by the "Erlang: Who uses it for games?" thread I thought about
>> starting a community project to implement a MMO game in Erlang/OTP.
>> The goal would be to collect some "best-practices" for different tasks.
>>
>> Actually I am more interested in the server side than how to implement
>> a top-notch-state-of-the-art client. Also I think Erlang is more suited
>> for the server side. But I am also interested in how to interface the
>> "server-side erlang" using a (C/C++, Java, Python) cross-plattform
>> client (using wxWidget or Qt as a base and OpenGL for graphics).
>>
>>
> I would completely recommend using a web front end, depending on the type of
> graphics involved dom / canvas / svg or webgl can be used for rendering, and
> comet or websockets for communication.
>
> erlang has long missed the boat on becoming a strong platform for building
> cross platform desktop clients, and considering how well suited it is for
> writing the server components of a web application I would suggest sticking
> to its strengths.
>
> (I would love to keep updates, and while I would love to contribute, the
> chances are I will be too busy, no harm in bugging me if you are looking for
> a web frontend though)
>
>
>> What I would like to see are reponses from other people who may also
>> be interested in such a project. Not only beginners with Erlang/OTP,
>> but also (or especially) experienced people to guide and support the
>> others. And most of all, to have some fun practising Erlang.
>>
>> Well, what do You think about it?
>>
>> Best regards,
>> Boris
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>



-- 
http://developingthedream.blogspot.com/,
http://diastrofunk.com,
http://www.youtube.com/user/revoltingx, ~Isaiah 55:8-9

From mjtruog@REDACTED  Sat Jul 10 02:14:48 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Fri, 09 Jul 2010 17:14:48 -0700
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in
 	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com> <AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
Message-ID: <4C37BB78.4060205@gmail.com>

I am interested in contributing to server-side MMOG work, open-source
and otherwise.  I think and MMOG server could be done in a way where the
front-end could be web based, or a graphics intensive application
(probably .NET C++ or C#... or cross-platform if truly innovative).  It
would be nice to somehow abstract away the difference between AJAX
communication and Websockets, to have a very compatible web front-end
working.  However, all the core logic should not require hard-coding the
server communication and client front-end.

We need an Erlang-based MMOG server that is open-source, and the easiest
way to get one, is to create one.  It would not be easy or productive to
convince other projects to suddenly change what they are doing, to use a
better server programming paradigm (and with open-source, the best
project generally wins, by surviving the longest).

I think many common components could be developed that MMOGs generally
need: object/PC/NPC persistence and database caching, efficient
physics/AI code access, DSL for game scripting, etc..  I do not think
the Erlang-based server would be too inefficient.  Such an attitude
seems to come from much of the focus on only testing within the Erlang
community and the focus on only premature optimization within the gaming
community.

Many Erlang servers have scalability characteristics that easily exceed
the rushed coding of production game servers (that contain much more
complexity and more SLOC than is easily maintainable).

C and C++ integration is required for using efficient libraries that are
required for complex tasks (a best case scenario might be only a physics
engine).  One major problem is not having memory leaks, since that is
normally the cause of any MMOG's daily server reboot (which is very
typical).  That would mean that linked-in driver (NIF) usage would
require much scrutiny, and an Erlang port might offer redundancy if the
delay was acceptable (i.e., managing the computational latency).

It would probably be best to have a game scripting language (DSL)
layered on the Erlang VM, and to keep as much logic within Erlang as
possible... until the logic delves into data structures that must be
immutable.

So, I am interested and have been thinking about it awhile.  I have
worked on previous MMOGs and would enjoy working on an Erlang-based
solution.

On 07/09/2010 12:33 PM, Miguel Morales wrote:
> It would be feasible to do the client side using wxWidgets and/or esdl.
> However, I think having a web frontend is the way to go.
> I'm too busy on my own project to help, how about perhaps contributing
> to existing mmorpg engines such as: http://www.next-gen.cc/
> There goes a lot into making a game, not just programming.  A lot of
> art is needed, plus people to design characters and story lines.  One
> would have to think carefully as to what type of mmorpg to make before
> even getting started.
>
> On Fri, Jul 9, 2010 at 11:10 AM, Dale Harvey <dale@REDACTED> wrote:
>   
>> On 9 July 2010 18:55, Boris M?hmer <boris.muehmer@REDACTED> wrote:
>>
>>     
>>> It looks like some people are interested in Erlang game programming.
>>> On the other hand getting started in Erlang and OTP isn't too easy.
>>> Especially for people with a strong C/C++/C#/Java/etc background.
>>>
>>> Inspired by the "Erlang: Who uses it for games?" thread I thought about
>>> starting a community project to implement a MMO game in Erlang/OTP.
>>> The goal would be to collect some "best-practices" for different tasks.
>>>
>>> Actually I am more interested in the server side than how to implement
>>> a top-notch-state-of-the-art client. Also I think Erlang is more suited
>>> for the server side. But I am also interested in how to interface the
>>> "server-side erlang" using a (C/C++, Java, Python) cross-plattform
>>> client (using wxWidget or Qt as a base and OpenGL for graphics).
>>>
>>>
>>>       
>> I would completely recommend using a web front end, depending on the type of
>> graphics involved dom / canvas / svg or webgl can be used for rendering, and
>> comet or websockets for communication.
>>
>> erlang has long missed the boat on becoming a strong platform for building
>> cross platform desktop clients, and considering how well suited it is for
>> writing the server components of a web application I would suggest sticking
>> to its strengths.
>>
>> (I would love to keep updates, and while I would love to contribute, the
>> chances are I will be too busy, no harm in bugging me if you are looking for
>> a web frontend though)
>>
>>
>>     
>>> What I would like to see are reponses from other people who may also
>>> be interested in such a project. Not only beginners with Erlang/OTP,
>>> but also (or especially) experienced people to guide and support the
>>> others. And most of all, to have some fun practising Erlang.
>>>
>>> Well, what do You think about it?
>>>
>>> Best regards,
>>> Boris
>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>>
>>>       
>>     
>
>
>   


From raould@REDACTED  Sat Jul 10 02:21:31 2010
From: raould@REDACTED (Raoul Duke)
Date: Fri, 9 Jul 2010 17:21:31 -0700
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <4C37BB78.4060205@gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
Message-ID: <AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>

On Fri, Jul 9, 2010 at 5:14 PM, Michael Truog <mjtruog@REDACTED> wrote:
>  DSL for game scripting, etc..

http://github.com/rvirding/lfe

:-)

From corticalcomputer@REDACTED  Sat Jul 10 02:37:09 2010
From: corticalcomputer@REDACTED (G.S.)
Date: Fri, 9 Jul 2010 17:37:09 -0700
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
Message-ID: <AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>

I'll join. I can do Physics/AI, or some other part.

Regards,
-Gene

On Fri, Jul 9, 2010 at 5:21 PM, Raoul Duke <raould@REDACTED> wrote:
> On Fri, Jul 9, 2010 at 5:14 PM, Michael Truog <mjtruog@REDACTED> wrote:
>> ?DSL for game scripting, etc..
>
> http://github.com/rvirding/lfe
>
> :-)
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From boris.muehmer@REDACTED  Sat Jul 10 07:40:18 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Sat, 10 Jul 2010 07:40:18 +0200
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
Message-ID: <AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>

Thank You for the first responses in such a short time.

Where should we set up a project? Would "Google Code" be a good place
to start at? Maybe use "Google Groups"/"Google Wave" for
communication? What other alternatives are there? I currently only
know of C#/.Net places... An "no", I don't work for Google, still I
like the tools they provide... :-)

I had a brief look at some sites. Many need a "license" for a project.
Which one should be used?

What kind of repository system should be used? Would "Git" be ok?

  - boris

From mjtruog@REDACTED  Sat Jul 10 08:09:27 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Fri, 09 Jul 2010 23:09:27 -0700
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in
 	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>	<4C37BB78.4060205@gmail.com>	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com> <AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
Message-ID: <4C380E97.6090505@gmail.com>

I vote for "Google Groups"/"Google Wave"/GitHub/BSD_License
I am neutral on "Google Code"

This is not legal advice!

The BSD license does make it easier for companies to profit directly
from all work, but it also helps the code get more external development
which impacts the core open-source code.  The direction the GPL license
has gone (even trying to discourage commercial usage of GPL code as a
service without submitting the code changes) seems to discourage much
serious usage of open-source software in competitive industries (i.e.,
industries that depend on lots of proprietary secrets that must
integrate directly with open-source software).

I don't think there is a problem with the old style of the BSD license,
but die-hard GPL believers would probably disagree (and favor the new
style BSD license).

I have not seen a good reason why the LGPL is better than a BSD/MIT
license (BSD seems clearer and more concise to me).  The difference
seems like it is the difference between SYSV and BSD (i.e., different
people with different ideas doing the same stuff in different ways).

So, the BSD license can help companies take an active role in
development, if they choose to.  It would be counter-productive for a
company to not help out the project they depend on, if that is the case.

This is not legal advice!

On 07/09/2010 10:40 PM, Boris M?hmer wrote:
> Thank You for the first responses in such a short time.
>
> Where should we set up a project? Would "Google Code" be a good place
> to start at? Maybe use "Google Groups"/"Google Wave" for
> communication? What other alternatives are there? I currently only
> know of C#/.Net places... An "no", I don't work for Google, still I
> like the tools they provide... :-)
>
> I had a brief look at some sites. Many need a "license" for a project.
> Which one should be used?
>
> What kind of repository system should be used? Would "Git" be ok?
>
>   - boris
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>
>   


From ttmrichter@REDACTED  Sat Jul 10 08:32:04 2010
From: ttmrichter@REDACTED (Michael Richter)
Date: Sat, 10 Jul 2010 14:32:04 +0800
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <4C380E97.6090505@gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
Message-ID: <AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>

On 10 July 2010 14:09, Michael Truog <mjtruog@REDACTED> wrote:

> I vote for "Google Groups"/"Google Wave"/GitHub/BSD_License
> I am neutral on "Google Code"
>

I vote AGAINST Google Wave and Google Code.  I've never had a good
experience on Google Code and Google Wave is painfully slow and incoherent
for anything serious IME.

-- 
"Perhaps people don't believe this, but throughout all of the discussions of
entering China our focus has really been what's best for the Chinese people.
It's not been about our revenue or profit or whatnot."
--Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.

From dawid.figiel@REDACTED  Sat Jul 10 11:15:47 2010
From: dawid.figiel@REDACTED (Dawid Figiel)
Date: Sat, 10 Jul 2010 10:15:47 +0100
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
Message-ID: <AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>

bitbucket ?


On Sat, Jul 10, 2010 at 7:32 AM, Michael Richter <ttmrichter@REDACTED>wrote:

> On 10 July 2010 14:09, Michael Truog <mjtruog@REDACTED> wrote:
>
> > I vote for "Google Groups"/"Google Wave"/GitHub/BSD_License
> > I am neutral on "Google Code"
> >
>
> I vote AGAINST Google Wave and Google Code.  I've never had a good
> experience on Google Code and Google Wave is painfully slow and incoherent
> for anything serious IME.
>
> --
> "Perhaps people don't believe this, but throughout all of the discussions
> of
> entering China our focus has really been what's best for the Chinese
> people.
> It's not been about our revenue or profit or whatnot."
> --Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.
>



-- 
Dawid

From ttmrichter@REDACTED  Sat Jul 10 11:50:53 2010
From: ttmrichter@REDACTED (Michael Richter)
Date: Sat, 10 Jul 2010 17:50:53 +0800
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
Message-ID: <AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>

BitBucket, GitHub both sure, although I favour the former.

On 10 July 2010 17:15, Dawid Figiel <dawid.figiel@REDACTED> wrote:

> bitbucket ?
>
>
> On Sat, Jul 10, 2010 at 7:32 AM, Michael Richter <ttmrichter@REDACTED
> >wrote:
>
> > On 10 July 2010 14:09, Michael Truog <mjtruog@REDACTED> wrote:
> >
> > > I vote for "Google Groups"/"Google Wave"/GitHub/BSD_License
> > > I am neutral on "Google Code"
> > >
> >
> > I vote AGAINST Google Wave and Google Code.  I've never had a good
> > experience on Google Code and Google Wave is painfully slow and
> incoherent
> > for anything serious IME.
> >
> > --
> > "Perhaps people don't believe this, but throughout all of the discussions
> > of
> > entering China our focus has really been what's best for the Chinese
> > people.
> > It's not been about our revenue or profit or whatnot."
> > --Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.
> >
>
>
>
> --
> Dawid
>



-- 
"Perhaps people don't believe this, but throughout all of the discussions of
entering China our focus has really been what's best for the Chinese people.
It's not been about our revenue or profit or whatnot."
--Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.

From boris.muehmer@REDACTED  Sat Jul 10 13:21:43 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Sat, 10 Jul 2010 13:21:43 +0200
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>
Message-ID: <AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>

I will have a look at bitbucket and github. Does bitbucket have a
"free plan" for many users? I didn't see it at my first glance...

I know Linux doesn't have any problems with git, mercurial, or
whatever. How about Windows and Mac OS X? Sometimes I use subversion
on windows, but I don't have too much experience about git or
mercurial. I also have an old G4 Mac, even with Mac OS X, but I never
did any programming on that machine.

Also how should we name the project?

Somehow I don't want to have the term "Game" in the name, because I
think a general approach wouldn't only be interesting for games (like
Fantasy-/SF-MMO[RP]Gs), but also "Virtual Worlds" (like Second Life),
maybe it could also be of interest for "Virtual-Classrooms".

Maybe we need more than one project. Like one for the major "backbone"
components (cluster management, monitoring, load balancing,
accounting, reporting, tools) and other for "instances" like "Erlang
Vast Exploration Online", "Universe of Erlang", "My Erlang Farm",
"Erlang Mafia Disputes", "Erlang Aquarium", "Erlang Life", "Cafe
Erlang"...

Should we discuss those things using "erlang-questions" or move to
Google Groups or another mailing list? I don't want to annoy to many
people with crazy thoughts...


  - boris

From e_d_k@REDACTED  Sat Jul 10 15:18:22 2010
From: e_d_k@REDACTED (Ed Keith)
Date: Sat, 10 Jul 2010 06:18:22 -0700 (PDT)
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in  Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
Message-ID: <2179.1971.qm@web120506.mail.ne1.yahoo.com>

--- On Sat, 7/10/10, Boris M?hmer <boris.muehmer@REDACTED> wrote:

> From: Boris M?hmer <boris.muehmer@REDACTED>
> Subject: Re: [erlang-questions] Let's start a project for a (MMO-)Game in  Erlang... (inspired by "Erlang: Who uses it for games?")
> To: "erlang-questions" <erlang-questions@REDACTED>
> Date: Saturday, July 10, 2010, 7:21 AM
> I will have a look at bitbucket and
> github. Does bitbucket have a
> "free plan" for many users? I didn't see it at my first
> glance...

You can have several user on a project at Bitbucket.

> 
> I know Linux doesn't have any problems with git, mercurial,
> or
> whatever. How about Windows and Mac OS X? Sometimes I use
> subversion
> on windows, but I don't have too much experience about git
> or
> mercurial. I also have an old G4 Mac, even with Mac OS X,
> but I never
> did any programming on that machine.

I have used both subversion and mercurial on Windows, using both the command line and the excelant Tortoise frount ends (TortoiseHg (http://tortoisehg.bitbucket.org/about.html) & TortoiseSVN (http://tortoisesvn.tigris.org/). I have never used GIT. 

> 
> Also how should we name the project?
> 
> Somehow I don't want to have the term "Game" in the name,
> because I
> think a general approach wouldn't only be interesting for
> games (like
> Fantasy-/SF-MMO[RP]Gs), but also "Virtual Worlds" (like
> Second Life),
> maybe it could also be of interest for
> "Virtual-Classrooms".

I am more intrestd in the "Virtual-Classrooms" posabilities than just a game.

> 
> Maybe we need more than one project. Like one for the major
> "backbone"
> components (cluster management, monitoring, load
> balancing,
> accounting, reporting, tools) and other for "instances"
> like "Erlang
> Vast Exploration Online", "Universe of Erlang", "My Erlang
> Farm",
> "Erlang Mafia Disputes", "Erlang Aquarium", "Erlang Life",
> "Cafe
> Erlang"...

sound like a good idea, but it could be too big and endup callapsing under its own waight.


Ed Keith
e_d_k@REDACTED

Blog: edkeith.blogspot.com




      

From zeno490@REDACTED  Sat Jul 10 17:56:01 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Sat, 10 Jul 2010 11:56:01 -0400
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <2179.1971.qm@web120506.mail.ne1.yahoo.com>
References: <AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
	<2179.1971.qm@web120506.mail.ne1.yahoo.com>
Message-ID: <AANLkTiny-NO202puzYdVZEG2VVUe3cwvQApNqHTuFvjy@mail.gmail.com>

I would love to contribute however I legally cannot due to my current
contract. While I cannot code, I can still give advice.
IMO that sounds like a great idea. Since you'll likely create a custom
protocol over TCP, you'll be able to make a frontend in just about any
language. I would advise against a web solution if you ever want to achieve
any kind of meaningful performance. For heavy scenes, you'll almost always
have to end up shifting a lot of work off the server and onto the client
(stuff that doesn't need the server, like vfx particles bouncing off physics
objects (ie: destructible)) and you'll have a hard time doing efficient work
in javascript (I use it in my project for rendering tasks and it is terribly
slow still..). Good luck trying to have your browser call c++ code locally
(as in external library) without creating a custom plugin.

If however you don't aim to support hardcore gaming and more for casual,
slow paced games like second life or farmville, then yes, a web frontend
would be ideal. While I haven't tried webgl yet, I've found that svg was
faster overall than canvas for heavy scenes.

An other problem you'll hit if you go the web frontend route is that you'll
find javascript poorly suited for binary parsing and you'll most likely want
to have your underlying protocol use json or some delimiter based strings
(to save on bandwidth and parsing time).
That might not be such a bad idea in fact, just have all the protocol
messages be in json (later on you can always add a message to request binary
messages for efficiency in games that require it). Most languages have
libraries to parse json and it'll integrate well with javascript if need be.
You could even, have javascript be the game's scripting language both on the
server side and client side.

Do spent a good amount of time designing the authoring tool(s) and how they
will tie in with the rest of the engine. Those are usually critical for
acceptance. (ie: Unreal3 has a horrible engine, code wise and performance
wise, but because it has good tools for artists, a lot of games go for
unreal) That could very well turn out be the most critical part of the
project. While you may be able to build most supporting tools and pipelines
(in fact I would vote for you to use erlang for the data building
pipelines), you may have to use something else for the authoring tools.
You'll need to be able to render large scenes in low res and have it be very
responsive. You'll definitely need opengl/directx support for it. Perhaps
python or c# could be good fits here, I'm not sure.
Likewise, spent a good deal amount of time designing the data building
pipelines. This is where designers/artists spend a good deal of their time
(waiting for things to build). You'll most definitely want to have assets
build separately and be cached to avoid needless rebuilding. You may wish to
bundle them together but only referencing a hash or key. You'll then be able
to stream them to the clients on demand when they load a level. (There might
be an opportunity to abuse javascript caching in browsers if you go the web
frontend route (ie: when loading assets, dynamicaly add <script> tags
pointing to your server with their hash, if the url is the same, the browser
can read from the cache instead, saving bandwidth))


Anyhow, 2cents
Nicholas

On Sat, Jul 10, 2010 at 9:18 AM, Ed Keith <e_d_k@REDACTED> wrote:

> --- On Sat, 7/10/10, Boris M?hmer <boris.muehmer@REDACTED> wrote:
>
> > From: Boris M?hmer <boris.muehmer@REDACTED>
> > Subject: Re: [erlang-questions] Let's start a project for a (MMO-)Game in
>  Erlang... (inspired by "Erlang: Who uses it for games?")
> > To: "erlang-questions" <erlang-questions@REDACTED>
> > Date: Saturday, July 10, 2010, 7:21 AM
> > I will have a look at bitbucket and
> > github. Does bitbucket have a
> > "free plan" for many users? I didn't see it at my first
> > glance...
>
> You can have several user on a project at Bitbucket.
>
> >
> > I know Linux doesn't have any problems with git, mercurial,
> > or
> > whatever. How about Windows and Mac OS X? Sometimes I use
> > subversion
> > on windows, but I don't have too much experience about git
> > or
> > mercurial. I also have an old G4 Mac, even with Mac OS X,
> > but I never
> > did any programming on that machine.
>
> I have used both subversion and mercurial on Windows, using both the
> command line and the excelant Tortoise frount ends (TortoiseHg (
> http://tortoisehg.bitbucket.org/about.html) & TortoiseSVN (
> http://tortoisesvn.tigris.org/). I have never used GIT.
>
> >
> > Also how should we name the project?
> >
> > Somehow I don't want to have the term "Game" in the name,
> > because I
> > think a general approach wouldn't only be interesting for
> > games (like
> > Fantasy-/SF-MMO[RP]Gs), but also "Virtual Worlds" (like
> > Second Life),
> > maybe it could also be of interest for
> > "Virtual-Classrooms".
>
> I am more intrestd in the "Virtual-Classrooms" posabilities than just a
> game.
>
> >
> > Maybe we need more than one project. Like one for the major
> > "backbone"
> > components (cluster management, monitoring, load
> > balancing,
> > accounting, reporting, tools) and other for "instances"
> > like "Erlang
> > Vast Exploration Online", "Universe of Erlang", "My Erlang
> > Farm",
> > "Erlang Mafia Disputes", "Erlang Aquarium", "Erlang Life",
> > "Cafe
> > Erlang"...
>
> sound like a good idea, but it could be too big and endup callapsing under
> its own waight.
>
>
> Ed Keith
> e_d_k@REDACTED
>
> Blog: edkeith.blogspot.com
>
>
>
>
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From joe@REDACTED  Sun Jul 11 04:03:21 2010
From: joe@REDACTED (Joe Williams)
Date: Sat, 10 Jul 2010 19:03:21 -0700
Subject: kernel panic debugging
Message-ID: <47234DDE-3BCE-4FAC-B6EE-18399DFFCF95@joetify.com>


Hey list,

I have a perplexing issue with a few Ubuntu 8.10 nodes running R13B04. Recently these machines have been crashing with kernel panics and the best I can tell is Erlang *might* be related. The last message I see in the resultant call trace is "Pid: 5299, comm: beam.smp Tainted G D 2.6.27-17-server #1", just prior to that it mentions smp.c calls as well. Unfortunately I can't go back further in the console history to see more details. I am not ruling out hardware or other issues but figured I would check to see if anyone else has seen something similar.

Thanks.
-Joe



Name: Joseph A. Williams
Email: joe@REDACTED
Blog: http://www.joeandmotorboat.com/
Twitter: http://twitter.com/williamsjoe


From michael.eugene.turner@REDACTED  Sun Jul 11 06:21:52 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Sun, 11 Jul 2010 13:21:52 +0900
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
Message-ID: <AANLkTimgL4KtIxo6RadLtZjHcmAiH7beS04aWLs9uRkb@mail.gmail.com>

If you have a personal itch to write game development systems in Erlang, do
it.  However, if you have a personal itch to make it so good for that
purpose that other programmers will learn Erlang just to use it, you should
never forget what the sales points need to be -- and the inevitable
drawbacks, too.  As Eric Raymond also says,

  When you lose interest in a program, your last duty to it is to hand it
off to a competent successor.

Open source software survives in large part because the code gets handed off
by the first torch-bearers to worthy and enthusiastic successors, to carry
onward.  Do it for fun, but keep that long-term responsibility in mind as
well.  If it starts to look like you can't meet that responsibility, well
... no blame.  At least you tried.  And had some fun.  And learned some
lessons about what doesn't work,  And got better at Erlang.  So you really
can't lose.

-michael turner

My vague sense is that Erlang is actually very good for this purpose
(server-side, anyway).  As desktop multicore populations grow, it could even
become competitive in games on the client side.  If you don't aim to write a
successful *game* (that's like producing a feature film), it's not too
ambitious.  But there are risks.

Since this would be an open-source project, you have to think about how such
projects succeed.  I always go back to Eric Raymond on this.  Not that he is
God, or even infallible when he's talking about Open Source.  But he had a
good point when he wrote:

  Every good work of software starts by scratching a developer's *personal
itch*.

What's an itch?  We know it when we feel it.  And a lot of us feel the same
ones.  As programmers we work with a lot of the same kinds of programming
tools every day -- languages, compilers, interpreters, editors, shells,
IDEs, debuggers, checkers, version control systems, operating systems, and
so on.  As programmers, we think about a lot of things in very similar ways.
 So if I "scratch my itch" caused by some tool, I've probably invented a
back-scratcher that would give a lot of other programmers relief.

Of course, some things are a matter of taste.  But we solve that with
tolerant diversity -- I call your Python module from my Perl code, you call
my C++ code from your Ruby code, I call your Java module from my Erlang
code, I call your COBOL code from -- wait a second: *your* COBOL code?
 How'd *you* get in here?

But with the end results that ultimately gets programmers paid, which is
what makes programming a profession -- i.e., with products that users will
use -- tools are invisible.  Whether it's written in COBOL or Python is
invisible.  Was it written using vim or emacs?  Users won't know.  Users
don't care.  That's the water's edge, where taste starts to matter.

Look at how it worked out in open source where the "itch" was really more a
matter of taste than implementation: window systems.  (Yes, you could even
write a window system in 99% COBOL.  Theoretically.)  The programmer's idea
of a window system that scratches many itches was the infinitely
customizable one.  Users didn't agree: they mainly wanted something
predictable and uniform.  Not only was an historic opportunity for open
source OSes lost in the desktop computer space, it even took forever to get
some kind of convergence within the (relatively very small) open source
desktop OS world.  There is a window system *product* that gets a large
number of users while sitting on top of an open source OS.  But it's running
on the Macintosh.  And it's closed-source and dictated by Apple.  Luckily
(well, it's not really luck), what gets dictated by Apple is actually pretty
reasonable.

With an open-source game system, the game-players won't care that it's
written in Erlang.  They won't even know that.  So you have to think: what
does Erlang do so much better that it would persuade existing game
developers to move away from whatever system they have now?

Don't say "free" (as in beer).  There are plenty of those already available
for free.  That's not enough.

Don't say "free" (as in speech).  There are also plenty of those already
available in that sesne of "free" as well.

Erlang actually starts from behind in the "free as in speech" respect,
because "free speech" only works when people understand what you're saying.
 Very few programmers can look at an Erlang program, with no experience in
Erlang, without some head-scratching.  And it's head-scratching that
relieves no itches by itself: you have to go read about Erlang, and even
write a fair amount of it, before you can really get what the code is
saying. [*]

Eric Raymond also said:

  When you lose interest in a program, your last duty to it is to hand it
off to a competent successor.

So keeping that "sales objection" in mind (i.e., that "this programming
language looks -- and feels -- very weird") will help in you meeting that
final responsibility.  If it turns out you can't meet it, well, no blame.
 At least you tried.  And learned something about what doesn't work.  And
got better at Erlang and game system architecture.  And had some fun.

-michael turner


[*] To be sure: I don't think this added barrier exists because Erlang is
*inherently* obscure.  In a way, the problem is that it's so *natural* -- in
the sense outlined by Joe Armstrong in chapter 7 of his book.  That chapter
is very short, very easy to read, but deeply philosophical in the best way:
as someone once said, nothing is more practical than a good theory.
 Erlang's relative naturalness is a big part of what makes it look so
unfamiliar to most programmers, because most programming languages are so
*unnatural*.)

On Sat, Jul 10, 2010 at 2:55 AM, Boris M?hmer <boris.muehmer@REDACTED>
 wrote:

> It looks like some people are interested in Erlang game programming.
> On the other hand getting started in Erlang and OTP isn't too easy.
> Especially for people with a strong C/C++/C#/Java/etc background.
>
> Inspired by the "Erlang: Who uses it for games?" thread I thought about
> starting a community project to implement a MMO game in Erlang/OTP.
> The goal would be to collect some "best-practices" for different tasks.
>
> Actually I am more interested in the server side than how to implement
> a top-notch-state-of-the-art client. Also I think Erlang is more suited
> for the server side. But I am also interested in how to interface the
> "server-side erlang" using a (C/C++, Java, Python) cross-plattform
> client (using wxWidget or Qt as a base and OpenGL for graphics).
>
> What I would like to see are reponses from other people who may also
> be interested in such a project. Not only beginners with Erlang/OTP,
> but also (or especially) experienced people to guide and support the
> others. And most of all, to have some fun practising Erlang.
>
> Well, what do You think about it?
>
> Best regards,
> Boris
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From michael.eugene.turner@REDACTED  Sun Jul 11 06:23:12 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Sun, 11 Jul 2010 13:23:12 +0900
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTimgL4KtIxo6RadLtZjHcmAiH7beS04aWLs9uRkb@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTimgL4KtIxo6RadLtZjHcmAiH7beS04aWLs9uRkb@mail.gmail.com>
Message-ID: <AANLkTikwTHnlHs7D3uVw_nZF5oO6mK8wTDiDhFJYEbhW@mail.gmail.com>

Oops, sorry for the scrambled final edit.  Take this up *after* my first
sig.



On Sun, Jul 11, 2010 at 1:21 PM, Michael Turner <
michael.eugene.turner@REDACTED> wrote:

>
> If you have a personal itch to write game development systems in Erlang, do
> it.  However, if you have a personal itch to make it so good for that
> purpose that other programmers will learn Erlang just to use it, you should
> never forget what the sales points need to be -- and the inevitable
> drawbacks, too.  As Eric Raymond also says,
>
>   When you lose interest in a program, your last duty to it is to hand it
> off to a competent successor.
>
> Open source software survives in large part because the code gets handed
> off by the first torch-bearers to worthy and enthusiastic successors, to
> carry onward.  Do it for fun, but keep that long-term responsibility in mind
> as well.  If it starts to look like you can't meet that responsibility, well
> ... no blame.  At least you tried.  And had some fun.  And learned some
> lessons about what doesn't work,  And got better at Erlang.  So you really
> can't lose.
>
> -michael turner
>
> My vague sense is that Erlang is actually very good for this purpose
> (server-side, anyway).  As desktop multicore populations grow, it could even
> become competitive in games on the client side.  If you don't aim to write a
> successful *game* (that's like producing a feature film), it's not too
> ambitious.  But there are risks.
>
> Since this would be an open-source project, you have to think about how
> such projects succeed.  I always go back to Eric Raymond on this.  Not that
> he is God, or even infallible when he's talking about Open Source.  But he
> had a good point when he wrote:
>
>   Every good work of software starts by scratching a developer's *personal
> itch*.
>
> What's an itch?  We know it when we feel it.  And a lot of us feel the same
> ones.  As programmers we work with a lot of the same kinds of programming
> tools every day -- languages, compilers, interpreters, editors, shells,
> IDEs, debuggers, checkers, version control systems, operating systems, and
> so on.  As programmers, we think about a lot of things in very similar ways.
>  So if I "scratch my itch" caused by some tool, I've probably invented a
> back-scratcher that would give a lot of other programmers relief.
>
> Of course, some things are a matter of taste.  But we solve that with
> tolerant diversity -- I call your Python module from my Perl code, you call
> my C++ code from your Ruby code, I call your Java module from my Erlang
> code, I call your COBOL code from -- wait a second: *your* COBOL code?
>  How'd *you* get in here?
>
> But with the end results that ultimately gets programmers paid, which is
> what makes programming a profession -- i.e., with products that users will
> use -- tools are invisible.  Whether it's written in COBOL or Python is
> invisible.  Was it written using vim or emacs?  Users won't know.  Users
> don't care.  That's the water's edge, where taste starts to matter.
>
> Look at how it worked out in open source where the "itch" was really more a
> matter of taste than implementation: window systems.  (Yes, you could even
> write a window system in 99% COBOL.  Theoretically.)  The programmer's idea
> of a window system that scratches many itches was the infinitely
> customizable one.  Users didn't agree: they mainly wanted something
> predictable and uniform.  Not only was an historic opportunity for open
> source OSes lost in the desktop computer space, it even took forever to get
> some kind of convergence within the (relatively very small) open source
> desktop OS world.  There is a window system *product* that gets a large
> number of users while sitting on top of an open source OS.  But it's running
> on the Macintosh.  And it's closed-source and dictated by Apple.  Luckily
> (well, it's not really luck), what gets dictated by Apple is actually pretty
> reasonable.
>
> With an open-source game system, the game-players won't care that it's
> written in Erlang.  They won't even know that.  So you have to think: what
> does Erlang do so much better that it would persuade existing game
> developers to move away from whatever system they have now?
>
> Don't say "free" (as in beer).  There are plenty of those already available
> for free.  That's not enough.
>
> Don't say "free" (as in speech).  There are also plenty of those already
> available in that sesne of "free" as well.
>
> Erlang actually starts from behind in the "free as in speech" respect,
> because "free speech" only works when people understand what you're saying.
>  Very few programmers can look at an Erlang program, with no experience in
> Erlang, without some head-scratching.  And it's head-scratching that
> relieves no itches by itself: you have to go read about Erlang, and even
> write a fair amount of it, before you can really get what the code is
> saying. [*]
>
> Eric Raymond also said:
>
>   When you lose interest in a program, your last duty to it is to hand it
> off to a competent successor.
>
> So keeping that "sales objection" in mind (i.e., that "this programming
> language looks -- and feels -- very weird") will help in you meeting that
> final responsibility.  If it turns out you can't meet it, well, no blame.
>  At least you tried.  And learned something about what doesn't work.  And
> got better at Erlang and game system architecture.  And had some fun.
>
> -michael turner
>
>
> [*] To be sure: I don't think this added barrier exists because Erlang is
> *inherently* obscure.  In a way, the problem is that it's so *natural* -- in
> the sense outlined by Joe Armstrong in chapter 7 of his book.  That chapter
> is very short, very easy to read, but deeply philosophical in the best way:
> as someone once said, nothing is more practical than a good theory.
>  Erlang's relative naturalness is a big part of what makes it look so
> unfamiliar to most programmers, because most programming languages are so
> *unnatural*.)
>
> On Sat, Jul 10, 2010 at 2:55 AM, Boris M?hmer <
> boris.muehmer@REDACTED> wrote:
>
> It looks like some people are interested in Erlang game programming.
>> On the other hand getting started in Erlang and OTP isn't too easy.
>> Especially for people with a strong C/C++/C#/Java/etc background.
>>
>> Inspired by the "Erlang: Who uses it for games?" thread I thought about
>> starting a community project to implement a MMO game in Erlang/OTP.
>> The goal would be to collect some "best-practices" for different tasks.
>>
>> Actually I am more interested in the server side than how to implement
>> a top-notch-state-of-the-art client. Also I think Erlang is more suited
>> for the server side. But I am also interested in how to interface the
>> "server-side erlang" using a (C/C++, Java, Python) cross-plattform
>> client (using wxWidget or Qt as a base and OpenGL for graphics).
>>
>> What I would like to see are reponses from other people who may also
>> be interested in such a project. Not only beginners with Erlang/OTP,
>> but also (or especially) experienced people to guide and support the
>> others. And most of all, to have some fun practising Erlang.
>>
>> Well, what do You think about it?
>>
>> Best regards,
>> Boris
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>

From boris.muehmer@REDACTED  Sun Jul 11 09:14:58 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Sun, 11 Jul 2010 09:14:58 +0200
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>
	<AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
Message-ID: <AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com>

I have choosen "PEMMOX" as an (interim) title for this "project".
"PEMMOX" is the abbreviation for "Project Erlang Massively Multiplayer
Online eXperience".

For further discussions I created the Google Groups group named
"PEMMOX". People interested in further discussions should visit
"http://groups.google.com/group/pemmox/", please.


  - boris

From kenji.rikitake@REDACTED  Sun Jul 11 10:06:02 2010
From: kenji.rikitake@REDACTED (Kenji Rikitake)
Date: Sun, 11 Jul 2010 17:06:02 +0900
Subject: NIFnized version of SFMT PRNG (Re: [erlang-questions] native
	Erlang version of SFMT PRNG)
In-Reply-To: <20100704073201.GA37621@k2r.org>
References: <20100704073201.GA37621@k2r.org>
Message-ID: <20100711080602.GA17522@k2r.org>

On SFMT PRNG library for Erlang/OTP:

Now I included sfmt-extstate code as a NIF library
and it's working on Erlang/OTP R14A on FreeBSD.
It's ~40 times faster than the pure Erlang code
and now ~17 times faster than the random module code.
It's on
http://github.com/jj1bdx/sfmt-erlang/tree/0.3.0_RELEASE/
(and it's on the "master" branch of
http://github.com/jj1bdx/sfmt-erlang/
)

I'm new to NIF (and Erlang/OTP memory/code-loading management), and your
comments are always welcome.

Regards,
Kenji Rikitake

In the message <20100704073201.GA37621@REDACTED>
dated Sun, Jul 04, 2010 at 04:31:37PM +0900,
Kenji Rikitake <kenji.rikitake@REDACTED> writes:
> A crude pure Erlang version of SFMT
> (SIMD-oriented Fast Mersenne Twister) PRNG:
> http://github.com/jj1bdx/sfmt-erlang
> 
> Note: this code is still ~300 times slower than the C code of SFMT
> even when HiPE enabled on Erlang/OTP R14A at FreeBSD 7.3-RELEASE x86;
> a NIF set will boost the speed.  I've already dissected the original
> SFMT code for a thread-safe implementation at:
> http://github.com/jj1bdx/sfmt-extstate
> 
> Kenji Rikitake
> (well, if nobody does something for me, I have to do it anyway :))
> 
> In the message <20100530075320.GA29981@REDACTED>
> dated Sun, May 30, 2010 at 04:52:56PM +0900,
> Kenji Rikitake <kenji.rikitake@REDACTED> writes:
> > Anybody has implemented a NIF or port version of Mersenne Twister or SFMT?
> > http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html
> > 
> > (Mersenne Twister has been incorporated as the default RNG for Python
> > and R, so far as I know.)

From michael.eugene.turner@REDACTED  Sun Jul 11 13:12:15 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Sun, 11 Jul 2010 20:12:15 +0900
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>
	<AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
	<AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com>
Message-ID: <AANLkTik88zH2QMNsWXECmb_6TZx_B6dclPlxpbFfzlN3@mail.gmail.com>

I think you should call it Yopia.  Because you can't call it Myopia -- the
visual acuity condition caused by hacking game software 18 hours a day.
 (Or, by playing the games it would host, yes, it'll become that popular!)

No, you can't call it Myopia.  It's not allowed.

Or, in the spirit of Yaws, how about "Goiter"?  Games Online In The Erlang
... uh ... uh-oh, I've got Mnesia again.

;-)

-michael turner

On Sun, Jul 11, 2010 at 4:14 PM, Boris M?hmer
<boris.muehmer@REDACTED>wrote:

> I have choosen "PEMMOX" as an (interim) title for this "project".
> "PEMMOX" is the abbreviation for "Project Erlang Massively Multiplayer
> Online eXperience".
>
> For further discussions I created the Google Groups group named
> "PEMMOX". People interested in further discussions should visit
> "http://groups.google.com/group/pemmox/", please.
>
>
>  - boris
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From steven.charles.davis@REDACTED  Sun Jul 11 18:22:48 2010
From: steven.charles.davis@REDACTED (Steve Davis)
Date: Sun, 11 Jul 2010 09:22:48 -0700 (PDT)
Subject: Still problems with new SSL?
Message-ID: <8a325a1e-6869-41fb-b906-c5bd179efaa0@z8g2000yqz.googlegroups.com>

Can anyone make the code below (specifically against https://www.google.com)
work for

ssltest:run(new)?

I'm using the key.pem and cert.pem copied from ERLANG_HOME/lib/ssl-4.0/
examples/certs/etc/client

My results are:
2> ssltest:run(old).
{ok,<<"HTTP/1.1 200 OK\r\nDate: Sun, 11 Jul 2010 16:20:13 GMT\r
\nExpires: -1\r\nCache-Control: private, max-age=0\r\nConten"...>>}
3> ssltest:run(new).

=ERROR REPORT==== 11-Jul-2010::11:20:17 ===
SSL: decipher_error: ./ssl_record.erl:680:Fatal error: bad record mac
{error,"bad record mac"}
4>

----- module ssltest.erl ------
-module(ssltest).

-export([run/1]).

-define(HOST, "www.google.com").
-define(PORT, 443).
-define(REQUEST,
	<<"GET / HTTP/1.1\r\n",
	"Connection: close\r\n",
	"User-Agent: Mozilla/5.0 (Windows NT 5.1; en-US) Test/1.0.0\r\n",
	"Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/
plain;q=0.8,image/png,*/*;q=0.5\r\n",
	"Accept-Language: en-US,en;q=0.8\r\n",
	"Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n",
	"\r\n">>).

run(Impl) when Impl =:= old; Impl =:= new ->
	Opts = [binary, {ip, {0, 0, 0, 0}}, {active, false}, {packet, 0},
		{ssl_imp, Impl}, {verify, 0}, {depth, 1},
		{keyfile, "./key.pem"},
		{certfile, "./cert.pem"}],
	ssl:start(),
	{ok, Socket} = ssl:connect(?HOST, ?PORT, Opts),
	ok = ssl:send(Socket, ?REQUEST),
	catch ssl:recv(Socket, 0, 10000).

From mjtruog@REDACTED  Sun Jul 11 19:43:27 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Sun, 11 Jul 2010 10:43:27 -0700
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in
 	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTik88zH2QMNsWXECmb_6TZx_B6dclPlxpbFfzlN3@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>	<4C37BB78.4060205@gmail.com>	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>	<4C380E97.6090505@gmail.com>	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>	<AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>	<AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com> <AANLkTik88zH2QMNsWXECmb_6TZx_B6dclPlxpbFfzlN3@mail.gmail.com>
Message-ID: <4C3A02BF.3070904@gmail.com>

I have to say that "Goiter" is initially appealing when continuing the
bodily ailments theme.

"PEMMOX" reminded me of Annie Lennox's name being said quickly, or
perhaps a cleaning fluid (ignoring the company that makes furnaces,
http://www.lennox.com/).  However, it is a unique name and an
interesting name.

A fun name that is similar is "MOXIE":
Massively Online eXperience In Erlang

Unfortunately, this old word has been trademarked by a small dental
company in hollywood
(http://tarr.uspto.gov/tarr?regser=serial&entry=+%0985047523&action=Request+Status). 
So, "PEMMOX" is probably superior.

On 07/11/2010 04:12 AM, Michael Turner wrote:
> I think you should call it Yopia.  Because you can't call it Myopia -- the
> visual acuity condition caused by hacking game software 18 hours a day.
>  (Or, by playing the games it would host, yes, it'll become that popular!)
>
> No, you can't call it Myopia.  It's not allowed.
>
> Or, in the spirit of Yaws, how about "Goiter"?  Games Online In The Erlang
> ... uh ... uh-oh, I've got Mnesia again.
>
> ;-)
>
> -michael turner
>
> On Sun, Jul 11, 2010 at 4:14 PM, Boris M?hmer
> <boris.muehmer@REDACTED>wrote:
>
>   
>> I have choosen "PEMMOX" as an (interim) title for this "project".
>> "PEMMOX" is the abbreviation for "Project Erlang Massively Multiplayer
>> Online eXperience".
>>
>> For further discussions I created the Google Groups group named
>> "PEMMOX". People interested in further discussions should visit
>> "http://groups.google.com/group/pemmox/", please.
>>
>>
>>  - boris
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>>     
>   


From tony.arcieri@REDACTED  Sun Jul 11 20:47:03 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Sun, 11 Jul 2010 12:47:03 -0600
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com> 
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com> 
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com> 
	<4C37BB78.4060205@gmail.com> <AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
Message-ID: <AANLkTikwPcIIQk5ZOoRBSZIcTXgNfulnuQ013EkK7uAO@mail.gmail.com>

On Fri, Jul 9, 2010 at 6:21 PM, Raoul Duke <raould@REDACTED> wrote:

> On Fri, Jul 9, 2010 at 5:14 PM, Michael Truog <mjtruog@REDACTED> wrote:
> >  DSL for game scripting, etc..
>
> http://github.com/rvirding/lfe
>
> :-)


Or my language :)

http://github.com/tarcieri/reia

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From g@REDACTED  Mon Jul 12 06:43:54 2010
From: g@REDACTED (Garrett Smith)
Date: Sun, 11 Jul 2010 23:43:54 -0500
Subject: erlang:now/0 off by over 90 seconds
In-Reply-To: <AANLkTimcjfVSaRkoiUOJTglmYUXLG20I9E3E6wYJ5Hb6@mail.gmail.com>
References: <AANLkTimcjfVSaRkoiUOJTglmYUXLG20I9E3E6wYJ5Hb6@mail.gmail.com>
Message-ID: <AANLkTik0_zGD4VnT7ve1yJD0MVGc9-vVMD_r5FApTqff@mail.gmail.com>

I'm getting this:

1> {calendar:now_to_local_time(erlang:now()), erlang:localtime()}.
{{{2010,7,11},{23,36,54}},{{2010,7,11},{23,35,20}}}

erlang:now() is giving a result that's ~90 seconds in the future
(according to the OS clock - e.g. `date`)

I'm running VMWare and `hwclock` gives a "Cannot access the Hardware
Clock via any known method."

The docs state that "some other method" may be used to calculate the
now value if the OS doesn't support epoch time reporting.

Any thoughts on this?

Garrett

From hynek@REDACTED  Mon Jul 12 10:15:29 2010
From: hynek@REDACTED (Hynek Vychodil)
Date: Mon, 12 Jul 2010 10:15:29 +0200
Subject: [erlang-questions] string title bif?
In-Reply-To: <4C24F81C.3090103@tmit.bme.hu>
References: <AANLkTimcUYh_ZIrJsZGFS-NSPWM52butgu03YoPA_3WT@mail.gmail.com>
	<4C24F81C.3090103@tmit.bme.hu>
Message-ID: <AANLkTiklOT1626xEJCeW_dk7cqy0egc5j8UUJrEE3k00@mail.gmail.com>

You can found that straightforward solution is clearer and faster
(especially with HiPE) for this sort of state machines:

title([C|T]) -> [string:to_upper(C)|title_inner(T)];
title([]) -> [].

title_inner([$_|T]) -> [$\s|title(T)];
title_inner([C|T]) -> [C|title_inner(T)];
title_inner([]) -> [].

On Fri, Jun 25, 2010 at 8:40 PM, Zoltan Lajos Kis <kiszl@REDACTED> wrote:
> I think a tiny state-machine with "mapfoldl" is a cleaner (albeit more
> imperative :o)) approach for this.
>
> title(String) ->
> ? ?{Title, _} = lists:mapfoldl(fun f/2, 'sep', String),
> ? ?Title.
>
> f($_, _) -> {$ , 'sep'};
> f(C, 'sep') -> {string:to_upper(C), 'char'};
> f(C, _) -> {C, 'char'}.
>
> Regards,
> Zoltan.
>
>
> On 6/25/2010 8:23 PM, Wes James wrote:
>>
>> Is there a BIF that does this (I can't find one, if there is):
>>
>> string:title("this_is_a_title") -> ?"This Is A Title".
>>
>> Or something like this? ?If not I'll just create one.
>>
>> It would need to split the string at the "_" and then uppercase the
>> first character of each word.
>>
>> This test works:
>>
>> -------------------
>>
>> -module(title).
>>
>> -export([start/0]).
>>
>> start() ->
>> ? ? ? ?title(string:tokens("this_is_a_title","_")).
>>
>> title([H|T]) ->
>> ? ? ? ?[fc_upper(H)|title(T)];
>> title([]) -> ?[].
>>
>> fc_upper([C|R]) ->
>> ? ? ? ?[string:to_upper(C)]++R.
>>
>> ----------------
>>
>> thx.
>>
>> -wes
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
--Hynek (Pichi) Vychodil

Analyze your data in minutes. Share your insights instantly. Thrill
your boss.? Be a data hero!
Try GoodData now for free: www.gooddata.com

From hynek@REDACTED  Mon Jul 12 10:29:20 2010
From: hynek@REDACTED (Hynek Vychodil)
Date: Mon, 12 Jul 2010 10:29:20 +0200
Subject: [erlang-questions] using catch - getting error
In-Reply-To: <AANLkTileF7tdua7wpOiadJzVC2N7Muc9ZDkMqwwgzUEH@mail.gmail.com>
References: <AANLkTileF7tdua7wpOiadJzVC2N7Muc9ZDkMqwwgzUEH@mail.gmail.com>
Message-ID: <AANLkTimCh7zh715YQ2zLPYmGsdFz_qkkkyO3PNyFJlO2@mail.gmail.com>

Try use lists:keyfind/2 instead. proplists may be do little bit more
than you need and is this slower.

On Sat, Jun 26, 2010 at 12:16 AM, Wes James <comptekki@REDACTED> wrote:
> I have this function:
>
> lk(Key, L) ->
> ? ?{_, Error} = (catch {value, {_,Vale}} = lists:keysearch(Key, 1, L)),
> ? ?case length(Error) of
> ? ? ? ?0 ->
> ? ? ? ? ? ? ? ?Val = Vale;
> ? ? ? ?_ ->
> ? ? ? ? ? ? ? ?Val = 0
> ? ?end,
> ? ?Val.
>
> A list (L) should have all the keys necessary when lk is called, but
> if the key does not exist, the keysearch will throw an exception. ?I'm
> trying to catch that, but I get the error Vale is unsafe. What is the
> proper way to do this?
>
> If the key exists, then put it in Val and return Val, if the key does
> not exist, catch the error and set Val to 0.
>
> How should this be done?
>
> thx,
>
> -wes
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
--Hynek (Pichi) Vychodil

Analyze your data in minutes. Share your insights instantly. Thrill
your boss.? Be a data hero!
Try GoodData now for free: www.gooddata.com

From steven.charles.davis@REDACTED  Mon Jul 12 14:55:41 2010
From: steven.charles.davis@REDACTED (Steve Davis)
Date: Mon, 12 Jul 2010 05:55:41 -0700 (PDT)
Subject: Still problems with new SSL?
In-Reply-To: <8a325a1e-6869-41fb-b906-c5bd179efaa0@z8g2000yqz.googlegroups.com>
References: <8a325a1e-6869-41fb-b906-c5bd179efaa0@z8g2000yqz.googlegroups.com>
Message-ID: <b53920da-3615-4af7-80a3-a42240d1a109@x21g2000yqa.googlegroups.com>

A little more info...

It seems that this Mac error only occurs for sites which have secure
renegotiation (as per RFC 5746)
i.e. where (from ssl_record.hrl)
#connection_state{secure_renegotiation = true}

/s

From dawid.figiel@REDACTED  Mon Jul 12 15:17:40 2010
From: dawid.figiel@REDACTED (Dawid Figiel)
Date: Mon, 12 Jul 2010 15:17:40 +0200
Subject: Sequence does't apply to sub-groups in common tests?
Message-ID: <AANLkTintGO1iLXHXfZTtBqwiXb2q6xn-GE-xC9Kjz-56@mail.gmail.com>

Hi,

I need some feedback, why sequence doesn't apply to sub-groups in common
tests?

example:

This works:

groups() -> [{group1, [sequence], [test1,
                                   test2]}].

If test1 fail then test2 will be skipped.

And this does not work:

groups() -> [{group1, [sequence], [{subgroup1, [], [test1]},
                                   {subgroup2, [], [test2]}]}]

end_per_group(Group, Config) ->
    Status = ?config(tc_group_result, Config),
    case proplists:get_value(failed, Status) of
        [] -> {return_group_result, ok};
        _Failed -> {return_group_result, failed}
    end.

Test1 has failed, so subgroup1 is handled as a failed too, but subgroup2 is
not skipped although we have set up 'sequence'...why ?

According to documentation:

"A failed sub-group (Status == failed) will cause the execution of a
sequence to fail in the same way a test case does."


Any clues ?

-- 
regards,

Dawid

From erlang@REDACTED  Mon Jul 12 16:10:56 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Mon, 12 Jul 2010 16:10:56 +0200
Subject: some lexical questions
Message-ID: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>

Hello,

I've been trying to make a Erlang scanner/parser from a peg style
grammar and some specialized parser combinators.  The grammar at the
end of this mail can tokenize all but two files in the standard OTP
distribution. It's not blindingly efficient but it does the job and is
far easier to understand than erl_scan and friends. My goal is to
start with a grammar like the one below and transform it into
something as efficient as erl_scan ..

Two files defeat my scanner

	/usr/local/lib/erlang/lib/stdlib-1.16.5/src/edlin.erl
        /usr/local/lib/erlang/lib/asn1-1.6.13/src/asn1ct.erl

and contain character sequences not allow by the grammar below - and
which also appear to be illegal according to the documentation.

Now I have to ask:

1) Is there a "definitive" reference for the meaning of the
allowed escape sequences within a string?

The best I've found is in the on-line documentation in section 2.14
of http://www.erlang.org/doc/reference_manual/data_types.html

But the shell seems to parse "\^[" as [27] - now either table 2.14 is
incorrect or the implementation is incorrect since following \^ there
should be only be a character matching [a-zA-Z].

Also \X where X is non of the alternatives in table 2.14 defaults to
X - but it should be an error by table 2.14 since X is none of the defined
alternatives. The shell thinks "\a" is the same as "a" but I think this
is confusing, in any case its an undocumened feature.

2) There is a strange character in line 1678 of asn1ct.erl
   Emacs thinks this character is #xA0 encoded with iso-latin-1-unix

   What is this strange character?

   /Joe

PS - the erlang lexical grammar so far is :

    start     <- spaces / comment / DOT
               / ATOM / VAR
               / QATOM / STRING / FLOAT / CHAR / INTEGER / recorddef
               / recordsel;
    spaces    <- ws+;
    recorddef <- '#';
    recordsel <- '.';
    DOT       <- '.' & '%' / '.' ws;
    ws        <- '\r' / '\n' / '\s' / '\t' / '\14';
    CHAR      <- '$' schar;
    INTEGER   <- [0-9]+ '#' [0-9a-fA-F]+ / [0-9]+ ;
    FLOAT     <- [0-9]+ '.' [0-9]+ ('e' ('+'/'-')? [0-9]+)? ;
    ATOM      <- [a-z][a-zA-Z0-9_@]* ;
    VAR       <- [_A-Z][a-zA-Z0-9_]*;
    QATOM     <- ['] (![']  schar)* ['];
    STRING    <- '"' (! '"' schar)* '"';
    schar     <- [\\] echar
               / .;
    echar     <-  [0-3][0-7][0-7]
               /  [0-7][0-7]
               /  [0-7]
               /  '^' .
               /  .;
    comment   <- '%' eat_line
	       / '/*' ((!eof / ! '*/') .)* '*/';
    eat_line  <- (!eol .)*;
    eol       <- '\r\n' / '\n';
    eof       <- !.;

This seems far easier to understand than a yacc or LL(k) grammar :-)

From g@REDACTED  Mon Jul 12 17:06:58 2010
From: g@REDACTED (Garrett Smith)
Date: Mon, 12 Jul 2010 10:06:58 -0500
Subject: [erlang-questions] erlang:now/0 off by over 90 seconds
In-Reply-To: <AANLkTin1dhFrfrWePcBnnI9l2H8dfFnNYW_JlY0KuDDr@mail.gmail.com>
References: <AANLkTimcjfVSaRkoiUOJTglmYUXLG20I9E3E6wYJ5Hb6@mail.gmail.com>
	<AANLkTik0_zGD4VnT7ve1yJD0MVGc9-vVMD_r5FApTqff@mail.gmail.com>
	<AANLkTin1dhFrfrWePcBnnI9l2H8dfFnNYW_JlY0KuDDr@mail.gmail.com>
Message-ID: <AANLkTin1Q2qcRLVN2SrNu_jQI2X_ccxMS0kBR1XuFYed@mail.gmail.com>

Yah, this was indeed the issue. I wasn't running hwclock as root. The
potential drift between system time and "hardware" clock on VMWare is
pretty awful.

It is somewhat surprising though that calendar and erlang:now/0 use
different sources for their time.

Garrett

On Mon, Jul 12, 2010 at 8:59 AM, Salomon Elizondo <selizondo@REDACTED> wrote:
> double check that your system time is up2date.
> sudo /usr/sbin/ntpdate -u time-a.nist.gov
> sudo /sbin/hwclock --systohc
>
> bug in vmware search "vmware clock drift"
>
>
> On Sun, Jul 11, 2010 at 11:43 PM, Garrett Smith <g@REDACTED> wrote:
>> I'm getting this:
>>
>> 1> {calendar:now_to_local_time(erlang:now()), erlang:localtime()}.
>> {{{2010,7,11},{23,36,54}},{{2010,7,11},{23,35,20}}}
>>
>> erlang:now() is giving a result that's ~90 seconds in the future
>> (according to the OS clock - e.g. `date`)
>>
>> I'm running VMWare and `hwclock` gives a "Cannot access the Hardware
>> Clock via any known method."
>>
>> The docs state that "some other method" may be used to calculate the
>> now value if the OS doesn't support epoch time reporting.
>>
>> Any thoughts on this?
>>
>> Garrett
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>

From andrew@REDACTED  Mon Jul 12 17:09:47 2010
From: andrew@REDACTED (Andrew Thompson)
Date: Mon, 12 Jul 2010 11:09:47 -0400
Subject: [erlang-questions] some lexical questions
In-Reply-To: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>
Message-ID: <20100712150947.GO28418@hijacked.us>

On Mon, Jul 12, 2010 at 04:10:56PM +0200, Joe Armstrong wrote:
> Hello,
> 
> 1) Is there a "definitive" reference for the meaning of the
> allowed escape sequences within a string?
> 
> The best I've found is in the on-line documentation in section 2.14
> of http://www.erlang.org/doc/reference_manual/data_types.html
> 
> But the shell seems to parse "\^[" as [27] - now either table 2.14 is
> incorrect or the implementation is incorrect since following \^ there
> should be only be a character matching [a-zA-Z].

\^[ is a synonym for \e (ctrl-escape). Apparently if you input a string
with "\^[" in it in the shell (R14A) the returned value is "\e", I know
the terminal code won't let you pass a raw \e to the underlying
terminal.

I'm guessing the table listing is just incomplete.

Escaping \a and having it treated as \a is the same behaviour seen in
regular expressions, basically if the unescaped value isn't special, it
unescapes it.
> 
> Also \X where X is non of the alternatives in table 2.14 defaults to
> X - but it should be an error by table 2.14 since X is none of the defined
> alternatives. The shell thinks "\a" is the same as "a" but I think this
> is confusing, in any case its an undocumened feature.
> 
> 2) There is a strange character in line 1678 of asn1ct.erl
>    Emacs thinks this character is #xA0 encoded with iso-latin-1-unix
>

I can't even find this character in my copy of this file. Maybe the line
number is different with my copy (R14A).

Andrew

From fdmanana@REDACTED  Mon Jul 12 17:10:33 2010
From: fdmanana@REDACTED (Filipe David Manana)
Date: Mon, 12 Jul 2010 16:10:33 +0100
Subject: gen_server monitoring a process
Message-ID: <AANLkTimpG-9bITihKe2ZNuJt4UM4xZEolMDenfSabdCV@mail.gmail.com>

Hi,

Let's say I have a gen_server monitoring a process P1.
Is it possible that, a gen_server receives first the {'DOWN', ...} message
(handled by handle_info) before any other message sent from the monitored
process (through a gen_server:cast or gen_server:call) ?

If I weren't using a gen_server, than that would depend on the order of my
receive branches.

cheers



-- 
Filipe David Manana,
fdmanana@REDACTED

"Reasonable men adapt themselves to the world.
 Unreasonable men adapt the world to themselves.
 That's why all progress depends on unreasonable men."

From tuncer.ayaz@REDACTED  Mon Jul 12 17:12:31 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Mon, 12 Jul 2010 17:12:31 +0200
Subject: [erlang-questions] some lexical questions
In-Reply-To: <20100712150947.GO28418@hijacked.us>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com> 
	<20100712150947.GO28418@hijacked.us>
Message-ID: <AANLkTikHr2izTsBYA5j601AWXX7-_9ZQT00oUkuuwQtl@mail.gmail.com>

On Mon, Jul 12, 2010 at 5:09 PM, Andrew Thompson wrote:
> On Mon, Jul 12, 2010 at 04:10:56PM +0200, Joe Armstrong wrote:
>> 2) There is a strange character in line 1678 of asn1ct.erl
>> ? ?Emacs thinks this character is #xA0 encoded with iso-latin-1-unix
>>
>
> I can't even find this character in my copy of this file. Maybe the line
> number is different with my copy (R14A).

It's on 1677.

From andrew@REDACTED  Mon Jul 12 17:48:00 2010
From: andrew@REDACTED (Andrew Thompson)
Date: Mon, 12 Jul 2010 11:48:00 -0400
Subject: [erlang-questions] some lexical questions
In-Reply-To: <AANLkTikHr2izTsBYA5j601AWXX7-_9ZQT00oUkuuwQtl@mail.gmail.com>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com> <20100712150947.GO28418@hijacked.us> <AANLkTikHr2izTsBYA5j601AWXX7-_9ZQT00oUkuuwQtl@mail.gmail.com>
Message-ID: <20100712154800.GP28418@hijacked.us>

On Mon, Jul 12, 2010 at 05:12:31PM +0200, Tuncer Ayaz wrote:
> On Mon, Jul 12, 2010 at 5:09 PM, Andrew Thompson wrote:
> > On Mon, Jul 12, 2010 at 04:10:56PM +0200, Joe Armstrong wrote:
> >> 2) There is a strange character in line 1678 of asn1ct.erl
> >> ? ?Emacs thinks this character is #xA0 encoded with iso-latin-1-unix
> >>
> >
> > I can't even find this character in my copy of this file. Maybe the line
> > number is different with my copy (R14A).
> 
> It's on 1677.
>

I still don't see anything usual, what is the content of the line (so I
can search for it). I have vim in utf-8 mode, maybe that's why I can't
see it?

Andrew

From andrew@REDACTED  Mon Jul 12 17:53:05 2010
From: andrew@REDACTED (Andrew Thompson)
Date: Mon, 12 Jul 2010 11:53:05 -0400
Subject: [erlang-questions] some lexical questions
In-Reply-To: <AANLkTikHr2izTsBYA5j601AWXX7-_9ZQT00oUkuuwQtl@mail.gmail.com>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com> <20100712150947.GO28418@hijacked.us> <AANLkTikHr2izTsBYA5j601AWXX7-_9ZQT00oUkuuwQtl@mail.gmail.com>
Message-ID: <20100712155305.GQ28418@hijacked.us>

On Mon, Jul 12, 2010 at 05:12:31PM +0200, Tuncer Ayaz wrote:
> On Mon, Jul 12, 2010 at 5:09 PM, Andrew Thompson wrote:
> > On Mon, Jul 12, 2010 at 04:10:56PM +0200, Joe Armstrong wrote:
> >> 2) There is a strange character in line 1678 of asn1ct.erl
> >> ? ?Emacs thinks this character is #xA0 encoded with iso-latin-1-unix
> >>
> >
> > I can't even find this character in my copy of this file. Maybe the line
> > number is different with my copy (R14A).
> 
> It's on 1677.
>

Oh, I see it now, 0xA0 is that stupid non-breaking space character. I've
had problems with firefox inserting them in textareas before (in unicode
its a multibyte charater consisting of 0xC2 0xA0).

http://en.wikipedia.org/wiki/Non-breaking_space#Encodings

Andrew

From francis.joanis@REDACTED  Mon Jul 12 19:10:07 2010
From: francis.joanis@REDACTED (Francis Joanis)
Date: Mon, 12 Jul 2010 13:10:07 -0400
Subject: Setting type of service (ToS) byte on built-in Erlang to Erlang TCP 
	communications
Message-ID: <AANLkTimRwjnzLTTH-LNRPx4LNYLfiVhhAvZkyniRep6x@mail.gmail.com>

Hello all,

I'm currently evaluating Erlang for a new project and I'm pretty
excited about it :) I'm still learning the language so please bear
with me ;)

Is it possible to set the ToS byte on the IP packets used by Erlang
for node-to-node communications (i.e. when using net_adm:ping or when
sending a message to a remote process)?

I'd be interested into setting it once for all node-to-node packet
exchange. I've seen inet:setopts/2 which can take {tos, Integer}, but
I was wondering if it could be applied to the node-to-node socket(s)
at runtime or using a configuration param.

If it can't I guess there's always the path of recompiling OTP but I
was hoping for an alternative.

Thanks,
Francis

From bernie@REDACTED  Tue Jul 13 01:12:28 2010
From: bernie@REDACTED (Bernard Duggan)
Date: Tue, 13 Jul 2010 09:12:28 +1000
Subject: [erlang-questions] gen_server monitoring a process
In-Reply-To: <AANLkTimpG-9bITihKe2ZNuJt4UM4xZEolMDenfSabdCV@mail.gmail.com>
References: <AANLkTimpG-9bITihKe2ZNuJt4UM4xZEolMDenfSabdCV@mail.gmail.com>
Message-ID: <4C3BA15C.70201@m5net.com>

On 13/07/10 01:10, Filipe David Manana wrote:
> Hi,
>
> Let's say I have a gen_server monitoring a process P1.
> Is it possible that, a gen_server receives first the {'DOWN', ...} message
> (handled by handle_info) before any other message sent from the monitored
> process (through a gen_server:cast or gen_server:call) ?
>    
 From the manual:

"A 'DOWN' message will be sent to the monitoring process if Item dies, 
if Item does not exist, or if the connection is lost to the node which 
Item  resides on."

So, yes, of course you can receive the 'DOWN' message first, if the 
process doesn't exist, dies, or connection to the node is lost before 
the process manages to send anything else.
> If I weren't using a gen_server, than that would depend on the order of my
> receive branches.
>    
Well, yes, but if you're not looking for the DOWN or at least timing out 
your receive, then you may end up waiting forever if the process dies 
before sending the message you're trying to receive.

B

From ok@REDACTED  Tue Jul 13 01:22:45 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Tue, 13 Jul 2010 11:22:45 +1200
Subject: [erlang-questions] some lexical questions
In-Reply-To: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>
Message-ID: <32AD6BBF-06D3-4400-B509-7B4ADF6085CE@cs.otago.ac.nz>


On Jul 13, 2010, at 2:10 AM, Joe Armstrong wrote:
> 1) Is there a "definitive" reference for the meaning of the
> allowed escape sequences within a string?

I would expect \^ to allow any of the ASCII characters
in the range 16#3F to 16#5F after it ($? to $_) with the
meaning \^x = ($x - 16#40) band 127, so that
\^? is DEL, \^@ is NUL, \^L if FF, \^Z is SUB, \^_ is US.
And in particular, \^[ should be ESC.

> This seems far easier to understand than a yacc or LL(k) grammar :-)

Since it's for lexical structure, it should be simpler;
the right comparison would be with lex.

(And it's not _really_ a fair comparison until there's some
semantics in there.)  Come to think of it, where does that
grammar recognise any of (,)[|]{;} or any operator?


From ok@REDACTED  Tue Jul 13 02:13:26 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Tue, 13 Jul 2010 12:13:26 +1200
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <4C3A02BF.3070904@gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>	<4C37BB78.4060205@gmail.com>	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>	<4C380E97.6090505@gmail.com>	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>	<AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>	<AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com> <AANLkTik88zH2QMNsWXECmb_6TZx_B6dclPlxpbFfzlN3@mail.gmail.com> <4C3A02BF.3070904@gmail.com>
Message-ID: <B126EB73-1FC0-4ABA-AEA4-50AF8A92B716@cs.otago.ac.nz>


On Jul 12, 2010, at 5:43 AM, Michael Truog wrote:

> I have to say that "Goiter" is initially appealing when continuing the
> bodily ailments theme.

Except for those of us who spell it "goitre", of course.

> "PEMMOX" reminded me of Annie Lennox's name being said quickly, or
> perhaps a cleaning fluid (ignoring the company that makes furnaces,
> http://www.lennox.com/).  However, it is a unique name and an
> interesting name.

Checking an electronic Scrabble dictionary, the only words it
found ending with 'MOX' were 'LUMMOX' and 'FLUMMOX'.
The only word in the on-line OED beginning with "PEMM" is
"pemmican".

This all smells of "Erlang Gaming Online" (:-).



From tony.arcieri@REDACTED  Tue Jul 13 08:00:36 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Tue, 13 Jul 2010 00:00:36 -0600
Subject: Controlling the structure of gen_tcp active mode messages
Message-ID: <AANLkTiktwNUnMV6BZZMgJcFyasHw0Qic9ipH-QKG2M9W@mail.gmail.com>

Is there any way to alter the structure of the messages delivered by gen_tcp
when in active mode?  Specifically I would like a different term than the
originating port included in every message.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From erlang@REDACTED  Tue Jul 13 09:07:20 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Tue, 13 Jul 2010 09:07:20 +0200
Subject: [erlang-questions] some lexical questions
In-Reply-To: <20100712150947.GO28418@hijacked.us>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>
	<20100712150947.GO28418@hijacked.us>
Message-ID: <AANLkTinvUMRbxYC0UD1wQ9rGGnGsdfg_fj00l84lqYnh@mail.gmail.com>

On Mon, Jul 12, 2010 at 5:09 PM, Andrew Thompson <andrew@REDACTED> wrote:
> On Mon, Jul 12, 2010 at 04:10:56PM +0200, Joe Armstrong wrote:
>> Hello,
>>
>> 1) Is there a "definitive" reference for the meaning of the
>> allowed escape sequences within a string?
>>
>> The best I've found is in the on-line documentation in section 2.14
>> of http://www.erlang.org/doc/reference_manual/data_types.html
>>
>> But the shell seems to parse "\^[" as [27] - now either table 2.14 is
>> incorrect or the implementation is incorrect since following \^ there
>> should be only be a character matching [a-zA-Z].
>
> \^[ is a synonym for \e (ctrl-escape). Apparently if you input a string
> with "\^[" in it in the shell (R14A) the returned value is "\e", I know
> the terminal code won't let you pass a raw \e to the underlying
> terminal.
>
> I'm guessing the table listing is just incomplete.

or the implementation is incorrect. All I know is that the documentation
says one thing, the implementation does something different.

>
> Escaping \a and having it treated as \a is the same behaviour seen in
> regular expressions, basically if the unescaped value isn't special, it
> unescapes it.

I know - in fact the quoting conventions seem rather strange. The intention
was to provide a mechanism to allow any character code to be inserted into a
string (which is also a list). The problem is the \O.. and \x... conventions
\x has two forms \xHHH and \x{HHH} the curly brackets are useful when
the character immediately following HHH could be interpreted as a hex digit.
There is no such convention for octal digits, which become a pain if,
for example,
the character following a two digit octal number might build a valid three digit
octal number. It would be nice to write \o{12}3... and not \012\003...
to create the
list [8#12,3,...]


>>
>> Also \X where X is non of the alternatives in table 2.14 defaults to
>> X - but it should be an error by table 2.14 since X is none of the defined
>> alternatives. The shell thinks "\a" is the same as "a" but I think this
>> is confusing, in any case its an undocumened feature.
>>
>> 2) There is a strange character in line 1678 of asn1ct.erl
>> ? ?Emacs thinks this character is #xA0 encoded with iso-latin-1-unix
>>
>
> I can't even find this character in my copy of this file. Maybe the line
> number is different with my copy (R14A).
>
> Andrew
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From erlang@REDACTED  Tue Jul 13 09:13:00 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Tue, 13 Jul 2010 09:13:00 +0200
Subject: [erlang-questions] some lexical questions
In-Reply-To: <32AD6BBF-06D3-4400-B509-7B4ADF6085CE@cs.otago.ac.nz>
References: <AANLkTinLy_5t9Eyo3W5TGLS0VoWl_OMmpiKckDZHUwu1@mail.gmail.com>
	<32AD6BBF-06D3-4400-B509-7B4ADF6085CE@cs.otago.ac.nz>
Message-ID: <AANLkTim3eKdz6FM4fYWM0PY0bt70bMKr-cndPil7qOSo@mail.gmail.com>

On Tue, Jul 13, 2010 at 1:22 AM, Richard O'Keefe <ok@REDACTED> wrote:
>
> On Jul 13, 2010, at 2:10 AM, Joe Armstrong wrote:
>>
>> 1) Is there a "definitive" reference for the meaning of the
>> allowed escape sequences within a string?
>
> I would expect \^ to allow any of the ASCII characters
> in the range 16#3F to 16#5F after it ($? to $_) with the
> meaning \^x = ($x - 16#40) band 127, so that
> \^? is DEL, \^@ is NUL, \^L if FF, \^Z is SUB, \^_ is US.
> And in particular, \^[ should be ESC.
>
>> This seems far easier to understand than a yacc or LL(k) grammar :-)
>
> Since it's for lexical structure, it should be simpler;
> the right comparison would be with lex.
>
> (And it's not _really_ a fair comparison until there's some
> semantics in there.) ?Come to think of it, where does that
> grammar recognise any of (,)[|]{;} or any operator?
>

I only showed the lexical part of the grammar. In fact I have two grammars
one for the tokens (which I showed) the other (which I did not show) has
productions like

   list <- '[' ']' / '[' term (',' term)* ']'
   ...

all the non-terminals in the second grammar are added to the first grammar
to build a recognizer - but I didn't show this step.

I'm trying to build something like ANTLR with parser combinators

/Joe

From Antonio.Musumeci@REDACTED  Tue Jul 13 15:12:50 2010
From: Antonio.Musumeci@REDACTED (Musumeci, Antonio S)
Date: Tue, 13 Jul 2010 09:12:50 -0400
Subject: Different uids for ports
Message-ID: <01489E237C2C8F45AF7898E135F48E80066325BA87@NYWEXMBX2129.msad.ms.com>

Has anyone ever needed to spawn ports as different UIDs? The port API doesn't provide for it. Is the only way to acheive something like that is to use cnodes?

Thanks.

--------------------------------------------------------------------------
NOTICE: If received in error, please destroy, and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. We may monitor and store emails to the extent permitted by applicable law.

From krab@REDACTED  Tue Jul 13 16:18:38 2010
From: krab@REDACTED (Kresten Krab Thorup)
Date: Tue, 13 Jul 2010 16:18:38 +0200
Subject: [erlang-questions] Different uids for ports
In-Reply-To: <01489E237C2C8F45AF7898E135F48E80066325BA87@NYWEXMBX2129.msad.ms.com>
References: <01489E237C2C8F45AF7898E135F48E80066325BA87@NYWEXMBX2129.msad.ms.com>
Message-ID: <DF1C3563-205C-4E0C-AD75-BBE25C4E0EC8@trifork.com>

It would seem reasanble to try opening a port with "sudo -u UID <command>"; modulo whatever rights you need to be able to sudo.

Kresten


On Jul 13, 2010, at 15:12 , Musumeci, Antonio S wrote:

> Has anyone ever needed to spawn ports as different UIDs? The port API doesn't provide for it. Is the only way to acheive something like that is to use cnodes?
> 
> Thanks.
> 
> --------------------------------------------------------------------------
> NOTICE: If received in error, please destroy, and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. We may monitor and store emails to the extent permitted by applicable law.

Kresten Krab Thorup, CTO, Trifork


From xuxb1979@REDACTED  Tue Jul 13 17:26:23 2010
From: xuxb1979@REDACTED (=?utf-8?Q?=E5=BE=90=E6=99=93=E6=BB=A8?=)
Date: Tue, 13 Jul 2010 23:26:23 +0800
Subject: =?utf-8?Q?=E7=AD=94=E5=A4=8D:_Re:_[erlang-questions]_Re:_On_Windows_XP_(S?=
 =?utf-8?Q?P2):_wx_broken?=
Message-ID: <4c3c85c4.14528c0a.0563.4ce2@mx.google.com>



???T8588??

----- ???? -----
???: MapAndFold <mapandfold@REDACTED>
????: 2010?7?9? 9:54
???: Dan Gudmundsson <dangud@REDACTED>
??: erlang-questions@REDACTED
??: Re: [erlang-questions] Re: On Windows XP (SP2): wx broken

Yeah, I have tried again on R14A, and it is *almost* OK now.

But, another problem occurs:

Opening the sudoku demo, drag to resize the window, then things crash
with this message.

---------------------------------------------------------------------------------
---------------------------
Sudoku: werl.exe - Application Error
---------------------------
The instruction at "0x02292376" referenced memory at "0x00000010". The
memory could not be "read".
---------------------------------------------------------------------------------

My guest is that it seems to be related to the painting procedure of
the window. My little app which draws some graphics is also easy to
crash when resizing the window, while in wx:demo(), most of the
examples are OK (graphicsContext is easy to crash).

On Thu, Jul 8, 2010 at 3:44 PM, Dan Gudmundsson <dangud@REDACTED> wrote:
> Have you with this problem tried R14A, is it working now?
>
> I found that we had upgraded Visual Studio without recompiling
> wxWidgets DLL's causing the
> wx-driver to be dependent on two different versions of the runtime DLL,
> where only the latest where installed with erlang.
>
> Thanks for locating it.
>
> /Dan
>

________________________________________________________________
erlang-questions (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED



From tech@REDACTED  Tue Jul 13 21:28:53 2010
From: tech@REDACTED (tech@REDACTED)
Date: Tue, 13 Jul 2010 21:28:53 +0200
Subject: New SSL related observation / question
Message-ID: <201007132128.53540.tech@erlfinsys.net>

I have seen that using IE browsers connecting to https based servers returns a 
MAC_ERROR using the R14A implementations.

Investigating further I see that the connection from the IE browser connects, 
and in the ssl_cipher.erl module I saw that it shows the version as 3,1.  (3,1 
indicates TLS)

The code in ssl_cipher that handles this is the function is_correct_padding, I 
added the following pattern match as well:
## Added Code
is_correct_padding(_, {3, 1}) ->
    true;

, and the connection now seems to be working fine, is there any known problems 
and / or side effects that someone know about with this change?

Thanks



-- 
-----
Mobile : +27 84 468 3138
Skype : danielschutte
Office : +27 (0) 11 475 - 1654
             +27 (0) 11 475 - 1664
             +27 (0) 11 475 - 1674
             +27 (0) 11 475 - 1639


-------------------------------------------------------

From ingela@REDACTED  Tue Jul 13 22:39:28 2010
From: ingela@REDACTED (Ingela Andin)
Date: Tue, 13 Jul 2010 22:39:28 +0200
Subject: [erlang-questions] New SSL related observation / question
In-Reply-To: <201007132128.53540.tech@erlfinsys.net>
References: <201007132128.53540.tech@erlfinsys.net>
Message-ID: <AANLkTin9Rd3dvQNUSF4mbCXjIyis0WfmEIhTzHfb5Z_x@mail.gmail.com>

Hi!

Well, reading the RFC:s again I see that it is first in RFC 4346 TLS
1.1 (3.2 ) that it is an requierment that the
padding must be checked. RFC 2246 TLS 1.0 (3.1)  is a bit more vauge and says
that a MAC error should be returned if the padding is checked.  So
this gives us a little dilema should
we not check at all in TLS 1.0 to gain interopability with all
implementations or maybe we should just make it configurable?!

Regards Ingela Erlang/OTP team, Ericsson AB


2010/7/13  <tech@REDACTED>:
> I have seen that using IE browsers connecting to https based servers returns a
> MAC_ERROR using the R14A implementations.
>
> Investigating further I see that the connection from the IE browser connects,
> and in the ssl_cipher.erl module I saw that it shows the version as 3,1. ?(3,1
> indicates TLS)
>
> The code in ssl_cipher that handles this is the function is_correct_padding, I
> added the following pattern match as well:
> ## Added Code
> is_correct_padding(_, {3, 1}) ->
> ? ?true;
>
> , and the connection now seems to be working fine, is there any known problems
> and / or side effects that someone know about with this change?
>
> Thanks
>
>
>
> --
> -----
> Mobile : +27 84 468 3138
> Skype : danielschutte
> Office : +27 (0) 11 475 - 1654
> ? ? ? ? ? ? +27 (0) 11 475 - 1664
> ? ? ? ? ? ? +27 (0) 11 475 - 1674
> ? ? ? ? ? ? +27 (0) 11 475 - 1639
>
>
> -------------------------------------------------------
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From ingela@REDACTED  Tue Jul 13 22:53:56 2010
From: ingela@REDACTED (Ingela Andin)
Date: Tue, 13 Jul 2010 22:53:56 +0200
Subject: [erlang-questions] Still problems with new SSL?
In-Reply-To: <8a325a1e-6869-41fb-b906-c5bd179efaa0@z8g2000yqz.googlegroups.com>
References: <8a325a1e-6869-41fb-b906-c5bd179efaa0@z8g2000yqz.googlegroups.com>
Message-ID: <AANLkTinU81euUPu_dZgkPXftiKxVv9KwJz_zX8sjkXVz@mail.gmail.com>

Hi!

I have tested this with different openssl servers both with and
without secure renegotiation and it works fine.
I rather suspect that you  have the same problem as disucssed  by the
thread  "New SSL related observation / question"
e.i. that the padding is incorrect.  I get the same error as you with
the goggle server when trying it from home.
(Behinde a firewall at work).

Regards Ingela Erlang OTP/Team, Ericsson AB


2010/7/11 Steve Davis <steven.charles.davis@REDACTED>:
> Can anyone make the code below (specifically against https://www.google.com)
> work for
>
> ssltest:run(new)?
>
> I'm using the key.pem and cert.pem copied from ERLANG_HOME/lib/ssl-4.0/
> examples/certs/etc/client
>
> My results are:
> 2> ssltest:run(old).
> {ok,<<"HTTP/1.1 200 OK\r\nDate: Sun, 11 Jul 2010 16:20:13 GMT\r
> \nExpires: -1\r\nCache-Control: private, max-age=0\r\nConten"...>>}
> 3> ssltest:run(new).
>
> =ERROR REPORT==== 11-Jul-2010::11:20:17 ===
> SSL: decipher_error: ./ssl_record.erl:680:Fatal error: bad record mac
> {error,"bad record mac"}
> 4>
>
> ----- module ssltest.erl ------
> -module(ssltest).
>
> -export([run/1]).
>
> -define(HOST, "www.google.com").
> -define(PORT, 443).
> -define(REQUEST,
> ? ? ? ?<<"GET / HTTP/1.1\r\n",
> ? ? ? ?"Connection: close\r\n",
> ? ? ? ?"User-Agent: Mozilla/5.0 (Windows NT 5.1; en-US) Test/1.0.0\r\n",
> ? ? ? ?"Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/
> plain;q=0.8,image/png,*/*;q=0.5\r\n",
> ? ? ? ?"Accept-Language: en-US,en;q=0.8\r\n",
> ? ? ? ?"Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n",
> ? ? ? ?"\r\n">>).
>
> run(Impl) when Impl =:= old; Impl =:= new ->
> ? ? ? ?Opts = [binary, {ip, {0, 0, 0, 0}}, {active, false}, {packet, 0},
> ? ? ? ? ? ? ? ?{ssl_imp, Impl}, {verify, 0}, {depth, 1},
> ? ? ? ? ? ? ? ?{keyfile, "./key.pem"},
> ? ? ? ? ? ? ? ?{certfile, "./cert.pem"}],
> ? ? ? ?ssl:start(),
> ? ? ? ?{ok, Socket} = ssl:connect(?HOST, ?PORT, Opts),
> ? ? ? ?ok = ssl:send(Socket, ?REQUEST),
> ? ? ? ?catch ssl:recv(Socket, 0, 10000).
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From steven.charles.davis@REDACTED  Wed Jul 14 03:22:33 2010
From: steven.charles.davis@REDACTED (Steve Davis)
Date: Tue, 13 Jul 2010 18:22:33 -0700 (PDT)
Subject: Still problems with new SSL?
In-Reply-To: <AANLkTinU81euUPu_dZgkPXftiKxVv9KwJz_zX8sjkXVz@mail.gmail.com>
References: <8a325a1e-6869-41fb-b906-c5bd179efaa0@z8g2000yqz.googlegroups.com> 
	<AANLkTinU81euUPu_dZgkPXftiKxVv9KwJz_zX8sjkXVz@mail.gmail.com>
Message-ID: <d6335e30-58a1-4e56-ae6f-7e6bfd754c10@c33g2000yqm.googlegroups.com>

Hi Ingela,

Thanks for the reply. Looking at that thread, it does seem that is the
same issue.

I guess I'll have to brave those other rfc's and dig further, since
interoperability with Google's https comes rather high on my priority
list!

Regards,
Steve


On Jul 13, 3:53?pm, Ingela Andin <ing...@REDACTED> wrote:
> Hi!
>
> I have tested this with different openssl servers both with and
> without secure renegotiation and it works fine.
> I rather suspect that you ?have the same problem as disucssed ?by the
> thread ?"New SSL related observation / question"
> e.i. that the padding is incorrect. ?I get the same error as you with
> the goggle server when trying it from home.
> (Behinde a firewall at work).
>
> Regards Ingela Erlang OTP/Team, Ericsson AB
>
> 2010/7/11 Steve Davis <steven.charles.da...@REDACTED>:
>
>
>
>
>
> > Can anyone make the code below (specifically againsthttps://www.google.com)
> > work for
>
> > ssltest:run(new)?
>
> > I'm using the key.pem and cert.pem copied from ERLANG_HOME/lib/ssl-4.0/
> > examples/certs/etc/client
>
> > My results are:
> > 2> ssltest:run(old).
> > {ok,<<"HTTP/1.1 200 OK\r\nDate: Sun, 11 Jul 2010 16:20:13 GMT\r
> > \nExpires: -1\r\nCache-Control: private, max-age=0\r\nConten"...>>}
> > 3> ssltest:run(new).
>
> > =ERROR REPORT==== 11-Jul-2010::11:20:17 ===
> > SSL: decipher_error: ./ssl_record.erl:680:Fatal error: bad record mac
> > {error,"bad record mac"}
> > 4>
>
> > ----- module ssltest.erl ------
> > -module(ssltest).
>
> > -export([run/1]).
>
> > -define(HOST, "www.google.com").
> > -define(PORT, 443).
> > -define(REQUEST,
> > ? ? ? ?<<"GET / HTTP/1.1\r\n",
> > ? ? ? ?"Connection: close\r\n",
> > ? ? ? ?"User-Agent: Mozilla/5.0 (Windows NT 5.1; en-US) Test/1.0.0\r\n",
> > ? ? ? ?"Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/
> > plain;q=0.8,image/png,*/*;q=0.5\r\n",
> > ? ? ? ?"Accept-Language: en-US,en;q=0.8\r\n",
> > ? ? ? ?"Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3\r\n",
> > ? ? ? ?"\r\n">>).
>
> > run(Impl) when Impl =:= old; Impl =:= new ->
> > ? ? ? ?Opts = [binary, {ip, {0, 0, 0, 0}}, {active, false}, {packet, 0},
> > ? ? ? ? ? ? ? ?{ssl_imp, Impl}, {verify, 0}, {depth, 1},
> > ? ? ? ? ? ? ? ?{keyfile, "./key.pem"},
> > ? ? ? ? ? ? ? ?{certfile, "./cert.pem"}],
> > ? ? ? ?ssl:start(),
> > ? ? ? ?{ok, Socket} = ssl:connect(?HOST, ?PORT, Opts),
> > ? ? ? ?ok = ssl:send(Socket, ?REQUEST),
> > ? ? ? ?catch ssl:recv(Socket, 0, 10000).
>
> > ________________________________________________________________
> > erlang-questions (at) erlang.org mailing list.
> > Seehttp://www.erlang.org/faq.html
> > To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> Seehttp://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED

From mapandfold@REDACTED  Wed Jul 14 04:17:06 2010
From: mapandfold@REDACTED (MapAndFold)
Date: Wed, 14 Jul 2010 10:17:06 +0800
Subject: [erlang-questions] Re: On Windows XP (SP2): wx broken
In-Reply-To: <AANLkTin4pkTu2uo4d-dznl4uQrrH6mM20TskuktYVk6U@mail.gmail.com>
References: <aeb6a06d1003012305m62020dd1t7f11146db72a8ea9@mail.gmail.com>
	<9C6B96B5-37FA-4CF6-A7D3-663736CEE916@gmail.com>
	<69869ad8-a27a-48e6-8835-8303a87ed40d@g11g2000yqe.googlegroups.com>
	<93df43b61003032220m5b4d396dn4aca92270134d795@mail.gmail.com>
	<aeb6a06d1003041848k7e8a4d11h3b04cffa812ea3a@mail.gmail.com>
	<AANLkTingr_hHSs0MXhC9mRGuvedjcWM1vYBYabtoxCC4@mail.gmail.com>
	<AANLkTimwf8xVDhqglTw926VggJnX7l0EA5i9WvaXkZKG@mail.gmail.com>
	<AANLkTin4pkTu2uo4d-dznl4uQrrH6mM20TskuktYVk6U@mail.gmail.com>
Message-ID: <AANLkTilxjhdkhWIkOxvj7sA-1xpDtTPOag3tgge-rvgn@mail.gmail.com>

On Fri, Jul 9, 2010 at 6:07 PM, Antoine Koener <antoine.koener@REDACTED> wrote:
>
> While your talking about the sudoku application, it's worth saying that it
> takes 100% CPU.
> Don't know if it's wx related but for my point of view it's a complete
> failure.
> UI must not take too much cpu (I'm not talking about games...)
> Note that I know that this sudoku thing is only a proof of concept, and it
> is not designed as
> a top quality game, but this don't encourage myself to rely heavily on
> wx/erlang :/
>

Actually, I like the wx Sudoku game very much. Here, I just use it as
a regression to test wx on R14A.

/Li

From vinubalaji@REDACTED  Wed Jul 14 05:28:35 2010
From: vinubalaji@REDACTED (Vinubalaji Gopal)
Date: Tue, 13 Jul 2010 20:28:35 -0700
Subject: linked in driver port performance
Message-ID: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>

Hi all,
  I have been digging hard to write a port linked in driver which would
perform better and most of my searches resulted in dead threads (like
http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e)
and most of my experiments did not give me any good results . I tried to use
async threads but I am not able to call these async threads asynchronously.
If I try to make multiple erlang processes open the same port it just fails
saying that the driver has become permanent. If I try to open a single port
driver  - I have to do that in a single gen_server and it blocks when I
call  port_command - so all the messages are queued and processed
sequentially. Is there a way to write a linked in driver which will perform
better and/or better links to help (I have read the erl_driver
documentation, erl_ddll documentation numerous times).



-- 
Vinu

In a world without fences who needs gates?

From mjtruog@REDACTED  Wed Jul 14 07:10:44 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Tue, 13 Jul 2010 22:10:44 -0700
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>
Message-ID: <4C3D46D4.1080709@gmail.com>

I think you are having problems with the driver becoming permanent when
you make the first asynchronous call (there is code that locks the port
driver so the dll/so can not be unloaded (so it can't be reloaded)). 
The code is trying to protect the code from the possibility that a
thread finishes but the port driver has already been unloaded, which is
a valid concern (but could be handled in more complex ways).  The
problem has been mentioned before here
http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
.

ERL_DRV_FLAG_USE_PORT_LOCKING is the flag to make sure different
scheduler threads can call the port driver instances concurrently (the
entry in the driver_flags struct member
http://www.erlang.org/doc/man/driver_entry.html#driver_flags) as
discussed here http://www.erlang.org/doc/man/erl_driver.html#smp_support
.  I assume NIFs use the port driver default of "driver level locking"
(driver_flags == 0, i.e., not ERL_DRV_FLAG_USE_PORT_LOCKING), but I am
not sure.

- Michael

On 07/13/2010 08:28 PM, Vinubalaji Gopal wrote:
> Hi all,
>   I have been digging hard to write a port linked in driver which would
> perform better and most of my searches resulted in dead threads (like
> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e)
> and most of my experiments did not give me any good results . I tried to use
> async threads but I am not able to call these async threads asynchronously.
> If I try to make multiple erlang processes open the same port it just fails
> saying that the driver has become permanent. If I try to open a single port
> driver  - I have to do that in a single gen_server and it blocks when I
> call  port_command - so all the messages are queued and processed
> sequentially. Is there a way to write a linked in driver which will perform
> better and/or better links to help (I have read the erl_driver
> documentation, erl_ddll documentation numerous times).
>
>
>
>   


From mjtruog@REDACTED  Wed Jul 14 08:15:06 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Tue, 13 Jul 2010 23:15:06 -0700
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <4C3D46D4.1080709@gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com> <4C3D46D4.1080709@gmail.com>
Message-ID: <4C3D55EA.9030100@gmail.com>

Ok, I didn't realize that you had found the same linked in driver
permanent issue on trapexit.  I at least offered my explanation of what
you seem to be experiencing.

After looking at NIFs, they actually look like they are using port level
locking by default (as described at
http://erlang.org/doc/man/erl_nif.html by the "Threads and concurrency"
section).  It would be much easier to create a NIF, but there is no
interface for async threads through NIFs (though you can send a process
a message with enif_send, which might help facilitate asynchronous
behavior).  If you stick with a port driver, you would need to use
ERL_DRV_FLAG_USE_PORT_LOCKING as previously mentioned.  Either way you
want the C code to be quick, so you don't block the Erlang VM scheduler
thread.

- Michael
 
On 07/13/2010 10:10 PM, Michael Truog wrote:
> I think you are having problems with the driver becoming permanent when
> you make the first asynchronous call (there is code that locks the port
> driver so the dll/so can not be unloaded (so it can't be reloaded)). 
> The code is trying to protect the code from the possibility that a
> thread finishes but the port driver has already been unloaded, which is
> a valid concern (but could be handled in more complex ways).  The
> problem has been mentioned before here
> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
> .
>
> ERL_DRV_FLAG_USE_PORT_LOCKING is the flag to make sure different
> scheduler threads can call the port driver instances concurrently (the
> entry in the driver_flags struct member
> http://www.erlang.org/doc/man/driver_entry.html#driver_flags) as
> discussed here http://www.erlang.org/doc/man/erl_driver.html#smp_support
> .  I assume NIFs use the port driver default of "driver level locking"
> (driver_flags == 0, i.e., not ERL_DRV_FLAG_USE_PORT_LOCKING), but I am
> not sure.
>
> - Michael
>
> On 07/13/2010 08:28 PM, Vinubalaji Gopal wrote:
>   
>> Hi all,
>>   I have been digging hard to write a port linked in driver which would
>> perform better and most of my searches resulted in dead threads (like
>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e)
>> and most of my experiments did not give me any good results . I tried to use
>> async threads but I am not able to call these async threads asynchronously.
>> If I try to make multiple erlang processes open the same port it just fails
>> saying that the driver has become permanent. If I try to open a single port
>> driver  - I have to do that in a single gen_server and it blocks when I
>> call  port_command - so all the messages are queued and processed
>> sequentially. Is there a way to write a linked in driver which will perform
>> better and/or better links to help (I have read the erl_driver
>> documentation, erl_ddll documentation numerous times).
>>
>>
>>
>>   
>>     
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>
>   


From dawid.figiel@REDACTED  Wed Jul 14 08:21:03 2010
From: dawid.figiel@REDACTED (Dawid Figiel)
Date: Wed, 14 Jul 2010 08:21:03 +0200
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <B126EB73-1FC0-4ABA-AEA4-50AF8A92B716@cs.otago.ac.nz>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>
	<AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
	<AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com>
	<AANLkTik88zH2QMNsWXECmb_6TZx_B6dclPlxpbFfzlN3@mail.gmail.com>
	<4C3A02BF.3070904@gmail.com>
	<B126EB73-1FC0-4ABA-AEA4-50AF8A92B716@cs.otago.ac.nz>
Message-ID: <AANLkTimEMYM-sgpvpRdDls7eHd-5pU4UInySnqdoNT-2@mail.gmail.com>

Any short example of the game scenario ?;>
For me a good type of the scenario for the online game is something like
'farmers' (who doesn't know what am I talking about ?;>)

On Tue, Jul 13, 2010 at 2:13 AM, Richard O'Keefe <ok@REDACTED> wrote:

>
> On Jul 12, 2010, at 5:43 AM, Michael Truog wrote:
>
>  I have to say that "Goiter" is initially appealing when continuing the
>> bodily ailments theme.
>>
>
> Except for those of us who spell it "goitre", of course.
>
>
>  "PEMMOX" reminded me of Annie Lennox's name being said quickly, or
>> perhaps a cleaning fluid (ignoring the company that makes furnaces,
>> http://www.lennox.com/).  However, it is a unique name and an
>> interesting name.
>>
>
> Checking an electronic Scrabble dictionary, the only words it
> found ending with 'MOX' were 'LUMMOX' and 'FLUMMOX'.
> The only word in the on-line OED beginning with "PEMM" is
> "pemmican".
>
> This all smells of "Erlang Gaming Online" (:-).
>
>
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>


-- 
Dawid

From dawid.figiel@REDACTED  Wed Jul 14 08:30:14 2010
From: dawid.figiel@REDACTED (Dawid Figiel)
Date: Wed, 14 Jul 2010 08:30:14 +0200
Subject: Sequence does't apply to sub-groups in common tests?
In-Reply-To: <AANLkTintGO1iLXHXfZTtBqwiXb2q6xn-GE-xC9Kjz-56@mail.gmail.com>
References: <AANLkTintGO1iLXHXfZTtBqwiXb2q6xn-GE-xC9Kjz-56@mail.gmail.com>
Message-ID: <AANLkTilNdGHg_XLHd6h8fC6MFsKEXSxCspY06ah6V2C1@mail.gmail.com>

Same here.
If anyone wants to try out what we're talking about, try the following:

Code:
-module(test_SUITE).

-export([all/0,
    groups/0,
    init_per_suite/1,
    end_per_suite/1,
    init_per_group/2,
    end_per_group/2,
    init_per_testcase/2,
    end_per_testcase/2]).

-export([failing_tc/1, ok_tc/1]).

all() ->
    [{group, test}].

groups() ->
    [{failing_group, [], [failing_tc]},
     {ok_group, [], [ok_tc]},
     {test, [sequence], [{group, failing_group}, {group, ok_group}]}].

init_per_suite(Config) -> Config.
end_per_suite(_Config) -> ok.

init_per_group(_Group, Config) -> Config.
end_per_group(failing_group, _Config) -> {return_group_result, failed};
end_per_group(_Group, _Config) -> ok.

init_per_testcase(_TestCase, Config) -> Config.
end_per_testcase(_TestCase, _Config) -> ok.

failing_tc(_Config) -> 2=3.
ok_tc(_Config) -> ok.


running using:
>run_test -suite test_SUITE -logdir <logdir>
(run_test as described in
http://www.erlang.org/doc/apps/common_test/run_test_chapter.html#id2267273)

it should give (in short):
Code:
- - - - - - - - - - - - - - - - - - - - - - - - - -
test_SUITE:failing_tc could not be executed
Reason: {badmatch,3}
- - - - - - - - - - - - - - - - - - - - - - - - - -

Testing Erlang.group_test.test_SUITE: *** FAILED *** test case 1 of 2
Testing Erlang.group_test.test_SUITE: TEST COMPLETE, 1 ok, 1 failed of 2
test cases


*Even though the second tc should be skipped.*




On Mon, Jul 12, 2010 at 3:17 PM, Dawid Figiel <dawid.figiel@REDACTED>wrote:

> Hi,
>
> I need some feedback, why sequence doesn't apply to sub-groups in common
> tests?
>
> example:
>
> This works:
>
> groups() -> [{group1, [sequence], [test1,
>                                    test2]}].
>
> If test1 fail then test2 will be skipped.
>
> And this does not work:
>
> groups() -> [{group1, [sequence], [{subgroup1, [], [test1]},
>                                    {subgroup2, [], [test2]}]}]
>
> end_per_group(Group, Config) ->
>     Status = ?config(tc_group_result, Config),
>     case proplists:get_value(failed, Status) of
>         [] -> {return_group_result, ok};
>         _Failed -> {return_group_result, failed}
>     end.
>
> Test1 has failed, so subgroup1 is handled as a failed too, but subgroup2 is
> not skipped although we have set up 'sequence'...why ?
>
> According to documentation:
>
> "A failed sub-group (Status == failed) will cause the execution of a
> sequence to fail in the same way a test case does."
>
>
> Any clues ?
>
> --
> regards,
>
> Dawid
>



-- 
Dawid

From boris.muehmer@REDACTED  Wed Jul 14 08:31:17 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Wed, 14 Jul 2010 08:31:17 +0200
Subject: [erlang-questions] Let's start a project for a (MMO-)Game in 
	Erlang... (inspired by "Erlang: Who uses it for games?")
In-Reply-To: <AANLkTimEMYM-sgpvpRdDls7eHd-5pU4UInySnqdoNT-2@mail.gmail.com>
References: <AANLkTik5V0pd2IHLp219NRraMaczvuaMTXj91wolqFcO@mail.gmail.com>
	<AANLkTilP83N3049OsxgteoQmivhBJlHusdGIEENAmMUX@mail.gmail.com>
	<AANLkTilGd5_22oelhcKjogH-Jz18Y8noGhY9C5xHzQpi@mail.gmail.com>
	<4C37BB78.4060205@gmail.com>
	<AANLkTins0ZXCqkHx7SPaDw18i1pphNq7f2GqPl11Y3C4@mail.gmail.com>
	<AANLkTilMv5wVjKYZgw8XkI-v2fD__z2TLChWm3vSq9GZ@mail.gmail.com>
	<AANLkTinaLrBxm4DZYhE3DvbS4uM5_Dxbl-bBs6wSQViO@mail.gmail.com>
	<4C380E97.6090505@gmail.com>
	<AANLkTilfWqt7Rhkv9-O6doM-zm5_bNSfyR7v6JDEDv7I@mail.gmail.com>
	<AANLkTinSUxpHy8x3OYayeEmq3z8VT5lI7wYGMfoXuks6@mail.gmail.com>
	<AANLkTimsljbIsctNnAcOeJ7Ej7A2alYg3mUzwLXF9L06@mail.gmail.com>
	<AANLkTik54K_n40lV8ONe1Q1o95v7PN4OwPgFedZa5tHl@mail.gmail.com>
	<AANLkTilItZmm7_GRg6llB9XMTwtdtMOSjcnp3ct5SIP1@mail.gmail.com>
	<AANLkTik88zH2QMNsWXECmb_6TZx_B6dclPlxpbFfzlN3@mail.gmail.com>
	<4C3A02BF.3070904@gmail.com>
	<B126EB73-1FC0-4ABA-AEA4-50AF8A92B716@cs.otago.ac.nz>
	<AANLkTimEMYM-sgpvpRdDls7eHd-5pU4UInySnqdoNT-2@mail.gmail.com>
Message-ID: <AANLkTinT5ale4EFmJaSks7x1P9lSO6h0d4jasEb7_sC7@mail.gmail.com>

2010/7/14 Dawid Figiel <dawid.figiel@REDACTED>:
> Any short example of the game scenario ?;>
> For me a good type of the scenario for the online game is something like
> 'farmers' (who doesn't know what am I talking about ?;>)

There is one thread about our 1st "target eXperience" at our
discussion site PEMMOX at "Google Groups"
(http://groups.google.de/group/pemmox/).

Well, currently we are collection ideas... I try to write down as many
ideas as possible (to be discussed), but my work and real life at home
keeps me pretty busy, so I don't have that much time to write down as
much as I want to. Others already contributed some ideas.


  - boris

From max.lapshin@REDACTED  Wed Jul 14 09:41:09 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Wed, 14 Jul 2010 11:41:09 +0400
Subject: [erlang-questions] mmap file to binary
In-Reply-To: <C76C304D-E471-412D-B1EC-1F5E76CE48F7@rogvall.se>
References: <z2pe2a8f3fc1004022357x1eec0a13ye192048e886bd3ba@mail.gmail.com>
	<o2je2a8f3fc1004082235z2ee146bfo171cd7cf7942bcfd@mail.gmail.com>
	<1270804285.2277.30.camel@wazowski.semmle>
	<201004091223.47956.clist@uah.es>
	<z2ve2a8f3fc1004090332h664bf460h82286f7d79210972@mail.gmail.com>
	<7A08415A-8730-4B61-9D6B-0394A1EC4F55@rogvall.se>
	<s2he2a8f3fc1004090446mda3924dbo699e8e2963ff3a60@mail.gmail.com>
	<4D758E50-91CC-4E0C-873E-4018CF0F4AC6@rogvall.se>
	<4BBF5898.4020205@erix.ericsson.se>
	<19391.30636.410791.181135@pilspetsen.it.uu.se>
	<C76C304D-E471-412D-B1EC-1F5E76CE48F7@rogvall.se>
Message-ID: <AANLkTinsjA0kR2Vso0--leRQcCMBMUZacRr_4o6w2PgX@mail.gmail.com>

Thanks a lot for enif_make_resource_binary, it works just as I wished,
but there is one small problem now.
I'm opening mmaped file in one process and magic binary with mmap
resource is created in that spawned process.
I open binary, prints some of its contents and than close it. Process
dies, I call erlang:garbage_collect() for several times,
but I don't see printf("Hi") from destructor.

Is it possible to get out, what binaries, are there in system and
maybe print out reference count for one binary?

From max.lapshin@REDACTED  Wed Jul 14 09:53:03 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Wed, 14 Jul 2010 11:53:03 +0400
Subject: [erlang-questions] mmap file to binary
In-Reply-To: <AANLkTinsjA0kR2Vso0--leRQcCMBMUZacRr_4o6w2PgX@mail.gmail.com>
References: <z2pe2a8f3fc1004022357x1eec0a13ye192048e886bd3ba@mail.gmail.com>
	<o2je2a8f3fc1004082235z2ee146bfo171cd7cf7942bcfd@mail.gmail.com>
	<1270804285.2277.30.camel@wazowski.semmle>
	<201004091223.47956.clist@uah.es>
	<z2ve2a8f3fc1004090332h664bf460h82286f7d79210972@mail.gmail.com>
	<7A08415A-8730-4B61-9D6B-0394A1EC4F55@rogvall.se>
	<s2he2a8f3fc1004090446mda3924dbo699e8e2963ff3a60@mail.gmail.com>
	<4D758E50-91CC-4E0C-873E-4018CF0F4AC6@rogvall.se>
	<4BBF5898.4020205@erix.ericsson.se>
	<19391.30636.410791.181135@pilspetsen.it.uu.se>
	<C76C304D-E471-412D-B1EC-1F5E76CE48F7@rogvall.se>
	<AANLkTinsjA0kR2Vso0--leRQcCMBMUZacRr_4o6w2PgX@mail.gmail.com>
Message-ID: <AANLkTinXpHOD5Mu1Fv5-u2fODzbsdU8gRrekn9TrAtHz@mail.gmail.com>

I have to do so:


    Mmap *mm;
    mm = (Mmap *)enif_alloc_resource(mmap_resource, sizeof(Mmap));

    mm->ptr = m;
    mm->size = (size_t)file_stat.st_size;


    m_bin = enif_make_resource_binary(env, mm, mm->ptr, mm->size);
    enif_release_resource(mm);   % <---------
    return enif_make_tuple2(env, enif_make_atom(env, "ok"), m_bin);


If I don't add enif_release_resource, it will never be garbage
collected. Why I have to do so?

From sverker@REDACTED  Wed Jul 14 11:47:34 2010
From: sverker@REDACTED (Sverker Eriksson)
Date: Wed, 14 Jul 2010 11:47:34 +0200
Subject: [erlang-questions] mmap file to binary
In-Reply-To: <AANLkTinXpHOD5Mu1Fv5-u2fODzbsdU8gRrekn9TrAtHz@mail.gmail.com>
References: <z2pe2a8f3fc1004022357x1eec0a13ye192048e886bd3ba@mail.gmail.com>	<o2je2a8f3fc1004082235z2ee146bfo171cd7cf7942bcfd@mail.gmail.com>	<1270804285.2277.30.camel@wazowski.semmle>	<201004091223.47956.clist@uah.es>	<z2ve2a8f3fc1004090332h664bf460h82286f7d79210972@mail.gmail.com>	<7A08415A-8730-4B61-9D6B-0394A1EC4F55@rogvall.se>	<s2he2a8f3fc1004090446mda3924dbo699e8e2963ff3a60@mail.gmail.com>	<4D758E50-91CC-4E0C-873E-4018CF0F4AC6@rogvall.se>	<4BBF5898.4020205@erix.ericsson.se>	<19391.30636.410791.181135@pilspetsen.it.uu.se>	<C76C304D-E471-412D-B1EC-1F5E76CE48F7@rogvall.se>	<AANLkTinsjA0kR2Vso0--leRQcCMBMUZacRr_4o6w2PgX@mail.gmail.com> <AANLkTinXpHOD5Mu1Fv5-u2fODzbsdU8gRrekn9TrAtHz@mail.gmail.com>
Message-ID: <4C3D87B6.5070407@erix.ericsson.se>

Max Lapshin wrote:
> I have to do so:
>
>
>     Mmap *mm;
>     mm = (Mmap *)enif_alloc_resource(mmap_resource, sizeof(Mmap));
>
>     mm->ptr = m;
>     mm->size = (size_t)file_stat.st_size;
>
>
>     m_bin = enif_make_resource_binary(env, mm, mm->ptr, mm->size);
>     enif_release_resource(mm);   % <---------
>     return enif_make_tuple2(env, enif_make_atom(env, "ok"), m_bin);
>
>
> If I don't add enif_release_resource, it will never be garbage
> collected. Why I have to do so
That was a design choice. Ownership of resources are never transfered.

enif_allloc_resource gives you ("the NIF") ownership of the resource.
enif_make_resource and enif_make_resource_binary adds a new ownership 
from the created Erlang term.

So, to really free a resource, both "the NIF" ownership has to be 
released by calling enif_release_resource and all referring terms has to 
be garbage collected.


/Sverker, Erlang/OTP


From sverker@REDACTED  Wed Jul 14 12:15:11 2010
From: sverker@REDACTED (Sverker Eriksson)
Date: Wed, 14 Jul 2010 12:15:11 +0200
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <4C3D55EA.9030100@gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com> <4C3D46D4.1080709@gmail.com> <4C3D55EA.9030100@gmail.com>
Message-ID: <4C3D8E2F.4030503@erix.ericsson.se>

Actually, NIFs don't use ports so there is no locking at all needed to 
call a NIF, except
the locks already held on the running process. If you introduce data 
that could be shared
between concurrent NIF calls, then you have to serialize that access 
with your own
locking. Using enif_mutex_* for example.

You can't use async-threads from a NIF, but you can create custom 
threads with
enif_thread_create and send messages from that thread with enif_send.

/Sverker, Erlang/OTP

Michael Truog wrote:
> Ok, I didn't realize that you had found the same linked in driver
> permanent issue on trapexit.  I at least offered my explanation of what
> you seem to be experiencing.
>
> After looking at NIFs, they actually look like they are using port level
> locking by default (as described at
> http://erlang.org/doc/man/erl_nif.html by the "Threads and concurrency"
> section).  It would be much easier to create a NIF, but there is no
> interface for async threads through NIFs (though you can send a process
> a message with enif_send, which might help facilitate asynchronous
> behavior).  If you stick with a port driver, you would need to use
> ERL_DRV_FLAG_USE_PORT_LOCKING as previously mentioned.  Either way you
> want the C code to be quick, so you don't block the Erlang VM scheduler
> thread.
>
> - Michael
>  
> On 07/13/2010 10:10 PM, Michael Truog wrote:
>   
>> I think you are having problems with the driver becoming permanent when
>> you make the first asynchronous call (there is code that locks the port
>> driver so the dll/so can not be unloaded (so it can't be reloaded)). 
>> The code is trying to protect the code from the possibility that a
>> thread finishes but the port driver has already been unloaded, which is
>> a valid concern (but could be handled in more complex ways).  The
>> problem has been mentioned before here
>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
>> .
>>
>> ERL_DRV_FLAG_USE_PORT_LOCKING is the flag to make sure different
>> scheduler threads can call the port driver instances concurrently (the
>> entry in the driver_flags struct member
>> http://www.erlang.org/doc/man/driver_entry.html#driver_flags) as
>> discussed here http://www.erlang.org/doc/man/erl_driver.html#smp_support
>> .  I assume NIFs use the port driver default of "driver level locking"
>> (driver_flags == 0, i.e., not ERL_DRV_FLAG_USE_PORT_LOCKING), but I am
>> not sure.
>>
>> - Michael
>>
>> On 07/13/2010 08:28 PM, Vinubalaji Gopal wrote:
>>   
>>     
>>> Hi all,
>>>   I have been digging hard to write a port linked in driver which would
>>> perform better and most of my searches resulted in dead threads (like
>>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e)
>>> and most of my experiments did not give me any good results . I tried to use
>>> async threads but I am not able to call these async threads asynchronously.
>>> If I try to make multiple erlang processes open the same port it just fails
>>> saying that the driver has become permanent. If I try to open a single port
>>> driver  - I have to do that in a single gen_server and it blocks when I
>>> call  port_command - so all the messages are queued and processed
>>> sequentially. Is there a way to write a linked in driver which will perform
>>> better and/or better links to help (I have read the erl_driver
>>> documentation, erl_ddll documentation numerous times).
>>>
>>>
>>>
>>>   
>>>     
>>>       
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>>   
>>     
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>   


From anthonym@REDACTED  Wed Jul 14 22:24:56 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Wed, 14 Jul 2010 13:24:56 -0700
Subject: [erlang-questions] Improving performance on a thrift to protobuf proxy
In-Reply-To: <20100614185259.GA4934@alumni.caltech.edu>
References: <20100614185259.GA4934@alumni.caltech.edu>
Message-ID: <20100714202456.GB63136@alumni.caltech.edu>

Hi,

  While I haven't yet answered all my own questions I did discover 2 things
which might help future erlang programmers.

1. use ibrowse as an http client, not httpc.  httpc leaks memory and is buggy
   in R13B04
2. R13B04 is better than R12B05, much better.  It used half the CPU (or at
   least did after switching from httpc to ibrowse).

If I discover more I will send more.

-Anthony

On Mon, Jun 14, 2010 at 11:52:59AM -0700, Anthony Molinaro wrote:
> Hi,
> 
>   I have a thrift server (using the generated thrift server from the thrift
> distribution) which contains a single method.  The method takes two thrift
> objects (a context, and a list of places to call).  The thrift method handler
> spawns a process for each place to call.  Each of those processes, takes the
> context, combines it with some meta info particular to the place to call,
> and serializes the request as a protobuf.  It then makes an http call using
> httpc with a timeout, and calls the place to call passing the protobuf as the
> body of an HTTP GET request.
> 
>   For each incoming request I end up with 6-10 outgoing requests.  Right now
> the server runs pretty well, but it seems to use a lot of CPU, also even
> though I set a pretty tight timeout on my httpc call (120 msecs), the
> server often doesn't respond within 200 msecs to the caller.
> 
>   I did a little bit of profiling in isolation (using eprof), but that didn't
> really show any low hanging fruit (however, I'm not entirely sure I used the
> right profiling).  So I'm looking for pointers to help improve throughput
> and lower CPU usage.
> 
> Specifically,
> 
>   - what is the best way to profile this sort of application?  using tracing?
>     fprof? eprof? on the live server or try to test in isolation (I profiled
>     in isolation before, but as I said no real low hanging fruit).
>   - is httpc the ideal http client?  are there better http client libraries?
>     should I roll my own using event driven non-blocking techniques?  does
>     the timeout in httpc really work, or should I do something with a timer?
>   - this is really just sort of a glorified web crawler, has anyone out there
>     written a crawler and have pointers?
> 
> Any other hints or tips would be greatly appreciated.
> 
> Thanks,
> 
> -Anthony
> 
> -- 
> ------------------------------------------------------------------------
> Anthony Molinaro                           <anthonym@REDACTED>
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From anthonym@REDACTED  Wed Jul 14 22:26:30 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Wed, 14 Jul 2010 13:26:30 -0700
Subject: [erlang-questions] Re: Possible leak in inets httpc.
In-Reply-To: <20100709162648.GB18058@alumni.caltech.edu>
References: <AANLkTikTQsWjSRiEe6FtTxUYpRnBxtwv9vRtBS75NioA@mail.gmail.com> <AANLkTimE0EvtcpSSGLqd9J0xqCbFkjLQKl6pRHw15WTi@mail.gmail.com> <20100708201341.GB9969@alumni.caltech.edu> <20100708213410.GC9969@alumni.caltech.edu> <AANLkTiluo6r8ehcdcCFrhrcKsaTtku3OOuOumQ3sJsVD@mail.gmail.com> <AANLkTimA8WAaN_VXAFjktbWbCDvmEAZCRPxmlvR5u9zY@mail.gmail.com> <20100709162648.GB18058@alumni.caltech.edu>
Message-ID: <20100714202630.GC63136@alumni.caltech.edu>

Well, the leak was there in a big way under production traffic patterns, so
I switched from httpc to ibrowse.  All the leaks went away.  Just an FYI
for anyone out there making a decision between httpc and ibrowse.

-Anthony

On Fri, Jul 09, 2010 at 09:26:48AM -0700, Anthony Molinaro wrote:
> Yeah, I managed to get the entire set of patches, basically used
> 
> git diff 201ccdd08bd2a591fe1e348a9a1df3d94a3606e4 141ff3c087ca856d21d0 lib/inets
> 
> Which seemed to get them all.  However, I still see memory leaked
> 
> Erlang R13B04 (erts-5.7.5) [source] [64-bit] [smp:2:2] [rq:2] [async-threads:0]
> [kernel-poll:false]
> 
> Eshell V5.7.5  (abort with ^G)
> 1> inets:start().
> ok
> 2> ets:i().
> ...
>  16402           httpc_manager__session_cookie_db bag   0      316      httpc_manager
>  httpc_manager__handler_db httpc_manager__handler_db set   0      316      httpc_manager
>  httpc_manager__session_db httpc_manager__session_db set   0      316      httpc_manager
> ...
> 3> http:request (post, { "http://www.example.com", [], "application/octet-stream", <<"hello">>}, [{connect_timeout, 100},{timeout, 10}], [{body_format, binary} ]).
> {error,timeout}
> 4> ets:i().
> ...
>  16402           httpc_manager__session_cookie_db bag   0      316      httpc_manager
>  httpc_manager__handler_db httpc_manager__handler_db set   1      333      httpc_manager
>  httpc_manager__session_db httpc_manager__session_db set   0      316      httpc_manager
> ...
> 5> ets:i(httpc_manager__handler_db).
> <1   > {handler_info,#Ref<0.0.0.142>,undefined,<0.60.0>,<0.33.0>,operational}
> 
> 6> m(inets).
> Module inets compiled: Date: July 8 2010, Time: 06.45
> Compiler options:  [{d,'SERVER_SOFTWARE',"inets/5.3.3"},
>                     {cwd,"/home/molinaro/projects/work/vendor/erlang/R13B04/rpmbuild/BUILD/otp_src_R13B04/lib/inets/src/inets_app"},
>                     {outdir,"/home/molinaro/projects/work/vendor/erlang/R13B04/rpmbuild/BUILD/otp_src_R13B04/lib/inets/src/inets_app/../../ebin"},
>                     {attribute,insert,app_vsn,"inets-5.3.3"},
>                     {parse_transform,sys_pre_attributes},
>                     debug_info]
> Object file: /usr/lib64/erlang/lib/inets-5.3.3/ebin/inets.beam
> ...
> 
> So it seems if you connect but then timeout you leak some memory even with
> 5.3.3.  I've not tried 5.4 which is in dev but the only changes there seem
> to be related to ssl...
> 
> Can anyone else confirm this is still broken?
> 
> -Anthony
> 
> On Fri, Jul 09, 2010 at 12:12:13PM +0200, Micael Karlberg wrote:
> > This problem was fixed in inets-5.3.2. The fix was reported by Lev Walkin:
> > 
> > http://www.erlang.org/cgi-bin/ezmlm-cgi/2/1766
> > 
> > Unfortunately, github was not updated in one commit, but in several, here
> > are some of them:
> > 
> > http://github.com/erlang/otp/commit/4b87b22ce97abf2759eb551222a862e17c5f4dcb
> > http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
> > 
> > So you have to do a bit of cut-and-paste. The last version of inets in
> > R13B was 5.3.3,
> > but I don't know if that made it into github.
> > 
> > Regards,
> >     /BMK
> > 
> > On Fri, Jul 9, 2010 at 8:12 AM, Andrey Popp <8mayday@REDACTED> wrote:
> > > We have updated to R14 (thanks to deb packages in debian squeeze
> > > repository) and all seems to be ok for now.
> > >
> > > On Fri, Jul 9, 2010 at 1:34 AM, Anthony Molinaro
> > > <anthonym@REDACTED> wrote:
> > >> Well, looks like the answer is yes and no. ?I was able to get a patch
> > >> which applied cleanly, however, the problem does not appear to be fixed.
> > >> The ets table still fills up with every request that times out
> > >> (I unfortunately don't have a standalone test, but I've tested
> > >> repeatedly and it always seem to get an extra entry for every request
> > >> that times out).
> > >>
> > >> This is sort of a show stopper for me upgrading, so I'll be trying to
> > >> figure out a fix, but if anyone more familiar with the code wants to
> > >> help me out, it would be appreciated.
> > >>
> > >> Thanks,
> > >>
> > >> -Anthony
> > >>
> > >> On Thu, Jul 08, 2010 at 01:13:41PM -0700, Anthony Molinaro wrote:
> > >>> Hi, anyone know if its safe to backport this fix to R13B04? ?I'm in the process
> > >>> of deploying R13B04 as an upgrade from R12B05 and since I make heavy use of
> > >>> httpc this will bite me. ?Ideally, I can just grab the appropriate files from
> > >>> git and plop them into my R13B04 when I build an rpm (of course I need to
> > >>> remember enough git to do that :) ), so wondering if it's possible or if
> > >>> there are deps outside of the inets directory which matter?
> > >>>
> > >>> Thanks,
> > >>>
> > >>> -Anthony
> > >>>
> > >>> On Thu, Jul 08, 2010 at 02:12:07PM +0400, Andrey Popp wrote:
> > >>> > It seems it has been fixed with [1] in inets-5.3.2. Sorry.
> > >>> >
> > >>> > [1]: http://github.com/erlang/otp/commit/91c89d54d45989a85367f10d5902b9b508754a49
> > >>> >
> > >>> > On Thu, Jul 8, 2010 at 1:57 PM, Andrey Popp <8mayday@REDACTED> wrote:
> > >>> > > Hello,
> > >>> > >
> > >>> > > I have application that makes huge number of HTTP requests with httpc
> > >>> > > and I have spotted that `httpc_manager__handler_db` ETS table growing
> > >>> > > in size and doesn't clean up. That is the example records from this
> > >>> > > table (ets:i(httpc_manager__handler_db)):
> > >>> > >
> > >>> > > <1 ? > {handler_info,#Ref<0.0.0.18800>,undefined,<0.177.0>,undefined,operational}
> > >>> > > <2 ? > {handler_info,#Ref<0.0.0.35242>,undefined,<0.3075.0>,undefined,operational}
> > >>> > > <3 ? > {handler_info,#Ref<0.0.0.61713>,undefined,<0.5755.0>,undefined,operational}
> > >>> > > <4 ? > {handler_info,#Ref<0.0.0.68114>,undefined,<0.6943.0>,undefined,operational}
> > >>> > > <5 ? > {handler_info,#Ref<0.0.0.85303>,undefined,<0.8305.0>,undefined,operational}
> > >>> > >
> > >>> > > and processes with handler pids are no longer alive. Also, note that I
> > >>> > > have no timeout setting in my http:request HTTPOptions, but I think
> > >>> > > inets should not leak even in that case.
> > >>> > >
> > >>> > > Thanks.
> > >>> > >
> > >>> > > --
> > >>> > > Andrey Popp
> > >>> > >
> > >>> > > phone: +7 911 740 24 91
> > >>> > > e-mail: 8mayday@REDACTED
> > >>> > >
> > >>> >
> > >>> >
> > >>> >
> > >>> > --
> > >>> > Andrey Popp
> > >>> >
> > >>> > phone: +7 911 740 24 91
> > >>> > e-mail: 8mayday@REDACTED
> > >>> >
> > >>> > ________________________________________________________________
> > >>> > erlang-questions (at) erlang.org mailing list.
> > >>> > See http://www.erlang.org/faq.html
> > >>> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> > >>> >
> > >>>
> > >>> --
> > >>> ------------------------------------------------------------------------
> > >>> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
> > >>
> > >> --
> > >> ------------------------------------------------------------------------
> > >> Anthony Molinaro ? ? ? ? ? ? ? ? ? ? ? ? ? <anthonym@REDACTED>
> > >>
> > >> ________________________________________________________________
> > >> erlang-questions (at) erlang.org mailing list.
> > >> See http://www.erlang.org/faq.html
> > >> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> > >>
> > >>
> > >
> > >
> > >
> > > --
> > > Andrey Popp
> > >
> > > phone: +7 911 740 24 91
> > > e-mail: 8mayday@REDACTED
> > >
> > > ________________________________________________________________
> > > erlang-questions (at) erlang.org mailing list.
> > > See http://www.erlang.org/faq.html
> > > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> > >
> > >
> > 
> > ________________________________________________________________
> > erlang-questions (at) erlang.org mailing list.
> > See http://www.erlang.org/faq.html
> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> > 
> 
> -- 
> ------------------------------------------------------------------------
> Anthony Molinaro                           <anthonym@REDACTED>

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From vinubalaji@REDACTED  Thu Jul 15 03:22:04 2010
From: vinubalaji@REDACTED (Vinubalaji Gopal)
Date: Wed, 14 Jul 2010 18:22:04 -0700
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <4C3D8E2F.4030503@erix.ericsson.se>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>
	<4C3D46D4.1080709@gmail.com>
	<4C3D55EA.9030100@gmail.com>
	<4C3D8E2F.4030503@erix.ericsson.se>
Message-ID: <AANLkTikurqyjPtDXnsuQCrFtpHJsR5hQ3LGDSj5G98nf@mail.gmail.com>

great so is NIF stable enough and the recommended solution for any kind of
interfacing with C/C++?

I read in the following link that NIF is good  for simple CPU bound
operations and linked in port driver is good for IO  and fine grained
concurrency. Is that not true anymore?

http://www.erlang-factory.com/upload/presentations/215/ErlangFactorySFBay2010-CliffMoon.pdf

On Wed, Jul 14, 2010 at 3:15 AM, Sverker Eriksson
<sverker@REDACTED>wrote:

> Actually, NIFs don't use ports so there is no locking at all needed to call
> a NIF, except
> the locks already held on the running process. If you introduce data that
> could be shared
> between concurrent NIF calls, then you have to serialize that access with
> your own
> locking. Using enif_mutex_* for example.
>
> You can't use async-threads from a NIF, but you can create custom threads
> with
> enif_thread_create and send messages from that thread with enif_send.
>
> /Sverker, Erlang/OTP
>
>
> Michael Truog wrote:
>
>> Ok, I didn't realize that you had found the same linked in driver
>> permanent issue on trapexit.  I at least offered my explanation of what
>> you seem to be experiencing.
>>
>> After looking at NIFs, they actually look like they are using port level
>> locking by default (as described at
>> http://erlang.org/doc/man/erl_nif.html by the "Threads and concurrency"
>> section).  It would be much easier to create a NIF, but there is no
>> interface for async threads through NIFs (though you can send a process
>> a message with enif_send, which might help facilitate asynchronous
>> behavior).  If you stick with a port driver, you would need to use
>> ERL_DRV_FLAG_USE_PORT_LOCKING as previously mentioned.  Either way you
>> want the C code to be quick, so you don't block the Erlang VM scheduler
>> thread.
>>
>> - Michael
>>  On 07/13/2010 10:10 PM, Michael Truog wrote:
>>
>>
>>> I think you are having problems with the driver becoming permanent when
>>> you make the first asynchronous call (there is code that locks the port
>>> driver so the dll/so can not be unloaded (so it can't be reloaded)). The
>>> code is trying to protect the code from the possibility that a
>>> thread finishes but the port driver has already been unloaded, which is
>>> a valid concern (but could be handled in more complex ways).  The
>>> problem has been mentioned before here
>>>
>>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
>>> .
>>>
>>> ERL_DRV_FLAG_USE_PORT_LOCKING is the flag to make sure different
>>> scheduler threads can call the port driver instances concurrently (the
>>> entry in the driver_flags struct member
>>> http://www.erlang.org/doc/man/driver_entry.html#driver_flags) as
>>> discussed here http://www.erlang.org/doc/man/erl_driver.html#smp_support
>>> .  I assume NIFs use the port driver default of "driver level locking"
>>> (driver_flags == 0, i.e., not ERL_DRV_FLAG_USE_PORT_LOCKING), but I am
>>> not sure.
>>>
>>> - Michael
>>>
>>> On 07/13/2010 08:28 PM, Vinubalaji Gopal wrote:
>>>
>>>
>>>> Hi all,
>>>>  I have been digging hard to write a port linked in driver which would
>>>> perform better and most of my searches resulted in dead threads (like
>>>>
>>>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
>>>> )
>>>> and most of my experiments did not give me any good results . I tried to
>>>> use
>>>> async threads but I am not able to call these async threads
>>>> asynchronously.
>>>> If I try to make multiple erlang processes open the same port it just
>>>> fails
>>>> saying that the driver has become permanent. If I try to open a single
>>>> port
>>>> driver  - I have to do that in a single gen_server and it blocks when I
>>>> call  port_command - so all the messages are queued and processed
>>>> sequentially. Is there a way to write a linked in driver which will
>>>> perform
>>>> better and/or better links to help (I have read the erl_driver
>>>> documentation, erl_ddll documentation numerous times).
>>>>
>>>>
>>>>
>>>>
>>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>>
>>>
>>>
>>
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>>
>
>


-- 
Vinu

In a world without fences who needs Gates?

From vinubalaji@REDACTED  Thu Jul 15 03:43:23 2010
From: vinubalaji@REDACTED (Vinubalaji Gopal)
Date: Wed, 14 Jul 2010 18:43:23 -0700
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <4C3D55EA.9030100@gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>
	<4C3D46D4.1080709@gmail.com>
	<4C3D55EA.9030100@gmail.com>
Message-ID: <AANLkTinvcwkem-VTzioI4ROqsitSXxiDi6NuknTtC_P0@mail.gmail.com>

Hi Michael,
  I do use ERL_DRV_FLAG_USE_PORT_LOCKING in my driver entry.
Here is the structure of my program (pseudo code which mimics the original
code):

static int worker_call(ErlDrvData handle, unsigned int command, char *buf,
                   int len, char **rbuf, int rlen, unsigned int *flags) {
// decode the pid and ref using ei_decode_pid and ei_decode_ref

// decode other stuff

// get a worker from a pool
// *worker  = worker_pool->get();
// load the worker with data
 driver_async(port, NULL, do_work, worker, NULL);
}

static void do_work(void *worker_data) {
// get worker with worker data
// do the work
}

static void ready_async(ErlDrvData handle, ErlDrvThreadData worker_data) {
//get worker from the data
// output the results of the worker back to the
//give back the worker to the pool
worker_pool->release(worker)
}

The Erlang side: I had to make the gen server have the following structure
to accept calls in a parallel fashion - not sure if this is the most
efficient way - but got this idea from a program generated by dryverl.  It
still doesn't perform that well :(

handle_call({do_work, Param1, Param2}, {FromPid, FromTag}, State)
      when is_pid(FromPid), is_reference(FromTag) ->
   erlang:port_call(State#state.port, Type, {FromPid, FromTag, Param1,
Param2}),
    {noreply, State}.


// get the real reply asynchronously from the driver and send it back to the
real caller
handle_info({worker_reply, Port, EncOutputMainTerm, Output1, Output2},
State)
              when Port == State#state.port ->
   {FromPid, FromTag} = binary_to_term(EncOutputMainTerm),
    Reply = {Output1, Output2}
    FromPid ! {FromTag, Reply},
    {noreply, State}.

Thanks for the explanation on the linked in driver permanent issue.


On Tue, Jul 13, 2010 at 11:15 PM, Michael Truog <mjtruog@REDACTED> wrote:

> Ok, I didn't realize that you had found the same linked in driver
> permanent issue on trapexit.  I at least offered my explanation of what
> you seem to be experiencing.
>
> After looking at NIFs, they actually look like they are using port level
> locking by default (as described at
> http://erlang.org/doc/man/erl_nif.html by the "Threads and concurrency"
> section).  It would be much easier to create a NIF, but there is no
> interface for async threads through NIFs (though you can send a process
> a message with enif_send, which might help facilitate asynchronous
> behavior).  If you stick with a port driver, you would need to use
> ERL_DRV_FLAG_USE_PORT_LOCKING as previously mentioned.  Either way you
> want the C code to be quick, so you don't block the Erlang VM scheduler
> thread.
>
> - Michael
>
> On 07/13/2010 10:10 PM, Michael Truog wrote:
> > I think you are having problems with the driver becoming permanent when
> > you make the first asynchronous call (there is code that locks the port
> > driver so the dll/so can not be unloaded (so it can't be reloaded)).
> > The code is trying to protect the code from the possibility that a
> > thread finishes but the port driver has already been unloaded, which is
> > a valid concern (but could be handled in more complex ways).  The
> > problem has been mentioned before here
> >
> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
> > .
> >
> > ERL_DRV_FLAG_USE_PORT_LOCKING is the flag to make sure different
> > scheduler threads can call the port driver instances concurrently (the
> > entry in the driver_flags struct member
> > http://www.erlang.org/doc/man/driver_entry.html#driver_flags) as
> > discussed here http://www.erlang.org/doc/man/erl_driver.html#smp_support
> > .  I assume NIFs use the port driver default of "driver level locking"
> > (driver_flags == 0, i.e., not ERL_DRV_FLAG_USE_PORT_LOCKING), but I am
> > not sure.
> >
> > - Michael
> >
> > On 07/13/2010 08:28 PM, Vinubalaji Gopal wrote:
> >
> >> Hi all,
> >>   I have been digging hard to write a port linked in driver which would
> >> perform better and most of my searches resulted in dead threads (like
> >>
> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
> )
> >> and most of my experiments did not give me any good results . I tried to
> use
> >> async threads but I am not able to call these async threads
> asynchronously.
> >> If I try to make multiple erlang processes open the same port it just
> fails
> >> saying that the driver has become permanent. If I try to open a single
> port
> >> driver  - I have to do that in a single gen_server and it blocks when I
> >> call  port_command - so all the messages are queued and processed
> >> sequentially. Is there a way to write a linked in driver which will
> perform
> >> better and/or better links to help (I have read the erl_driver
> >> documentation, erl_ddll documentation numerous times).
> >>
> >>
> >>
> >>
> >>
> >
> > ________________________________________________________________
> > erlang-questions (at) erlang.org mailing list.
> > See http://www.erlang.org/faq.html
> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >
> >
> >
>
>


-- 
Vinu

In a world without fences who needs Gates?

From jarrod@REDACTED  Thu Jul 15 04:55:48 2010
From: jarrod@REDACTED (Jarrod Roberson)
Date: Wed, 14 Jul 2010 22:55:48 -0400
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <AANLkTikurqyjPtDXnsuQCrFtpHJsR5hQ3LGDSj5G98nf@mail.gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>
	<4C3D46D4.1080709@gmail.com>
	<4C3D55EA.9030100@gmail.com>
	<4C3D8E2F.4030503@erix.ericsson.se>
	<AANLkTikurqyjPtDXnsuQCrFtpHJsR5hQ3LGDSj5G98nf@mail.gmail.com>
Message-ID: <AANLkTilUhLcz6b6XjnXQJGDsqlbi7Cn70WClaZcMyOWM@mail.gmail.com>

On Wed, Jul 14, 2010 at 9:22 PM, Vinubalaji Gopal <vinubalaji@REDACTED>
wrote:
> great so is NIF stable enough and the recommended solution for any kind of
> interfacing with C/C++?
>
> I read in the following link that NIF is good  for simple CPU bound
> operations and linked in port driver is good for IO  and fine grained
> concurrency. Is that not true anymore?
>
>
http://www.erlang-factory.com/upload/presentations/215/ErlangFactorySFBay2010-CliffMoon.pdf

My understanding is NIF(s) are for one shot function calls that will block
the main Erlang thread.

>From the docs <http://ftp.sunet.se/pub/lang/erlang/doc/man/erl_nif.html>:

"*Avoid doing lengthy work in NIF calls as that may degrade the
responsiveness of the VM.
NIFs are called directly by the same scheduler thread that executed the
calling Erlang code.
The calling scheduler will thus be blocked from doing any other work until
the NIF returns*."

-- 
Jarrod Roberson
www.vertigrated.com/blog

From mjtruog@REDACTED  Thu Jul 15 06:01:49 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Wed, 14 Jul 2010 21:01:49 -0700
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <AANLkTilUhLcz6b6XjnXQJGDsqlbi7Cn70WClaZcMyOWM@mail.gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>	<4C3D46D4.1080709@gmail.com>	<4C3D55EA.9030100@gmail.com>	<4C3D8E2F.4030503@erix.ericsson.se>	<AANLkTikurqyjPtDXnsuQCrFtpHJsR5hQ3LGDSj5G98nf@mail.gmail.com> <AANLkTilUhLcz6b6XjnXQJGDsqlbi7Cn70WClaZcMyOWM@mail.gmail.com>
Message-ID: <4C3E882D.4050403@gmail.com>

Yes, that is correct, but there should be a scheduler thread per core,
being used within the Erlang VM.  So, it is the main Erlang thread of
execution, but there should be more than one on a multicore machine
running in smp mode (that detects, or is told, about how many cores
exist).  BIFs like erlang:now() (which hits gettimeofday() in C land)
should have the same constraints as a NIF, so you may already be
blocking a scheduler thread with the tasks you are doing, without
realizing it.

The async thread pool is separate and is shared by all port drivers that
use asynchronous threads (so they compete for all the threads, the count
specified with "+A number") and asynchronous threads do not have a
shared job queue, so it is more efficient, but easy to clog up if you
have long running jobs.  The only port driver that always uses the async
thread pool by default (behavior can be changed with obscure environment
variables) is used by the file module.  I think the crypto application
had code for async port driver usage when using openssl, but last I
checked it wasn't being used (don't remember).

If you are seeing poor performance with the async thread pool, you need
to increase the count of async threads, keeping in mind the job queue is
not shared.  So, that means any long running async thread pool tasks
will delay all later jobs in a non-deterministic way, if the async
thread pool is too small.  That makes a person tempted to give "+A 128"
just to make sure no port driver is clogging an async thread, despite
the person only has 4 possible cores, which already have Erlang VM
scheduler threads running.

Based on the NIF documentation, NIFs should be stable at R14B, so we are
getting really close to NIFs being stable.  Since NIFs are much easier
and more natural in Erlang, I would go with making a NIF.  Most usage of
the async thread pool seems to end in complaints on the mailing list. 
Most people then seem to move on to making their own thread pool outside
the Erlang VM, hopefully in a port (or perhaps a scary port driver). 
The problem then is that the custom thread pool is fighting for control
of CPUs, with the Erlang scheduler threads, and it is relying on the
kernel scheduler, which has no clue about what is being executed... just
that it is code (i.e., not what is important based on message queuing or
Erlang VM priority).  The async thread pool seems to have the same
problem as a custom thread pool.

Hopefully you could avoid the idea of a NIF that has a thread pool, and
just rely on the NIF sending messages, if Erlang code needed to consume
data asynchronously.  If you needed to produce data asynchronously in C,
where the latency was tested to be too great to allow a scheduler thread
to block for the work, you might benefit from an Erlang port with a
possible thread pool.  You could always put your own thread pool into a
NIF, and it is made easier with the provided functions like
"enif_thread_create".  However, the NIF with extra threads would lack
any barrier with the VM, such that any small errors would create new and
exciting crash dumps (if you are lucky).  So, you could create a NIF
with its own thread pool, but you would need to test a lot and really
try to justify your decision, for yourself.

- Michael

On 07/14/2010 07:55 PM, Jarrod Roberson wrote:
> On Wed, Jul 14, 2010 at 9:22 PM, Vinubalaji Gopal <vinubalaji@REDACTED>
> wrote:
>   
>> great so is NIF stable enough and the recommended solution for any kind of
>> interfacing with C/C++?
>>
>> I read in the following link that NIF is good  for simple CPU bound
>> operations and linked in port driver is good for IO  and fine grained
>> concurrency. Is that not true anymore?
>>
>>
>>     
> http://www.erlang-factory.com/upload/presentations/215/ErlangFactorySFBay2010-CliffMoon.pdf
>
> My understanding is NIF(s) are for one shot function calls that will block
> the main Erlang thread.
>
> >From the docs <http://ftp.sunet.se/pub/lang/erlang/doc/man/erl_nif.html>:
>
> "*Avoid doing lengthy work in NIF calls as that may degrade the
> responsiveness of the VM.
> NIFs are called directly by the same scheduler thread that executed the
> calling Erlang code.
> The calling scheduler will thus be blocked from doing any other work until
> the NIF returns*."
>
>   


From torben.lehoff@REDACTED  Thu Jul 15 13:31:40 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Thu, 15 Jul 2010 13:31:40 +0200
Subject: Lack of warning for overlapping clauses with
Message-ID: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>

Hi,

I had a very large module where I could not figure out why a specific thing
was not happening and it turned out that the root of the problem was a
construct like the following:

-module(problem).

-compile(export_all).

f(N) when N==1; N==2 ->
    false;
f(1) ->
    ok.

I would have hoped that the compiler or dialyzer would have caught that the
f(1) clause will never be executed, but that is not the case.
It seems that the use of the when-clause changes the game so that the
overlap is not detected.
I accept that I am shooting myself in the foot here, but I would have liked
to be helped by the compiler or dialyzer since figuring this one out after
going through hefty logs is not fun.

Now that I know this I can work around it, but it would be nice to get the
warning since the code in my f(N) branch is actually not that small. Of
course I could create a function to do the operation and rewrite like this:

-module(problem).

-compile(export_all).

f(1) ->
    g();
f(2) ->
    g();
f(1) ->
    ok.

In which case the compiler will warn me about the overlap, but I find that
to be somewhat ugly.

Any comments on this?

Cheers,
Torben
-- 
http://www.linkedin.com/in/torbenhoffmann

From sverker@REDACTED  Thu Jul 15 15:15:30 2010
From: sverker@REDACTED (Sverker Eriksson)
Date: Thu, 15 Jul 2010 15:15:30 +0200
Subject: [erlang-questions] linked in driver port performance
In-Reply-To: <AANLkTikurqyjPtDXnsuQCrFtpHJsR5hQ3LGDSj5G98nf@mail.gmail.com>
References: <AANLkTims8AmA8JgBOdDqpLcgEEJlpiHtN96dEM3EdEM7@mail.gmail.com>	<4C3D46D4.1080709@gmail.com>	<4C3D55EA.9030100@gmail.com>	<4C3D8E2F.4030503@erix.ericsson.se> <AANLkTikurqyjPtDXnsuQCrFtpHJsR5hQ3LGDSj5G98nf@mail.gmail.com>
Message-ID: <4C3F09F2.6000707@erix.ericsson.se>

Yes, NIFs are "stable enough", with respect to both runtime behavior and 
interface backward compatibility. The plan is to remove the 
"experimental" label from R14B and make no incompatible interface 
changes from R14A.

 > I read in the following link that NIF is good for simple CPU bound
 > operations and linked in port driver is good for IO and fine grained
 > concurrency. Is that not true anymore?

It's basically true except the "fine grained" part. NIFs have no shared 
state by default (like a port) that needs locking. If you choose to 
introduce shared state then you have the freedom (and burden) to 
implement whatever level of locking granularity you want for your data. 

NIFs excel at relatively short synchronous function calls. You can do 
long (CPU or IO bound) calls but then you probably need to do your own 
threading to not block the calling scheduler thread.

There is also a trick to get finer granularity locking for drivers by 
using a pool of ports. Look at the crypto application before R14A when 
it was rewritting using NIFs.

/Sverker, Erlang/OTP


Vinubalaji Gopal wrote:
> great so is NIF stable enough and the recommended solution for any kind of
> interfacing with C/C++?
>
> I read in the following link that NIF is good  for simple CPU bound
> operations and linked in port driver is good for IO  and fine grained
> concurrency. Is that not true anymore?
>
> http://www.erlang-factory.com/upload/presentations/215/ErlangFactorySFBay2010-CliffMoon.pdf
>
> On Wed, Jul 14, 2010 at 3:15 AM, Sverker Eriksson
> <sverker@REDACTED>wrote:
>
>   
>> Actually, NIFs don't use ports so there is no locking at all needed to call
>> a NIF, except
>> the locks already held on the running process. If you introduce data that
>> could be shared
>> between concurrent NIF calls, then you have to serialize that access with
>> your own
>> locking. Using enif_mutex_* for example.
>>
>> You can't use async-threads from a NIF, but you can create custom threads
>> with
>> enif_thread_create and send messages from that thread with enif_send.
>>
>> /Sverker, Erlang/OTP
>>
>>
>> Michael Truog wrote:
>>
>>     
>>> Ok, I didn't realize that you had found the same linked in driver
>>> permanent issue on trapexit.  I at least offered my explanation of what
>>> you seem to be experiencing.
>>>
>>> After looking at NIFs, they actually look like they are using port level
>>> locking by default (as described at
>>> http://erlang.org/doc/man/erl_nif.html by the "Threads and concurrency"
>>> section).  It would be much easier to create a NIF, but there is no
>>> interface for async threads through NIFs (though you can send a process
>>> a message with enif_send, which might help facilitate asynchronous
>>> behavior).  If you stick with a port driver, you would need to use
>>> ERL_DRV_FLAG_USE_PORT_LOCKING as previously mentioned.  Either way you
>>> want the C code to be quick, so you don't block the Erlang VM scheduler
>>> thread.
>>>
>>> - Michael
>>>  On 07/13/2010 10:10 PM, Michael Truog wrote:
>>>
>>>
>>>       
>>>> I think you are having problems with the driver becoming permanent when
>>>> you make the first asynchronous call (there is code that locks the port
>>>> driver so the dll/so can not be unloaded (so it can't be reloaded)). The
>>>> code is trying to protect the code from the possibility that a
>>>> thread finishes but the port driver has already been unloaded, which is
>>>> a valid concern (but could be handled in more complex ways).  The
>>>> problem has been mentioned before here
>>>>
>>>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
>>>> .
>>>>
>>>> ERL_DRV_FLAG_USE_PORT_LOCKING is the flag to make sure different
>>>> scheduler threads can call the port driver instances concurrently (the
>>>> entry in the driver_flags struct member
>>>> http://www.erlang.org/doc/man/driver_entry.html#driver_flags) as
>>>> discussed here http://www.erlang.org/doc/man/erl_driver.html#smp_support
>>>> .  I assume NIFs use the port driver default of "driver level locking"
>>>> (driver_flags == 0, i.e., not ERL_DRV_FLAG_USE_PORT_LOCKING), but I am
>>>> not sure.
>>>>
>>>> - Michael
>>>>
>>>> On 07/13/2010 08:28 PM, Vinubalaji Gopal wrote:
>>>>
>>>>
>>>>         
>>>>> Hi all,
>>>>>  I have been digging hard to write a port linked in driver which would
>>>>> perform better and most of my searches resulted in dead threads (like
>>>>>
>>>>> http://www.trapexit.org/forum/viewtopic.php?t=14295&sid=5de3c47e32136682080511d8d95d458e
>>>>> )
>>>>> and most of my experiments did not give me any good results . I tried to
>>>>> use
>>>>> async threads but I am not able to call these async threads
>>>>> asynchronously.
>>>>> If I try to make multiple erlang processes open the same port it just
>>>>> fails
>>>>> saying that the driver has become permanent. If I try to open a single
>>>>> port
>>>>> driver  - I have to do that in a single gen_server and it blocks when I
>>>>> call  port_command - so all the messages are queued and processed
>>>>> sequentially. Is there a way to write a linked in driver which will
>>>>> perform
>>>>> better and/or better links to help (I have read the erl_driver
>>>>> documentation, erl_ddll documentation numerous times).
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>           
>>>> ________________________________________________________________
>>>> erlang-questions (at) erlang.org mailing list.
>>>> See http://www.erlang.org/faq.html
>>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>>
>>>>
>>>>
>>>>
>>>>         
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>>
>>>
>>>       
>>     
>
>
>   


From mevans@REDACTED  Thu Jul 15 15:41:01 2010
From: mevans@REDACTED (Evans, Matthew)
Date: Thu, 15 Jul 2010 09:41:01 -0400
Subject: mnesia recovery
Message-ID: <B293D35E9E20694A8D9DFFE1BC655C55647884351A@vvexch.verivue.com>

Hi,

This is a rather convoluted question.

We have a distributed system with disc copies/disc only copies of mnesia tables on nodes A and B.  Other nodes in the system C through M have RAM only copies of those tables.

Ordinarily if node A fails and recovers shortly later we are fine since mnesia is smart enough to re-sync data back to node A from node B.

We hit a situation yesterday where node A failed, some time later the whole distributed system was restarted but node B never recovered.

The logic is such that startup is effectively blocked since we know the "good" data is on node B.

How to handle this in the field? If, for reasons beyond our control node B can not be recovered easily, I am wondering is there a way to get the data from node B to node A (I am assuming we can access the partition on node B)?

Would it be possible to:

1) Stop mnesia on all nodes
2) Copy the contents of the mnesia directory from node B to node A (minus the schema definitions)
3) Empty the mnesia directory from node B
4) Restart everything

In this case I am hoping that mnesia would see node A as good and node B as having no data and would copy data to the new node B.

Basically this situation needs to be resolved on the field by engineers with little or no Erlang skills. Certainly escripts could be written to help.

Thanks

Matt

From mixolyde@REDACTED  Thu Jul 15 18:39:03 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Thu, 15 Jul 2010 12:39:03 -0400
Subject: werl R14A on windows 7 frequently crashes during file access
Message-ID: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>

I'm not entirely sure what combination of running software is causing
this. I have a program that opens a list of log files (~100kb to
~200kb), reads one a line at a time, matches the line against some
regexes, prints a report and finishes). Sometimes it works without a
problem. But other times werl will crash one or two lines into reading
the first log file, or when it opens up the report file. I have my
.erl, .beam and final report file in a Dropbox directory, which may be
affecting it. But the log files I'm opening for read are in a normal
directory. None of the files are in use by another running program,
except the .erl is open in my editor.

Win7 gives me a report like this when it crashes:
Problem signature:
  Problem Event Name:	APPCRASH
  Application Name:	werl.exe
  Application Version:	0.0.0.0
  Application Timestamp:	4c17b8f1
  Fault Module Name:	beam.smp.dll
  Fault Module Version:	0.0.0.0
  Fault Module Timestamp:	4c17b83a
  Exception Code:	c0000005
  Exception Offset:	000cc562
  OS Version:	6.1.7600.2.0.0.256.48
  Locale ID:	1033
  Additional Information 1:	0a9e
  Additional Information 2:	0a9e372d3b4ad19135b953a78882e789
  Additional Information 3:	0a9e
  Additional Information 4:	0a9e372d3b4ad19135b953a78882e789

The file open/close/read code is:
%% Iterarate over files and generate report
% initialize report accumulator
report(Files) -> report(Files, []).
report([], Reports) ->
    case file:open("ErrorReport.txt", write) of
        {ok, Dev} ->
            io:format("Opened Report file for writing~n", []),
            map(fun({FileName, Report}) -> print_report(Dev, FileName,
Report) end, lists:reverse(Reports)),
            file:close(Dev);
        {error, Reason} ->
            io:format("Error opening final report file: ~p~n", [Reason]),
            {error, Reason}
    end;
report([FileName | Rest], Acc) ->
    io:format("Attempting to open: ~p~n", [FileName]),
    % read file into memory
    case file:open(FileName, read) of
        {ok, Dev} ->
            % scan the lines for string matches, one line at a time
            {ok, WarningExp} = re:compile("warning", [caseless]),
            {ok, ErrorExp} = re:compile("error", [caseless]),

            Compiled_Tests = [
                {warnings, warning_exps(), WarningExp},
                {errors, error_exps(), ErrorExp}],
            Report = scan_lines(Compiled_Tests, Dev, io:get_line(Dev, '')),
            % close file
            file:close(Dev),
            % recurse
            report(Rest, [{FileName, Report} | Acc]);
        {error, Reason} ->
            report(Rest, [{error, Reason} | Acc])
    end.

Not sure how I can prevent werl from crashing and figure out what's
going on. Has anyone else seen this?

-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From tony.arcieri@REDACTED  Fri Jul 16 04:15:30 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Thu, 15 Jul 2010 20:15:30 -0600
Subject: Can gen_tcp/inets store connection-specific user state?
Message-ID: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>

Many operating systems provide high-performance stateful I/O multiplexing
APIs.  Some examples of these APIs include Linux's epoll, *BSD's kqueue,
Solaris's event completion ports, and Windows I/O completion ports.

A common characteristic of these APIs is the ability to include a pointer to
a piece of user state.  This provides a simple way to look up the state
necessary to dispatch an event.  A skillful user of these APIs will bundle
all the state necessary to dispatch a request into a single pointer, and
these APIs will keep track of that pointer, all the way down to the kernel
level.

As far as I can tell, gen_tcp/inets do not do this.  I am not seeing any
APIs that will allow me to provide an Erlang term when I flip on active mode
on a particular socket which will be delivered in the messages I receive
from inets.

Am I missing something?  Is there a way to do this?  If not, the recourses I
have seem particularly disadvantageous compared to the underlying API
carrying a single piece of state for me from end-to-end.  Either I can use a
proxy process per connection, involving all the complexity of managing an
external process in the API I expose to an end user, and requiring a process
per connection where if gen_tcp/inets held onto the state for me I'd only
require one, or having a single process which used a mapping data structure
to go between the port the message originated from and the piece of user
state I actually care about.  I find both of these solutions particularly
suboptimal, especially considering that the kernel-level APIs are designed
to round trip a particular piece of user state you care about end-to-end.

The underlying functionality is there at the kernel level, but as far as I
can tell Erlang does not expose it as a language.  Is there something I'm
missing?

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From igorrs@REDACTED  Fri Jul 16 05:24:38 2010
From: igorrs@REDACTED (Igor Ribeiro Sucupira)
Date: Fri, 16 Jul 2010 00:24:38 -0300
Subject: [erlang-questions] mnesia recovery
In-Reply-To: <B293D35E9E20694A8D9DFFE1BC655C55647884351A@vvexch.verivue.com>
References: <B293D35E9E20694A8D9DFFE1BC655C55647884351A@vvexch.verivue.com>
Message-ID: <AANLkTim6dVuckUJrkjfSG0j9CQPtPMYiVP5EATnws4p5@mail.gmail.com>

On Thu, Jul 15, 2010 at 10:41 AM, Evans, Matthew <mevans@REDACTED> wrote:
> Hi,
>
> This is a rather convoluted question.
>
> We have a distributed system with disc copies/disc only copies of mnesia tables on nodes A and B. ?Other nodes in the system C
> through M have RAM only copies of those tables.

I'm assuming all nodes have exactly the same tables and the same data
(including the schema). Is that the case? If it's not, could you
describe the pool in more detail?

> Ordinarily if node A fails and recovers shortly later we are fine since mnesia is smart enough to re-sync data back to node A from
> node B.
>
> We hit a situation yesterday where node A failed, some time later the whole distributed system was restarted but node B never
> recovered.

What does that mean? Is node B corrupted? Or is it just refusing to
start because the other nodes are down and B is not the most
up-to-date node? I don't see any other case for "never recovered" and
I'm assuming you have the former (corruption), since you said the
other nodes were restarted and that B has "good" data.

> The logic is such that startup is effectively blocked since we know the "good" data is on node B.
>
> How to handle this in the field? If, for reasons beyond our control node B can not be recovered easily, I am wondering is there a
> way to get the data from node B to node A (I am assuming we can access the partition on node B)?

Assuming B is the most up-to-date node and has some corrupted tables,
you can copy the working files of those tables from some other node to
node B (yeah... they may be outdated, but there's not much to do in
this case) and than start node B. Everything should work fine.

If that's not your problem, maybe this function could help you, anyway:
http://erlang.org/doc/man/mnesia.html#force_load_table-1

I've used force_load_table/1 in situations where Mnesia was refusing
to load the table in some node because it believed its copy was not
current (but I knew it was).

Good luck.
Igor.

> Would it be possible to:
>
> 1) Stop mnesia on all nodes
> 2) Copy the contents of the mnesia directory from node B to node A (minus the schema definitions)
> 3) Empty the mnesia directory from node B
> 4) Restart everything
>
> In this case I am hoping that mnesia would see node A as good and node B as having no data and would copy data to the new
> node B.
>
> Basically this situation needs to be resolved on the field by engineers with little or no Erlang skills. Certainly escripts could be
> written to help.
>
> Thanks
>
> Matt

From dangud@REDACTED  Fri Jul 16 08:23:20 2010
From: dangud@REDACTED (Dan Gudmundsson)
Date: Fri, 16 Jul 2010 08:23:20 +0200
Subject: [erlang-questions] mnesia recovery
In-Reply-To: <AANLkTim6dVuckUJrkjfSG0j9CQPtPMYiVP5EATnws4p5@mail.gmail.com>
References: <B293D35E9E20694A8D9DFFE1BC655C55647884351A@vvexch.verivue.com>
	<AANLkTim6dVuckUJrkjfSG0j9CQPtPMYiVP5EATnws4p5@mail.gmail.com>
Message-ID: <AANLkTimoXj7KL2Pb_vo3xSGxzRxldZE7eIYHx8nzcqh2@mail.gmail.com>

Also you can bootstrap a disc_node like you do with a ram_node..

Delete everything on the mnesia_dir (not the dir), start mnesia and
call mnesia:change_config(extra_db_nodes, [AliveAndKicking]).

That should copy every table that the node should have a copy of and
 if it is available in the system

/Dan

On Fri, Jul 16, 2010 at 5:24 AM, Igor Ribeiro Sucupira <igorrs@REDACTED> wrote:
> On Thu, Jul 15, 2010 at 10:41 AM, Evans, Matthew <mevans@REDACTED> wrote:
>> Hi,
>>
>> This is a rather convoluted question.
>>
>> We have a distributed system with disc copies/disc only copies of mnesia tables on nodes A and B. ?Other nodes in the system C
>> through M have RAM only copies of those tables.
>
> I'm assuming all nodes have exactly the same tables and the same data
> (including the schema). Is that the case? If it's not, could you
> describe the pool in more detail?
>
>> Ordinarily if node A fails and recovers shortly later we are fine since mnesia is smart enough to re-sync data back to node A from
>> node B.
>>
>> We hit a situation yesterday where node A failed, some time later the whole distributed system was restarted but node B never
>> recovered.
>
> What does that mean? Is node B corrupted? Or is it just refusing to
> start because the other nodes are down and B is not the most
> up-to-date node? I don't see any other case for "never recovered" and
> I'm assuming you have the former (corruption), since you said the
> other nodes were restarted and that B has "good" data.
>
>> The logic is such that startup is effectively blocked since we know the "good" data is on node B.
>>
>> How to handle this in the field? If, for reasons beyond our control node B can not be recovered easily, I am wondering is there a
>> way to get the data from node B to node A (I am assuming we can access the partition on node B)?
>
> Assuming B is the most up-to-date node and has some corrupted tables,
> you can copy the working files of those tables from some other node to
> node B (yeah... they may be outdated, but there's not much to do in
> this case) and than start node B. Everything should work fine.
>
> If that's not your problem, maybe this function could help you, anyway:
> http://erlang.org/doc/man/mnesia.html#force_load_table-1
>
> I've used force_load_table/1 in situations where Mnesia was refusing
> to load the table in some node because it believed its copy was not
> current (but I knew it was).
>
> Good luck.
> Igor.
>
>> Would it be possible to:
>>
>> 1) Stop mnesia on all nodes
>> 2) Copy the contents of the mnesia directory from node B to node A (minus the schema definitions)
>> 3) Empty the mnesia directory from node B
>> 4) Restart everything
>>
>> In this case I am hoping that mnesia would see node A as good and node B as having no data and would copy data to the new
>> node B.
>>
>> Basically this situation needs to be resolved on the field by engineers with little or no Erlang skills. Certainly escripts could be
>> written to help.
>>
>> Thanks
>>
>> Matt
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From hawk.mattsson@REDACTED  Fri Jul 16 10:55:36 2010
From: hawk.mattsson@REDACTED (=?ISO-8859-1?Q?H=E5kan_Mattsson?=)
Date: Fri, 16 Jul 2010 10:55:36 +0200
Subject: [erlang-questions] mnesia recovery
In-Reply-To: <AANLkTimoXj7KL2Pb_vo3xSGxzRxldZE7eIYHx8nzcqh2@mail.gmail.com>
References: <B293D35E9E20694A8D9DFFE1BC655C55647884351A@vvexch.verivue.com>
	<AANLkTim6dVuckUJrkjfSG0j9CQPtPMYiVP5EATnws4p5@mail.gmail.com>
	<AANLkTimoXj7KL2Pb_vo3xSGxzRxldZE7eIYHx8nzcqh2@mail.gmail.com>
Message-ID: <AANLkTinHvgosxWym7qq86oRlvURhCuqSZY3TzUH7zhbV@mail.gmail.com>

On Fri, Jul 16, 2010 at 8:23 AM, Dan Gudmundsson <dangud@REDACTED> wrote:
> Also you can bootstrap a disc_node like you do with a ram_node..
>
> Delete everything on the mnesia_dir (not the dir), start mnesia and
> call mnesia:change_config(extra_db_nodes, [AliveAndKicking]).
>
> That should copy every table that the node should have a copy of and
> ?if it is available in the system

This method can be very useful if Mnesia's  files have got corrupted or if
you have replaced the hardware.

Otherwise you can use mnesia:set_master_nodes/1 to force Mnesia to
load its tables from another node.

/H?kan

From sacha@REDACTED  Fri Jul 16 12:27:29 2010
From: sacha@REDACTED (Alexander Kotelnikov)
Date: Fri, 16 Jul 2010 14:27:29 +0400
Subject: Is it possible to create an application release without kernel,
 stdlib and sasl?
In-Reply-To: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> (Tony
 Arcieri's message of "Thu, 15 Jul 2010 20:15:30 -0600")
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>
Message-ID: <85iq4fn2lq.fsf@myxomop.com>

Hello.

I've never bothered to create OTP releases before and now decided to
learn about it.

I am playing with a tiny application. Normally when a release is
created it includes whole erlang system - kernel, stdlib and sasl.

Bu on
http://www.erlang.org/doc/design_principles/release_structure.html#id2273097
I nocitced that documentation tells about possibly several ROOT
directories, which sounds to be a handy approach: I would not touch my
systems's erlang core installation and in my own ROOT I would have my
application with their ows release processes.

Is there a way to do so? systools provides some means to exclude
undesired applications from a release, but I had not found a way to
install such release to a new ROOT where core erlang applications are
not installed.

Alexander

From ulf.wiger@REDACTED  Fri Jul 16 13:34:11 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Fri, 16 Jul 2010 13:34:11 +0200
Subject: [erlang-questions] Is it possible to create an application release
 without kernel, stdlib and sasl?
In-Reply-To: <85iq4fn2lq.fsf@myxomop.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> <85iq4fn2lq.fsf@myxomop.com>
Message-ID: <4C4043B3.4070900@erlang-solutions.com>


Kernel and stdlib are mandatory. Sasl isn't.

BR,
Ulf W

Alexander Kotelnikov wrote:
> Hello.
> 
> I've never bothered to create OTP releases before and now decided to
> learn about it.
> 
> I am playing with a tiny application. Normally when a release is
> created it includes whole erlang system - kernel, stdlib and sasl.
> 
> Bu on
> http://www.erlang.org/doc/design_principles/release_structure.html#id2273097
> I nocitced that documentation tells about possibly several ROOT
> directories, which sounds to be a handy approach: I would not touch my
> systems's erlang core installation and in my own ROOT I would have my
> application with their ows release processes.
> 
> Is there a way to do so? systools provides some means to exclude
> undesired applications from a release, but I had not found a way to
> install such release to a new ROOT where core erlang applications are
> not installed.
> 
> Alexander
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 


-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From juanjo@REDACTED  Fri Jul 16 14:41:06 2010
From: juanjo@REDACTED (Juan Jose Comellas)
Date: Fri, 16 Jul 2010 09:41:06 -0300
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>
Message-ID: <AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>

The beauty of Erlang is precisely that you don't have to worry about this.
If you enable kernel polling (+K true) the VM will take care of using epoll,
kqueue, etc. (I'm not sure that IOCP is supported on Windows yet), and will
send the received data to the corresponding process, where you'll be able to
deal with it easily and without worrying about the underlying complexity of
low level I/O.

Why are you worried about having one Erlang process per connection? They are
very lightweight and that's where you're supposed to keep the state
associated to each connection if you want them to run in parallel.


On Thu, Jul 15, 2010 at 11:15 PM, Tony Arcieri <tony.arcieri@REDACTED>wrote:

> Many operating systems provide high-performance stateful I/O multiplexing
> APIs.  Some examples of these APIs include Linux's epoll, *BSD's kqueue,
> Solaris's event completion ports, and Windows I/O completion ports.
>
> A common characteristic of these APIs is the ability to include a pointer
> to
> a piece of user state.  This provides a simple way to look up the state
> necessary to dispatch an event.  A skillful user of these APIs will bundle
> all the state necessary to dispatch a request into a single pointer, and
> these APIs will keep track of that pointer, all the way down to the kernel
> level.
>
> As far as I can tell, gen_tcp/inets do not do this.  I am not seeing any
> APIs that will allow me to provide an Erlang term when I flip on active
> mode
> on a particular socket which will be delivered in the messages I receive
> from inets.
>
> Am I missing something?  Is there a way to do this?  If not, the recourses
> I
> have seem particularly disadvantageous compared to the underlying API
> carrying a single piece of state for me from end-to-end.  Either I can use
> a
> proxy process per connection, involving all the complexity of managing an
> external process in the API I expose to an end user, and requiring a
> process
> per connection where if gen_tcp/inets held onto the state for me I'd only
> require one, or having a single process which used a mapping data structure
> to go between the port the message originated from and the piece of user
> state I actually care about.  I find both of these solutions particularly
> suboptimal, especially considering that the kernel-level APIs are designed
> to round trip a particular piece of user state you care about end-to-end.
>
> The underlying functionality is there at the kernel level, but as far as I
> can tell Erlang does not expose it as a language.  Is there something I'm
> missing?
>
> --
> Tony Arcieri
> Medioh! A Kudelski Brand
>

From max.lapshin@REDACTED  Fri Jul 16 14:44:24 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Fri, 16 Jul 2010 16:44:24 +0400
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>
Message-ID: <AANLkTim7fqTKmZaxJ2wDQuljUuV68GLUUI_F9vVGuSPz@mail.gmail.com>

In fact, erlang process is exactly that entity, you want to track pointer to.

From sacha@REDACTED  Fri Jul 16 17:18:46 2010
From: sacha@REDACTED (Alexander Kotelnikov)
Date: Fri, 16 Jul 2010 19:18:46 +0400
Subject: [erlang-questions] Is it possible to create an application
 release without kernel, stdlib and sasl?
In-Reply-To: <4C4043B3.4070900@erlang-solutions.com> (Ulf Wiger's message of
 "Fri, 16 Jul 2010 13:34:11 +0200")
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>
	<85iq4fn2lq.fsf@myxomop.com> <4C4043B3.4070900@erlang-solutions.com>
Message-ID: <85bpa7mp49.fsf@myxomop.com>

But it is still unclear, what does this sentence mean:

"Applications are not required to be located under the $ROOT/lib
directory. Accordingly, several installation directories may exist
which contain different parts of a system. For example, the previous
example could be extended as follows:"

And how this might be used.

Alexander

>>>>> On Fri, 16 Jul 2010 13:34:11 +0200
>>>>> "UW" == Ulf Wiger <ulf.wiger@REDACTED> wrote:
UW> 
UW> Kernel and stdlib are mandatory. Sasl isn't.

From tuncer.ayaz@REDACTED  Sat Jul 17 23:29:09 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Sat, 17 Jul 2010 23:29:09 +0200
Subject: [erlang-questions] Nested Record Pattern Matching in R14A
In-Reply-To: <AANLkTiln5veifvt43lnZgcacXC3aFDT_QtZDVtuCjqQz@mail.gmail.com>
References: <AANLkTiln5veifvt43lnZgcacXC3aFDT_QtZDVtuCjqQz@mail.gmail.com>
Message-ID: <AANLkTikVOPESErQEuXM0QqH6Fh4BXDG4LrYQy0Y8YWdO@mail.gmail.com>

On Thu, Jul 8, 2010 at 3:34 PM, Brian Williams wrote:
> I converted a small search algorithm project to use the new nested
> record syntax in R14A.
> My records are:
> -record(state, {yard_state}).
> -record(solution_state, {state = #state{}, moves, depth}).
> -record(astar_solution_state, {solution_state = #solution_state{}, fvalue}).
>
> I was able to use a line like this to access a field in the nested record:
> Astar_Solution_State#astar_solution_state.solution_state#solution_state.state
>
> Based on the example in the reference manual, I thought the pattern
> for matching the state field would be:
>
> function_call(#astar_solution_state.solution_state#solution_state{state
> = State})

Hi Brian,

this is invalid and it's not how records are matched.

It almost looks like an expression to update a record field:
foo(Astar) when is_record(Astar, astar_solution_state) ->
  State = #state{yard_state=foo_yard},
  Astar#astar_solution_state.solution_state#solution_state{state=State}.

> However, that gave me "illegal pattern" errors, and after a bit of
> fiddling, I got this to work:
> #astar_solution_state{solution_state = #solution_state{state = State}}
>
> Is this intended? Or a bug?

It is intended.

From tuncer.ayaz@REDACTED  Sat Jul 17 23:30:48 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Sat, 17 Jul 2010 23:30:48 +0200
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
Message-ID: <AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>

On Thu, Jul 15, 2010 at 6:39 PM, Brian Williams wrote:
> I'm not entirely sure what combination of running software is causing
> this. I have a program that opens a list of log files (~100kb to
> ~200kb), reads one a line at a time, matches the line against some
> regexes, prints a report and finishes). Sometimes it works without a
> problem. But other times werl will crash one or two lines into reading
> the first log file, or when it opens up the report file. I have my
> .erl, .beam and final report file in a Dropbox directory, which may be

Hi Brian,

I don't expect Dropbox to be the problem but have you tested on
a Windows 7 install without Dropbox ever installed?

> Win7 gives me a report like this when it crashes:
> Problem signature:
> Problem Event Name:   APPCRASH
> Application Name:     werl.exe
> Application Version:  0.0.0.0
> Application Timestamp:        4c17b8f1
> Fault Module Name:    beam.smp.dll
> Fault Module Version: 0.0.0.0
> Fault Module Timestamp:       4c17b83a
> Exception Code:       c0000005
> Exception Offset:     000cc562
> OS Version:   6.1.7600.2.0.0.256.48
> Locale ID:    1033
> Additional Information 1:     0a9e
> Additional Information 2:     0a9e372d3b4ad19135b953a78882e789
> Additional Information 3:     0a9e
> Additional Information 4:     0a9e372d3b4ad19135b953a78882e789

If you have a Windows crash dump for that I would make a backup of
the dump. Just in case...

>            {ok, WarningExp} = re:compile("warning", [caseless]),
>            {ok, ErrorExp} = re:compile("error", [caseless]),
>
>            Compiled_Tests = [
>                {warnings, warning_exps(), WarningExp},
>                {errors, error_exps(), ErrorExp}],
>            Report = scan_lines(Compiled_Tests, Dev, io:get_line(Dev, '')),

What's the definition of scan_lines/3 (what does it do with
the result of io:get_line/2 and with the compiled patterns)?

From rzezeski@REDACTED  Sun Jul 18 06:58:45 2010
From: rzezeski@REDACTED (Ryan Zezeski)
Date: Sun, 18 Jul 2010 00:58:45 -0400
Subject: EUnit best practices?
Message-ID: <AANLkTikobLULvJllEHyVycxpgk45JoUAlUhAvjfxexhs@mail.gmail.com>

Is it a code smell to write a test function that has the following form?

test_foo() ->
  Stuff = make_stuff(),
  {ok, ...} = Stuff, % match some stuff
  ?assert(...),
  ?assert(...),
  ...
  ?assert(...).

Specifically, I'm curious if it's non-idiomatic to call multiple asserts in
a "simple test function?"  Should I be using a "test generating function?"
 If so, why?  What advantages does it offer me over the above?

-Ryan

From wiener.guy@REDACTED  Sun Jul 18 15:29:25 2010
From: wiener.guy@REDACTED (Guy Wiener)
Date: Sun, 18 Jul 2010 16:29:25 +0300
Subject: Looking for open-source Erlang applications
Message-ID: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>

Hello everyone,
I want to run some program analyses on Erlang applications for an academic
study. The applications need to be:
1. Open source
2. Non-infrastructure (i.e, not a library or a framework for Erlang, but an
application written in Erlang)

Any suggestions? No information about a specific application will be
discussed in the study.

Thanks,
  Guy Wiener.

From max.lapshin@REDACTED  Sun Jul 18 15:33:59 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Sun, 18 Jul 2010 17:33:59 +0400
Subject: [erlang-questions] Looking for open-source Erlang applications
In-Reply-To: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
References: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
Message-ID: <AANLkTimxHLUtI2aFpvAzwC6dYGYxap41Dl0TLoK-v0nd@mail.gmail.com>

On Sun, Jul 18, 2010 at 5:29 PM, Guy Wiener <wiener.guy@REDACTED> wrote:
> Hello everyone,
> I want to run some program analyses on Erlang applications for an academic
> study. The applications need to be:
> 1. Open source
> 2. Non-infrastructure (i.e, not a library or a framework for Erlang, but an
> application written in Erlang)
>

http://github.com/erlyvideo/erlyvideo/

From erlangy@REDACTED  Sun Jul 18 16:18:02 2010
From: erlangy@REDACTED (Michael McDaniel)
Date: Sun, 18 Jul 2010 07:18:02 -0700
Subject: [erlang-questions] Looking for open-source Erlang applications
In-Reply-To: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
References: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
Message-ID: <20100718141801.GX13880@delora.autosys.us>

On Sun, Jul 18, 2010 at 04:29:25PM +0300, Guy Wiener wrote:
> Hello everyone,
> I want to run some program analyses on Erlang applications for an academic
> study. The applications need to be:
> 1. Open source
> 2. Non-infrastructure (i.e, not a library or a framework for Erlang, but an
> application written in Erlang)
> 
> Any suggestions? No information about a specific application will be
> discussed in the study.
> 
> Thanks,
>   Guy Wiener.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  http://edids.org




From als@REDACTED  Sun Jul 18 17:04:43 2010
From: als@REDACTED (Anthony Shipman)
Date: Mon, 19 Jul 2010 01:04:43 +1000
Subject: dialyzer problem with exceptions
Message-ID: <201007190104.43210.als@iinet.net.au>

This is release 12B4 with options  -Wno_unused -Wno_return

It appears that the second branch of reportMissing is ignored when determining 
the success typing, perhaps because it always raises an exception.

bssBoss.erl:182: The call
bssBoss:reportMissing(["operator"],FuncName::
[1..255,...],Pos::any(),State::any())
will fail since it differs in argument position 1 from the success typing
arguments: ([],[1..255,...],any(),any())

bssBoss.erl:197: The call
bssBoss:reportMissing(["user"],FuncName::[1..255,...],Pos::any(),State::any())
will fail since it differs in argument position 1 from the success typing
arguments: ([],[1..255,...],any(),any())



reportMissing([], _FuncName, _Pos, _State) ->
    ok;

reportMissing(Keys, FuncName, Pos, State) ->
    Names = util:join(Keys, ", "),
    valueError("missing keys: " ++ Names, FuncName, Pos, State).


valueError(Text, FuncName, Pos, State) ->
    Msg = io_lib:format("~s() ~s", [FuncName, Text]),
    except:raiseBuiltinWithMsg(<<"ValueError">>, Msg, Pos, State).


-- 
Anthony Shipman                    Mamas don't let your babies 
als@REDACTED                   grow up to be outsourced.

From james.aimonetti@REDACTED  Sun Jul 18 17:48:40 2010
From: james.aimonetti@REDACTED (James Aimonetti)
Date: Sun, 18 Jul 2010 08:48:40 -0700
Subject: ifplug.d style eventing?
Message-ID: <AANLkTilSRFwGkI1hlUPtpDjxuWjdLSYfBTbhPoYcfdJA@mail.gmail.com>

I have a board with three ethernet nics and have some monitoring
software running in erlang that polls the nics for their config data
(addr, broadaddr, netmask) every 30 seconds or so. I'm using
inet:getiflist/0 and inet:ifget/2 to do the data retrieval. This data
is then sent to a remote server and processed, with the response being
tailored to the data sent, and the monitoring code updating various
config files (a dhcp server, some iptables rules, etc).

Side note: is there a simple way to authoritatively find out the
gateway address for a nic? It could prove useful down the road, but I
didn't see it as an option to inet:ifget/2.

I was wondering if there was a way, in Erlang, to have an event
listener on the nics that I could subscribe to instead of polling?
Where I could detect a nic coming up or going down because a cable was
plugged/unplugged, or, if the nic is configured with dhcp when the IP
changes, things of that nature.

The other piece I'm having trouble with is testing, of the nics that
are up, which have WAN access. I'd like, during all of this
polling/eventing, that I could test if a configured nic is able to
access our remote server. So if eth0 and eth1 are up (say on init),
test both connections to see if I can reach the server; later, should
eth0 go down for whatever reason, and both had WAN access, I could
modify my configs to use eth1 as the failover WAN.

I appreciate any help.

James

From kostis@REDACTED  Sun Jul 18 18:41:10 2010
From: kostis@REDACTED (Kostis Sagonas)
Date: Sun, 18 Jul 2010 19:41:10 +0300
Subject: [erlang-questions] dialyzer problem with exceptions
In-Reply-To: <201007190104.43210.als@iinet.net.au>
References: <201007190104.43210.als@iinet.net.au>
Message-ID: <4C432EA6.6060005@cs.ntua.gr>

Anthony Shipman wrote:
> This is release 12B4 with options  -Wno_unused -Wno_return
> 
> It appears that the second branch of reportMissing is ignored when determining 
> the success typing, perhaps because it always raises an exception.

Yes.  This is intentional.

   Success Typings == the types for which a function will return a value.

   Branch raises exception => Branch does not return/succeed.
     (from the perspective of success typings,
      it's as if that particular branch is not there)

Kostis

From kiszl@REDACTED  Sun Jul 18 19:20:29 2010
From: kiszl@REDACTED (Zoltan Lajos Kis)
Date: Sun, 18 Jul 2010 19:20:29 +0200
Subject: [erlang-questions] dialyzer problem with exceptions
In-Reply-To: <201007190104.43210.als@iinet.net.au>
References: <201007190104.43210.als@iinet.net.au>
Message-ID: <4C4337DD.7080300@tmit.bme.hu>

On 7/18/2010 5:04 PM, Anthony Shipman wrote:
> This is release 12B4 with options  -Wno_unused -Wno_return
>
> It appears that the second branch of reportMissing is ignored when determining
> the success typing, perhaps because it always raises an exception.
>
> bssBoss.erl:182: The call
> bssBoss:reportMissing(["operator"],FuncName::
> [1..255,...],Pos::any(),State::any())
> will fail since it differs in argument position 1 from the success typing
> arguments: ([],[1..255,...],any(),any())
>
> bssBoss.erl:197: The call
> bssBoss:reportMissing(["user"],FuncName::[1..255,...],Pos::any(),State::any())
> will fail since it differs in argument position 1 from the success typing
> arguments: ([],[1..255,...],any(),any())
>
>
>
> reportMissing([], _FuncName, _Pos, _State) ->
>      ok;
>
> reportMissing(Keys, FuncName, Pos, State) ->
>      Names = util:join(Keys, ", "),
>      valueError("missing keys: " ++ Names, FuncName, Pos, State).
>
>
> valueError(Text, FuncName, Pos, State) ->
>      Msg = io_lib:format("~s() ~s", [FuncName, Text]),
>      except:raiseBuiltinWithMsg(<<"ValueError">>, Msg, Pos, State).
>
>
>    
I had a similar issue, where I ended up wrapping the cause of those 
warnings into fake function calls, putting
the original expression to the argument of this function. During 
compilation I run a parse transform on all modules
which replaces these fake calls with their arguments, so the compiled 
code becomes the same as it would be
without the fake calls.

I run Dialyzer checks on the source code without the parse transform. As 
the fake function calls will be unknown to
Dialyzer, it will not replace my original specification with its 
inferred one.

For example in a module, which I dynamically recompile every now and 
then, initially I would have the following:

-spec( my_fun() -> [atom()] ).
my_fun() -> [].

which Dialyzer would re-spec as my_fun() -> []. With the fake call it 
will handle my_fun() as if it returned [atom()]:

my_fun() -> '_fake':call( [] ).

In case of throws, Dialyzer (un)fortunately is smart enough to detect 
that a call like

my_fun() -> '_fake':call( throw('my_bad') ).

will never return, because of the throw. Therefore, my parse transform 
also checks whether the argument is in
the form of {throw, term()}, and replaces it with a call to throw, 
passing in the second element of the tuple:

my_fun() -> '_fake':call( {throw, 'my_bad'} ).

Raising exceptions and exits, and probably anything else can be handled 
in a similar way.

The downsides of this solution are minimal:
- you need to use a parse transform, which must be compiled before the 
other modules
- Dialyzer will list '_fake':call/1 as unknown function (you still get a 
"passed successfully")

I hope this helped.

Kindest Regards,
Zoltan.

From anthonym@REDACTED  Sun Jul 18 20:54:19 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Sun, 18 Jul 2010 11:54:19 -0700
Subject: [erlang-questions] Looking for open-source Erlang applications
In-Reply-To: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
References: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
Message-ID: <20100718185419.GD79210@alumni.caltech.edu>


On Sun, Jul 18, 2010 at 04:29:25PM +0300, Guy Wiener wrote:
> Hello everyone,
> I want to run some program analyses on Erlang applications for an academic
> study. The applications need to be:
> 1. Open source
> 2. Non-infrastructure (i.e, not a library or a framework for Erlang, but an
> application written in Erlang)
> 
> Any suggestions? No information about a specific application will be
> discussed in the study.

I've never used it personally, but it probably is along the lines of what
you are looking for

http://www.wings3d.com/

Open source 3d modeller written in erlang.

-Anthony

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From doug.fort@REDACTED  Sun Jul 18 21:06:07 2010
From: doug.fort@REDACTED (Doug Fort)
Date: Sun, 18 Jul 2010 15:06:07 -0400
Subject: [erlang-questions] Looking for open-source Erlang applications
In-Reply-To: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
References: <AANLkTimJ8I5j0-m2Kw9aHR_W6FOcpsCEwQqjDs5PzkW6@mail.gmail.com>
Message-ID: <AANLkTimiLREIcQ5nmXotS38KLOBglcQgONNUNVyYWCa6@mail.gmail.com>

On Sun, Jul 18, 2010 at 9:29 AM, Guy Wiener <wiener.guy@REDACTED> wrote:
> Hello everyone,
> I want to run some program analyses on Erlang applications for an academic
> study. The applications need to be:
> 1. Open source
> 2. Non-infrastructure (i.e, not a library or a framework for Erlang, but an
> application written in Erlang)
>
> Any suggestions? No information about a specific application will be
> discussed in the study.

Here's the first Erlang application open sourced at SpiderOak. Not the
last, I hope.

https://spideroak.com/blog/20100628192232-an-erlangotp-ssl-proxy-and-load-balancer-for-python-twisteds-perspective-broker


>
> Thanks,
> ?Guy Wiener.
>



-- 
Doug Fort, Consulting Programmer
http://www.dougfort.com

From hynek@REDACTED  Mon Jul 19 08:17:56 2010
From: hynek@REDACTED (Hynek Vychodil)
Date: Mon, 19 Jul 2010 08:17:56 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
Message-ID: <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>

f(N) when N==1; N==2 ->
? ?false;
f(1) ->
? ?ok.

is not same as

f(1) ->
? ?false;
f(2) ->
? ?false;
f(1) ->
? ?ok.

Following is:

f(N) when N=:=1; N=:=2 ->
? ?false;
f(1) ->
? ?ok.

Former is hard to realize for compiler even it is possible.

On Thu, Jul 15, 2010 at 1:31 PM, Torben Hoffmann
<torben.lehoff@REDACTED> wrote:
> Hi,
>
> I had a very large module where I could not figure out why a specific thing
> was not happening and it turned out that the root of the problem was a
> construct like the following:
>
> -module(problem).
>
> -compile(export_all).
>
> f(N) when N==1; N==2 ->
> ? ?false;
> f(1) ->
> ? ?ok.
>
> I would have hoped that the compiler or dialyzer would have caught that the
> f(1) clause will never be executed, but that is not the case.
> It seems that the use of the when-clause changes the game so that the
> overlap is not detected.
> I accept that I am shooting myself in the foot here, but I would have liked
> to be helped by the compiler or dialyzer since figuring this one out after
> going through hefty logs is not fun.
>
> Now that I know this I can work around it, but it would be nice to get the
> warning since the code in my f(N) branch is actually not that small. Of
> course I could create a function to do the operation and rewrite like this:
>
> -module(problem).
>
> -compile(export_all).
>
> f(1) ->
> ? ?g();
> f(2) ->
> ? ?g();
> f(1) ->
> ? ?ok.
>
> In which case the compiler will warn me about the overlap, but I find that
> to be somewhat ugly.
>
> Any comments on this?
>
> Cheers,
> Torben
> --
> http://www.linkedin.com/in/torbenhoffmann
>



-- 
--Hynek (Pichi) Vychodil

Analyze your data in minutes. Share your insights instantly. Thrill
your boss.? Be a data hero!
Try GoodData now for free: www.gooddata.com

From bernie@REDACTED  Mon Jul 19 08:34:46 2010
From: bernie@REDACTED (Bernard Duggan)
Date: Mon, 19 Jul 2010 16:34:46 +1000
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com> <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
Message-ID: <4C43F206.1010804@m5net.com>

You're right, but the catch is that your second example doesn't produce 
a warning either.  There may, of course, be a very good reason that 
these cases don't do so, but the difference between == and =:= is not it.

B

On 19/07/10 16:17, Hynek Vychodil wrote:
> f(N) when N==1; N==2 ->
>     false;
> f(1) ->
>     ok.
>
> is not same as
>
> f(1) ->
>     false;
> f(2) ->
>     false;
> f(1) ->
>     ok.
>
> Following is:
>
> f(N) when N=:=1; N=:=2 ->
>     false;
> f(1) ->
>     ok.
>
> Former is hard to realize for compiler even it is possible.
>
> On Thu, Jul 15, 2010 at 1:31 PM, Torben Hoffmann
> <torben.lehoff@REDACTED>  wrote:
>    
>> Hi,
>>
>> I had a very large module where I could not figure out why a specific thing
>> was not happening and it turned out that the root of the problem was a
>> construct like the following:
>>
>> -module(problem).
>>
>> -compile(export_all).
>>
>> f(N) when N==1; N==2 ->
>>     false;
>> f(1) ->
>>     ok.
>>
>> I would have hoped that the compiler or dialyzer would have caught that the
>> f(1) clause will never be executed, but that is not the case.
>> It seems that the use of the when-clause changes the game so that the
>> overlap is not detected.
>> I accept that I am shooting myself in the foot here, but I would have liked
>> to be helped by the compiler or dialyzer since figuring this one out after
>> going through hefty logs is not fun.
>>
>> Now that I know this I can work around it, but it would be nice to get the
>> warning since the code in my f(N) branch is actually not that small. Of
>> course I could create a function to do the operation and rewrite like this:
>>
>> -module(problem).
>>
>> -compile(export_all).
>>
>> f(1) ->
>>     g();
>> f(2) ->
>>     g();
>> f(1) ->
>>     ok.
>>
>> In which case the compiler will warn me about the overlap, but I find that
>> to be somewhat ugly.
>>
>> Any comments on this?
>>
>> Cheers,
>> Torben
>> --
>> http://www.linkedin.com/in/torbenhoffmann
>>
>>      
>
>
>    


From mixolyde@REDACTED  Mon Jul 19 15:24:24 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Mon, 19 Jul 2010 09:24:24 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
Message-ID: <AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>

On Sat, Jul 17, 2010 at 5:30 PM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
> On Thu, Jul 15, 2010 at 6:39 PM, Brian Williams wrote:
>> I'm not entirely sure what combination of running software is causing
>> this. I have a program that opens a list of log files (~100kb to
>> ~200kb), reads one a line at a time, matches the line against some
>> regexes, prints a report and finishes). Sometimes it works without a
>> problem. But other times werl will crash one or two lines into reading
>> the first log file, or when it opens up the report file. I have my
>> .erl, .beam and final report file in a Dropbox directory, which may be
>
> Hi Brian,
>
> I don't expect Dropbox to be the problem but have you tested on
> a Windows 7 install without Dropbox ever installed?
>

I have run a bunch of other examples and my own code right off beams
in drop box before. Just none that have done file i/o, but I can move
these files elsewhere and try that, too.


>> Win7 gives me a report like this when it crashes:
>> Problem signature:
>> Problem Event Name: ? APPCRASH
>> Application Name: ? ? werl.exe
>> Application Version: ?0.0.0.0
>> Application Timestamp: ? ? ? ?4c17b8f1
>> Fault Module Name: ? ?beam.smp.dll
>> Fault Module Version: 0.0.0.0
>> Fault Module Timestamp: ? ? ? 4c17b83a
>> Exception Code: ? ? ? c0000005
>> Exception Offset: ? ? 000cc562
>> OS Version: ? 6.1.7600.2.0.0.256.48
>> Locale ID: ? ?1033
>> Additional Information 1: ? ? 0a9e
>> Additional Information 2: ? ? 0a9e372d3b4ad19135b953a78882e789
>> Additional Information 3: ? ? 0a9e
>> Additional Information 4: ? ? 0a9e372d3b4ad19135b953a78882e789
>
> If you have a Windows crash dump for that I would make a backup of
> the dump. Just in case...
>

Where would I look for this dump? Would I be able to make sense of it at all?

>> ? ? ? ? ? ?{ok, WarningExp} = re:compile("warning", [caseless]),
>> ? ? ? ? ? ?{ok, ErrorExp} = re:compile("error", [caseless]),
>>
>> ? ? ? ? ? ?Compiled_Tests = [
>> ? ? ? ? ? ? ? ?{warnings, warning_exps(), WarningExp},
>> ? ? ? ? ? ? ? ?{errors, error_exps(), ErrorExp}],
>> ? ? ? ? ? ?Report = scan_lines(Compiled_Tests, Dev, io:get_line(Dev, '')),
>
> What's the definition of scan_lines/3 (what does it do with
> the result of io:get_line/2 and with the compiled patterns)?
>

Here's the rest except for the report printing, which is pretty simple.

% starts an empty report for accumulation
scan_lines(Compiled_Tests, Dev, Line) ->
    scan_lines(Compiled_Tests, Dev, Line,
        [{warnings, []}, {errors, []}]).
% reached end of file, return report
scan_lines(_Compiled_Tests, _Dev, eof, Report) -> Report;
scan_lines(Compiled_Tests, Dev, Line, Report) ->
    % match line and update report
    % io:format("Attempting to match line: ~s~n", [Line]),
    UpdatedReport = update_report(Compiled_Tests, Line, Report),
    % get next line and recurse
    scan_lines(Compiled_Tests, Dev, io:get_line(Dev, ''), UpdatedReport).

%% Takes a line, scans for errors and warnings and updates the report
update_report([], _Line, Report) -> Report;
update_report([{Group, Tests, GroupMatch} | Compiled_Tests], Line, Report) ->
    case re:run(Line, GroupMatch) of
            {match, _Captured} ->
                % io:format("Matched ~p, checking for specific ~p
errors~n", [Group, Group]),
                check_test(Line, Group, Tests, Report);
            nomatch -> update_report(Compiled_Tests, Line, Report)
    end.

check_test(Line, Group, [], Report) ->
    io:format("Unmatched ~p for line: ~s", [Group, Line]),
    increment_report(Report, {Group, unknown, "Non-matched line"});
check_test(Line, Group, [{TestName, Exp, Test} | RestTests], Report) ->
    case re:run(Line, Exp) of
        {match, _TestCapture} ->
            % return new report, don't recurse
            % io:format("Matched a test, incrementing: ~p~n", [TestName]),
            increment_report(Report, {Group, TestName, Test});
        nomatch ->
            % try the next test
            check_test(Line, Group, RestTests, Report)
    end.

increment_report(Report, {Group, TestName, Test}) ->
    % get the group of counts in the report that we're working with
    {Group, Counts} = lists:keyfind(Group, 1, Report),
    % io:format("Got counts: ~p for test group: ~p~n", [Counts, Group]),
    case lists:keyfind(TestName, 1, Counts) of
        % if that test is already in the report, increment
        {TestName, CurrentCount, _MatchTest} ->
            % io:format("Replacing count with ~p~n", [{TestName,
CurrentCount +1}]),
            lists:keyreplace(Group, 1, Report, {Group,
                lists:keyreplace(TestName, 1, Counts, {TestName,
CurrentCount + 1, Test})});
        % else, add it in with initial count of 1
        false ->
            % io:format("Couldn't find test ~p in report, adding a new
one~n", [TestName]),
            lists:keyreplace(Group, 1, Report, {Group, [{TestName, 1,
Test} | Counts]})
    end.


-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From tony.arcieri@REDACTED  Mon Jul 19 19:51:47 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Mon, 19 Jul 2010 11:51:47 -0600
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> 
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>
Message-ID: <AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com>

On Fri, Jul 16, 2010 at 6:41 AM, Juan Jose Comellas <juanjo@REDACTED>wrote:

> The beauty of Erlang is precisely that you don't have to worry about this.


That seems to be a common reaction when I pose a question in this manner.  I
would suggest that round tripping lots of explicit state is very much the
norm of Erlang, and while that's a bit ugly IMO, here I'm running into a
case where I'd like to do it where it isn't possible.

Why are you worried about having one Erlang process per connection?
>

I already spelled that out in my previous email, but beyond that, they are
unneeded in this case and add additional overhead.  The requirement to use a
process is imposed only by the design of the gen_tcp/inets APIs.

It seems like attaching a single piece of immutable state to each connection
is going to add a lot of complexity.  In order to expose a sequential,
side-effect based API to the end user, I'm going to have to proxy all
communication between inets and the end user, and also provide process
management.

Let's just say I consider this an unparsimonious and inelegant solution with
more overhead than leveraging the end-to-end potential for associating
connection specific state with particular sockets.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From tuncer.ayaz@REDACTED  Mon Jul 19 22:22:37 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Mon, 19 Jul 2010 20:22:37 +0000
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com> 
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com> 
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
Message-ID: <AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>

On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>
> Where would I look for this dump?

Default should be C:\Windows\minidumps and I think it's configurable.

> Would I be able to make sense of it at all?

As you saw a crash dialog and no debugger was started it's safe
to assume that no postmortem debugger is configured.
Therefore a tool called DrWatson should have written a crashdump file.

You can use windbg to load the dump file and beam.smp.pdb to see
where it crashed. The PDB file contains debug info/symbols and you
should find it here: <ErlangInstallDir>\erts-5.8\bin\beam.smp.pdb.

If you don't have windbg installed, start here:
http://www.microsoft.com/whdc/devtools/debugging/default.mspx

If you have never used windbg, continue here:
http://www.codeproject.com/KB/debug/windbg_part1.aspx#_Toc64133675

If you want to reproduce the crash and not search for the dump file,
consider configuring windbg as the portmortem debugger:
http://msdn.microsoft.com/en-us/library/ff539055%28v=VS.85%29.aspx
http://www.codeproject.com/KB/debug/windbg_part1.aspx#_Toc64133667

From tony@REDACTED  Tue Jul 20 00:48:26 2010
From: tony@REDACTED (Tony Rogvall)
Date: Tue, 20 Jul 2010 00:48:26 +0200
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific  user state?
In-Reply-To: <AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>  <AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com> <AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com>
Message-ID: <8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se>

Why not use a global ets table? (use socket/port as a key)
If you would attach any kind of data to a socket you would have to copy it any how...
(There is a hidden way of doing it, but it's already taken by inet ;-)

/Tony


On 19 jul 2010, at 19.51, Tony Arcieri wrote:

> On Fri, Jul 16, 2010 at 6:41 AM, Juan Jose Comellas <juanjo@REDACTED>wrote:
> 
>> The beauty of Erlang is precisely that you don't have to worry about this.
> 
> 
> That seems to be a common reaction when I pose a question in this manner.  I
> would suggest that round tripping lots of explicit state is very much the
> norm of Erlang, and while that's a bit ugly IMO, here I'm running into a
> case where I'd like to do it where it isn't possible.
> 
> Why are you worried about having one Erlang process per connection?
>> 
> 
> I already spelled that out in my previous email, but beyond that, they are
> unneeded in this case and add additional overhead.  The requirement to use a
> process is imposed only by the design of the gen_tcp/inets APIs.
> 
> It seems like attaching a single piece of immutable state to each connection
> is going to add a lot of complexity.  In order to expose a sequential,
> side-effect based API to the end user, I'm going to have to proxy all
> communication between inets and the end user, and also provide process
> management.
> 
> Let's just say I consider this an unparsimonious and inelegant solution with
> more overhead than leveraging the end-to-end potential for associating
> connection specific state with particular sockets.
> 
> -- 
> Tony Arcieri
> Medioh! A Kudelski Brand


From tony.arcieri@REDACTED  Tue Jul 20 00:57:26 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Mon, 19 Jul 2010 16:57:26 -0600
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> 
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com> 
	<AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com> 
	<8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se>
Message-ID: <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com>

On Mon, Jul 19, 2010 at 4:48 PM, Tony Rogvall <tony@REDACTED> wrote:

> Why not use a global ets table? (use socket/port as a key)
>

Then you lose the O(1) properties of having the whole system round trip
state for you.  In that regard I'd prefer to use a process per connection.


> (There is a hidden way of doing it, but it's already taken by inet ;-)


Ooh really!  What's the hidden way of doing it?

I'm using this as part of implementing Reia and want Reia's socket objects
included in the active mode messages as opposed to raw Erlang ports.  So I
wouldn't be opposed to doing some crazy hacks so long as I can get them to
peacefully coexist with inets.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From rvirding@REDACTED  Tue Jul 20 02:41:44 2010
From: rvirding@REDACTED (Robert Virding)
Date: Tue, 20 Jul 2010 02:41:44 +0200
Subject: [erlang-questions] Nested Record Pattern Matching in R14A
In-Reply-To: <AANLkTikVOPESErQEuXM0QqH6Fh4BXDG4LrYQy0Y8YWdO@mail.gmail.com>
References: <AANLkTiln5veifvt43lnZgcacXC3aFDT_QtZDVtuCjqQz@mail.gmail.com>
	<AANLkTikVOPESErQEuXM0QqH6Fh4BXDG4LrYQy0Y8YWdO@mail.gmail.com>
Message-ID: <AANLkTik4HBNgnOYa1ouxkYvZwZAtdMjda0i7s-GM5u9M@mail.gmail.com>

I just want to expand a little on what Tuncer has written.

No, it is not a bug, it is most definitely intended.

The basic principle is that the syntax used to match and pull apart a
term is the same as that used to construct it. So you both construct
and match a list using syntax like [A,B|C] and for a tuple syntax like
{A,B,C}. For binaries the same principle applies though with them you
have more options. In all cases it is very explicit. This is both a
blessing and a curse with pattern matching.

While records in one sense are more abstract than lists or tuples the
same principle applies here as well, you use the same syntax to match
a record as to construct it. This is why the case that worked looked
like it does. What you were trying to do was use the syntax for
accessing fields in the records, it resembles trying to match a tuple
by writing a head like:

function_call(element(3) = State) -> ... ;

I hope this helps some,

Robert


On 17/07/2010, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
> On Thu, Jul 8, 2010 at 3:34 PM, Brian Williams wrote:
>> I converted a small search algorithm project to use the new nested
>> record syntax in R14A.
>> My records are:
>> -record(state, {yard_state}).
>> -record(solution_state, {state = #state{}, moves, depth}).
>> -record(astar_solution_state, {solution_state = #solution_state{},
>> fvalue}).
>>
>> I was able to use a line like this to access a field in the nested record:
>> Astar_Solution_State#astar_solution_state.solution_state#solution_state.state
>>
>> Based on the example in the reference manual, I thought the pattern
>> for matching the state field would be:
>>
>> function_call(#astar_solution_state.solution_state#solution_state{state
>> = State})
>
> Hi Brian,
>
> this is invalid and it's not how records are matched.
>
> It almost looks like an expression to update a record field:
> foo(Astar) when is_record(Astar, astar_solution_state) ->
>   State = #state{yard_state=foo_yard},
>   Astar#astar_solution_state.solution_state#solution_state{state=State}.
>
>> However, that gave me "illegal pattern" errors, and after a bit of
>> fiddling, I got this to work:
>> #astar_solution_state{solution_state = #solution_state{state = State}}
>>
>> Is this intended? Or a bug?
>
> It is intended.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From torben.lehoff@REDACTED  Tue Jul 20 10:12:26 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Tue, 20 Jul 2010 10:12:26 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <4C43F206.1010804@m5net.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
Message-ID: <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>

I am afraid that Bernard is right - there is no difference... neither erlc
or Dialyzer picks it up.

I would like to hear from the OTP team and/or the Dialyzer team to
understand what is cooking here.

I have not tried this out in Haskel (or any other FP language) since I am
trying to keep my computer clean, ie, only Erlang and what that entails ;-)
But I suspect that Haskel is capable of detecting this.

Cheers,
Torben

On Mon, Jul 19, 2010 at 08:34, Bernard Duggan <bernie@REDACTED> wrote:

> You're right, but the catch is that your second example doesn't produce a
> warning either.  There may, of course, be a very good reason that these
> cases don't do so, but the difference between == and =:= is not it.
>
> B
>
>
> On 19/07/10 16:17, Hynek Vychodil wrote:
>
>> f(N) when N==1; N==2 ->
>>    false;
>> f(1) ->
>>    ok.
>>
>> is not same as
>>
>> f(1) ->
>>    false;
>> f(2) ->
>>    false;
>> f(1) ->
>>    ok.
>>
>> Following is:
>>
>> f(N) when N=:=1; N=:=2 ->
>>    false;
>> f(1) ->
>>    ok.
>>
>> Former is hard to realize for compiler even it is possible.
>>
>> On Thu, Jul 15, 2010 at 1:31 PM, Torben Hoffmann
>> <torben.lehoff@REDACTED>  wrote:
>>
>>
>>> Hi,
>>>
>>> I had a very large module where I could not figure out why a specific
>>> thing
>>> was not happening and it turned out that the root of the problem was a
>>> construct like the following:
>>>
>>> -module(problem).
>>>
>>> -compile(export_all).
>>>
>>> f(N) when N==1; N==2 ->
>>>    false;
>>> f(1) ->
>>>    ok.
>>>
>>> I would have hoped that the compiler or dialyzer would have caught that
>>> the
>>> f(1) clause will never be executed, but that is not the case.
>>> It seems that the use of the when-clause changes the game so that the
>>> overlap is not detected.
>>> I accept that I am shooting myself in the foot here, but I would have
>>> liked
>>> to be helped by the compiler or dialyzer since figuring this one out
>>> after
>>> going through hefty logs is not fun.
>>>
>>> Now that I know this I can work around it, but it would be nice to get
>>> the
>>> warning since the code in my f(N) branch is actually not that small. Of
>>> course I could create a function to do the operation and rewrite like
>>> this:
>>>
>>> -module(problem).
>>>
>>> -compile(export_all).
>>>
>>> f(1) ->
>>>    g();
>>> f(2) ->
>>>    g();
>>> f(1) ->
>>>    ok.
>>>
>>> In which case the compiler will warn me about the overlap, but I find
>>> that
>>> to be somewhat ugly.
>>>
>>> Any comments on this?
>>>
>>> Cheers,
>>> Torben
>>> --
>>> http://www.linkedin.com/in/torbenhoffmann
>>>
>>>
>>>
>>
>>
>>
>>
>
>


-- 
http://www.linkedin.com/in/torbenhoffmann

From marc@REDACTED  Tue Jul 20 10:32:23 2010
From: marc@REDACTED (Marc Worrell)
Date: Tue, 20 Jul 2010 10:32:23 +0200
Subject: Looking for an Erlang job?
Message-ID: <DAE30E37-C229-4E4B-A447-F7ED495E487E@worrell.nl>

Hi,

Upon request we added support for those of us that search an Erlang job.
You can now publish your profile on http://totally-erlang.com/

When you have an Erlang related job then you can also publish it on the same site.

Maybe we can bring together those that search people and those of us that like to work with Erlang.

Of course all free of charge and it will remain free of charge.

Kind Regards,

Marc Worrell


From kostis@REDACTED  Tue Jul 20 11:03:31 2010
From: kostis@REDACTED (Kostis Sagonas)
Date: Tue, 20 Jul 2010 12:03:31 +0300
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>	<4C43F206.1010804@m5net.com> <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
Message-ID: <4C456663.4030508@cs.ntua.gr>

Torben Hoffmann wrote:
> I am afraid that Bernard is right - there is no difference... neither erlc
> or Dialyzer picks it up.
> 
> I would like to hear from the OTP team and/or the Dialyzer team to
> understand what is cooking here.

There is not much to say here, nor anything fishy is cooking. It's just 
that or's/orelse's in guards are not so common in their proper treatment 
is not so easy.

Neither erlc not dialyzer ever promised that it will generate all 
possible warnings. In fact, as far as dialyzer is concerned the only 
thing that was promised is that it will not generate a false warning.

Now, having written that, thanks for your mail because it gives us a 
concrete test case to improve erlc and/or dialyzer.

Kostis

From erlang@REDACTED  Tue Jul 20 11:28:38 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Tue, 20 Jul 2010 11:28:38 +0200
Subject: Parsing C with leex and yecc
Message-ID: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>

I'm trying to parser ANSI C with leex and yecc and have run into
two problems.

1) /* ... */ comments. Leex is (as I understand things) greedy
   thus I can't just write a regexp to match comments, since it
   will consume no-only the current comment, but all comments until
   the last comment in the file.

   To solve this I have just written a simple pre-processor to remove comments
   from the original source.

2) The typedef problem.

   How can I parse typedefs using leex and yecc?

   The traditional yacc/lex approach solves this with a context
   sensitive lex and feedback between yacc and lex. But the Erlang
   leex and yacc seem to be written as separated passes, are there some
   internal functions that allow feedback between leex and yacc?

/Joe

From torben.lehoff@REDACTED  Tue Jul 20 11:30:29 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Tue, 20 Jul 2010 11:30:29 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <4C456663.4030508@cs.ntua.gr>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
	<AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
	<4C456663.4030508@cs.ntua.gr>
Message-ID: <AANLkTikq-OKspa9CUN3SH347YC-RF5HpntW2unU1QG4v@mail.gmail.com>

On Tue, Jul 20, 2010 at 11:03, Kostis Sagonas <kostis@REDACTED> wrote:

> Torben Hoffmann wrote:
>
>> I am afraid that Bernard is right - there is no difference... neither erlc
>> or Dialyzer picks it up.
>>
>> I would like to hear from the OTP team and/or the Dialyzer team to
>> understand what is cooking here.
>>
>
> There is not much to say here, nor anything fishy is cooking. It's just
> that or's/orelse's in guards are not so common in their proper treatment is
> not so easy.
>
That was my fear/expectation - as Joe once said "It is easy to get the
typing right in 98% of the cases and then you'll have to fight hard to get
the last 2%"


>
> Neither erlc not dialyzer ever promised that it will generate all possible
> warnings. In fact, as far as dialyzer is concerned the only thing that was
> promised is that it will not generate a false warning.
>
That is fair enough - I was just surprised that this one got through, but
the handling of or in a guard is going to create some nasty scenarios.


>
> Now, having written that, thanks for your mail because it gives us a
> concrete test case to improve erlc and/or dialyzer.
>
Great - this reinforces my belief in sharing experiences!

Cheers,
Torben


>
> Kostis
>



-- 
http://www.linkedin.com/in/torbenhoffmann

From mikpe@REDACTED  Tue Jul 20 12:13:23 2010
From: mikpe@REDACTED (Mikael Pettersson)
Date: Tue, 20 Jul 2010 12:13:23 +0200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
Message-ID: <19525.30403.851157.611767@pilspetsen.it.uu.se>

Joe Armstrong writes:
 > I'm trying to parser ANSI C with leex and yecc and have run into
 > two problems.
...
 > 2) The typedef problem.
 > 
 >    How can I parse typedefs using leex and yecc?
 > 
 >    The traditional yacc/lex approach solves this with a context
 >    sensitive lex and feedback between yacc and lex. But the Erlang
 >    leex and yacc seem to be written as separated passes, are there some
 >    internal functions that allow feedback between leex and yacc?

The simplest solution in my experience is to make the scanner
proper ignore the typedef problem and just return identifier
for any identifier-like token that isn't a reserved word.  Then
you place a context-sensitive shim between then parser and the
scanner proper, where you maintain needed state to resolve
identifier-vs-typename.  Depending on implementation language
and parser technology, this may require tweaking the interface
between then parser and the shim (e.g. for state) or even embedding
the shim in the parser, but at least the scanner proper can remain clean.

From sverker@REDACTED  Tue Jul 20 12:32:36 2010
From: sverker@REDACTED (Sverker Eriksson)
Date: Tue, 20 Jul 2010 12:32:36 +0200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
Message-ID: <4C457B44.3060906@erix.ericsson.se>

Joe Armstrong wrote:
> I'm trying to parser ANSI C with leex and yecc and have run into
> two problems.
>
> 1) /* ... */ comments. Leex is (as I understand things) greedy
>    thus I can't just write a regexp to match comments, since it
>    will consume no-only the current comment, but all comments until
>    the last comment in the file.
>
>    To solve this I have just written a simple pre-processor to remove comments
>    from the original source.
>
>   
re:run("/***first comment***/ /* next comment */", 
"/\\*([^*]|(\\*+([^*/])))*\\*+/").

http://ostermiller.org/findcomment.html

/Sverker


From mixolyde@REDACTED  Tue Jul 20 14:26:55 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Tue, 20 Jul 2010 08:26:55 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
Message-ID: <AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>

On Mon, Jul 19, 2010 at 4:22 PM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
> On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>>
>> Where would I look for this dump?
>
> Default should be C:\Windows\minidumps and I think it's configurable.
>

That directory doesn't exist. I guess I have to configure it in
Windows somewhere? I don't know where to do that.

>> Would I be able to make sense of it at all?
>
> As you saw a crash dialog and no debugger was started it's safe
> to assume that no postmortem debugger is configured.
> Therefore a tool called DrWatson should have written a crashdump file.
>
> You can use windbg to load the dump file and beam.smp.pdb to see
> where it crashed. The PDB file contains debug info/symbols and you
> should find it here: <ErlangInstallDir>\erts-5.8\bin\beam.smp.pdb.
>
> If you don't have windbg installed, start here:
> http://www.microsoft.com/whdc/devtools/debugging/default.mspx
>
> If you have never used windbg, continue here:
> http://www.codeproject.com/KB/debug/windbg_part1.aspx#_Toc64133675
>
> If you want to reproduce the crash and not search for the dump file,
> consider configuring windbg as the portmortem debugger:
> http://msdn.microsoft.com/en-us/library/ff539055%28v=VS.85%29.aspx
> http://www.codeproject.com/KB/debug/windbg_part1.aspx#_Toc64133667
>

I'll grab that and take a look, thanks!

-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From tuncer.ayaz@REDACTED  Tue Jul 20 14:30:21 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Tue, 20 Jul 2010 14:30:21 +0200
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com> 
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com> 
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com> 
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com> 
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
Message-ID: <AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>

On Tue, Jul 20, 2010 at 2:26 PM, Brian Williams wrote:
> On Mon, Jul 19, 2010 at 4:22 PM, Tuncer Ayaz wrote:
>> On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>>>
>>> Where would I look for this dump?
>>
>> Default should be C:\Windows\minidumps and I think it's configurable.
>>
>
> That directory doesn't exist. I guess I have to configure it in
> Windows somewhere? I don't know where to do that.

What about C:\Windows\minidump?

From mixolyde@REDACTED  Tue Jul 20 14:31:24 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Tue, 20 Jul 2010 08:31:24 -0400
Subject: [erlang-questions] Nested Record Pattern Matching in R14A
In-Reply-To: <AANLkTik4HBNgnOYa1ouxkYvZwZAtdMjda0i7s-GM5u9M@mail.gmail.com>
References: <AANLkTiln5veifvt43lnZgcacXC3aFDT_QtZDVtuCjqQz@mail.gmail.com>
	<AANLkTikVOPESErQEuXM0QqH6Fh4BXDG4LrYQy0Y8YWdO@mail.gmail.com>
	<AANLkTik4HBNgnOYa1ouxkYvZwZAtdMjda0i7s-GM5u9M@mail.gmail.com>
Message-ID: <AANLkTil7JztFAGX3PGLqNR-V0vW6dza19AI3nLXHV4F-@mail.gmail.com>

That does help, thanks.

If anyone wants to see the search problem I wrote this astar algorithm
for, it's at:
http://www.cis.udel.edu/~decker/courses/681s07/prog1.html

Pretty fun for a homework assignment, IMHO.
Brian

On Mon, Jul 19, 2010 at 8:41 PM, Robert Virding <rvirding@REDACTED> wrote:
> I just want to expand a little on what Tuncer has written.
>
> No, it is not a bug, it is most definitely intended.
>
> The basic principle is that the syntax used to match and pull apart a
> term is the same as that used to construct it. So you both construct
> and match a list using syntax like [A,B|C] and for a tuple syntax like
> {A,B,C}. For binaries the same principle applies though with them you
> have more options. In all cases it is very explicit. This is both a
> blessing and a curse with pattern matching.
>
> While records in one sense are more abstract than lists or tuples the
> same principle applies here as well, you use the same syntax to match
> a record as to construct it. This is why the case that worked looked
> like it does. What you were trying to do was use the syntax for
> accessing fields in the records, it resembles trying to match a tuple
> by writing a head like:
>
> function_call(element(3) = State) -> ... ;
>
> I hope this helps some,
>
> Robert
>
>
> On 17/07/2010, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
>> On Thu, Jul 8, 2010 at 3:34 PM, Brian Williams wrote:
>>> I converted a small search algorithm project to use the new nested
>>> record syntax in R14A.
>>> My records are:
>>> -record(state, {yard_state}).
>>> -record(solution_state, {state = #state{}, moves, depth}).
>>> -record(astar_solution_state, {solution_state = #solution_state{},
>>> fvalue}).
>>>
>>> I was able to use a line like this to access a field in the nested record:
>>> Astar_Solution_State#astar_solution_state.solution_state#solution_state.state
>>>
>>> Based on the example in the reference manual, I thought the pattern
>>> for matching the state field would be:
>>>
>>> function_call(#astar_solution_state.solution_state#solution_state{state
>>> = State})
>>
>> Hi Brian,
>>
>> this is invalid and it's not how records are matched.
>>
>> It almost looks like an expression to update a record field:
>> foo(Astar) when is_record(Astar, astar_solution_state) ->
>> ? State = #state{yard_state=foo_yard},
>> ? Astar#astar_solution_state.solution_state#solution_state{state=State}.
>>
>>> However, that gave me "illegal pattern" errors, and after a bit of
>>> fiddling, I got this to work:
>>> #astar_solution_state{solution_state = #solution_state{state = State}}
>>>
>>> Is this intended? Or a bug?
>>
>> It is intended.
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>



-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From tony@REDACTED  Tue Jul 20 13:37:45 2010
From: tony@REDACTED (Tony Rogvall)
Date: Tue, 20 Jul 2010 13:37:45 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTikq-OKspa9CUN3SH347YC-RF5HpntW2unU1QG4v@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com> <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com> <4C43F206.1010804@m5net.com> <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com> <4C456663.4030508@cs.ntua.gr> <AANLkTikq-OKspa9CUN3SH347YC-RF5HpntW2unU1QG4v@mail.gmail.com>
Message-ID: <65F43D7B-9BAD-4A16-B395-F623DF9E99E8@rogvall.se>

I also think that case analysis could be improved, but I guess you are aware of that
the general problem is a hard nut. Just look at this very academic example ;-)

f(1,1), f(1,2), f(1,3) are actually overlaps, can you see why? ;-) 
If there was a theorem prover built in to the compiler it may prove that, and warn about the overlap.
But how long time do you want for the compiler to complete?

----------
-define(p(Pi,Hj), ((P =:= (Pi)) and (H =:= (Hj)))).
-define(pi(Pi), (?p(Pi,0) or ?p(Pi,1) or ?p(Pi,2))).
-define(hi(Hi),
	(not (?p(0,Hi) and ?p(1,Hi)) and
	 not (?p(0,Hi) and ?p(2,Hi)) and
	 not (?p(0,Hi) and ?p(3,Hi)) and
	 not (?p(1,Hi) and ?p(2,Hi)) and
	 not (?p(1,Hi) and ?p(3,Hi)) and
	 not (?p(2,Hi) and ?p(3,Hi)))).

f(P,H) 
  when P>=0, P =< 3, H >=0, H =< 2,
       not (?pi(0) and ?pi(1) and ?pi(2) and ?pi(3) and
	    ?hi(0) and ?hi(1) and ?hi(2)) ->
    1;
f(1,1) -> 2;
f(1,2) -> 3;
f(1,3) -> 4;
f(_P,_H) ->
    erlang:error(badarg).
------------

/Tony


On 20 jul 2010, at 11.30, Torben Hoffmann wrote:

> On Tue, Jul 20, 2010 at 11:03, Kostis Sagonas <kostis@REDACTED> wrote:
> 
>> Torben Hoffmann wrote:
>> 
>>> I am afraid that Bernard is right - there is no difference... neither erlc
>>> or Dialyzer picks it up.
>>> 
>>> I would like to hear from the OTP team and/or the Dialyzer team to
>>> understand what is cooking here.
>>> 
>> 
>> There is not much to say here, nor anything fishy is cooking. It's just
>> that or's/orelse's in guards are not so common in their proper treatment is
>> not so easy.
>> 
> That was my fear/expectation - as Joe once said "It is easy to get the
> typing right in 98% of the cases and then you'll have to fight hard to get
> the last 2%"
> 
> 
>> 
>> Neither erlc not dialyzer ever promised that it will generate all possible
>> warnings. In fact, as far as dialyzer is concerned the only thing that was
>> promised is that it will not generate a false warning.
>> 
> That is fair enough - I was just surprised that this one got through, but
> the handling of or in a guard is going to create some nasty scenarios.
> 
> 
>> 
>> Now, having written that, thanks for your mail because it gives us a
>> concrete test case to improve erlc and/or dialyzer.
>> 
> Great - this reinforces my belief in sharing experiences!
> 
> Cheers,
> Torben
> 
> 
>> 
>> Kostis
>> 
> 
> 
> 
> -- 
> http://www.linkedin.com/in/torbenhoffmann


From mixolyde@REDACTED  Tue Jul 20 14:47:50 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Tue, 20 Jul 2010 08:47:50 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>
Message-ID: <AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>

On Tue, Jul 20, 2010 at 8:30 AM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
> On Tue, Jul 20, 2010 at 2:26 PM, Brian Williams wrote:
>> On Mon, Jul 19, 2010 at 4:22 PM, Tuncer Ayaz wrote:
>>> On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>>>>
>>>> Where would I look for this dump?
>>>
>>> Default should be C:\Windows\minidumps and I think it's configurable.
>>>
>>
>> That directory doesn't exist. I guess I have to configure it in
>> Windows somewhere? I don't know where to do that.
>
> What about C:\Windows\minidump?
>

No. I should probably add that this is a windows 7 box. Is that
location determined by the OS when it detects the crash, or by werl
before it dies?

-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From tony@REDACTED  Tue Jul 20 13:57:55 2010
From: tony@REDACTED (Tony Rogvall)
Date: Tue, 20 Jul 2010 13:57:55 +0200
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific  user state?
In-Reply-To: <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>  <AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>  <AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com>  <8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se> <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com>
Message-ID: <AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se>


On 20 jul 2010, at 00.57, Tony Arcieri wrote:

> On Mon, Jul 19, 2010 at 4:48 PM, Tony Rogvall <tony@REDACTED> wrote:
> Why not use a global ets table? (use socket/port as a key)
> 
> Then you lose the O(1) properties of having the whole system round trip state for you.  In that regard I'd prefer to use a process per connection.
>  

Why do you lose the O(1) ? ets:lookup on a set table is O(1) ?  ordered_set is O(log(N)) .
Please enlighten me ;-)

> (There is a hidden way of doing it, but it's already taken by inet ;-)
> 
> Ooh really!  What's the hidden way of doing it?

It's not really hidden, it's in the source among the built in function. It will not solve your problem, not any 
better than a global ets table anyhow.

24> {ok,S} = gen_tcp:connect("www.google.org", 80, [{active,false}]).
{ok,#Port<0.2958>}
25> erlang:port_get_data(S).
inet_tcp

As you can see the data bound to the socket is the protocol module atom. This is use for dispatching
to the correct module when using gen_tcp/gen_udp.
You can call erlang:port_set_data(S, foo) but then the gen_tcp calls will not work anymore.

If you put anything other than a "constant" the data will be copied, since the garbage collector for a process
has a limited view. This is true for built in timers, ets tables etc.

> 
> I'm using this as part of implementing Reia and want Reia's socket objects included in the active mode messages as opposed to raw Erlang ports.  So I wouldn't be opposed to doing some crazy hacks so long as I can get them to peacefully coexist with inets.
>  

I have not peeked into Reia. What is the idea here? I think you will have to copy data enyway!

/Tony

> -- 
> Tony Arcieri
> Medioh! A Kudelski Brand


From erlang@REDACTED  Tue Jul 20 15:00:09 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Tue, 20 Jul 2010 15:00:09 +0200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <4C457B44.3060906@erix.ericsson.se>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
	<4C457B44.3060906@erix.ericsson.se>
Message-ID: <AANLkTim-9c_kw3kwqxVLJ6frxGZPDCweXa5m47c2jK0d@mail.gmail.com>

On Tue, Jul 20, 2010 at 12:32 PM, Sverker Eriksson
<sverker@REDACTED> wrote:
> Joe Armstrong wrote:
>>
>> I'm trying to parser ANSI C with leex and yecc and have run into
>> two problems.
>>
>> 1) /* ... */ comments. Leex is (as I understand things) greedy
>> ? thus I can't just write a regexp to match comments, since it
>> ? will consume no-only the current comment, but all comments until
>> ? the last comment in the file.
>>
>> ? To solve this I have just written a simple pre-processor to remove
>> comments
>> ? from the original source.
>>
>>
>
> re:run("/***first comment***/ /* next comment */",
> "/\\*([^*]|(\\*+([^*/])))*\\*+/").
>
> http://ostermiller.org/findcomment.html

  Ummm ... this will incorrectly match a literal string, containing a
comment  ... for example:

      char *p = "hi /* not a comment */ how are you?";

  Which is not what I want ..

  Easiest seems to be  bit of pure Erlang:




On Tue, Jul 20, 2010 at 12:32 PM, Sverker Eriksson
<sverker@REDACTED> wrote:
> Joe Armstrong wrote:
>>
>> I'm trying to parser ANSI C with leex and yecc and have run into
>> two problems.
>>
>> 1) /* ... */ comments. Leex is (as I understand things) greedy
>>   thus I can't just write a regexp to match comments, since it
>>   will consume no-only the current comment, but all comments until
>>   the last comment in the file.
>>
>>   To solve this I have just written a simple pre-processor to remove
>> comments
>>   from the original source.
>>
>>
>
> re:run("/***first comment***/ /* next comment */",
> "/\\*([^*]|(\\*+([^*/])))*\\*+/").
>
> http://ostermiller.org/findcomment.html

  Ummm ... this will incorrectly match a literal string, containing a
comment, for example:

      char *p = "hi /* not a comment */ how are you?";

  Which is not what I want ..

  Easiest seems to be  bit of pure Erlang:

%% remove_comments(Str) -> Str'
%%    remove C'style comments from a string
%%    note1: We retain any embedded NLs in the comment
%%           this is so that line number calculations in the tokenizer
%%           will still be correct
%%    note2. We copy literal strings. Since a literal string might
%%           contain a comment we have to parse the string
%%    note3: Comments must be replaced by at least one space
%%           Since otherwise "123/* comment */456" would be
%%           transformed into 123456 (a single integer) instead
%%           of two integers 123 and 456. This is why we add a
%%           space in the last line of skip_comment/2.

remove_comments(Str) -> remove_comments(Str, []).

remove_comments("/*" ++ T, L) -> skip_comment(T, L);
remove_comments([$"|T], L)    -> copy_string_literal(T, [$"|L]);
remove_comments([H|T], L)     -> remove_comments(T, [H|L]);
remove_comments([], L)        -> reverse(L).

skip_comment("*/" ++ T, L)   -> remove_comments(T, L);
skip_comment("\n" ++ T, L)   -> skip_comment(T, [$\n|L]);
skip_comment([_|T], L)       -> skip_comment(T, L);
skip_comment([], L)          -> remove_comments([], [$\s|L]).

copy_string_literal([$\\,$"|T], L) -> copy_string_literal(T, [$",$\\|L]);
copy_string_literal([$"|T], L)     -> copy_string_literal(T, [$"|L]);
copy_string_literal([H|T], L)      -> copy_string_literal(T, [H|L]);
copy_string_literal([], L)         -> copy([], L).

/Joe

>
> /Sverker
>
>

From tuncer.ayaz@REDACTED  Tue Jul 20 15:03:56 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Tue, 20 Jul 2010 15:03:56 +0200
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com> 
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com> 
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com> 
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com> 
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com> 
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com> 
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>
Message-ID: <AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com>

On Tue, Jul 20, 2010 at 2:47 PM, Brian Williams wrote:
> On Tue, Jul 20, 2010 at 8:30 AM, Tuncer Ayaz wrote:
>> On Tue, Jul 20, 2010 at 2:26 PM, Brian Williams wrote:
>>> On Mon, Jul 19, 2010 at 4:22 PM, Tuncer Ayaz wrote:
>>>> On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>>>>>
>>>>> Where would I look for this dump?
>>>>
>>>> Default should be C:\Windows\minidumps and I think it's configurable.
>>>>
>>>
>>> That directory doesn't exist. I guess I have to configure it in
>>> Windows somewhere? I don't know where to do that.
>>
>> What about C:\Windows\minidump?
>>
>
> No. I should probably add that this is a windows 7 box. Is that
> location determined by the OS when it detects the crash, or by werl
> before it dies?

It is determined by the crash handler configured in the OS settings
and possible that no crash dump has been written or that it's in a
different directory. I don't have a Windows install to check. You
might want to read the docs about configuring user-mode minidumps and
enabling crash dumps. Have a look in the MSDN.

You can also install windbg as the postmortem debugger and have it
spawned on each unhandled crash if you don't want to configure crash
dump settings. Also some applications like popular web browsers have
their own crash handler to collect and submit crash info to their
online database. These may not trigger a system level debugger at all
if their crash handler is not disabled.

From rvirding@REDACTED  Tue Jul 20 16:01:29 2010
From: rvirding@REDACTED (Robert Virding)
Date: Tue, 20 Jul 2010 16:01:29 +0200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTim-9c_kw3kwqxVLJ6frxGZPDCweXa5m47c2jK0d@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com> 
	<4C457B44.3060906@erix.ericsson.se> <AANLkTim-9c_kw3kwqxVLJ6frxGZPDCweXa5m47c2jK0d@mail.gmail.com>
Message-ID: <AANLkTimcpRfMHJFH408qSvs4JvelKOom8ZNE64dJ7uWo@mail.gmail.com>

If you use the comment regexp Sverker sent for a leex comment token
(which you then ignore at will) together with a C string regexp for a
string token then you should not have any problems. The comment regexp
will not match inside the string regexp and vice versa. You will only
get problems if you try to use it remove comments in a pre-parse.

The typedef problem is difficult. Anyway "real" C didn't have typedef's. :-)

Robert

On 20 July 2010 15:00, Joe Armstrong <erlang@REDACTED> wrote:
> On Tue, Jul 20, 2010 at 12:32 PM, Sverker Eriksson
> <sverker@REDACTED> wrote:
>> Joe Armstrong wrote:
>>>
>>> I'm trying to parser ANSI C with leex and yecc and have run into
>>> two problems.
>>>
>>> 1) /* ... */ comments. Leex is (as I understand things) greedy
>>> ? thus I can't just write a regexp to match comments, since it
>>> ? will consume no-only the current comment, but all comments until
>>> ? the last comment in the file.
>>>
>>> ? To solve this I have just written a simple pre-processor to remove
>>> comments
>>> ? from the original source.
>>>
>>>
>>
>> re:run("/***first comment***/ /* next comment */",
>> "/\\*([^*]|(\\*+([^*/])))*\\*+/").
>>
>> http://ostermiller.org/findcomment.html
>
> ?Ummm ... this will incorrectly match a literal string, containing a
> comment ?... for example:
>
> ? ? ?char *p = "hi /* not a comment */ how are you?";
>
> ?Which is not what I want ..
>
> ?Easiest seems to be ?bit of pure Erlang:
>
>
>
>
> On Tue, Jul 20, 2010 at 12:32 PM, Sverker Eriksson
> <sverker@REDACTED> wrote:
>> Joe Armstrong wrote:
>>>
>>> I'm trying to parser ANSI C with leex and yecc and have run into
>>> two problems.
>>>
>>> 1) /* ... */ comments. Leex is (as I understand things) greedy
>>> ? thus I can't just write a regexp to match comments, since it
>>> ? will consume no-only the current comment, but all comments until
>>> ? the last comment in the file.
>>>
>>> ? To solve this I have just written a simple pre-processor to remove
>>> comments
>>> ? from the original source.
>>>
>>>
>>
>> re:run("/***first comment***/ /* next comment */",
>> "/\\*([^*]|(\\*+([^*/])))*\\*+/").
>>
>> http://ostermiller.org/findcomment.html
>
> ?Ummm ... this will incorrectly match a literal string, containing a
> comment, for example:
>
> ? ? ?char *p = "hi /* not a comment */ how are you?";
>
> ?Which is not what I want ..
>
> ?Easiest seems to be ?bit of pure Erlang:
>
> %% remove_comments(Str) -> Str'
> %% ? ?remove C'style comments from a string
> %% ? ?note1: We retain any embedded NLs in the comment
> %% ? ? ? ? ? this is so that line number calculations in the tokenizer
> %% ? ? ? ? ? will still be correct
> %% ? ?note2. We copy literal strings. Since a literal string might
> %% ? ? ? ? ? contain a comment we have to parse the string
> %% ? ?note3: Comments must be replaced by at least one space
> %% ? ? ? ? ? Since otherwise "123/* comment */456" would be
> %% ? ? ? ? ? transformed into 123456 (a single integer) instead
> %% ? ? ? ? ? of two integers 123 and 456. This is why we add a
> %% ? ? ? ? ? space in the last line of skip_comment/2.
>
> remove_comments(Str) -> remove_comments(Str, []).
>
> remove_comments("/*" ++ T, L) -> skip_comment(T, L);
> remove_comments([$"|T], L) ? ?-> copy_string_literal(T, [$"|L]);
> remove_comments([H|T], L) ? ? -> remove_comments(T, [H|L]);
> remove_comments([], L) ? ? ? ?-> reverse(L).
>
> skip_comment("*/" ++ T, L) ? -> remove_comments(T, L);
> skip_comment("\n" ++ T, L) ? -> skip_comment(T, [$\n|L]);
> skip_comment([_|T], L) ? ? ? -> skip_comment(T, L);
> skip_comment([], L) ? ? ? ? ?-> remove_comments([], [$\s|L]).
>
> copy_string_literal([$\\,$"|T], L) -> copy_string_literal(T, [$",$\\|L]);
> copy_string_literal([$"|T], L) ? ? -> copy_string_literal(T, [$"|L]);
> copy_string_literal([H|T], L) ? ? ?-> copy_string_literal(T, [H|L]);
> copy_string_literal([], L) ? ? ? ? -> copy([], L).
>
> /Joe
>
>>
>> /Sverker
>>
>>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From tony.arcieri@REDACTED  Tue Jul 20 18:46:41 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Tue, 20 Jul 2010 10:46:41 -0600
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> 
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com> 
	<AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com> 
	<8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se> <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com> 
	<AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se>
Message-ID: <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com>

On Tue, Jul 20, 2010 at 5:57 AM, Tony Rogvall <tony@REDACTED> wrote:

> Why do you lose the O(1) ? ets:lookup on a set table is O(1) ?  ordered_set
> is O(log(N)) .
> Please enlighten me ;-)
>

I'm afraid you're the one who will have to enlighten me here.

My understanding is that ETS are implemented as Judy tables, which I know
very little about and sound rather complicated.  I can't find specific
details about the algorithmic complexity of Judy lookup, except one
reference to it being worse case O(log_256 n).  Are you suggesting it
is amortized O(1) or something?

Round tripping the state end-to-end ensures it never needs to be placed in
any kind of associative data structure and precludes the issue entirely.
 However, as you mentioned, yes it would seem that there would be a degree
of copying involved, or rather the construction of new terms which
delivering the gen_tcp messages has to do anyway.

It's sounding to me like a proxy process is probably the best way to go.
 This at least lets me link the proxy to the controlling process of a
particular socket, so I don't have to worry about "garbage collecting" the
ports/socket objects from an ets table.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From jesper.louis.andersen@REDACTED  Tue Jul 20 18:55:13 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Tue, 20 Jul 2010 18:55:13 +0200
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> 
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com> 
	<AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com> 
	<8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se> <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com> 
	<AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se> <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com>
Message-ID: <AANLkTinmtxrxmoS_sgpRlH5uo7FYPIzmFJj37rZSVmk5@mail.gmail.com>

On Tue, Jul 20, 2010 at 6:46 PM, Tony Arcieri <tony.arcieri@REDACTED> wrote:

> I'm afraid you're the one who will have to enlighten me here.
>
> My understanding is that ETS are implemented as Judy tables, which I know
> very little about and sound rather complicated. ?I can't find specific
> details about the algorithmic complexity of Judy lookup, except one
> reference to it being worse case O(log_256 n). ?Are you suggesting it
> is amortized O(1) or something?

O(log_256 n) is probably O(1) for most practical purposes. I am not
sure the VM uses Judy-arrays. The idea in the Judy-system is to beat
the real problem in modern CPU architectures: Memory bandwidth. Clock
cycles are "practically free" now. The question is how much data you
have to load. Judy-arrays provides a compact memory representation
which is then unpacked while in the CPU registers, trading memory
bandwidth for CPU cycles. In fact Judy has several possible
representations of an node in its tree-structure and can change
between them to ensure a good memory bandwidth usage.

Personally, I would pick ETS. It is a a rather simple start and it is
about the only thing we have in erlang when you want something
array-like or fast access.
> Round tripping the state end-to-end ensures it never needs to be placed in
> any kind of associative data structure and precludes the issue entirely.
> ?However, as you mentioned, yes it would seem that there would be a degree
> of copying involved, or rather the construction of new terms which
> delivering the gen_tcp messages has to do anyway.
>
> It's sounding to me like a proxy process is probably the best way to go.
> ?This at least lets me link the proxy to the controlling process of a
> particular socket, so I don't have to worry about "garbage collecting" the
> ports/socket objects from an ets table.
>
> --
> Tony Arcieri
> Medioh! A Kudelski Brand
>



-- 
J.

From tony@REDACTED  Tue Jul 20 19:00:43 2010
From: tony@REDACTED (Tony Rogvall)
Date: Tue, 20 Jul 2010 19:00:43 +0200
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific  user state?
In-Reply-To: <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>  <AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>  <AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com>  <8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se> <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com>  <AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se> <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com>
Message-ID: <7CFA916D-DAC0-456C-99EA-765045FFACD9@rogvall.se>


On 20 jul 2010, at 18.46, Tony Arcieri wrote:

> On Tue, Jul 20, 2010 at 5:57 AM, Tony Rogvall <tony@REDACTED> wrote:
> 
>> Why do you lose the O(1) ? ets:lookup on a set table is O(1) ?  ordered_set
>> is O(log(N)) .
>> Please enlighten me ;-)
>> 
> 
> I'm afraid you're the one who will have to enlighten me here.
> 
> My understanding is that ETS are implemented as Judy tables, which I know
> very little about and sound rather complicated.  I can't find specific
> details about the algorithmic complexity of Judy lookup, except one
> reference to it being worse case O(log_256 n).  Are you suggesting it
> is amortized O(1) or something?

ets set tables are implemented using linear hashing.
ets ordered_set tables are implemented  using avl tree.

/Tony


From max.lapshin@REDACTED  Tue Jul 20 19:11:46 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Tue, 20 Jul 2010 21:11:46 +0400
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <7CFA916D-DAC0-456C-99EA-765045FFACD9@rogvall.se>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com>
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com>
	<AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com>
	<8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se>
	<AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com>
	<AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se>
	<AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com>
	<7CFA916D-DAC0-456C-99EA-765045FFACD9@rogvall.se>
Message-ID: <AANLkTikKWsM9wGu-4NY7qa28Os93tRU8JtSrNmQXWgLa@mail.gmail.com>

Man, what ets tables if you will have copy on each access to ETS table?
Have you measured processes? Is one process per socket real overhead to you?

From mixolyde@REDACTED  Tue Jul 20 19:24:56 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Tue, 20 Jul 2010 13:24:56 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>
	<AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com>
Message-ID: <AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com>

On Tue, Jul 20, 2010 at 9:03 AM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
> On Tue, Jul 20, 2010 at 2:47 PM, Brian Williams wrote:
>> On Tue, Jul 20, 2010 at 8:30 AM, Tuncer Ayaz wrote:
>>> On Tue, Jul 20, 2010 at 2:26 PM, Brian Williams wrote:
>>>> On Mon, Jul 19, 2010 at 4:22 PM, Tuncer Ayaz wrote:
>>>>> On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>>>>>>
>>>>>> Where would I look for this dump?
>>>>>
>>>>> Default should be C:\Windows\minidumps and I think it's configurable.
>>>>>
>>>>
>>>> That directory doesn't exist. I guess I have to configure it in
>>>> Windows somewhere? I don't know where to do that.
>>>
>>> What about C:\Windows\minidump?
>>>
>>
>> No. I should probably add that this is a windows 7 box. Is that
>> location determined by the OS when it detects the crash, or by werl
>> before it dies?
>
> It is determined by the crash handler configured in the OS settings
> and possible that no crash dump has been written or that it's in a
> different directory. I don't have a Windows install to check. You
> might want to read the docs about configuring user-mode minidumps and
> enabling crash dumps. Have a look in the MSDN.
>
> You can also install windbg as the postmortem debugger and have it
> spawned on each unhandled crash if you don't want to configure crash
> dump settings. Also some applications like popular web browsers have
> their own crash handler to collect and submit crash info to their
> online database. These may not trigger a system level debugger at all
> if their crash handler is not disabled.
>

Looks like in windows 7, after turning mini dumps on in advanced
settings, they go to:

C:\Users\<username>\AppData\Local\CrashDumps


-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From tony.arcieri@REDACTED  Tue Jul 20 19:30:40 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Tue, 20 Jul 2010 11:30:40 -0600
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AANLkTinmtxrxmoS_sgpRlH5uo7FYPIzmFJj37rZSVmk5@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> 
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com> 
	<AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com> 
	<8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se> <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com> 
	<AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se> <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com> 
	<AANLkTinmtxrxmoS_sgpRlH5uo7FYPIzmFJj37rZSVmk5@mail.gmail.com>
Message-ID: <AANLkTim2bZx6dUc5YH3l5rCXjl9RZbTw-kn8VEP1v0Hv@mail.gmail.com>

On Tue, Jul 20, 2010 at 10:55 AM, Jesper Louis Andersen <
jesper.louis.andersen@REDACTED> wrote:

> Personally, I would pick ETS. It is a a rather simple start and it is
> about the only thing we have in erlang when you want something
> array-like or fast access.


Why would you pick ETS over a proxy process for something ephemeral like a
socket, and how would you manage garbage collecting the terms in all cases
when the socket closes?

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From tony.arcieri@REDACTED  Tue Jul 20 19:34:14 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Tue, 20 Jul 2010 11:34:14 -0600
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
Message-ID: <AANLkTilcC5L1rz3WG8AQiXl-NzDZnnXVm3OFAE41Za1d@mail.gmail.com>

On Tue, Jul 20, 2010 at 3:28 AM, Joe Armstrong <erlang@REDACTED> wrote:

>   The traditional yacc/lex approach solves this with a context
>   sensitive lex and feedback between yacc and lex. But the Erlang
>   leex and yacc seem to be written as separated passes, are there some
>   internal functions that allow feedback between leex and yacc?


I've run into the need for lexer/parser feedback myself, specifically
processing interpolated strings (that contain expressions from the outer
language) in Reia.  I haven't found a good solution.  Interpolation works
but only on a subset of expressions... for example you can't nest strings
within strings.

Have you thought about using neotoma?

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From jesper.louis.andersen@REDACTED  Tue Jul 20 20:07:37 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Tue, 20 Jul 2010 20:07:37 +0200
Subject: [erlang-questions] Can gen_tcp/inets store connection-specific 
	user state?
In-Reply-To: <AANLkTim2bZx6dUc5YH3l5rCXjl9RZbTw-kn8VEP1v0Hv@mail.gmail.com>
References: <AANLkTiksNc6pwyRHcmxrpiGLp-dzpGN4l9yWCgdtEcfb@mail.gmail.com> 
	<AANLkTilwORLUmbGuuV_LtkSliqCE2N6IIETon3WP-ZNz@mail.gmail.com> 
	<AANLkTilS6y924SnQ4KJ-Ok6TchNg9eUfi7paQ5JLWki_@mail.gmail.com> 
	<8EE995C5-D04B-4E1F-8BCF-C7289C7C6DC6@rogvall.se> <AANLkTilHJPxMJhEmzRaru354tIUaRyCDaZ2GiKSVgkIv@mail.gmail.com> 
	<AE5DF672-7634-4142-BAF1-E8E056F46708@rogvall.se> <AANLkTilk-5yXCRFPShx_DSbC6UyETCefppPHFIoOPkGo@mail.gmail.com> 
	<AANLkTinmtxrxmoS_sgpRlH5uo7FYPIzmFJj37rZSVmk5@mail.gmail.com> 
	<AANLkTim2bZx6dUc5YH3l5rCXjl9RZbTw-kn8VEP1v0Hv@mail.gmail.com>
Message-ID: <AANLkTilDCLzyABOrQOTLlXxwE4_VUuHKoat7nTitDzOQ@mail.gmail.com>

On Tue, Jul 20, 2010 at 7:30 PM, Tony Arcieri <tony.arcieri@REDACTED> wrote:
>
> Why would you pick ETS over a proxy process for something ephemeral like a
> socket, and how would you manage garbage collecting the terms in all cases
> when the socket closes?

Oh! For a Socket I would go for the proxy process.


-- 
J.

From erlang@REDACTED  Tue Jul 20 20:39:47 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Tue, 20 Jul 2010 20:39:47 +0200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTilcC5L1rz3WG8AQiXl-NzDZnnXVm3OFAE41Za1d@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
	<AANLkTilcC5L1rz3WG8AQiXl-NzDZnnXVm3OFAE41Za1d@mail.gmail.com>
Message-ID: <AANLkTilUnFp3v-5oHl-UZU_R_vXHSUDX7KkTsM20XRDr@mail.gmail.com>

On Tue, Jul 20, 2010 at 7:34 PM, Tony Arcieri <tony.arcieri@REDACTED> wrote:
> On Tue, Jul 20, 2010 at 3:28 AM, Joe Armstrong <erlang@REDACTED> wrote:
>>
>> ??The traditional yacc/lex approach solves this with a context
>> ? sensitive lex and feedback between yacc and lex. But the Erlang
>> ? leex and yacc seem to be written as separated passes, are there some
>> ? internal functions that allow feedback between leex and yacc?
>
> I've run into the need for lexer/parser feedback myself, specifically
> processing interpolated strings (that contain expressions from the outer
> language) in Reia. ?I haven't found a good solution. ?Interpolation works
> but only on a subset of expressions... for example you can't nest strings
> within strings.
> Have you thought about using neotoma?

Yes - I've also been playing with my own peg combinator library :-).
The problem is that LALR(1) parsers can give you pretty good automatic error
diagnostics on faulty input. Peg grammars just fail - period - and you
have to write
your own error recovery in the grammar - on the other hand the peg grammar
is much nicer than the yacc grammar

/Joe


>
> --
> Tony Arcieri
> Medioh! A Kudelski Brand
>

From tony.arcieri@REDACTED  Tue Jul 20 20:43:27 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Tue, 20 Jul 2010 12:43:27 -0600
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTilUnFp3v-5oHl-UZU_R_vXHSUDX7KkTsM20XRDr@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com> 
	<AANLkTilcC5L1rz3WG8AQiXl-NzDZnnXVm3OFAE41Za1d@mail.gmail.com> 
	<AANLkTilUnFp3v-5oHl-UZU_R_vXHSUDX7KkTsM20XRDr@mail.gmail.com>
Message-ID: <AANLkTikvLphc9jgLHLw8zFIJufgL7sXDKeA5iY8nGJyP@mail.gmail.com>

On Tue, Jul 20, 2010 at 12:39 PM, Joe Armstrong <erlang@REDACTED> wrote:

> Yes - I've also been playing with my own peg combinator library :-).
> The problem is that LALR(1) parsers can give you pretty good automatic
> error
> diagnostics on faulty input. Peg grammars just fail - period - and you
> have to write
> your own error recovery in the grammar - on the other hand the peg grammar
> is much nicer than the yacc grammar
>

That's been my observation as well, and why I've continued to use leex and
yecc for Reia.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From tschwarzkopf@REDACTED  Tue Jul 20 18:57:04 2010
From: tschwarzkopf@REDACTED (Thomas Schwarzkopf)
Date: Tue, 20 Jul 2010 18:57:04 +0200
Subject: Deleting rows in Mnesia
Message-ID: <4C45D560.1070000@gmx.net>

Hi,

when I try to delete a row in a Mnesia table like this:

F = fun() -> mnesia:delete({sometable, somekey}) end.
mnesia:transaction(F).

returns

{atomic, ok}

even if somekey does not exist. Why is this?
I would expect an aborted transaction like in the case of a non-existing
tablename.

Thanks

Thomas

From arun.suresh@REDACTED  Tue Jul 20 21:59:43 2010
From: arun.suresh@REDACTED (Arun Suresh)
Date: Wed, 21 Jul 2010 01:29:43 +0530
Subject: [erlang-questions] Distributed erlang not working after upgrading to 
	OSX Snow leopard
Message-ID: <AANLkTik8wmCKZz5VyaRTH8bm9OhQ_LF0hGzdHy13dF7Y@mail.gmail.com>

Hi

Im currently running erlang R13B04 (erts-5.7.5) which I built from source.
After upgrading to Snow leopard, I can get distributed erlang to work...

On terminal 1:

[asuresh@REDACTED ~] erl -sname test1 -setcookie hello
Erlang R13B04 (erts-5.7.5) [source] [smp:2:2] [rq:2] [async-threads:0]
[hipe] [kernel-poll:false]

Eshell V5.7.5  (abort with ^G)
(test1@REDACTED)1>

On terminal 2:

[asuresh@REDACTED ~] erl -sname test2 -setcookie hello
Erlang R13B04 (erts-5.7.5) [source] [smp:2:2] [rq:2] [async-threads:0]
[hipe] [kernel-poll:false]

Eshell V5.7.5  (abort with ^G)
(test2@REDACTED)1> net_adm:ping('test1@REDACTED').
pang
(test2@REDACTED)2>


As you can see.. net_adm:ping() returns a pang.. Could someone please give
me some pointers as to how I might start debugging this issue ?
I have me /etc/hosts file correctly configured

-Arun

From ok@REDACTED  Tue Jul 20 23:53:37 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Wed, 21 Jul 2010 09:53:37 +1200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com> <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com> <4C43F206.1010804@m5net.com> <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
Message-ID: <A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>


On Jul 20, 2010, at 8:12 PM, Torben Hoffmann wrote:

> I have not tried this out in Haskel (or any other FP language) since  
> I am
> trying to keep my computer clean, ie, only Erlang and what that  
> entails ;-)
> But I suspect that Haskel is capable of detecting this.

There are several Haskell compilers.

Let's construct two little Haskell functions.

    transparent 1 = False
    transparent 2 = False
    transparent 1 = True

    opaque n | n == 1 || n == 2 = False
    opaque 1                    = True

    main = print (transparent 1, transparent 2, opaque 1, opaque 2)

and see what Haskell makes of them.
	f% ghci		# This is version 6.6.1
	Prelude> :load test.hs
	[1 of 1] Compiling Main             ( test.hs, interpreted )

	test.hs:1:0:
	    Warning: Pattern match(es) are overlapped
	             In the definition of `transparent': transparent 1 = ...
	Ok, modules loaded: Main.

	f% nhc98 test.hs
	f% a.out
	(False,False,False,False)

So nhc98 was completely silent, and ghc 6.6.1 did notice the
explicit pattern duplication but did *NOT* notice the duplication
of a pattern in a guard, any more than Erlang did.

I can't construct an SML analogue, because SML has no guards.

This is expecting far more cleverness from the Erlang system than
I would expect people to expect.


From ok@REDACTED  Wed Jul 21 00:20:10 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Wed, 21 Jul 2010 10:20:10 +1200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
Message-ID: <6D5C0441-0BB7-4A36-B28A-24056B207984@cs.otago.ac.nz>


On Jul 20, 2010, at 9:28 PM, Joe Armstrong wrote:

> I'm trying to parser ANSI C with leex and yecc and have run into
> two problems.
>
> 1) /* ... */ comments. Leex is (as I understand things) greedy
>   thus I can't just write a regexp to match comments, since it
>   will consume no-only the current comment, but all comments until
>   the last comment in the file.

Actually you CAN write a regular expression which matches
C comments.  The trivial /[/][*].*[*][/]/ is not going to work,
but it isn't particularly difficult to write a regular expression
that WILL work.  In fact, some books about Lex and Yacc give it
to you.  Oh heck.  I'm not going to leave it as an exercise for
the reader after all.  Think of a C comment as
	"/*"
	zero or more blocks of (not star)* (star)+ (not star or slash)
	one block of (not star)* (star)+ /

	/\/\*([^*]*\*+[^/*])*[^*]*\*+\//

Lex books recommend NOT doing this, not because there's any great
difficulty in constructing a regular expression, but because
recognising a comment that way means *storing* the comment as if it
were a token.  If you want to keep the comments, that's a great
thing to do.  If you don't, you have to allocate a huge token
buffer you wouldn't otherwise need.

There's another approach in (f)lex, which is to use states.
Does Leex support those?

However, there's another approach that might be worth considering.
Run the C files through the preprocessor first, and let *it*
strip out the comments.



From torben.lehoff@REDACTED  Wed Jul 21 00:24:02 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Wed, 21 Jul 2010 00:24:02 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
	<AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
	<A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>
Message-ID: <AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>

On Tue, Jul 20, 2010 at 23:53, Richard O'Keefe <ok@REDACTED> wrote:

>
> On Jul 20, 2010, at 8:12 PM, Torben Hoffmann wrote:
>
>  I have not tried this out in Haskel (or any other FP language) since I am
>> trying to keep my computer clean, ie, only Erlang and what that entails
>> ;-)
>> But I suspect that Haskel is capable of detecting this.
>>
>
> There are several Haskell compilers.
>
> Let's construct two little Haskell functions.
>
>   transparent 1 = False
>   transparent 2 = False
>   transparent 1 = True
>
>   opaque n | n == 1 || n == 2 = False
>   opaque 1                    = True
>
>   main = print (transparent 1, transparent 2, opaque 1, opaque 2)
>
> and see what Haskell makes of them.
>        f% ghci         # This is version 6.6.1
>        Prelude> :load test.hs
>        [1 of 1] Compiling Main             ( test.hs, interpreted )
>
>        test.hs:1:0:
>            Warning: Pattern match(es) are overlapped
>                     In the definition of `transparent': transparent 1 = ...
>        Ok, modules loaded: Main.
>
>        f% nhc98 test.hs
>        f% a.out
>        (False,False,False,False)
>
> So nhc98 was completely silent, and ghc 6.6.1 did notice the
> explicit pattern duplication but did *NOT* notice the duplication
> of a pattern in a guard, any more than Erlang did.
>
I stand corrected! Thanks for putting my assumptions to a timely death!!


>
> I can't construct an SML analogue, because SML has no guards.
>
> This is expecting far more cleverness from the Erlang system than
> I would expect people to expect.
>
> Well, I actually ran into a problem with this in a real program and it was
by sheer coincidence that I noticed the overlapping clauses, so I would have
liked the compiler to spot this.

Given the Haskel evidence it seems that the problem is even harder than I
imagined at first, so maybe I am expecting too much... expecting too much
becomes so natural when you work with Erlang.

This means that there are two or more actions to be taken on this:
1. Ask a bright person who is into type checking to look at this in his
thesis project.
2. Change my style of programming so that it stays within the bounds of what
the compiler will warn me about.
3. [Optional] Put some explanations/warnings in the Erlang documentation so
that people are not let astray like me.

Action 3 is probably very low priority since it seems to almost only me that
has had this problem.

Thanks for all the inputs!
Cheers,
Torben



-- 
http://www.linkedin.com/in/torbenhoffmann

From g@REDACTED  Wed Jul 21 00:36:30 2010
From: g@REDACTED (Garrett Smith)
Date: Tue, 20 Jul 2010 17:36:30 -0500
Subject: gen_server2 proliferation
Message-ID: <AANLkTinmfXs1jMSQt6W1XOwWh54hXGhjJNXFFeOXLdPz@mail.gmail.com>

I've been using sed quite a bit, renaming gen_server2 modules to
resolve naming conflict across projects.

Appending the last three chars of a hex digest of the project name
works well. That's room for 4k versions!

Short of military tribunal, does anyone have a thought on how to resolve this?

Is there a common set of changes that could possibly make it into
Erlang? Should someone approach the projects with a request to prefix
the names, as it typically done?

Of course, this is only a problem when projects coexist :)

Garrett

From ok@REDACTED  Wed Jul 21 01:43:59 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Wed, 21 Jul 2010 11:43:59 +1200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com> <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com> <4C43F206.1010804@m5net.com> <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com> <A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz> <AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
Message-ID: <2F3067FF-BE2D-4E08-8AB8-286499350480@cs.otago.ac.nz>


On Jul 21, 2010, at 10:24 AM, Torben Hoffmann wrote:
>
>
> Well, I actually ran into a problem with this in a real program and  
> it was by sheer coincidence that I noticed the overlapping clauses,  
> so I would have liked the compiler to spot this.

It would be really really good to see the actual code, if possible.
>
> Given the Haskel evidence it seems that the problem is even harder  
> than I imagined at first, so maybe I am expecting too much...  
> expecting too much becomes so natural when you work with Erlang.
>
> This means that there are two or more actions to be taken on this:
> 1. Ask a bright person who is into type checking to look at this in  
> his thesis project.

There is no type problem here; everything is well typed.

Let's take a really abstract look at this.
We have two clauses
	...
	f(<patterns 1>) when <guard 1> -> <body 1>
	...
	f(<patterns 2>) when <guard 2> -> <body 2>
	...
and the question is whether there exist <arguments>
such that
	(<patterns 1> = <arguments> and then <guard 1>)
and
	(<patterns 2> = <arguments> and then <guard 2>)
has a solution.  A program to solve this problem would
presumably be able to display such <arguments>, at least
schematically.

Now, it's clear that *both* clauses have a match only if
at least one of them has a match.  So the problem of
checking for an overlap is at least as hard as the problem
of determining whether *one* clause can reach its ->

Let X1,...,Xn be variables.
Let P(X1,...,Xn) be a polynomial in X1,...,Xn with
integer coefficients.  That is, it involves integers,
head variables, add, subtract, and multiply, and is
clearly a legal guard expression.
Consider the clause

	f(X1, ..., Xn)
	  when is_integer(X1), ..., is_integer(Xn),
	       P(X1, ..., Xn) =:= 0 ->
	    <body>

The general problem of detecting whether two clauses
has to be AT LEAST as hard as detecting whether THIS
clause can start executing its body.

Matiyasevich showed in 1970 that there is NO algorithm
that can decide this.  (Hilbert's tenth problem: find
an algorithm to decide whether any Diophantine equation
has a solution; the answer is sorry, can't do that.)

Thus we have a typical "Full employment theorem" for
writers of Erlang (or Haskell) checkers: it will
always be possible to find overlap examples that cannot
be detected by the current algorithm, so it will always
be possible to improve the current algorithm.

And note that this applies with very limited guards:
there is no disjunction here, no reaching into data
structures, in fact no data structures other than integers.


> 2. Change my style of programming so that it stays within the bounds  
> of what the compiler will warn me about.

I have a bad feeling about the solvability of "do these two
binary patterns have a common instance", so you had better
avoid binary patterns.  (:-)

You can't expect a compiler to warn you about every conceivable
problem.  As a trivial example,

	f() -> m:g(1).

If m:g/1 is not available to the compiler, who knows what it might
do?  How could the compiler warn you "this function will always
crash" when it hasn't seen that function?  Worse, suppose the
compiler *can* see a definition of m:g/1, but at run time it is
replaced by a different one.  Is the compiler to warn you about
every remote call
	Warning: you are calling a function that might be
	replaced at run time by another definition that might
	do all sorts of horrible things.

I suppose we could call this a full employment theorem for
testers and debuggers:  in any nontrivial programming language
there will be bugs expressible that no algorithm can
infallibly detect.  (Note: the Dialyzer does NOT claim to
infallibly detect bugs.  It makes the weaker claim that the
things it detects are bugs; it will certainly miss some.)

Keep your style as clear as you can so that other people can
understand it.  Write specifications and test cases.  (Ulrich
Neumerkel -- hope I've spelled that right -- has worked on a
teaching environment for Prolog called GUPU that requires
students to write test cases first, and tests the tests.  A
neat idea.)  When you find something that the compiler didn't,
ask if the compiler can be improved to detect it.  It's an
economic trade-off:  how likely is the bug, what are the
expected consequences of not finding it, how costly will it
be to improve the compiler to that level.

> 3. [Optional] Put some explanations/warnings in the Erlang  
> documentation so that people are not led astray like me.

It's not clear precisely what you want people to be warned
against.  "Expect the compiler to be right but dumb" is about
all I can think of here.


From toby@REDACTED  Wed Jul 21 02:00:13 2010
From: toby@REDACTED (Toby Thain)
Date: Tue, 20 Jul 2010 20:00:13 -0400
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTimcpRfMHJFH408qSvs4JvelKOom8ZNE64dJ7uWo@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>  <4C457B44.3060906@erix.ericsson.se> <AANLkTim-9c_kw3kwqxVLJ6frxGZPDCweXa5m47c2jK0d@mail.gmail.com> <AANLkTimcpRfMHJFH408qSvs4JvelKOom8ZNE64dJ7uWo@mail.gmail.com>
Message-ID: <3E12FB9D-EAFD-4791-99CD-BDA29AB5B9EC@telegraphics.com.au>


On 20-Jul-10, at 10:01 AM, Robert Virding wrote:

> ...
>
> The typedef problem is difficult. Anyway "real" C didn't have  
> typedef's. :-)

^^ what "real" C are you referring to?

--Toby


From arun.suresh@REDACTED  Wed Jul 21 06:17:47 2010
From: arun.suresh@REDACTED (Arun Suresh)
Date: Wed, 21 Jul 2010 09:47:47 +0530
Subject: [erlang-questions] Distributed erlang not working after upgrading 
	to OSX Snow leopard
In-Reply-To: <AANLkTilZ92XgSPk6OolAiI_YW7zW9odvxNXqJOvs20Ca@mail.gmail.com>
References: <AANLkTik8wmCKZz5VyaRTH8bm9OhQ_LF0hGzdHy13dF7Y@mail.gmail.com>
	<AANLkTilZ92XgSPk6OolAiI_YW7zW9odvxNXqJOvs20Ca@mail.gmail.com>
Message-ID: <AANLkTineyDdHF6TQ5LdyYnDkQF3K7mLBZk9Mwq6peGYC@mail.gmail.com>

Thanx michal..
that seems to have done the trick..

-Arun

On Wed, Jul 21, 2010 at 2:57 AM, Michal Zajda <zajdamichal@REDACTED> wrote:

> Recompile your otp with --enable-darwin-64bit option to configure script.
> It is described in INSTALL.md file (in OTP sources).
>
> On 20 July 2010 21:59, Arun Suresh <arun.suresh@REDACTED> wrote:
>
>> Hi
>>
>> Im currently running erlang R13B04 (erts-5.7.5) which I built from source.
>> After upgrading to Snow leopard, I can get distributed erlang to work...
>>
>> On terminal 1:
>>
>> [asuresh@REDACTED ~] erl -sname test1 -setcookie hello
>> Erlang R13B04 (erts-5.7.5) [source] [smp:2:2] [rq:2] [async-threads:0]
>> [hipe] [kernel-poll:false]
>>
>> Eshell V5.7.5  (abort with ^G)
>> (test1@REDACTED)1>
>>
>> On terminal 2:
>>
>> [asuresh@REDACTED ~] erl -sname test2 -setcookie hello
>> Erlang R13B04 (erts-5.7.5) [source] [smp:2:2] [rq:2] [async-threads:0]
>> [hipe] [kernel-poll:false]
>>
>> Eshell V5.7.5  (abort with ^G)
>> (test2@REDACTED)1> net_adm:ping('test1@REDACTED').
>> pang
>> (test2@REDACTED)2>
>>
>>
>> As you can see.. net_adm:ping() returns a pang.. Could someone please give
>> me some pointers as to how I might start debugging this issue ?
>> I have me /etc/hosts file correctly configured
>>
>> -Arun
>>
>
>

From Mike.French@REDACTED  Wed Jul 21 10:21:36 2010
From: Mike.French@REDACTED (French, Mike)
Date: Wed, 21 Jul 2010 09:21:36 +0100
Subject: [erlang-questions] Parsing C with leex and yecc
Message-ID: <3F8EEA01CF53D74DB4A9EC314D82B4F3224792@wells154942>



> -----Original Message-----
> From: erlang-questions@REDACTED 
> [mailto:erlang-questions@REDACTED]On
> Behalf Of Joe Armstrong
> Sent: 20 July 2010 19:40
> To: Tony Arcieri
> Cc: Erlang
> Subject: Re: [erlang-questions] Parsing C with leex and yecc
...
> Yes - I've also been playing with my own peg combinator library :-).
> The problem is that LALR(1) parsers can give you pretty good automatic
error
> diagnostics on faulty input. Peg grammars just fail - period - and you
> have to write your own error recovery in the grammar ...

I think PEGs can be written to handle errors elegantly.
Each combinator applies an exploration strategy to the input top-down,
and passes the remaining input on to subsequent analysis steps.
When an error occurs, it should pass back the reason for the failure.
Each error ultimately originates from a failed character lexing rule.

Just as input is reduced by moving forwards, so errors are accumulated 
flowing backwards. Each combinator is then responsible for merging the 
error reports coming back into it. The error handling process is in 
some sense dual to the original input processing, so in some sense, 
each parser combinator must contain an error co-combinator.

Failure occurs when all available paths have been explored.
Depending how errors have been filtered and discarded,
it is possible for full tree of errors to be returned to the original rule.
In practice, the only interesting co-combinator is in the choice rule.
A simple co-combinator policy is to keep the deepest (rightmost) error,
so the final report is a stack trace of failed rules and input positions.
This may or may not correspond to the 'real' error. 

Mike

 

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From hawk.mattsson@REDACTED  Wed Jul 21 10:33:38 2010
From: hawk.mattsson@REDACTED (=?ISO-8859-1?Q?H=E5kan_Mattsson?=)
Date: Wed, 21 Jul 2010 10:33:38 +0200
Subject: [erlang-questions] Deleting rows in Mnesia
In-Reply-To: <4C45D560.1070000@gmx.net>
References: <4C45D560.1070000@gmx.net>
Message-ID: <AANLkTikqviufNceg5hGdCUH0bDDvu_eBkfcnGwkG_PSR@mail.gmail.com>

On Tue, Jul 20, 2010 at 6:57 PM, Thomas Schwarzkopf
<tschwarzkopf@REDACTED> wrote:
> Hi,
>
> when I try to delete a row in a Mnesia table like this:
>
> F = fun() -> mnesia:delete({sometable, somekey}) end.
> mnesia:transaction(F).
>
> returns
>
> {atomic, ok}
>
> even if somekey does not exist. Why is this?
> I would expect an aborted transaction like in the case of a non-existing
> tablename.

Access of a non-existing table is regarded as an error. It is very likely
that the application is not properly installed (forgot to create the table).

Whether a record with a given key exists or not at a given timepoint
is very application dependent. Mnesia does not bother.

/H?kan

From michal.ptaszek@REDACTED  Wed Jul 21 10:40:17 2010
From: michal.ptaszek@REDACTED (Michal Ptaszek)
Date: Wed, 21 Jul 2010 08:40:17 +0000 (GMT)
Subject: Erlang internal scheduler implementation
Message-ID: <1771089662.619901279701617136.JavaMail.root@zimbra>

Hi All,

is there any kind of detailed documentation
(except the comments in the source code) on 
behaviour/conception/strategy for Erlang 
process scheduler?

How the processes are given CPU time, when they
are pre-empted, can we and why do we migrate 
processes between different scheduler queues? 

I've already found Ulf Wiger's explanation 
in the mailing list archive:
http://www.erlang.org/pipermail/erlang-questions/2001-April/003131.html
Nevertheless, this email is 9 years old so probably
a lot of things changed (e.g. better SMP 
support). 

Best regards,
Michal Ptaszek

From mail@REDACTED  Wed Jul 21 11:14:55 2010
From: mail@REDACTED (Tim Fletcher)
Date: Wed, 21 Jul 2010 02:14:55 -0700 (PDT)
Subject: gen_server2 proliferation
In-Reply-To: <AANLkTinmfXs1jMSQt6W1XOwWh54hXGhjJNXFFeOXLdPz@mail.gmail.com>
References: <AANLkTinmfXs1jMSQt6W1XOwWh54hXGhjJNXFFeOXLdPz@mail.gmail.com>
Message-ID: <c20e1cf1-de3d-4dfb-9aa8-b969eec95230@i31g2000yqm.googlegroups.com>

> Short of military tribunal, does anyone have a thought on how to resolve this?

I posted about this a while ago, but nobody commented:

  http://groups.google.com/group/erlang-programming/msg/1710c37051c2bd6a

  http://www.erlang.org/cgi-bin/ezmlm-cgi/4/50438


Is it possible to just use gen_server2 when starting processes (i.e.
gen_server2:start_link etc), and use gen_server for all other calls
(i.e. gen_server:call etc)? That's a smaller change to make than using
gen_server2 all over.

I don't think including a copy of gen_server2 in every project is
sensible, but that's my opinion. Alternatives seem to be listing it as
a dependency, or as you say, prefixing the project name (e.g.
riak_gen_server.erl). The former is more hassle for users of a
project, the latter is not much different from including gen_server2
except that you don't get clashes with coexisting projects.


> Is there a common set of changes that could possibly make
> it into Erlang?

There was a thread about the possibility of merging the changes back
into OTP:

  http://groups.google.com/group/erlang-programming/browse_thread/thread/112e6692ab6fadcd

  http://www.erlang.org/cgi-bin/ezmlm-cgi?4:sss:45410:200907:pklailjkmmfghgejommi


Not sure if anything came of that (?).

Tim

From attila.r.nohl@REDACTED  Wed Jul 21 11:48:13 2010
From: attila.r.nohl@REDACTED (Attila Rajmund Nohl)
Date: Wed, 21 Jul 2010 11:48:13 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
	<AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
	<A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>
	<AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
Message-ID: <AANLkTin77Bq2vfNgT7Mf1TZzreCATWHFkPeXgpJ-T92q@mail.gmail.com>

2010/7/21, Torben Hoffmann <torben.lehoff@REDACTED>:
> On Tue, Jul 20, 2010 at 23:53, Richard O'Keefe <ok@REDACTED> wrote:
[...]
>> So nhc98 was completely silent, and ghc 6.6.1 did notice the
>> explicit pattern duplication but did *NOT* notice the duplication
>> of a pattern in a guard, any more than Erlang did.
>>
> I stand corrected! Thanks for putting my assumptions to a timely death!!

I think there's one more thing: Erlang function clauses overlap all
the time. It's a common pattern that:

f(1) -> ok;
f(2) -> ok;
f(_) -> not_ok.

and obviously the third pattern overlaps with the first two, but we
really don't want a warning for that.

From Mike.French@REDACTED  Wed Jul 21 13:35:29 2010
From: Mike.French@REDACTED (French, Mike)
Date: Wed, 21 Jul 2010 12:35:29 +0100
Subject: [erlang-questions] Parsing C with leex and yecc
Message-ID: <3F8EEA01CF53D74DB4A9EC314D82B4F3224796@wells154942>


> -----Original Message-----
> From: erlang-questions@REDACTED 
> [mailto:erlang-questions@REDACTED]On
> Behalf Of French, Mike
> Sent: 21 July 2010 09:22
> To: 'Joe Armstrong'; Tony Arcieri
> Cc: Erlang
> Subject: RE: [erlang-questions] Parsing C with leex and yecc
> 
> > -----Original Message-----
> > From: erlang-questions@REDACTED 
> > [mailto:erlang-questions@REDACTED]On
> > Behalf Of Joe Armstrong
> > Sent: 20 July 2010 19:40
> > To: Tony Arcieri
> > Cc: Erlang
> > Subject: Re: [erlang-questions] Parsing C with leex and yecc
> ...
> > Yes - I've also been playing with my own peg combinator library :-).
> > The problem is that LALR(1) parsers can give you pretty good automatic
error
> > diagnostics on faulty input. Peg grammars just fail - period - and you
> > have to write your own error recovery in the grammar ...
> 
> I think PEGs can be written to handle errors elegantly.
> Each combinator applies an exploration strategy to the input top-down,
> and passes the remaining input on to subsequent analysis steps.
> When an error occurs, it should pass back the reason for the failure.
> Each error ultimately originates from a failed character lexing rule.
> 
> Just as input is reduced by moving forwards, so errors are accumulated 
> flowing backwards. Each combinator is then responsible for merging the 
> error reports coming back into it. The error handling process is in 
> some sense dual to the original input processing, so in some sense, 
> each parser combinator must contain an error co-combinator.

This duality becomes clearer with a slight change of terminology.
It's not really an 'error' until all rules have not matched.
So if you replace 'parser' with 'match' and 'error' with 'non-match', then:

  "Each match combinator must contain a non-match co-combinator".

Mike


Thales UK Ltd (Wells) DISCLAIMER: The information contained in this e-mail
is confidential. It may also be legally privileged. It is intended only for
the stated addressee(s) and access to it by any other person is
unauthorised. If you are not an addressee, you must not disclose, copy,
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868273

From ulf.wiger@REDACTED  Wed Jul 21 14:53:09 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Wed, 21 Jul 2010 14:53:09 +0200
Subject: [erlang-questions] Erlang internal scheduler implementation
In-Reply-To: <1771089662.619901279701617136.JavaMail.root@zimbra>
References: <1771089662.619901279701617136.JavaMail.root@zimbra>
Message-ID: <4C46EDB5.9070103@erlang-solutions.com>


It is true that some things have changed, but only
a few. :)

http://www.erlang.org/cgi-bin/ezmlm-cgi/4/26802

explains how each scheduler thread in an SMP system
works essentially like the old non-SMP scheduler, but
as the scheduler threads themselves are preemptively
scheduled, the strict priorities high and max are not
blocking in quite the same way as before.

A few additional comments, perhaps...

- Rickard wrote in the above post that the 'max'
   priority level is undocumented. This is not true (anymore).
   Scheduling is documented to some degree in the erlang
   man page under process_flag(priority, Level).

- The latest versions of OTP implement process migration
   between schedulers to prevent schedulers from running
   out of work (if they do, they will busy-loop for a while
   in order to avoid having to suspend and wake up the OS
   thread unnecessarily). The AFAICT wholly undocumented
   process_flag(scheduler, No) binds a process to a specific
   scheduler so that it cannot be migrated, presumably to
   allow for process affinity.
   ...or at least that's what I imagine that it ought to be
   doing. The value cannot be inspected, and at first sight,
   I couldn't find a way to 'unbind' a process again, so
   perhaps we should just ignore this facility for now? :)

- A process is punished with extra reductions if it sends
   a message to a process with a very long message queue.
   This is possibly undesirable in a manycore system, since
   it is tricky to implement without risking contention.

BR,
Ulf W

Michal Ptaszek wrote:
> Hi All,
> 
> is there any kind of detailed documentation
> (except the comments in the source code) on 
> behaviour/conception/strategy for Erlang 
> process scheduler?
> 
> How the processes are given CPU time, when they
> are pre-empted, can we and why do we migrate 
> processes between different scheduler queues? 
> 
> I've already found Ulf Wiger's explanation 
> in the mailing list archive:
> http://www.erlang.org/pipermail/erlang-questions/2001-April/003131.html
> Nevertheless, this email is 9 years old so probably
> a lot of things changed (e.g. better SMP 
> support). 
> 
> Best regards,
> Michal Ptaszek
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 


-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From egil@REDACTED  Wed Jul 21 15:23:39 2010
From: egil@REDACTED (=?UTF-8?B?QmrDtnJuLUVnaWwgRGFobGJlcmc=?=)
Date: Wed, 21 Jul 2010 15:23:39 +0200
Subject: [erlang-questions] Erlang internal scheduler implementation
In-Reply-To: <4C46EDB5.9070103@erlang-solutions.com>
References: <1771089662.619901279701617136.JavaMail.root@zimbra> <4C46EDB5.9070103@erlang-solutions.com>
Message-ID: <4C46F4DB.2030700@erix.ericsson.se>

On 2010-07-21 14:53, Ulf Wiger wrote:
> - The latest versions of OTP implement process migration
> between schedulers to prevent schedulers from running
> out of work (if they do, they will busy-loop for a while
> in order to avoid having to suspend and wake up the OS
> thread unnecessarily). The AFAICT wholly undocumented
> process_flag(scheduler, No) binds a process to a specific
> scheduler so that it cannot be migrated, presumably to
> allow for process affinity.
> ...or at least that's what I imagine that it ought to be
> doing. The value cannot be inspected, and at first sight,
> I couldn't find a way to 'unbind' a process again, so
> perhaps we should just ignore this facility for now? :)

It is actually there for testing only and there isn't a way to unbind 
it. Process to scheduler affinity will probably be a bit more automatic.

// Bj?rn-Egil


From comptekki@REDACTED  Wed Jul 21 23:11:03 2010
From: comptekki@REDACTED (Wes James)
Date: Wed, 21 Jul 2010 15:11:03 -0600
Subject: bad arg error with re:replace
Message-ID: <AANLkTinC7AEGTfOBkPgwRwnUct9itwtxUFIEZafKJuJA@mail.gmail.com>

I am trying to do this:

re:replace("test\\","\\","\\\\",[{return,list}])

but I'm getting a bad arg error.  This is assuming  for each "\" I
need "\\" from here:

http://www.erlang.org/doc/man/re.html#replace-4

I'm trying to replace each "\" with "\\".

thx,

-wes

From francesco@REDACTED  Wed Jul 21 23:43:11 2010
From: francesco@REDACTED (Francesco Cesarini)
Date: Wed, 21 Jul 2010 22:43:11 +0100
Subject: Speak at the 2010 Erlang User Conference: Call for presentations
 & tutorials
Message-ID: <4C4769EF.80608@erlang-solutions.com>



Do you have what it takes to lead a conference session or tutorial? Have 
you made an interesting innovation, open source application or product 
with Erlang/OTP? Have you used Erlang in a real-world project and want 
to present a case study? Or have you developed a cool tool and want to 
give a hands-on tutorial? Tell us about it, and help spread the word. 
The URL to submit talks proposals is

http://www.erlang-factory.com/conference/ErlangUserConference2010/submit_talk

We welcome submissions from developers, system designers, testers, 
community leaders, inventors, CTOs, evangelists, students, researchers 
and entrepreneurs alike. Participants at the Erlang User Conference want 
to hear about how Erlang/OTP is used real-world scenarios, talks about 
tricks, tools and applications which increase productivity or enable 
developers to write better code.

Please submit original session ideas. Ask yourself who your target 
audience is. The Erlang User Conference is aimed at Erlang Architects, 
Programmers, Project managers, Software and Platform Innovators, 
existing Erlang users as well as Erlang newbies; in fact anyone 
interested in Erlang, concurrent and sequential programming. So both 
technical and non technical talks are welcome.

Some of the topics we hope to see at the Erlang User Conference include:

    * Erlang and Web Development
    * Tools and Gadgets
    * Erlang and Test Driven Development
    * Enterprise Integration
    * Cool Applications
    * Erlang in Your Infrastructure
    * Erlang and Cloud Computing
    * Erlang and Instant Messaging

We need you to submit your talk proposals by September 10th at the 
latest. Once all submissions have been received the conference committee 
will evaluate them and successful speakers will be notified by 15th of 
September. If your proposal is accepted, you will receive free access to 
the Erlang User Conference! Any questions, let me know.

See you there,
Francesco

-- 
Erlang Solutions Ltd.
http://www.erlang-solutions.com


From comptekki@REDACTED  Wed Jul 21 23:49:32 2010
From: comptekki@REDACTED (Wes James)
Date: Wed, 21 Jul 2010 15:49:32 -0600
Subject: bad arg error with re:replace
In-Reply-To: <AANLkTinC7AEGTfOBkPgwRwnUct9itwtxUFIEZafKJuJA@mail.gmail.com>
References: <AANLkTinC7AEGTfOBkPgwRwnUct9itwtxUFIEZafKJuJA@mail.gmail.com>
Message-ID: <AANLkTimkOekqvcPT7EfvWl9sPcZSUBoobXRdmt64IFNf@mail.gmail.com>

I figured it out:

T.
"test\\"
13> re:replace(T,"\\\\","\\\\\\",[{return,list}]).
"test\\\\"

On Wed, Jul 21, 2010 at 3:11 PM, Wes James <comptekki@REDACTED> wrote:
> I am trying to do this:
>
> re:replace("test\\","\\","\\\\",[{return,list}])
>
> but I'm getting a bad arg error. ?This is assuming ?for each "\" I
> need "\\" from here:
>
> http://www.erlang.org/doc/man/re.html#replace-4
>
> I'm trying to replace each "\" with "\\".
>
> thx,
>
> -wes
>

From torben.lehoff@REDACTED  Wed Jul 21 23:53:14 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Wed, 21 Jul 2010 23:53:14 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <2F3067FF-BE2D-4E08-8AB8-286499350480@cs.otago.ac.nz>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
	<AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
	<A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>
	<AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
	<2F3067FF-BE2D-4E08-8AB8-286499350480@cs.otago.ac.nz>
Message-ID: <AANLkTinBdDHo7CC4yr4c7b5WQI1EyQo8KOqw7Ihdrpwm@mail.gmail.com>

On Wed, Jul 21, 2010 at 01:43, Richard O'Keefe <ok@REDACTED> wrote:

>
> On Jul 21, 2010, at 10:24 AM, Torben Hoffmann wrote:
>
>>
>>
>> Well, I actually ran into a problem with this in a real program and it was
>> by sheer coincidence that I noticed the overlapping clauses, so I would have
>> liked the compiler to spot this.
>>
>
> It would be really really good to see the actual code, if possible.

Not possible, but the general problem was the same only with matching on
fields of the incoming records. I tried the changes in my simplified example
on the real code and the results were exactly the same.


>
>
>> Given the Haskel evidence it seems that the problem is even harder than I
>> imagined at first, so maybe I am expecting too much... expecting too much
>> becomes so natural when you work with Erlang.
>>
>> This means that there are two or more actions to be taken on this:
>> 1. Ask a bright person who is into type checking to look at this in his
>> thesis project.
>>
>
> There is no type problem here; everything is well typed.
>

Well, typing and semantic analysis blends together in my head every now and
then, so the correct assignment would be to explore which practical
extensions one can make to the analysis of function clauses with the
requirement that it should not overly complicate matters.

<nice examples removed from reply>

>
>  2. Change my style of programming so that it stays within the bounds of
>> what the compiler will warn me about.
>>
>
> I have a bad feeling about the solvability of "do these two
> binary patterns have a common instance", so you had better
> avoid binary patterns.  (:-)
>

I wouldn't go as far as that, but in the real code the when-clause was used
to avoid duplicating code since two different values for a specific field
had the same implementation. One could extract the common code into a
function and see how well the code reads after that. I will do that
experiment and see if I like the result.
But you are right about the continued need for programmers - not everything
can be handled by the compilers.


>
> You can't expect a compiler to warn you about every conceivable
> problem.  As a trivial example,
>
>        f() -> m:g(1).
>
> If m:g/1 is not available to the compiler, who knows what it might
> do?  How could the compiler warn you "this function will always
> crash" when it hasn't seen that function?  Worse, suppose the
> compiler *can* see a definition of m:g/1, but at run time it is
> replaced by a different one.  Is the compiler to warn you about
> every remote call
>        Warning: you are calling a function that might be
>        replaced at run time by another definition that might
>        do all sorts of horrible things.
>

I can live with that since it clearly places responsibility outside the
current module - quite different from the original problem.


>
> I suppose we could call this a full employment theorem for
> testers and debuggers:  in any nontrivial programming language
> there will be bugs expressible that no algorithm can
> infallibly detect.  (Note: the Dialyzer does NOT claim to
> infallibly detect bugs.  It makes the weaker claim that the
> things it detects are bugs; it will certainly miss some.)
>
> Keep your style as clear as you can so that other people can
> understand it.  Write specifications and test cases.  (Ulrich
> Neumerkel -- hope I've spelled that right -- has worked on a
> teaching environment for Prolog called GUPU that requires
> students to write test cases first, and tests the tests.  A
> neat idea.)  When you find something that the compiler didn't,
> ask if the compiler can be improved to detect it.  It's an
> economic trade-off:  how likely is the bug, what are the
> expected consequences of not finding it, how costly will it
> be to improve the compiler to that level.
>

Exactly and that is why the thesis proposal above should have this sort of
trade-offs included in the problem statement.
Given the large amount of code written in Erlang, Haskel and the likes there
is plenty of code where the improved static analysis could be tested on to
see how many potential problems it finds compared to the original algorithm.


But you did hit a sore spot here - the code was written without a
comprehensive test suite due to familiar problems such as incomplete
knowledge of one of the protocols and lack of experience with Erlang and in
particular testing (eunit and QuickCheck) when we started the project. It is
always expensive to be poor...


>
>  3. [Optional] Put some explanations/warnings in the Erlang documentation
>> so that people are not led astray like me.
>>
>
> It's not clear precisely what you want people to be warned
> against.  "Expect the compiler to be right but dumb" is about
> all I can think of here.
>

Well, I think that it would be okay to ask for a few examples of how
function clauses using when clauses work together with regards to utilising
one of the greatest strengths of Erlang (and other FP languages): pattern
matching.
I have gazed through the documentation and I have not found anything on the
warnings that will be emitted by the compiler and what it will not detect.
The things not detected should then be on the check list used when doing a
code review since those things is where we still have a chance to make money
as programmers.

Again, this the effort required for this has to be weighed against the
occurrence of the problem and I cannot quite figure out if others have big
enough pains to warrant an investment.

Cheers,
Torben
-- 
http://www.linkedin.com/in/torbenhoffmann

From comptekki@REDACTED  Thu Jul 22 00:04:45 2010
From: comptekki@REDACTED (Wes James)
Date: Wed, 21 Jul 2010 16:04:45 -0600
Subject: bad arg error with re:replace
In-Reply-To: <AANLkTimkOekqvcPT7EfvWl9sPcZSUBoobXRdmt64IFNf@mail.gmail.com>
References: <AANLkTinC7AEGTfOBkPgwRwnUct9itwtxUFIEZafKJuJA@mail.gmail.com>
	<AANLkTimkOekqvcPT7EfvWl9sPcZSUBoobXRdmt64IFNf@mail.gmail.com>
Message-ID: <AANLkTilW8t-H3-m0VlQYywwWXazYmrz3Ce9bPz41BVJ6@mail.gmail.com>

I had to add global for all instances to be changed

....[{return,list}, global])

On Wed, Jul 21, 2010 at 3:49 PM, Wes James <comptekki@REDACTED> wrote:
> I figured it out:
>
> T.
> "test\\"
> 13> re:replace(T,"\\\\","\\\\\\",[{return,list}]).
> "test\\\\"
>
> On Wed, Jul 21, 2010 at 3:11 PM, Wes James <comptekki@REDACTED> wrote:
>> I am trying to do this:
>>
>> re:replace("test\\","\\","\\\\",[{return,list}])
>>
>> but I'm getting a bad arg error. ?This is assuming ?for each "\" I
>> need "\\" from here:
>>
>> http://www.erlang.org/doc/man/re.html#replace-4
>>
>> I'm trying to replace each "\" with "\\".
>>
>> thx,
>>
>> -wes
>>
>

From tony.arcieri@REDACTED  Thu Jul 22 00:54:33 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Wed, 21 Jul 2010 16:54:33 -0600
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com>
Message-ID: <AANLkTinjXOsyONLk_azXSYqE1Bt4iTrFeE2KGNJI9G51@mail.gmail.com>

On Tue, Jul 20, 2010 at 3:28 AM, Joe Armstrong <erlang@REDACTED> wrote:

>   How can I parse typedefs using leex and yecc?
>
>   The traditional yacc/lex approach solves this with a context
>   sensitive lex and feedback between yacc and lex. But the Erlang
>   leex and yacc seem to be written as separated passes, are there some
>   internal functions that allow feedback between leex and yacc?
>

The bic C(++) parser from jungerl seems to use leex and yecc.  No idea if it
runs afoul of the cases you're running into:

http://gist.github.com/gebi/jungerl/tree/master/lib/bic

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From erlang@REDACTED  Thu Jul 22 10:33:45 2010
From: erlang@REDACTED (Joe Armstrong)
Date: Thu, 22 Jul 2010 10:33:45 +0200
Subject: Volunteers wanted for new project
Message-ID: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>

Volunteers wanted --

So here's a little project that I'd like to do (hobby hack #3367 :-)

Here's the problem:

    The other day I wanted to see if anybody had written a parser for
    C in Erlang.  I did not know of such a parser, so I Googled a bit
    and turned up nothing.  I posted to the Erlang list - after a few
    days I got a tip that lead me some code that almost did what I
    wanted - a much better starting point than hacking the thing from
    scratch.

         This is crazy - almost exactly what I want had already been
         written 4 years ago - but a Google search did not reveal it,
         nor was it in any catalogs. I didn't know about this (I knew
         about jungerl) (of course). Now I'm hardly an Erlang newby so
         if I can't find it (or even know about it) how can a real
         Erlang newby find anything?

What I want is a "report a resource" thing on the web.

All you should have to do is go to a web site fill in a form with the
following:

           resource type: erlang
           reported by: <name>
           url: <url>
           keywords: <k1,k2,k3>
           description: <....>
           <click>

Or send email to some web site.

    I guess you'd need some sort of authentication so that spammers
    could not hijack your <name> Some kind of voting or reputation
    system could be used to rank resources depending upon who voted
    for them ...

We also need a search engine to answer resource queries.

    My guess is that a reputation based system would be pretty good. I
    don't want to name names but we all know that if <XYZ> recommended
    something it must be pretty good.

So if this doesn't exist I think we should build it as a group effort.
Even if it does exist we should build it, I'll tell you why later.

Volunteers are needed for the various bits:

     - an architect                             (decides on the
interfaces, the components)
     - an integrator                            (takes delivery of the
components)
     - a hoster                                 (somebody needs to
host the thing)
     - a front end                              (handles HTTP and
email requests)
     - a database/query backend                 (handles queries)
     - admin / authorization / anti-spam stuff  (handles security)
     - an artist /css guru                      (makes the site beautiful)
     - a few programmers

    This project sounds simple - actually it *is* simple - I can hear
    you thinking "I could do this is 5 minutes with lamp/RoR/mySQL/PHP
    ..."  but it gives an excellent opportunity to try and make an
    infinitely scalable-flexable thing and try integrating our
    favorite tools.

We could do a simple yaws/menisia/vanilla HTML solution or
a Riak/couchDB/rabbit/nitrogen/xmpp thingy

    RATHER THAN MAKING A FANCY-WEB SITE USING SIMPLE TECHNOLOGIES WE
    MAKE A VERY VERY SIMPLE WEB-SITE WITH FANCY TECHNOLOGIES.

    THE KICKER IS THAT WE TRY TO MAKE IT INFINITELY SCALABLE,
    INFINITELY FAULT-TOLERANT, AMAZINGLY EASY TO SCALE AND DEPLOY.

This is why this should be a collaborative effort - rather than
a one man hack - this is to *force* collaboration between
the couch and the rabbits of the Erlang world.


/Joe

From zerthurd@REDACTED  Thu Jul 22 12:04:27 2010
From: zerthurd@REDACTED (Maxim Treskin)
Date: Thu, 22 Jul 2010 17:04:27 +0700
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <AANLkTinTGTkkEXu--FuhSLyXTM2nqr86UhcH3rlEYgFf@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTinTGTkkEXu--FuhSLyXTM2nqr86UhcH3rlEYgFf@mail.gmail.com>
Message-ID: <AANLkTinmyqcTUR3j10qxtXtBZSx8HsCRsNCd9xMmiVNR@mail.gmail.com>

Just what I think now:

Authentication:

reported by: <name> ? An Jabber ID (GTalk or other XMPP-server).

Typical workflow:
1. User establishes XMPP-chat connection with service JID
2.1. XMPP scenario:
      * He sends whole resource description or starts new transaction and
add/edit fields of resource description then commits
2.2. HTTP scenario:
      * He sends request for HTTP address, service JID replies to with it
      * User goes to this address, fills resource description, submits
3. User has access to his record and edit it.

Service JID realises link between XMPP-frontend, HTTP-frontend and core of
service, based on RabbitMQ and Riak :)



On 22 July 2010 15:33, Joe Armstrong <erlang@REDACTED> wrote:

> Volunteers wanted --
>
> So here's a little project that I'd like to do (hobby hack #3367 :-)
>
> Here's the problem:
>
>    The other day I wanted to see if anybody had written a parser for
>    C in Erlang.  I did not know of such a parser, so I Googled a bit
>    and turned up nothing.  I posted to the Erlang list - after a few
>    days I got a tip that lead me some code that almost did what I
>    wanted - a much better starting point than hacking the thing from
>    scratch.
>
>         This is crazy - almost exactly what I want had already been
>         written 4 years ago - but a Google search did not reveal it,
>         nor was it in any catalogs. I didn't know about this (I knew
>         about jungerl) (of course). Now I'm hardly an Erlang newby so
>         if I can't find it (or even know about it) how can a real
>         Erlang newby find anything?
>
> What I want is a "report a resource" thing on the web.
>
> All you should have to do is go to a web site fill in a form with the
> following:
>
>           resource type: erlang
>           reported by: <name>
>           url: <url>
>           keywords: <k1,k2,k3>
>           description: <....>
>           <click>
>
> Or send email to some web site.
>
>    I guess you'd need some sort of authentication so that spammers
>    could not hijack your <name> Some kind of voting or reputation
>    system could be used to rank resources depending upon who voted
>    for them ...
>
> We also need a search engine to answer resource queries.
>
>    My guess is that a reputation based system would be pretty good. I
>    don't want to name names but we all know that if <XYZ> recommended
>    something it must be pretty good.
>
> So if this doesn't exist I think we should build it as a group effort.
> Even if it does exist we should build it, I'll tell you why later.
>
> Volunteers are needed for the various bits:
>
>     - an architect                             (decides on the
> interfaces, the components)
>     - an integrator                            (takes delivery of the
> components)
>     - a hoster                                 (somebody needs to
> host the thing)
>     - a front end                              (handles HTTP and
> email requests)
>     - a database/query backend                 (handles queries)
>     - admin / authorization / anti-spam stuff  (handles security)
>     - an artist /css guru                      (makes the site beautiful)
>     - a few programmers
>
>    This project sounds simple - actually it *is* simple - I can hear
>    you thinking "I could do this is 5 minutes with lamp/RoR/mySQL/PHP
>    ..."  but it gives an excellent opportunity to try and make an
>    infinitely scalable-flexable thing and try integrating our
>    favorite tools.
>
> We could do a simple yaws/menisia/vanilla HTML solution or
> a Riak/couchDB/rabbit/nitrogen/xmpp thingy
>
>    RATHER THAN MAKING A FANCY-WEB SITE USING SIMPLE TECHNOLOGIES WE
>    MAKE A VERY VERY SIMPLE WEB-SITE WITH FANCY TECHNOLOGIES.
>
>    THE KICKER IS THAT WE TRY TO MAKE IT INFINITELY SCALABLE,
>    INFINITELY FAULT-TOLERANT, AMAZINGLY EASY TO SCALE AND DEPLOY.
>
> This is why this should be a collaborative effort - rather than
> a one man hack - this is to *force* collaboration between
> the couch and the rabbits of the Erlang world.
>
>
> /Joe
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>


-- 
Maxim Treskin

From mail@REDACTED  Thu Jul 22 12:09:07 2010
From: mail@REDACTED (Tim Fletcher)
Date: Thu, 22 Jul 2010 03:09:07 -0700 (PDT)
Subject: Volunteers wanted for new project
In-Reply-To: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
Message-ID: <82619625-0dd0-425e-aa64-388ffee05e2a@u26g2000yqu.googlegroups.com>

> The other day I wanted to see if anybody had written a parser for
> C in Erlang. ?I did not know of such a parser, so I Googled a bit
> and turned up nothing.

I'm not too surprised by that, an Erlang C parser would seem to be
quite a "niche" thing.

I've found that using the "erlang-" prefix in project names makes them
easier to discover via search engines. That won't be of interest to
big projects like Riak/CouchDB who need the marketing, but for
"boring" library code the "erlang-" prefix works well. If there was a
http://github.com/joearms/erlang-c-parser, you would be able to find
that easily via Google.

> Now I'm hardly an Erlang newby so if I can't find it (or even know
> about it) how can a real Erlang newby find anything?

I think the difficulty is due to the fragmentation. There's the
"Unsupported User Contributions" on erlang.org, there's Jungerl,
there's Trapexit, there's code on Github/Bitbucket etc. Everyone's
doing their own thing. Contrast that with the Node community, who have
a single wiki page listing 3rd party modules:

http://wiki.github.com/ry/node/modules

> What I want is a "report a resource" thing on the web.

Functionality wise, that's not too different from a community
maintained wiki. The hard things are non-technical: getting everyone
to use it and keeping it up-to-date. I think it might help more to
combine some of the existing resources first though, before adding new
ones.

> This is why this should be a collaborative effort - rather than
> a one man hack - this is to *force* collaboration between
> the couch and the rabbits of the Erlang world.

That's a great aim. I'd love to help with a project along these lines,
but i'm not entirely sold on this particular idea.

Tim

From bgustavsson@REDACTED  Thu Jul 22 12:11:21 2010
From: bgustavsson@REDACTED (=?UTF-8?Q?Bj=C3=B6rn_Gustavsson?=)
Date: Thu, 22 Jul 2010 12:11:21 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTinBdDHo7CC4yr4c7b5WQI1EyQo8KOqw7Ihdrpwm@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
	<AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
	<A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>
	<AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
	<2F3067FF-BE2D-4E08-8AB8-286499350480@cs.otago.ac.nz>
	<AANLkTinBdDHo7CC4yr4c7b5WQI1EyQo8KOqw7Ihdrpwm@mail.gmail.com>
Message-ID: <AANLkTil8au45r_GhKiVX00vKjuXFKfd08Yxsft9UezIG@mail.gmail.com>

> I have gazed through the documentation and I have not found anything on the
> warnings that will be emitted by the compiler and what it will not detect.
> The things not detected should then be on the check list used when doing a
> code review since those things is where we still have a chance to make money
> as programmers.

There is some information that can be found
at the end of the documentation for compile:file/2
(after documentation of all options):

http://www.erlang.org/doc/man/compile.html#file-2

It would be possible to extend that section, but
a list of issues that will be detected could easily
become out-of-date and I don't think it is really
possible to list all issues it will not detect.


The purpose of the compiler is to generate good
code, not to inform you about mistakes in your program.

However, we noticed that some kind of blunders
were common, and that it would be trivial to produce
warnings about them during optimization or code
generation. For instance, since the compiler attempts
to evaluate constant expressions, it makes sense
to warn for expressions that will always fail, such
a 1/0. There is, however, no warning for X/0 since
the compiler does not try to evaluate that expression.

We want to the compiler to be as fast as possible,
so we don't want to add extra code to search for more
problems and produce more warnings. If you want to
find as many problems as possible before running
your code, use Dialyzer. It will do a much better job
that the compiler can ever hope to do.


I'll end with a quote from the documentation for
compile:file/2:

Obviously, the absence of warnings does not mean that there are no
remaining errors in the code.

-- 
Bj?rn Gustavsson, Erlang/OTP, Ericsson AB

From dale@REDACTED  Thu Jul 22 12:23:05 2010
From: dale@REDACTED (Dale Harvey)
Date: Thu, 22 Jul 2010 11:23:05 +0100
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
Message-ID: <AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>

On 22 July 2010 09:33, Joe Armstrong <erlang@REDACTED> wrote:

> Volunteers wanted --
>
> So here's a little project that I'd like to do (hobby hack #3367 :-)
>
> Here's the problem:
>
>    The other day I wanted to see if anybody had written a parser for
>    C in Erlang.  I did not know of such a parser, so I Googled a bit
>    and turned up nothing.  I posted to the Erlang list - after a few
>    days I got a tip that lead me some code that almost did what I
>    wanted - a much better starting point than hacking the thing from
>    scratch.
>
>         This is crazy - almost exactly what I want had already been
>         written 4 years ago - but a Google search did not reveal it,
>         nor was it in any catalogs. I didn't know about this (I knew
>         about jungerl) (of course). Now I'm hardly an Erlang newby so
>         if I can't find it (or even know about it) how can a real
>         Erlang newby find anything?
>
> What I want is a "report a resource" thing on the web.
>
> All you should have to do is go to a web site fill in a form with the
> following:
>
>           resource type: erlang
>           reported by: <name>
>           url: <url>
>           keywords: <k1,k2,k3>
>           description: <....>
>           <click>
>
> Or send email to some web site.
>
>    I guess you'd need some sort of authentication so that spammers
>    could not hijack your <name> Some kind of voting or reputation
>    system could be used to rank resources depending upon who voted
>    for them ...
>
> We also need a search engine to answer resource queries.
>
>    My guess is that a reputation based system would be pretty good. I
>    don't want to name names but we all know that if <XYZ> recommended
>    something it must be pretty good.
>
> So if this doesn't exist I think we should build it as a group effort.
> Even if it does exist we should build it, I'll tell you why later.
>
>
Most open source projects live in github these days, including most erlang
ones, we can search based on languages and keyword, followers / watchers is
a reputation system.

I think we already have this, just a matter of making sure the rest use it
(and possibly a custom / improved search?)


> Volunteers are needed for the various bits:
>
>     - an architect                             (decides on the
> interfaces, the components)
>     - an integrator                            (takes delivery of the
> components)
>     - a hoster                                 (somebody needs to
> host the thing)
>     - a front end                              (handles HTTP and
> email requests)
>     - a database/query backend                 (handles queries)
>     - admin / authorization / anti-spam stuff  (handles security)
>     - an artist /css guru                      (makes the site beautiful)
>     - a few programmers
>
>    This project sounds simple - actually it *is* simple - I can hear
>    you thinking "I could do this is 5 minutes with lamp/RoR/mySQL/PHP
>    ..."  but it gives an excellent opportunity to try and make an
>    infinitely scalable-flexable thing and try integrating our
>    favorite tools.
>
> We could do a simple yaws/menisia/vanilla HTML solution or
> a Riak/couchDB/rabbit/nitrogen/xmpp thingy
>
>    RATHER THAN MAKING A FANCY-WEB SITE USING SIMPLE TECHNOLOGIES WE
>    MAKE A VERY VERY SIMPLE WEB-SITE WITH FANCY TECHNOLOGIES.
>
>    THE KICKER IS THAT WE TRY TO MAKE IT INFINITELY SCALABLE,
>    INFINITELY FAULT-TOLERANT, AMAZINGLY EASY TO SCALE AND DEPLOY.
>
> This is why this should be a collaborative effort - rather than
> a one man hack - this is to *force* collaboration between
> the couch and the rabbits of the Erlang world.
>
>
> /Joe
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From tuncer.ayaz@REDACTED  Thu Jul 22 12:58:12 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Thu, 22 Jul 2010 12:58:12 +0200
Subject: [erlang-questions] Distributed erlang not working after upgrading 
	to OSX Snow leopard
In-Reply-To: <AANLkTineyDdHF6TQ5LdyYnDkQF3K7mLBZk9Mwq6peGYC@mail.gmail.com>
References: <AANLkTik8wmCKZz5VyaRTH8bm9OhQ_LF0hGzdHy13dF7Y@mail.gmail.com> 
	<AANLkTilZ92XgSPk6OolAiI_YW7zW9odvxNXqJOvs20Ca@mail.gmail.com> 
	<AANLkTineyDdHF6TQ5LdyYnDkQF3K7mLBZk9Mwq6peGYC@mail.gmail.com>
Message-ID: <AANLkTikt1OFT6ILhdMkLSCI-kE5wm9gY2q8c4lnHRyVB@mail.gmail.com>

On Wed, Jul 21, 2010 at 6:17 AM, Arun Suresh wrote:
> Thanx michal..
> that seems to have done the trick..
>
> On Wed, Jul 21, 2010 at 2:57 AM, Michal Zajda wrote:
>
>> Recompile your otp with --enable-darwin-64bit option to configure
>> script. It is described in INSTALL.md file (in OTP sources).

I have to admit I'm a little curious why using a 64bit emulator fixed
the problem. I don't remember having issues with both 32bit and 64bit
emulators on Linux or Darwin. Any detail I'm missing?

>> On 20 July 2010 21:59, Arun Suresh wrote:
>>
>>> Hi
>>>
>>> Im currently running erlang R13B04 (erts-5.7.5) which I built from
>>> source. After upgrading to Snow leopard, I can get distributed
>>> erlang to work...

[...]

>>> As you can see.. net_adm:ping() returns a pang.. Could someone
>>> please give me some pointers as to how I might start debugging
>>> this issue ? I have me /etc/hosts file correctly configured

From ulf.wiger@REDACTED  Thu Jul 22 12:58:41 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Thu, 22 Jul 2010 12:58:41 +0200
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com> <AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
Message-ID: <4C482461.3000707@erlang-solutions.com>


I think that http://projects.trapexit.org/ seems like a
reasonably good fit for what you are asking for.

It crawls github, sourceforge, bitbucket and google code
searching for erlang-related projects. If you have an
account (free of charge) on trapexit, you can rate
components, and add comments/info on related trapexit
forums and wiki.

There are several improvements that could be considered.
One is to move it to faster hardware. Please give feedback.

BR,
Ulf W

Dale Harvey wrote:
> On 22 July 2010 09:33, Joe Armstrong <erlang@REDACTED> wrote:
>>
>> What I want is a "report a resource" thing on the web.
>>
>> All you should have to do is go to a web site fill in a form with the
>> following:
>>
>>           resource type: erlang
>>           reported by: <name>
>>           url: <url>
>>           keywords: <k1,k2,k3>
>>           description: <....>
>>           <click>
>>
>> [...]
>>
>> We also need a search engine to answer resource queries.
>>
>>    My guess is that a reputation based system would be pretty good. I
>>    don't want to name names but we all know that if <XYZ> recommended
>>    something it must be pretty good.
>>
>> So if this doesn't exist I think we should build it as a group effort.
>> Even if it does exist we should build it, I'll tell you why later.
>>
>>
> Most open source projects live in github these days, including most erlang
> ones, we can search based on languages and keyword, followers / watchers is
> a reputation system.
> 
> I think we already have this, just a matter of making sure the rest use it
> (and possibly a custom / improved search?)
[...]

-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From torben.lehoff@REDACTED  Thu Jul 22 13:39:35 2010
From: torben.lehoff@REDACTED (Torben Hoffmann)
Date: Thu, 22 Jul 2010 13:39:35 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTil8au45r_GhKiVX00vKjuXFKfd08Yxsft9UezIG@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com>
	<AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com>
	<4C43F206.1010804@m5net.com>
	<AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com>
	<A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz>
	<AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com>
	<2F3067FF-BE2D-4E08-8AB8-286499350480@cs.otago.ac.nz>
	<AANLkTinBdDHo7CC4yr4c7b5WQI1EyQo8KOqw7Ihdrpwm@mail.gmail.com>
	<AANLkTil8au45r_GhKiVX00vKjuXFKfd08Yxsft9UezIG@mail.gmail.com>
Message-ID: <AANLkTiksLibV5ZffGEZ2UweONtzCzPcWcf0XR_r6sq_v@mail.gmail.com>

2010/7/22 Bj?rn Gustavsson <bgustavsson@REDACTED>

> > I have gazed through the documentation and I have not found anything on
> the
> > warnings that will be emitted by the compiler and what it will not
> detect.
> > The things not detected should then be on the check list used when doing
> a
> > code review since those things is where we still have a chance to make
> money
> > as programmers.
>
> There is some information that can be found
> at the end of the documentation for compile:file/2
> (after documentation of all options):
>
> http://www.erlang.org/doc/man/compile.html#file-2
>
> It would be possible to extend that section, but
> a list of issues that will be detected could easily
> become out-of-date and I don't think it is really
> possible to list all issues it will not detect.
>
>
> The purpose of the compiler is to generate good
> code, not to inform you about mistakes in your program.
>
Not 100% aligned with you on this, but I appreciate that you have a clear
policy and that you are following it.
That clarity alone is worth something.


>
> However, we noticed that some kind of blunders
> were common, and that it would be trivial to produce
> warnings about them during optimization or code
> generation. For instance, since the compiler attempts
> to evaluate constant expressions, it makes sense
> to warn for expressions that will always fail, such
> a 1/0. There is, however, no warning for X/0 since
> the compiler does not try to evaluate that expression.
>
> We want to the compiler to be as fast as possible,
> so we don't want to add extra code to search for more
> problems and produce more warnings. If you want to
> find as many problems as possible before running
> your code, use Dialyzer. It will do a much better job
> that the compiler can ever hope to do.
>

Given your clear mission above for the compiler it makes total sense to
delegate problem finding to Dialyzer - I will direct my findings and other
things to the Dialyzer team since I have a couple of ideas that might
improve things.


>
>
> I'll end with a quote from the documentation for
> compile:file/2:
>
> Obviously, the absence of warnings does not mean that there are no
> remaining errors in the code.
>

I appreciate that, but I still think that the mixing of when-clauses and
function clauses in my example is something that hits a grey zone, but now
that we have established the mission for the compiler (good code) I will put
my faith in Dialyzer instead when it comes to making my code clean.

Cheers,
Torben


>
> --
> Bj?rn Gustavsson, Erlang/OTP, Ericsson AB
>



-- 
http://www.linkedin.com/in/torbenhoffmann

From dmitrii@REDACTED  Thu Jul 22 13:48:02 2010
From: dmitrii@REDACTED (Dmitrii Dimandt)
Date: Thu, 22 Jul 2010 14:48:02 +0300
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <4C482461.3000707@erlang-solutions.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com> <AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com> <4C482461.3000707@erlang-solutions.com>
Message-ID: <0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>

Just to chip in... I've been running a Russian news site on Erlang for 4 years now, I think. I've been following so much Erlang that it doesn't fit my head anymore :)

Right now I probably know more abut various Erlang-related projects than anybody on the list :) I have over 200 links on the site mostly pointing to various erlang projects/code sources/repositories and the like.

I can safely say this (and I said it before): Erlang universe is a fragmented mess :) There's code on github (most of it), theres code on bitbucket, on google code... There are small projects that people put up on various blogs without ever bothering to post it to github. There is a small number of personal repositories...

All in all, when you're trying to find anything erlang-related... You're out of luck. Unless the project has gained track in the community or some publicity (YXA, Mochiweb, Riak etc.). 

What Erlang needs is an erlangforge. I've owned the domain for a year and didn't have time to do anything with it :( I own the erlforge.com domain (heck, just renewed it :)) and I'm willing to setup it anyway you want for anyone who can create an erlforge :)

In my view it should track various source hosting sites (like project.trapexit.org does) but also host copies of projects that are released simply as .zip-files and the like.



On Jul 22, 2010, at 13:58 , Ulf Wiger wrote:

> 
> I think that http://projects.trapexit.org/ seems like a
> reasonably good fit for what you are asking for.
> 
> It crawls github, sourceforge, bitbucket and google code
> searching for erlang-related projects. If you have an
> account (free of charge) on trapexit, you can rate
> components, and add comments/info on related trapexit
> forums and wiki.
> 
> There are several improvements that could be considered.
> One is to move it to faster hardware. Please give feedback.
> 
> BR,
> Ulf W
> 
> Dale Harvey wrote:
>> On 22 July 2010 09:33, Joe Armstrong <erlang@REDACTED> wrote:
>>> 
>>> What I want is a "report a resource" thing on the web.
>>> 
>>> All you should have to do is go to a web site fill in a form with the
>>> following:
>>> 
>>>          resource type: erlang
>>>          reported by: <name>
>>>          url: <url>
>>>          keywords: <k1,k2,k3>
>>>          description: <....>
>>>          <click>
>>> 
>>> [...]
>>> 
>>> We also need a search engine to answer resource queries.
>>> 
>>>   My guess is that a reputation based system would be pretty good. I
>>>   don't want to name names but we all know that if <XYZ> recommended
>>>   something it must be pretty good.
>>> 
>>> So if this doesn't exist I think we should build it as a group effort.
>>> Even if it does exist we should build it, I'll tell you why later.
>>> 
>>> 
>> Most open source projects live in github these days, including most erlang
>> ones, we can search based on languages and keyword, followers / watchers is
>> a reputation system.
>> I think we already have this, just a matter of making sure the rest use it
>> (and possibly a custom / improved search?)
> [...]
> 
> -- 
> Ulf Wiger
> CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
> http://www.erlang-solutions.com
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 


From masklinn@REDACTED  Thu Jul 22 13:51:38 2010
From: masklinn@REDACTED (Masklinn)
Date: Thu, 22 Jul 2010 13:51:38 +0200
Subject: [erlang-questions] Lack of warning for overlapping clauses with
In-Reply-To: <AANLkTin77Bq2vfNgT7Mf1TZzreCATWHFkPeXgpJ-T92q@mail.gmail.com>
References: <AANLkTikiIlhGZ8gt3Me7Bnnrg2M2f6MC_DWrhkQWEx0k@mail.gmail.com> <AANLkTinvpC4YwAte5v_BKYy1Z8WzIG3tsJuqHUGSYBMW@mail.gmail.com> <4C43F206.1010804@m5net.com> <AANLkTikkj4GVnnVguprAzLv2WOa_Tazumz_17CMqoWay@mail.gmail.com> <A4D04820-6817-4578-B7A1-67BD12447659@cs.otago.ac.nz> <AANLkTilv3YEK1V8d9VENoGkOO4JllOp_nZLjgKyZenOH@mail.gmail.com> <AANLkTin77Bq2vfNgT7Mf1TZzreCATWHFkPeXgpJ-T92q@mail.gmail.com>
Message-ID: <B17327DA-D01C-47E8-9E58-E0F51A8E730C@masklinn.net>


On 2010-07-21, at 11:48 , Attila Rajmund Nohl wrote:

> 2010/7/21, Torben Hoffmann <torben.lehoff@REDACTED>:
>> On Tue, Jul 20, 2010 at 23:53, Richard O'Keefe <ok@REDACTED> wrote:
> [...]
>>> So nhc98 was completely silent, and ghc 6.6.1 did notice the
>>> explicit pattern duplication but did *NOT* notice the duplication
>>> of a pattern in a guard, any more than Erlang did.
>>> 
>> I stand corrected! Thanks for putting my assumptions to a timely death!!
> 
> I think there's one more thing: Erlang function clauses overlap all
> the time. It's a common pattern that:
> 
> f(1) -> ok;
> f(2) -> ok;
> f(_) -> not_ok.
> 
> and obviously the third pattern overlaps with the first two, but we
> really don't want a warning for that.
But the catchall pattern is a bit of a special case, in that it really means "everything not matched yet" here.

From michael.eugene.turner@REDACTED  Thu Jul 22 13:53:45 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Thu, 22 Jul 2010 20:53:45 +0900
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <4C482461.3000707@erlang-solutions.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
Message-ID: <AANLkTi=4=RAFSZKSkK8JekfzXA8WMDACG-WDgbqrBUKE@mail.gmail.com>

"I think that http://projects.trapexit.org/ seems like a reasonably good fit
for what you are asking for.  It crawls github, sourceforge, bitbucket and
google code searching for erlang-related projects."

But when I try to find the parser that Joe finally got pointed to, I don't
see anything matching the description.

There are repositories called "stuff", though.  Just in case anybody
happened to want something called "stuff."

I like the bit of graphical fanciness of http://projects.trapexit.org/ but
it's dispensable.  What I don't like is getting an alphabetized list of 1450
items most of which don't amount to anything.  Wings 3D is listed twice.
 Its ranking in both cases is the same as for "stuff" -- zero stars.  Even
though Wings 3D a pretty solid piece of code with a large community of
users.

What this should be telling you is that you've got something very backwards
here, in terms of offering value to the Erlang community. Don't try to
automate the listing of Erlang-coded packages.  Instead, when you find what
might be an Erlang-coded package, make use of *human* intelligence: contact
the people responsible for the code, asking if they are interested in being
listed.  You probably won't get a reply from most of them.  You'll get about
1/10th to 1/5th the number of package listings.  But that's a feature, not a
bug.  Finding useful things will no longer be like pawing through a drawer
mostly full of unmatched socks.  If it takes someone's actual human effort
to get a thing listed, each thing on the list will be something that at
least one person in the world actually cares about.  And if at least one
person cares about it, the chances that there are two or more people who
would care are much higher.

-michael turner



On Thu, Jul 22, 2010 at 7:58 PM, Ulf Wiger
<ulf.wiger@REDACTED>wrote:

>
> I think that http://projects.trapexit.org/ seems like a
> reasonably good fit for what you are asking for.
>
> It crawls github, sourceforge, bitbucket and google code
> searching for erlang-related projects. If you have an
> account (free of charge) on trapexit, you can rate
> components, and add comments/info on related trapexit
> forums and wiki.
>
> There are several improvements that could be considered.
> One is to move it to faster hardware. Please give feedback.
>
> BR,
> Ulf W
>
> Dale Harvey wrote:
>
>> On 22 July 2010 09:33, Joe Armstrong <erlang@REDACTED> wrote:
>>
>>>
>>> What I want is a "report a resource" thing on the web.
>>>
>>> All you should have to do is go to a web site fill in a form with the
>>> following:
>>>
>>>          resource type: erlang
>>>          reported by: <name>
>>>          url: <url>
>>>          keywords: <k1,k2,k3>
>>>          description: <....>
>>>          <click>
>>>
>>> [...]
>>>
>>>
>>> We also need a search engine to answer resource queries.
>>>
>>>   My guess is that a reputation based system would be pretty good. I
>>>   don't want to name names but we all know that if <XYZ> recommended
>>>   something it must be pretty good.
>>>
>>> So if this doesn't exist I think we should build it as a group effort.
>>> Even if it does exist we should build it, I'll tell you why later.
>>>
>>>
>>>  Most open source projects live in github these days, including most
>> erlang
>> ones, we can search based on languages and keyword, followers / watchers
>> is
>> a reputation system.
>>
>> I think we already have this, just a matter of making sure the rest use it
>> (and possibly a custom / improved search?)
>>
> [...]
>
> --
> Ulf Wiger
> CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
> http://www.erlang-solutions.com
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From attila.r.nohl@REDACTED  Thu Jul 22 14:32:39 2010
From: attila.r.nohl@REDACTED (Attila Rajmund Nohl)
Date: Thu, 22 Jul 2010 14:32:39 +0200
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <AANLkTi=4=RAFSZKSkK8JekfzXA8WMDACG-WDgbqrBUKE@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
	<AANLkTi=4=RAFSZKSkK8JekfzXA8WMDACG-WDgbqrBUKE@mail.gmail.com>
Message-ID: <AANLkTilgdSuMn0l0dmzHAacWhDWH3KWZKJmbjb9lGliS@mail.gmail.com>

2010/7/22, Michael Turner <michael.eugene.turner@REDACTED>:
[...]
> Don't try to
> automate the listing of Erlang-coded packages.  Instead, when you find what
> might be an Erlang-coded package, make use of *human* intelligence: contact
> the people responsible for the code, asking if they are interested in being
> listed.

But at this point it's not a software project, but a social, not
something developers tend to like to do. Of course, this makes it more
valuable...

From mail@REDACTED  Thu Jul 22 15:07:23 2010
From: mail@REDACTED (Tim Fletcher)
Date: Thu, 22 Jul 2010 06:07:23 -0700 (PDT)
Subject: Volunteers wanted for new project
In-Reply-To: <0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com> 
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com> 
	<4C482461.3000707@erlang-solutions.com> <0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>
Message-ID: <ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com>

> I can safely say this (and I said it before): Erlang universe is a fragmented mess :)

Exactly.

> What Erlang needs is an erlangforge.

Except that would be yet *another* site for hosting/listing erlang
projects, which would only increase the fragmentation.


I don't think we need a new site for hosting/listing projects, just
better organisation of what already exists. The current erlang.org
isn't too far off what we need in spirit, it just needs freshening up.
What's the status of demo.erlang.org?

Combining functionality from other sites with the same design/domain
of erlang.org would reduce the fragmentation, i.e. how about moving...

  tryerlang.org to try.erlang.org

  planeterlang.org to planet.erlang.org

  totally-erlang.com to jobs.erlang.org

  trapexit.org to wiki.erlang.org


... and then re-designing all of them so they have consistent styling/
navigation. These could still be hosted by non-Ericsson individuals/
companies, just with the blessing of Ericsson.

Then add a single listing of projects, either maintained by willing
and enthusiastic volunteers, or by project maintainers. Use an
existing authentication mechanism (e.g. OpenID) so that we don't need
any additional logins.

The Ruby community did something similar with their "Visual Identity
Team" (http://rubyidentity.org/) a few years back.


Thoughts?


Tim

From studiomaggi@REDACTED  Thu Jul 22 15:17:07 2010
From: studiomaggi@REDACTED (Pietro Maggi)
Date: Thu, 22 Jul 2010 15:17:07 +0200
Subject: [erlang-questions] Re: Volunteers wanted for new project
In-Reply-To: <ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
	<0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>
	<ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com>
Message-ID: <AANLkTiko0FUXFQUoMM3MkfyFxfq-C6GsP46R3x4vllpR@mail.gmail.com>

Hi,
I'm an Erlang newbie so I'm qualified to talk about this :-)

On Thu, Jul 22, 2010 at 3:07 PM, Tim Fletcher <mail@REDACTED> wrote:
>
[SNIP]
>
> Combining functionality from other sites with the same design/domain
> of erlang.org would reduce the fragmentation, i.e. how about moving...
>
> ?tryerlang.org to try.erlang.org
>
> ?planeterlang.org to planet.erlang.org
>
> ?totally-erlang.com to jobs.erlang.org
>
> ?trapexit.org to wiki.erlang.org
>

This seems to me the best solution to this problem, by far.
Where can I sign to put my vote on this?

regards
Pietro

From michael.eugene.turner@REDACTED  Thu Jul 22 15:29:44 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Thu, 22 Jul 2010 22:29:44 +0900
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <AANLkTilgdSuMn0l0dmzHAacWhDWH3KWZKJmbjb9lGliS@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
	<AANLkTi=4=RAFSZKSkK8JekfzXA8WMDACG-WDgbqrBUKE@mail.gmail.com>
	<AANLkTilgdSuMn0l0dmzHAacWhDWH3KWZKJmbjb9lGliS@mail.gmail.com>
Message-ID: <AANLkTimkJSaSYD7UW1SHrN2LAYqRtC___AfvjooQt=HA@mail.gmail.com>

"But at this point it's not a software project, but a social, not something
developers tend to like to do...."

There's nothing very social required in responding to an inquiry about
submitting your software project to a database.  If the inquiry itself was
automatically generated, it requires nothing social at all: it's a human
being responding to a machine, not to another human being.  But at least you
haven't completely bypassed the only meaningful arbiter of quality: human
beings.

Bypassing human involvement entirely (the approach taken with the
erlang.orgprojects page) means that the job of building a good
database becomes an AI
problem.  Not a very well-posed one, in this case.  Nor very well-solved
either.

" Of course, this makes it more valuable..."

Good, cheap, soon -- pick any two.

The nice thing about open source is that if any significant portion of the
user base is willing to work for free at all, you can get a fair amount of
reasonably good work done cheap (though not necessarily soon.)  However,
that's provided you make the work easy enough to do, or interesting enough,
or both.  Piling all source packages together in one place if they only
match a few keywords in searches made in likely locations ... well, that
isn't making any of the remaining work very easy.  You're making it harder,
if anything.  And it's definitely not making the work very interesting.  In
this case, it seems the result is something that didn't even turn up what
Joe wanted.

Full automation for this kind of task: that gets you "very cheap", and "very
soon" -- but it doesn't get you "good enough."  Faster isn't better.
 Cheaper isn't better.  Only better is better.

-michael turner

On Thu, Jul 22, 2010 at 9:32 PM, Attila Rajmund Nohl <
attila.r.nohl@REDACTED> wrote:

> 2010/7/22, Michael Turner <michael.eugene.turner@REDACTED>:
> [...]
> > Don't try to
> > automate the listing of Erlang-coded packages.  Instead, when you find
> what
> > might be an Erlang-coded package, make use of *human* intelligence:
> contact
> > the people responsible for the code, asking if they are interested in
> being
> > listed.
>
> But at this point it's not a software project, but a social, not
> something developers tend to like to do. Of course, this makes it more
> valuable...
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From ulf.wiger@REDACTED  Thu Jul 22 15:43:39 2010
From: ulf.wiger@REDACTED (Ulf Wiger)
Date: Thu, 22 Jul 2010 15:43:39 +0200
Subject: [erlang-questions] Volunteers wanted for new project
In-Reply-To: <AANLkTimkJSaSYD7UW1SHrN2LAYqRtC___AfvjooQt=HA@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>	<4C482461.3000707@erlang-solutions.com>	<AANLkTi=4=RAFSZKSkK8JekfzXA8WMDACG-WDgbqrBUKE@mail.gmail.com>	<AANLkTilgdSuMn0l0dmzHAacWhDWH3KWZKJmbjb9lGliS@mail.gmail.com> <AANLkTimkJSaSYD7UW1SHrN2LAYqRtC___AfvjooQt=HA@mail.gmail.com>
Message-ID: <4C484B0B.6080003@erlang-solutions.com>

Michael Turner wrote:
> 
> Bypassing human involvement entirely (the approach taken with the
> erlang.orgprojects page) means that the job of building a good
> database becomes an AI
> problem.  Not a very well-posed one, in this case.  Nor very well-solved
> either.

The projects.trapexit.org page does not bypass human involvement.

It does crawl the popular repos for erlang projects (although it
doesn't give Jungerl special treatment, which is the reason you
didn't find the parser as a separate project.) That is the
automated part.

It then allows people to rate projects based on a number of different
categories, or to add a wiki page or discussion post on trapexit.
That is the human interaction part.

There are numerous ways in which it could be improved and extended,
of course. We welcome constructive feedback on that point.

BR,
Ulf W
-- 
Ulf Wiger
CTO, Erlang Solutions Ltd, formerly Erlang Training & Consulting Ltd
http://www.erlang-solutions.com

From michael.eugene.turner@REDACTED  Thu Jul 22 16:03:39 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Thu, 22 Jul 2010 23:03:39 +0900
Subject: [erlang-questions] Re: Volunteers wanted for new project
In-Reply-To: <AANLkTiko0FUXFQUoMM3MkfyFxfq-C6GsP46R3x4vllpR@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
	<0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>
	<ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com>
	<AANLkTiko0FUXFQUoMM3MkfyFxfq-C6GsP46R3x4vllpR@mail.gmail.com>
Message-ID: <AANLkTi=MJoxq2dA9j=K_YwwCJ=VUMdfETcuOpqqErACE@mail.gmail.com>

> I'm an Erlang newbie so I'm qualified to talk about this :-)

Perhaps in an emperor/new-clothes kind of way. ;-)

I think your suggestion of consolidating the various Erlang sites takes us
somewhere near the root of the problem: erlang.org isn't a typical
myfavoritelanguage.org site.  It's essentially the open-source face of
Erlang/OTP, which is a corporation's product.  If you click on "About
erlang.org", the only human identification for this supposed non-profit
organization is the word "we", in the sentence "we are releasing free of
charge [some source code, libraries and documentation]".  In context, "we"
is Ericsson giving permissions, and Ericsson Computer Science Laboratory
acting within the limits of those permissions.

In short, if something that non-customer users consider desirable for
Erlang/OTP hasn't happened at www.erlang.org, it's probably because there's
no corporate budgeting for it, but corporate *also* won't allow it to be
done by volunteers.

There's no Guido.  There's no Larry.  There's not even a Bjarne.  Say what
you want against BDFLs (and I have, I have), we're not getting some of the
benefits of having one.  There's just a big corporation that actually tried
to kill Erlang/OTP at one point, but which is now grudgingly putting in some
money and allowing some of us out here to see things and contribute patches.

I'm not keen to venture a strong opinion about what would happen to Erlang
if its center of gravity happened to shift to some point outside Ericsson
corporate walls.  It's possible the result might not be good for Erlang.
 (Several decades of industry-watching have given me a healthy respect for
the Law of Unintended Consequences.)  But there might be a more effective
community, even if that community couldn't substitute for all the benefits
Ericsson brings to Erlang.

BDFLs rule, in part, through the "B" (benevolent) part -- they know they
have to bend a little to serve a community of volunteers, or else those
volunteers -- and even the entire code base -- can just walk away, leaving
them powerless. Ericsson?  It probably doesn't care that much.  Corporations
are beholden to stockholders seeking ROI, customers wanting products and
services, governments requiring tax payments and regulatory compliance.
 Volunteer hackers on code it has open sourced?  Priority #12 or #13.

If I were at the VP level at Ericsson, and a proposal somehow got up to me
about organizing nicely cataloged user-contributed packages written with
Erlang/OTP (which would equally available to Ericsson competitors), I'd be
furrowing my brow and asking, "Sounds like a worthy cause, a great project,
but ... could you explain again what's in it for us?  I must have missed
that part."

-michael turner

On Thu, Jul 22, 2010 at 10:17 PM, Pietro Maggi <studiomaggi@REDACTED>wrote:

> Hi,
> I'm an Erlang newbie so I'm qualified to talk about this :-)
>
> On Thu, Jul 22, 2010 at 3:07 PM, Tim Fletcher <mail@REDACTED> wrote:
> >
> [SNIP]
> >
> > Combining functionality from other sites with the same design/domain
> > of erlang.org would reduce the fragmentation, i.e. how about moving...
> >
> >  tryerlang.org to try.erlang.org
> >
> >  planeterlang.org to planet.erlang.org
> >
> >  totally-erlang.com to jobs.erlang.org
> >
> >  trapexit.org to wiki.erlang.org
> >
>
> This seems to me the best solution to this problem, by far.
> Where can I sign to put my vote on this?
>
> regards
> Pietro
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From attila.r.nohl@REDACTED  Thu Jul 22 16:27:48 2010
From: attila.r.nohl@REDACTED (Attila Rajmund Nohl)
Date: Thu, 22 Jul 2010 16:27:48 +0200
Subject: [erlang-questions] Re: Volunteers wanted for new project
In-Reply-To: <AANLkTi=MJoxq2dA9j=K_YwwCJ=VUMdfETcuOpqqErACE@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
	<0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>
	<ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com>
	<AANLkTiko0FUXFQUoMM3MkfyFxfq-C6GsP46R3x4vllpR@mail.gmail.com>
	<AANLkTi=MJoxq2dA9j=K_YwwCJ=VUMdfETcuOpqqErACE@mail.gmail.com>
Message-ID: <AANLkTimWr7RmhfhkrveYbJ3dYEg45xnWqGlcz_wJcDpa@mail.gmail.com>

2010/7/22, Michael Turner <michael.eugene.turner@REDACTED>:
[...]
> If I were at the VP level at Ericsson, and a proposal somehow got up to me
> about organizing nicely cataloged user-contributed packages written with
> Erlang/OTP (which would equally available to Ericsson competitors), I'd be
> furrowing my brow and asking, "Sounds like a worthy cause, a great project,
> but ... could you explain again what's in it for us?  I must have missed
> that part."

The community might find (and fix) a bug in core Erlang, before the
Erlang-based product is released. I don't know if this ever happened,
but I do know a fix that is released in a product and came from
(partly) outside Ericsson.

From mail@REDACTED  Thu Jul 22 16:33:15 2010
From: mail@REDACTED (Tim Fletcher)
Date: Thu, 22 Jul 2010 07:33:15 -0700 (PDT)
Subject: Volunteers wanted for new project
In-Reply-To: <AANLkTi=MJoxq2dA9j=K_YwwCJ=VUMdfETcuOpqqErACE@mail.gmail.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com> 
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com> 
	<4C482461.3000707@erlang-solutions.com> <0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com> 
	<ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com> 
	<AANLkTiko0FUXFQUoMM3MkfyFxfq-C6GsP46R3x4vllpR@mail.gmail.com> 
	<AANLkTi=MJoxq2dA9j=K_YwwCJ=VUMdfETcuOpqqErACE@mail.gmail.com>
Message-ID: <7ae09fbc-6fdb-4242-8945-c9fca229162f@t10g2000yqg.googlegroups.com>

> In short, if something that non-customer users consider desirable for
> Erlang/OTP hasn't happened atwww.erlang.org, it's probably because there's
> no corporate budgeting for it, but corporate *also* won't allow it to be
> done by volunteers.

I can understand how there wouldn't be any financial/human resource
from Ericsson for this kind of thing, but I didn't want to rule out
the possibility of opening things up to a team of volunteers.

Another na?ve suggestion: Ericsson donates erlang.org to the community
(who enlists a team of volunteers to develop a more "typical" language
orientated site), and relocates their new OTP site to erlang-otp.com
(or similar).

Otherwise, develop the new language orientated site at a new domain,
e.g. erlang-programming.org (admittedly a bit lengthy, but erlang-
lang.org would be silly!).

Tim

From dale@REDACTED  Thu Jul 22 17:12:31 2010
From: dale@REDACTED (Dale Harvey)
Date: Thu, 22 Jul 2010 16:12:31 +0100
Subject: [erlang-questions] Re: Volunteers wanted for new project
In-Reply-To: <7ae09fbc-6fdb-4242-8945-c9fca229162f@t10g2000yqg.googlegroups.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<AANLkTino7Oco6W3fAjxvPP4DZpdA7yEOXkOfe-IPBnR_@mail.gmail.com>
	<4C482461.3000707@erlang-solutions.com>
	<0CDF008D-1134-4E25-9E1E-155874BDD722@gmail.com>
	<ae6a6245-8f41-44b9-816a-e28d2511c3d1@s9g2000yqd.googlegroups.com>
	<AANLkTiko0FUXFQUoMM3MkfyFxfq-C6GsP46R3x4vllpR@mail.gmail.com>
	<AANLkTi=MJoxq2dA9j=K_YwwCJ=VUMdfETcuOpqqErACE@mail.gmail.com>
	<7ae09fbc-6fdb-4242-8945-c9fca229162f@t10g2000yqg.googlegroups.com>
Message-ID: <AANLkTilVC2e8H6FJ7TGKGe84sQtWygG7BMkI5BazpmkP@mail.gmail.com>

On 22 July 2010 15:33, Tim Fletcher <mail@REDACTED> wrote:

> > In short, if something that non-customer users consider desirable for
> > Erlang/OTP hasn't happened atwww.erlang.org, it's probably because
> there's
> > no corporate budgeting for it, but corporate *also* won't allow it to be
> > done by volunteers.
>
> I can understand how there wouldn't be any financial/human resource
> from Ericsson for this kind of thing, but I didn't want to rule out
> the possibility of opening things up to a team of volunteers.
>
> Another na?ve suggestion: Ericsson donates erlang.org to the community
> (who enlists a team of volunteers to develop a more "typical" language
> orientated site), and relocates their new OTP site to erlang-otp.com
> (or similar).
>
> Otherwise, develop the new language orientated site at a new domain,
> e.g. erlang-programming.org (admittedly a bit lengthy, but erlang-
> lang.org would be silly!).
>
>
I think this is getting fairly off the original topic, so if anyone wants to
reply then
probably worth doing under a new topic, but I have erlangotp.com /
erlang-otp.com,
its currently a very quick wiki I put up, but its always been planned to
turn it
into a proper community resource, quite what that looks like right now is
hard to figure
out. but happy to get some input on it.



> Tim
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From jilani@REDACTED  Thu Jul 22 13:28:07 2010
From: jilani@REDACTED (Jilani Khaldi)
Date: Thu, 22 Jul 2010 13:28:07 +0200
Subject: Erlang again!
Message-ID: <4C482B47.6020004@cheapnet.it>

Hi All,
after a long time, here I am programming in Erlang again...
I have 2 lists:
L1=[1,2,3,4,5], L2=[1.1,2.2,3.3,4.4,5.5]
and I want to have a third list which is the difference of them:
L3=[
L2[1] - L1[1],
L2[2] - L1[2],
L2[3] - L1[3],
L2[4] - L1[4],
L2[5] - L1[5]
]
The result should be
L3=[0.1,0.2,0.3,0.4,0.5]

I have tried:

sub(L2,L1) -> [X2-X1||X1<-L1,X2<-L2].

but the result is so different from what I have excpected (the error due 
to floats calculation is not important).

[0.10000000000000009,1.2000000000000002,2.3,
  3.4000000000000004,4.5,-0.8999999999999999,
  0.20000000000000018,1.2999999999999998,2.4000000000000004,
  3.5,-1.9,-0.7999999999999998,0.2999999999999998,
  1.4000000000000004,2.5,-2.9,-1.7999999999999998,
  -0.7000000000000002,0.40000000000000036,1.5,-3.9,-2.8,
  -1.7000000000000002,-0.5999999999999996,0.5]

Any hint?
Thanks!

-- 
Jilani KHALDI
---------------------
http://www.iiiaugusta.com


From masklinn@REDACTED  Thu Jul 22 17:33:20 2010
From: masklinn@REDACTED (Masklinn)
Date: Thu, 22 Jul 2010 17:33:20 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C482B47.6020004@cheapnet.it>
References: <4C482B47.6020004@cheapnet.it>
Message-ID: <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>

On 2010-07-22, at 13:28 , Jilani Khaldi wrote:
> Hi All,
> after a long time, here I am programming in Erlang again...
> I have 2 lists:
> L1=[1,2,3,4,5], L2=[1.1,2.2,3.3,4.4,5.5]
> and I want to have a third list which is the difference of them:
> L3=[
> L2[1] - L1[1],
> L2[2] - L1[2],
> L2[3] - L1[3],
> L2[4] - L1[4],
> L2[5] - L1[5]
> ]
> The result should be
> L3=[0.1,0.2,0.3,0.4,0.5]
> 
> I have tried:
> 
> sub(L2,L1) -> [X2-X1||X1<-L1,X2<-L2].
> 
> but the result is so different from what I have excpected (the error due to floats calculation is not important).
> 
> [0.10000000000000009,1.2000000000000002,2.3,
> 3.4000000000000004,4.5,-0.8999999999999999,
> 0.20000000000000018,1.2999999999999998,2.4000000000000004,
> 3.5,-1.9,-0.7999999999999998,0.2999999999999998,
> 1.4000000000000004,2.5,-2.9,-1.7999999999999998,
> -0.7000000000000002,0.40000000000000036,1.5,-3.9,-2.8,
> -1.7000000000000002,-0.5999999999999996,0.5]
> 
> Any hint?
> Thanks!
listcomps don't iterate on both lists simultaneously, they perform a nested iteration. So for each X1 of L1 they iterate over all of L2.

What you want here is zip/2[0] or, even better, zipWith/3[1]. If the description isn't sufficient, you might be interested in the types of the equivalent function in Haskell[2].

In any case, your operation would be along the lines of:

sub(L2, L1) -> zipWith(fun(X2, X1) -> X2-X1 end, L2, L1).

[0] http://www.erlang.org/doc/man/lists.html#zip-2
[1] http://www.erlang.org/doc/man/lists.html#zipwith-3
[2] http://haskell.org/ghc/docs/6.12.1/html/libraries/base-4.2.0.0/Prelude.html#v:zipWith

From jesper.louis.andersen@REDACTED  Thu Jul 22 17:36:25 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Thu, 22 Jul 2010 17:36:25 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C482B47.6020004@cheapnet.it>
References: <4C482B47.6020004@cheapnet.it>
Message-ID: <AANLkTin5_xwJ4oMM-VkEeuHkfmmYPC2t7RJ7JpaaR9xG@mail.gmail.com>

On Thu, Jul 22, 2010 at 1:28 PM, Jilani Khaldi <jilani@REDACTED> wrote:
> I have tried:
>
> sub(L2,L1) -> [X2-X1||X1<-L1,X2<-L2].
>

You are asking for the cartesian product of the values, example:

1> [{X1, X2} || X1 <- [1,2,3], X2 <- [4,5,6]].
[{1,4},{1,5},{1,6},{2,4},{2,5},{2,6},{3,4},{3,5},{3,6}

What you really are after is the zip of the two lists:

2> [{X1, X2} || {X1, X2} <- lists:zip([1,2,3], [4,5,6])].
[{1,4},{2,5},{3,6}]

As Masklinn hints, the functions lists:zipwith/3 and lists:zip/2 are
your friends in this case.


-- 
J.

From csanto@REDACTED  Thu Jul 22 17:52:54 2010
From: csanto@REDACTED (Corrado Santoro)
Date: Thu, 22 Jul 2010 17:52:54 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C482B47.6020004@cheapnet.it>
References: <4C482B47.6020004@cheapnet.it>
Message-ID: <108cb29f6467319b10f5c6600bb1e370.squirrel@webmail.cdc.unict.it>

> Hi All,
> after a long time, here I am programming in Erlang again...
> I have 2 lists:
> L1=[1,2,3,4,5], L2=[1.1,2.2,3.3,4.4,5.5]
> and I want to have a third list which is the difference of them:
> L3=[
> L2[1] - L1[1],
> L2[2] - L1[2],
> L2[3] - L1[3],
> L2[4] - L1[4],
> L2[5] - L1[5]
> ]
> The result should be
> L3=[0.1,0.2,0.3,0.4,0.5]

Try this:

sub ([],[]) -> [];
sub (_, []) -> [];
sub ([], _) -> [];
sub ([H1 | T1], [H2 | T2]) -> [ H2 - H1 | sub (T1, T2)].


not tail-recursive... however :-)

--Corrado



From g9414002.pccu.edu.tw@REDACTED  Thu Jul 22 18:43:28 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Fri, 23 Jul 2010 00:43:28 +0800
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C482B47.6020004@cheapnet.it>
References: <4C482B47.6020004@cheapnet.it>
Message-ID: <AANLkTik-76GexFRebX2ulykYkrFk_3cDYmbCBeGAi_4L@mail.gmail.com>

On Thu, Jul 22, 2010 at 7:28 PM, Jilani Khaldi <jilani@REDACTED> wrote:


> sub(L2,L1) -> [X2-X1||X1<-L1,X2<-L2].
>
>
A comment for this line. It means that any element in L1 may be
subtracted by any elements in L2. Product of lists L1 and L2.

For your request, use Zip function (lists:zip/2 in Erlang) or write
a direct function:

    sub(Xs, Ys) when Xs = [] or Ys = 0 -> [];
    sub([X|Xs], [Y|Ys]) -> [X-Y|sub(Xs,Ys)].

By Map-After-Zip,

    sub(Xs, Ys) -> array.map(fun (X, Y) -> X-Y end, lists.zip(Xs, Ys)).

By lists.zipWith/3,

    sub(Xs, Ys) -> lists.zipWith(fun (X, Y) -> X-Y end, Xs, Ys).

From boris.muehmer@REDACTED  Thu Jul 22 18:55:13 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Thu, 22 Jul 2010 18:55:13 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>
References: <4C482B47.6020004@cheapnet.it>
	<B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>
Message-ID: <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>

2010/7/22 Masklinn <masklinn@REDACTED>:
> What you want here is zip/2[0] or, even better, zipWith/3[1].

Well, I didn't know about zip or zipwith (still not inside the
library), so my solution was like this:

    sub(L2,L1) ->
        lists:reverse(sub(L2,L1,[])).

    sub([],[],List) ->
        List;
    sub([H2|T2],[H1|T1],List) ->
        sub(T2,T1,[(H2-H1)|List]).

Ok, this is much longer than with zip or zipwith, but somehow this was
much easier to "develop". Well, at the end of the documentation of
zipwith there is almost a solution to the problem, but I wouldn't have
found it, if zip or zipwith wasn't mentioned.

Is such a solution plain bad, or just a newbie mistake/error?


  - boris

From g9414002.pccu.edu.tw@REDACTED  Thu Jul 22 19:09:08 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Fri, 23 Jul 2010 01:09:08 +0800
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it>
	<B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>
	<AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
Message-ID: <AANLkTikhr-OBBJJZL1Kft7-cKifLy-5xap23uX3tjTxD@mail.gmail.com>

Hi, boris.

On Fri, Jul 23, 2010 at 12:55 AM, Boris M?hmer <boris.muehmer@REDACTED
> wrote:

> 2010/7/22 Masklinn <masklinn@REDACTED>:
> > What you want here is zip/2[0] or, even better, zipWith/3[1].
>


>    sub(L2,L1) ->
>        lists:reverse(sub(L2,L1,[])).
>
>    sub([],[],List) ->
>        List;
>    sub([H2|T2],[H1|T1],List) ->
>        sub(T2,T1,[(H2-H1)|List]).
>
> Ok, this is much longer than with zip or zipwith, but somehow this was
> much easier to "develop". Well, at the end of the documentation of
> zipwith there is almost a solution to the problem, but I wouldn't have
> found it, if zip or zipwith wasn't mentioned.
>
> Is such a solution plain bad, or just a newbie mistake/error?
>
>  - boris
>
>
It's not bad. It's a technique that is not related to what zip/2 or
zipWith/3
means, but it is a general way to make tail-recursion by using a
accumulating parameter. It's an important programming strategy for
a newbie to become familiar with Erlang or functional programming.

From masklinn@REDACTED  Thu Jul 22 19:08:47 2010
From: masklinn@REDACTED (Masklinn)
Date: Thu, 22 Jul 2010 19:08:47 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it> <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net> <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
Message-ID: <F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>

On 2010-07-22, at 18:55 , Boris M?hmer wrote:
> 
> Is such a solution plain bad, or just a newbie mistake/error?

I would say it's a not-very-useful reimplementation of something which already exists in the stdlib. It's mostly a question of not knowing your toolbox, so I wouldn't say it's bad, but it definitely isn't optimum.

On the other hand, the Erlang toolbox isn't very discoverable/searchable so you have to read it all (several time if needed).

That's a big advantage of haskell and its strong typing: hoogle[0] lets you search functions by type. In this case you can search for [a] -> [b] -> [c] (a function taking a list of 'a's, a list of 'b's and returning a list of 'c's) and the first result is zipWith[1].

It's not perfect though, as a search for [Int] -> [Int] -> [Int] demonstrates[2] with zipWith ending up on the third page of the results, and the return of such functions as `drop :: Int -> [a] -> [a]`.

[0] http://haskell.org/hoogle/
[1] http://haskell.org/hoogle/?q=[a]%20->%20[b]%20->%20[c]
[2] http://haskell.org/hoogle/?hoogle=[Int]+->+[Int]+->+[Int]&start=41#more

From ok@REDACTED  Fri Jul 23 01:33:09 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Fri, 23 Jul 2010 11:33:09 +1200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C482B47.6020004@cheapnet.it>
References: <4C482B47.6020004@cheapnet.it>
Message-ID: <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz>


On Jul 22, 2010, at 11:28 PM, Jilani Khaldi wrote:

> Hi All,
> after a long time, here I am programming in Erlang again...
> I have 2 lists:
> L1=[1,2,3,4,5], L2=[1.1,2.2,3.3,4.4,5.5]
> and I want to have a third list which is the difference of them:
> L3=[
> L2[1] - L1[1],
> L2[2] - L1[2],
> L2[3] - L1[3],
> L2[4] - L1[4],
> L2[5] - L1[5]
> ]
> The result should be
> L3=[0.1,0.2,0.3,0.4,0.5]
> 
> I have tried:
> 
> sub(L2,L1) -> [X2-X1||X1<-L1,X2<-L2].

This says
    for each X1 in L1 {
        for each X2 in L2 {
            include X1 - X2 in the result
        }
    }
just like it does in Haskell and Clean.

Direct method:
   sub([X|Xs], [Y|Ys]) -> [X-Y | sub(Xs, Ys)];
   sub([],     [])     -> [].

Zip then enumerate pairs:
   sub(Xs, Ys) -> [X-Y || {X,Y} <- lists:zip(Xs, Ys)].

Zip with a function other than pairing:
   sub(Xs, Ys) -> lists:zipwith(fun (X, Y) -> X - Y end, Xs, Ys).

One expects a Haskell compiler to expand calls to zip.
One expects an Erlang compiler NOT to, and it doesn't.
There's an EEP proposing that you should be allowed to write

 ** sub(Xs, Ys) -> [X-Y || X <- Xs && Y <- Ys]

but that's not allowed in Erlang yet.


From ok@REDACTED  Fri Jul 23 01:44:55 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Fri, 23 Jul 2010 11:44:55 +1200
Subject: [erlang-questions] Parsing C with leex and yecc
In-Reply-To: <alpine.LSU.2.00.1007221839560.12262@hermes-2.csi.cam.ac.uk>
References: <AANLkTikKDyd8En0kdAwO0r5ZZf72GnOQuIT6XAIkhtr8@mail.gmail.com> <6D5C0441-0BB7-4A36-B28A-24056B207984@cs.otago.ac.nz> <alpine.LSU.2.00.1007221839560.12262@hermes-2.csi.cam.ac.uk>
Message-ID: <DA4B6C31-DE5C-45CE-8022-E9084168ACB5@cs.otago.ac.nz>


On Jul 23, 2010, at 6:00 AM, Tony Finch wrote:
>> 	/\/\*([^*]*\*+[^/*])*[^*]*\*+\//
> 
> This is sadly incomplete ("sadly" because it's a good example of C's
> syntactic unpleasantness) unless you have already performed translation
> phases 1 and 2 on the source. In phase one you translate trigraphs (in
> particular ??/ -> \) and in phase two you delete backslash-newline
> sequences (which might not be visible until after trigraph substitution).
> Comments are recognized in phase three.

Exactly so.  Which is why I suggested using a C preprocessor to do
the heavy lifting.  My "favourite" C comment is

	/??/	=> /\   =>	/**/
	*??/	   *\
	*??/	   *\
	/	   /
		trigraphs	backslash-newline removal

gcc actually gets this completely wrong unless you pass -trigraph
on the command line.

> 
>   2. Each instance of a backslash character (\) immediately followed by
>      a new-line character is deleted, splicing physical source lines to
>      form logical source lines. Only the last backslash on any physical
>      source line shall be eligible for being part of such a splice. A
>      source file that is not empty shall end in a new-line character,
>      which shall not be immediately preceded by a backslash character
>      before any such splicing takes place.

It's amazing how many Windows C programs violate this rule,
the file ending with say
	}<EOF>
and it's even more amazing that some compilers fail to diagnose this.


To adapt something Padlipski wrote,
	"There's a rumour that they're moving to 17 phases in the
	next standard, because 17 is a sacred number in Bali."



From ok@REDACTED  Fri Jul 23 01:47:23 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Fri, 23 Jul 2010 11:47:23 +1200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
References: <4C482B47.6020004@cheapnet.it> <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net> <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com> <F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
Message-ID: <69A7CFF1-955A-4AD2-B05D-EFA31FBC15DC@cs.otago.ac.nz>


On Jul 23, 2010, at 5:08 AM, Masklinn wrote:

> On 2010-07-22, at 18:55 , Boris M?hmer wrote:
>> 
>> Is such a solution plain bad, or just a newbie mistake/error?
> 
> I would say it's a not-very-useful reimplementation of something which already exists in the stdlib. It's mostly a question of not knowing your toolbox, so I wouldn't say it's bad, but it definitely isn't optimum.

Depends what you mean by "optimum".
Chances are that either the direct version or the reverse
version is significantly *faster* than the approaches using zip
or zipwith.  The direct version never allocates a word it doesn't
want to keep, so it's the kindest to the garbage collector too.

The cost is in development time and maintenance time.
> 


From ok@REDACTED  Fri Jul 23 01:51:20 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Fri, 23 Jul 2010 11:51:20 +1200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <108cb29f6467319b10f5c6600bb1e370.squirrel@webmail.cdc.unict.it>
References: <4C482B47.6020004@cheapnet.it> <108cb29f6467319b10f5c6600bb1e370.squirrel@webmail.cdc.unict.it>
Message-ID: <9D9A9A38-305A-4CC8-B154-97347398D441@cs.otago.ac.nz>


On Jul 23, 2010, at 3:52 AM, Corrado Santoro wrote:
> Try this:
> 
> sub ([],[]) -> [];
> sub (_, []) -> [];
> sub ([], _) -> [];
> sub ([H1 | T1], [H2 | T2]) -> [ H2 - H1 | sub (T1, T2)].

Don't.  Why write three clauses when one will do?

sub([X|Xs], [Y|Ys]) -> [X-Y | sub(Xs, Ys)];
sub(_,      _     ) -> [].

Then think about whether you really want sub(boojum, []) to answer
[], or whether you really want sub([2,3], [1|missing]) to return
[1], and make the second clause

sub([], []) -> [].
> 
> not tail-recursive... however :-)

Tail recursion is important, but body recursion is not the
Dark Side of the Source.

"FIRST make it right,
 THEN (try to) make it fast(er)."


From ok@REDACTED  Fri Jul 23 01:57:56 2010
From: ok@REDACTED (Richard O'Keefe)
Date: Fri, 23 Jul 2010 11:57:56 +1200
Subject: [erlang-questions] Re: Volunteers wanted for new project
In-Reply-To: <82619625-0dd0-425e-aa64-388ffee05e2a@u26g2000yqu.googlegroups.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com> <82619625-0dd0-425e-aa64-388ffee05e2a@u26g2000yqu.googlegroups.com>
Message-ID: <4BD341D3-1971-48EB-881C-E716496F8035@cs.otago.ac.nz>


On Jul 22, 2010, at 10:09 PM, Tim Fletcher wrote:

>> The other day I wanted to see if anybody had written a parser for
>> C in Erlang.  I did not know of such a parser, so I Googled a bit
>> and turned up nothing.
> 
> I'm not too surprised by that, an Erlang C parser would seem to be
> quite a "niche" thing.

Why?  I'm aware of C parsers in Java, Prolog, SML, OCaml, and Haskell.



From xramtsov@REDACTED  Fri Jul 23 04:18:03 2010
From: xramtsov@REDACTED (Evgeniy Khramtsov)
Date: Fri, 23 Jul 2010 12:18:03 +1000
Subject: Erlang consumes memory suddenly
Message-ID: <4C48FBDB.5040703@gmail.com>

Hi there!

Recently we played with emulator '+Musbct 5' flag in ejabberd to reduce 
memory consumption. All was fine in stress testing, so we tried it in 
production. Several hours everything was good but then suddenly Erlang 
started to consume RSS memory and finally we stopped it. We monitor 
memory, so you can see the spike here: 
http://kuku.jabber.ru/~xram/ejabberd_memory-day.png
As you can see, no processes/system memory was consumed.

So my questions are:
1) Is this a bug or a feature? If this is a feature, is it possible to 
know what consumed memory?
2) If +Musbct option works incorrectly, then what option should we use 
to decrease the difference between erlang:memory(total) and RSS? 
Sometimes this difference reaches up to 2Gb of RSS.

We are running R13B04, all linked-in drivers use 
driver_alloc/driver_free/driver_realloc (either directly or through 
provided memory callbacks).
Currently we are trying +Musbct 20 :)

-- 
Regards,
Evgeniy Khramtsov, ProcessOne.
xmpp:xram@REDACTED


From shenyute@REDACTED  Fri Jul 23 05:53:02 2010
From: shenyute@REDACTED (Yu-Teh Shen)
Date: Fri, 23 Jul 2010 11:53:02 +0800
Subject: about C Node get global register name
Message-ID: <AANLkTimSSxx9Zr3R8ppWc_mhwQ0ie7K9DQpC9YhBMz9C@mail.gmail.com>

i try to use C node to connect to an erlang node, and get the global
register names.

but i can not get the name, could anyone tell me why?

C Node:
    erl_init(NULL, 0);
    if (erl_connect_init(1, "aaa", 0) == -1)
        erl_err_quit("erl_connect_init");
    if ((fd = erl_connect("local@REDACTED")) < 0)
        erl_err_quit("erl_connect");

    reply = erl_global_names(fd, &count);
    if (reply) {
        printf("count = %d\n", count);
        for (i = 0; i < count; i++)
            printf("%s\n", reply[i]);
        free(reply);
    }

erlang node 1:
(master@REDACTED)5> global:registered_names().
["GMaster"]

erlang node 2:
(local@REDACTED)2> global:registered_names().
["GMaster"]

Shen, Yu-Teh

From vinoski@REDACTED  Fri Jul 23 07:20:38 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Fri, 23 Jul 2010 01:20:38 -0400
Subject: [erlang-questions] about C Node get global register name
In-Reply-To: <AANLkTimSSxx9Zr3R8ppWc_mhwQ0ie7K9DQpC9YhBMz9C@mail.gmail.com>
References: <AANLkTimSSxx9Zr3R8ppWc_mhwQ0ie7K9DQpC9YhBMz9C@mail.gmail.com>
Message-ID: <AANLkTil4lvzYtoVhM50E2UjjObkEfUI4ppA5O8dhnsoe@mail.gmail.com>

On Thu, Jul 22, 2010 at 11:53 PM, Yu-Teh Shen <shenyute@REDACTED> wrote:
> i try to use C node to connect to an erlang node, and get the global
> register names.
>
> but i can not get the name, could anyone tell me why?

The erl_global_names() function expects registered names to be atoms,
not strings. Try registering your globals using atoms for names and
your cnode code will work as expected.

--steve

From ttmrichter@REDACTED  Fri Jul 23 09:15:50 2010
From: ttmrichter@REDACTED (Michael Richter)
Date: Fri, 23 Jul 2010 15:15:50 +0800
Subject: This *SHOULD* be simple... compile a string to assembler.
Message-ID: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com>

This should be simple, given the sheer bewildering variety of parsing bits
in stdlib and tools, but I can't for the life of me figure out how to make
this work.

I want to take a string like "a() -> 42.".

I want to see what this looks like in the "assembler" output from the
compiler, but without having to save it to a file (artificially adding a
module definition), compiling that file with "assembler" output, then
displaying the output file.

For reference, here's how the equivalent would look using bash and the gcc
compiler:

echo 'int a() { return 42; }' | gcc -xc -S -o- -


Similar code works for clang too (no surprise since clang aims to shadow the
gcc command line):

echo 'int a() { return 42; }' | clang -xc -S -o- -


So... how to do the same in Erlang?  A quick glance at erlc tells me there's
no way to take input from stdin and put output to stdout, but that's not a
problem.  I'll just make an escript.  Let's look at what we can do after
reading over the docs:

1> {ok, Tokens, _} = erl_scan:string("a () -> 42.").
{ok,[{atom,1,a},
     {'(',1},
     {')',1},
     {'->',1},
     {integer,1,42},
     {dot,1}],
    1}

So far so good.  Let's keep it up.

2> {ok, AbsForm} = erl_parse:parse_form(Tokens).
{ok,{function,1,a,0,[{clause,1,[],[],[{integer,1,42}]}]}}

This is really promising.  Now how to turn this into assembler?  Ah!
 compile:forms/2 seems to be a good fit.  Let's give it a try.

3> compile:forms([AbsForm], 'S').
.:1: no module definition
.:1: Warning: function a/0 is unused
error

Oops!  Something is wrong here.  It wants a module, but I don't have one.
 Let's go back and add those.

4> {ok, Tokens2, _} =
erl_scan:string("-module(null).\n-compile(export_all).\na () -> 42.").
{ok,[{'-',1},
     {atom,1,module},
     {'(',1},
     {atom,1,null},
     {')',1},
     {dot,1},
     {'-',2},
     {atom,2,compile},
     {'(',2},
     {atom,2,export_all},
     {')',2},
     {dot,2},
     {atom,3,a},
     {'(',3},
     {')',3},
     {'->',3},
     {integer,3,42},
     {dot,3}],
    3}
5> {ok, AbsForm} = erl_parse:parse_form(Tokens2).

** exception error: no match of right hand side value
{error,{2,erl_parse,["syntax error before: ","'-'"]}}

...

What the ...?!

OK, maybe it doesn't like the compiler options there.  Let's try it with
just the module.

6> {ok, Tokens3, _} = erl_scan:string("-module(null).\na () -> 42.").
{ok,[{'-',1},
     {atom,1,module},
     {'(',1},
     {atom,1,null},
     {')',1},
     {dot,1},
     {atom,2,a},
     {'(',2},
     {')',2},
     {'->',2},
     {integer,2,42},
     {dot,2}],
    2}
7> {ok, AbsForm} = erl_parse:parse_form(Tokens3).
** exception error: no match of right hand side value
{error,{2,erl_parse,["syntax error before: ","a"]}}

Nope.  That didn't do it either.  It just doesn't like anything after I give
it the module.  That's ... odd.

Hang on!  The location of the error moved to now give an error in front of
code that USED TO COMPILE.  What's going on here?!

8> {ok, Tokens4, _} = erl_scan:string("a () -> 42.\nb () -> 24.").
{ok,[{atom,1,a},
     {'(',1},
     {')',1},
     {'->',1},
     {integer,1,42},
     {dot,1},
     {atom,2,b},
     {'(',2},
     {')',2},
     {'->',2},
     {integer,2,24},
     {dot,2}],
    2}
9> {ok, AbsForm} = erl_parse:parse_form(Tokens4).
** exception error: no match of right hand side value
{error,{2,erl_parse,["syntax error before: ","b"]}}

The parser... parses one . at a time it seems.  That's a bit odd.

Now here's where we stop because we hit my point for this message.  (For the
record, Mononcqc assisted me with this until we figured out how to
accomplish what was needed.  It's an embarrassing amount of work, however,
given that I'm trying to replicate a bash/gcc *one-liner* here, involving
splitting lists on magic token values, inserting hand-crafted forms to the
list of abstract forms, etc.)

The real point of this message lies in documentation.  There was a recent
thread in the mailing list in which some people made semi-to-fully-snide
comments about "knowing the toolbox" because someone hand-rolled a custom
zip* function instead of using lists:zip which he should have known about if
he had only read the docs.  (I'll let you picture the very Victorian back of
the hand to the forehead routine while reading that previous sentence's
closing clause.)

The problem here is that in this case, trying to solve what should be a
trivial problem, I did actually look very closely at my toolbox.  I looked
at the tools available.  I figured out which pieces would be needed
(erl_scan:string/1, erl_parse:parse_form/1 and compile:forms/2) *and could
not figure out how to piece them together*.  The docs on the individual
pieces are ... technically present, but lacking of important details (like
parse_form/1 only going through one {dot,1} token at a time) and showing *
zero* examples of how to put them all together in a working whole.  Instead
of having nice Lego pieces that snap together easily to make eye-pleasing
shapes we have cheap Chinese knock-off Legos with poorly-fitting pieces and
random pins and razor blades stuck into them to get pricked and/or cut by
while we play.

There is an embarrassing wealth of very useful functionality in the
Erlang/OTP distribution.  It is, however, mostly inaccessible because of
these sorts of documentation issues.  Were I not so pigheaded (and Monocqc
not so patient) I would have thrown the tools out and just hacked together a
stupid bash script to do what I wanted: output a bogus module into a
temporary file, append the string, call erlc -S on that and display the
resulting output file before deleting it all.  Why?  Because as comically
inept and hackish as that solution is, it's better than trying to figure out
the library's docs.

Now in my case, I'm going to look at the open source OTP distribution and
see if I can't contribute some actual *examples of use* to the docs for
these pieces.  That solves this little problem, but leaves us with a million
more still.  (Like the dire docs situation for the xref and related modules,
for example.)

So, please, next time someone adopts a "less than optimal" solution to a
problem because they didn't use a library function that did what they
wanted?  Please remember to try looking at the Erlang/OTP docs from a
newcomer's perspective.  Look at what's actually written in the docs and
compare it to the lore that's congealed in your head over your years of use.
 Run a diff over the two and maybe then you'll understand why so many
newcomers do such "broken" things.


(For the record, the solution to the problem I started working on can be
found at http://ideone.com/MXT11.  This is a replacement for a
shell/compiler one-liner.  I'm sure I haven't got the most efficient
possible code for this, but I doubt you could shrink it by an order of
magnitude to match the one-liner.)

-- 
"Perhaps people don't believe this, but throughout all of the discussions of
entering China our focus has really been what's best for the Chinese people.
It's not been about our revenue or profit or whatnot."
--Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.

From vladdu55@REDACTED  Fri Jul 23 09:28:24 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Fri, 23 Jul 2010 09:28:24 +0200
Subject: [erlang-questions] This *SHOULD* be simple... compile a string to 
	assembler.
In-Reply-To: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com>
References: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com>
Message-ID: <AANLkTim57YJXqn6g222NPHJyxmvS=c64F9s8pOkpVDV0@mail.gmail.com>

On Fri, Jul 23, 2010 at 09:15, Michael Richter <ttmrichter@REDACTED> wrote:
> 1> {ok, Tokens, _} = erl_scan:string("a () -> 42.").
> 2> {ok, AbsForm} = erl_parse:parse_form(Tokens).
> 4> {ok, Tokens2, _} =
> erl_scan:string("-module(null).\n-compile(export_all).\na () -> 42.").
> 5> {ok, AbsForm} = erl_parse:parse_form(Tokens2).

Hi,

On line 5 you are matching against the old AbsForm... Use AbsForm2
instead, or "f(AbsForm)".

regards,
Vlad

From vladdu55@REDACTED  Fri Jul 23 09:33:19 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Fri, 23 Jul 2010 09:33:19 +0200
Subject: [erlang-questions] This *SHOULD* be simple... compile a string to 
	assembler.
In-Reply-To: <AANLkTim57YJXqn6g222NPHJyxmvS=c64F9s8pOkpVDV0@mail.gmail.com>
References: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com> 
	<AANLkTim57YJXqn6g222NPHJyxmvS=c64F9s8pOkpVDV0@mail.gmail.com>
Message-ID: <AANLkTin8G-K1oVbEwfEk29dK5jTgYVXJhHb36pFhAHbi@mail.gmail.com>

On Fri, Jul 23, 2010 at 09:28, Vlad Dumitrescu <vladdu55@REDACTED> wrote:
> On Fri, Jul 23, 2010 at 09:15, Michael Richter <ttmrichter@REDACTED> wrote:
>> 1> {ok, Tokens, _} = erl_scan:string("a () -> 42.").
>> 2> {ok, AbsForm} = erl_parse:parse_form(Tokens).
>> 4> {ok, Tokens2, _} =
>> erl_scan:string("-module(null).\n-compile(export_all).\na () -> 42.").
>> 5> {ok, AbsForm} = erl_parse:parse_form(Tokens2).
>
> On line 5 you are matching against the old AbsForm... Use AbsForm2
> instead, or "f(AbsForm)".

Ok, this doesn't address your main problem, of course... I answered
too fast, sorry.

It's not a big deal to write a parse_forms that folds a list of
tokens, parsing one form at a time. Of course that should be part of
erl_parse -- now that you solved the problem maybe you could send a
patch?

regards,
Vlad

From mail@REDACTED  Fri Jul 23 10:01:22 2010
From: mail@REDACTED (Tim Fletcher)
Date: Fri, 23 Jul 2010 01:01:22 -0700 (PDT)
Subject: Volunteers wanted for new project
In-Reply-To: <4BD341D3-1971-48EB-881C-E716496F8035@cs.otago.ac.nz>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com> 
	<82619625-0dd0-425e-aa64-388ffee05e2a@u26g2000yqu.googlegroups.com> 
	<4BD341D3-1971-48EB-881C-E716496F8035@cs.otago.ac.nz>
Message-ID: <752f79ae-f9f0-427f-8e79-e0a9b1b9c7a1@w30g2000yqw.googlegroups.com>

> Why? I'm aware of C parsers in Java, Prolog, SML, OCaml, and Haskell.

Relatively speaking I don't expect many people to be writing about,
linking to, or searching for Erlang C parser code, that's all.
Searching for "prolog c parser" doesn't produce much either. Searching
for "java c parser" produces reasonable results, but there is more
Java in the world than there is Prolog :)

According to Google there are 170 global monthly Google searches for
"java c parser", and < 10 for "erlang c parser" and "prolog c parser".
Compared to 151,000,000 for "lady gaga".

From masklinn@REDACTED  Fri Jul 23 10:06:48 2010
From: masklinn@REDACTED (Masklinn)
Date: Fri, 23 Jul 2010 10:06:48 +0200
Subject: [erlang-questions] This *SHOULD* be simple... compile a string to assembler.
In-Reply-To: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com>
References: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com>
Message-ID: <9212B4A7-E969-4664-B3E3-A1C8BD9826E5@masklinn.net>

On 2010-07-23, at 09:15 , Michael Richter wrote:
> 
> The real point of this message lies in documentation.  There was a recent
> thread in the mailing list in which some people made semi-to-fully-snide
> comments about "knowing the toolbox" because someone hand-rolled a custom
> zip* function instead of using lists:zip which he should have known about if
> he had only read the docs.  (I'll let you picture the very Victorian back of
> the hand to the forehead routine while reading that previous sentence's
> closing clause.)

Given I'm apparently targeted here, I'm going to ask you to kindly go screw yourself. My remark was not snide in the least and a simple answer to a commenter asking whether his solution was thought as "plain bad or just a newbie mistake/error".

It was also highly mitigated by concerns about the discoverability of the Erlang documentations

Again, screw you.

From masklinn@REDACTED  Fri Jul 23 11:29:44 2010
From: masklinn@REDACTED (Masklinn)
Date: Fri, 23 Jul 2010 11:29:44 +0200
Subject: [erlang-questions] This *SHOULD* be simple... compile a string to assembler.
In-Reply-To: <9212B4A7-E969-4664-B3E3-A1C8BD9826E5@masklinn.net>
References: <AANLkTimTVc5ok_sqGfHL5C94ByC9xrNWkUzuORK3r2Z5@mail.gmail.com> <9212B4A7-E969-4664-B3E3-A1C8BD9826E5@masklinn.net>
Message-ID: <FAD9E30C-69A5-4EB6-A17E-878C418E6CC7@masklinn.net>

On 2010-07-23, at 10:06 , Masklinn wrote:
> 
> Given I'm apparently targeted here [snip]

I want to apologize to the list for having made this comment publicly in a place definitely not suited for it. This should have been sent privately and I am very sorry I behave that way.


From jesper.louis.andersen@REDACTED  Fri Jul 23 13:35:04 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Fri, 23 Jul 2010 13:35:04 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
References: <4C482B47.6020004@cheapnet.it> <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net> 
	<AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com> 
	<F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
Message-ID: <AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com>

On Thu, Jul 22, 2010 at 7:08 PM, Masklinn <masklinn@REDACTED> wrote:

> On the other hand, the Erlang toolbox isn't very discoverable/searchable so you have to read it all (several time if needed).

It is interesting you put forth that argument. I generally find the
Erlang documentation is on par with Haskells ditto. In certain areas
Erlangs documentation is far better: we have users guides strewn all
over the official site:

http://erlang.org/doc/

There are no users guide for the various Haskell libraries and the URL
is worse to boot:

http://haskell.org/ghc/docs/6.12.1/html/libraries/base-4.2.0.0/

Furthermore, the URL contain the version string in several places, so
it becomes obsolete every 3 months or so. It also wreaks havoc on
Googles search index to have all versions freely available: Older
pages tend to win up to a certain point unless you mitigate them with
a <link rel canonical> construction in the HTML.

Erlangs weakness, which you identified, is that you need to know which
module to search for in the standard documentation. But as soon as you
know the specific module, it becomes easy. I tend to use the command
line and write either of:

  erl -man MODULE
  man 3erl MODULE

because I am an old unix-geek and like to have man-pages for my
documentation. As a reference, man-pages are unbeatable. Yet, as you
indicate, as a discovery-tool, they are not that good. To nail the
coffin, We have an excellent web UI tool by Dale Harvey:

http://erldocs.com/

> That's a big advantage of haskell and its strong typing: hoogle[0] lets you search functions by type. In this case you can search for [a] -> [b] -> [c] (a function taking a list of 'a's, a list of 'b's and returning a list of 'c's) and the first result is zipWith[1].

(Detail aside: The typing terminology is not set in stone. When you
write "strong typing" I am going to assume you mean that a program can
be determined well-typed at compile time by a static semantics on the
abstract syntax tree of the program. Other people, myself included,
call this property "static typing" and we reserve the "strong typing"
to mean: There are no unchecked run-time type errors. So the program
will never segfault. end-of-aside)

Right now, you are right. There is no hoogle tool for Erlang.
Theoretically, I think you are wrong and here is why: Kostis Sagonas
has recently added -spec() contracts to the Erlang system which allows
you to gain some of the advantages of static typing while still
retaining the dynamic properties of Erlang. In principle, it should be
possible to write a hoogle-like system for Erlang on top of these
-spec() contracts and gain exactly the same kind of documentation
lookup.

Also, simply having the type specification for a given function is not
always enough. Let me draw up a simple example: Haskells iteratee
library by John W. Lato.

http://hackage.haskell.org/packages/archive/iteratee/0.3.5/doc/html/Data-Iteratee-Base.html

There is a Monad Reader article on how to use the library, and it is
definitely needed. It is not going to be easy to dissect the type
specification of the iteratee library without knowing anything about a
general "users guide" overview of what they do. The problem is not
limited to Haskell, but is present in other statically typed systems
as well. You can probably find good examples in the Coq system - it
would be the first place to look for my as it has all the cool
ingredients in its type system. Included a "full employment theorem
for type specialsts due to total incomprehension of a type" :-)




-- 
J.

From jesper.louis.andersen@REDACTED  Fri Jul 23 13:49:23 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Fri, 23 Jul 2010 13:49:23 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz>
References: <4C482B47.6020004@cheapnet.it> <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz>
Message-ID: <AANLkTin2PcVLJMJRYYMma9X0wvzTxeHoUJdo01YKavH9@mail.gmail.com>

On Fri, Jul 23, 2010 at 1:33 AM, Richard O'Keefe <ok@REDACTED> wrote:

> One expects a Haskell compiler to expand calls to zip.
> One expects an Erlang compiler NOT to, and it doesn't.

There are a lot of wisdom in those two sentences. A Haskell compiler
can, in general, transform a program much more and get away with it. I
believe it is one of the arguments John Hughes make in his "Why
functional programming matters" paper (I may be wrong, it is a long
time since I read the paper). An Erlang compiler can in principle make
the transformations but only after some extensive analysis and not
always. The beauty of Haskell is when you write succinct, modular
building blocks and then string them together AND the Haskell compiler
optimizes it. When it fails to optimize you have succinct, modular and
slow code.

A couple of years ago I would expect a Haskell compiler to produce
faster code than an Erlang compiler. As it stands currently, I am in
doubt: CPU cycles have become very cheap and the new bottleneck seem
to be memory bandwidth to the CPU. Lazy evaluation tend not to be
especially nice to the memory bandwidth. This can affect all programs
but those with a small heavy computation kernel. Even with a bytecode
interpreter (a state-of-the-art BC-interpreter though) my last
exploration into bittorrent clients told a story where Erlang and
Haskell were more or less on par with each other from a CPU-resource
perspective. A recent new IO manager for Haskell might change this
picture however.

-- 
J.

From dale@REDACTED  Fri Jul 23 13:58:46 2010
From: dale@REDACTED (Dale Harvey)
Date: Fri, 23 Jul 2010 12:58:46 +0100
Subject: [erlang-questions] Erlang again!
In-Reply-To: <F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
References: <4C482B47.6020004@cheapnet.it>
	<B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>
	<AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
	<F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
Message-ID: <AANLkTimBs9pa9pkG1WVtutTNP3vrum51BDqT-Fnvkpkx@mail.gmail.com>

On 22 July 2010 18:08, Masklinn <masklinn@REDACTED> wrote:

> On 2010-07-22, at 18:55 , Boris M?hmer wrote:
> >
> > Is such a solution plain bad, or just a newbie mistake/error?
>
> I would say it's a not-very-useful reimplementation of something which
> already exists in the stdlib. It's mostly a question of not knowing your
> toolbox, so I wouldn't say it's bad, but it definitely isn't optimum.
>
> On the other hand, the Erlang toolbox isn't very discoverable/searchable so
> you have to read it all (several time if needed).
>
>
The major reason I wrote erldocs, its makes the docs fairly discoverable
http://erldocs.com/?search=zip


> That's a big advantage of haskell and its strong typing: hoogle[0] lets you
> search functions by type. In this case you can search for [a] -> [b] -> [c]
> (a function taking a list of 'a's, a list of 'b's and returning a list of
> 'c's) and the first result is zipWith[1].
>
> It's not perfect though, as a search for [Int] -> [Int] -> [Int]
> demonstrates[2] with zipWith ending up on the third page of the results, and
> the return of such functions as `drop :: Int -> [a] -> [a]`.
>
> [0] http://haskell.org/hoogle/
> [1] http://haskell.org/hoogle/?q=[a]%20->%20[b]%20->%20[c]
> [2] http://haskell.org/hoogle/?hoogle=[Int]+-
> >+[Int]+->+[Int]&start=41#more
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From masklinn@REDACTED  Fri Jul 23 13:58:38 2010
From: masklinn@REDACTED (Masklinn)
Date: Fri, 23 Jul 2010 13:58:38 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it> <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>  <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>  <F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net> <AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com>
Message-ID: <6E4DEE3A-FC7A-4C51-A5C0-CD13BDA14D5B@masklinn.net>

On 2010-07-23, at 13:35 , Jesper Louis Andersen wrote:
> On Thu, Jul 22, 2010 at 7:08 PM, Masklinn <masklinn@REDACTED> wrote:
>> That's a big advantage of haskell and its strong typing: hoogle[0] lets you search functions by type. In this case you can search for [a] -> [b] -> [c] (a function taking a list of 'a's, a list of 'b's and returning a list of 'c's) and the first result is zipWith[1].
> 
> (Detail aside: The typing terminology is not set in stone. When you
> write "strong typing" I am going to assume you mean that a program can
> be determined well-typed at compile time by a static semantics on the
> abstract syntax tree of the program. Other people, myself included,
> call this property "static typing" and we reserve the "strong typing"
> to mean: There are no unchecked run-time type errors. So the program
> will never segfault. end-of-aside)
You are entirely correct and I stand red-faced, and dumbfounded I could have written "strong" here when I definitely thought "static".

> Right now, you are right. There is no hoogle tool for Erlang.
> Theoretically, I think you are wrong and here is why: Kostis Sagonas
> has recently added -spec() contracts to the Erlang system which allows
> you to gain some of the advantages of static typing while still
> retaining the dynamic properties of Erlang. In principle, it should be
> possible to write a hoogle-like system for Erlang on top of these
> -spec() contracts and gain exactly the same kind of documentation
> lookup.
Yes, but as you mentioned it only works for -spec. And I doubt -spec is as expressive as Haskell's type system either. Theoretically, hoogle can extract types even from fully unspecified (inferred) functions, which would correspond to -spec-less functions in Erlang, and make those searchable as well.

> Also, simply having the type specification for a given function is not
> always enough. Let me draw up a simple example: Haskells iteratee
> library by John W. Lato.
Oh definitely not and I apologize if it came across that way. I mostly meant that an expressive type system can provide great insight as to the purpose and behavior of a function.

From boris.muehmer@REDACTED  Fri Jul 23 14:08:04 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Fri, 23 Jul 2010 14:08:04 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it>
	<B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>
	<AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
	<F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
	<AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com>
Message-ID: <AANLkTi=PYsTRXD3VszK_81Ph06tKNLbzH8kf2cDfd2Pc@mail.gmail.com>

2010/7/23 Jesper Louis Andersen <jesper.louis.andersen@REDACTED>:
> [...] We have an excellent web UI tool by Dale Harvey:
>
> http://erldocs.com/

The link was unknown to me!

I just checked "http://erlang.org/doc.html" to make sure it isn't there...

Why is "http://erldocs.com/" not listed there?


  - boris

From ttmrichter@REDACTED  Fri Jul 23 14:08:37 2010
From: ttmrichter@REDACTED (Michael Richter)
Date: Fri, 23 Jul 2010 20:08:37 +0800
Subject: [erlang-questions] Re: Volunteers wanted for new project
In-Reply-To: <752f79ae-f9f0-427f-8e79-e0a9b1b9c7a1@w30g2000yqw.googlegroups.com>
References: <AANLkTil0Zpcl_rUaE2Rxz0DrKclupKg-5DGN0IFBCzc4@mail.gmail.com>
	<82619625-0dd0-425e-aa64-388ffee05e2a@u26g2000yqu.googlegroups.com>
	<4BD341D3-1971-48EB-881C-E716496F8035@cs.otago.ac.nz>
	<752f79ae-f9f0-427f-8e79-e0a9b1b9c7a1@w30g2000yqw.googlegroups.com>
Message-ID: <AANLkTim1jREXCpTSFvffiCOBdbAJxGwZg6UJs-ANS01z@mail.gmail.com>

On 23 July 2010 16:01, Tim Fletcher <mail@REDACTED> wrote:

> According to Google there are 170 global monthly Google searches for
> "java c parser", and < 10 for "erlang c parser" and "prolog c parser".
> Compared to 151,000,000 for "lady gaga".
>

Puts some perspective on things, doesn't it?

(A bit too much damned perspective for my tastes!)

-- 
"Perhaps people don't believe this, but throughout all of the discussions of
entering China our focus has really been what's best for the Chinese people.
It's not been about our revenue or profit or whatnot."
--Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.

From rumata-estor@REDACTED  Fri Jul 23 14:11:21 2010
From: rumata-estor@REDACTED (Dmitry Belyaev)
Date: Fri, 23 Jul 2010 16:11:21 +0400
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTi=PYsTRXD3VszK_81Ph06tKNLbzH8kf2cDfd2Pc@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it>	<B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>	<AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>	<F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>	<AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com> <AANLkTi=PYsTRXD3VszK_81Ph06tKNLbzH8kf2cDfd2Pc@mail.gmail.com>
Message-ID: <4C4986E9.8080406@nm.ru>

Maybe because there is http://demo.erlang.org/erldoc ?

Dmitry Belyaev


On 07/23/2010 04:08 PM, Boris M?hmer wrote:
> 2010/7/23 Jesper Louis Andersen<jesper.louis.andersen@REDACTED>:
>    
>> [...] We have an excellent web UI tool by Dale Harvey:
>>
>> http://erldocs.com/
>>      
> The link was unknown to me!
>
> I just checked "http://erlang.org/doc.html" to make sure it isn't there...
>
> Why is "http://erldocs.com/" not listed there?
>
>
>    - boris
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>
>    

From boris.muehmer@REDACTED  Fri Jul 23 14:25:33 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Fri, 23 Jul 2010 14:25:33 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C4986E9.8080406@nm.ru>
References: <4C482B47.6020004@cheapnet.it>
	<B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net>
	<AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
	<F63587DE-40B8-4FFF-932F-34FF1C010ECC@masklinn.net>
	<AANLkTi=rOE4=zYoZ-ExgQrN7cedqfKzmz+h905PtJN66@mail.gmail.com>
	<AANLkTi=PYsTRXD3VszK_81Ph06tKNLbzH8kf2cDfd2Pc@mail.gmail.com>
	<4C4986E9.8080406@nm.ru>
Message-ID: <AANLkTin7eKMUm7p_RtvTc1Lvdi_eet0D-ajwHo=BWP2L@mail.gmail.com>

2010/7/23 Dmitry Belyaev <rumata-estor@REDACTED>:
> Maybe because there is http://demo.erlang.org/erldoc ?

Huh... another link I need to add to my collection.

Isn't "demo.erlang.org" the new version of the "erlang.org" site?
Hopefully this site will be online (as in the real one) soon.


  - boris

From mixolyde@REDACTED  Fri Jul 23 15:42:31 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Fri, 23 Jul 2010 09:42:31 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>
	<AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com>
	<AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com>
Message-ID: <AANLkTi=gg3qgANJEeYc+DhfQhA1fkE984JVWbSN+DHQD@mail.gmail.com>

Interesting stuff from windbg on the crash dump:
Symbol search path is: C:\Program
Files\erl5.8\erts-5.8\bin;SRV*c:*http://msdl.microsoft.com/download/symbols

This dump file has an exception of interest stored in it.
The stored exception information can be accessed via .ecxr.
(3760.2d8c): Access violation - code c0000005 (first/second chance not
available)
eax=00000000 ebx=01b6f544 ecx=00000400 edx=00000000 esi=00000002 edi=00000000
eip=76fc64f4 esp=01b6f4f4 ebp=01b6f590 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000246
ntdll!KiFastSystemCallRet:
76fc64f4 c3              ret
0:001> .ecxr
eax=00000000 ebx=00000000 ecx=015a8830 edx=00000000 esi=00000074 edi=015a2632
eip=0139c562 esp=01b6fb40 ebp=001a081c iopl=0         nv up ei ng nz ac po cy
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010293
beam_smp!ConDrawText+0x92:
0139c562 66893442        mov     word ptr [edx+eax*2],si  ds:0023:00000000=????
0:001> .lastevent
Last event: 3760.2d8c: Access violation - code c0000005 (first/second
chance not available)
  debugger time: Fri Jul 23 09:16:53.209 2010 (UTC - 4:00)

I cannot set windbg as the post mortem as apparently I don't have the
proper permissions on this work box.
I still don't think I'm loading the symbols for the werl specific
stuff correctly.





On Tue, Jul 20, 2010 at 1:24 PM, Brian Williams <mixolyde@REDACTED> wrote:
> On Tue, Jul 20, 2010 at 9:03 AM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
>> On Tue, Jul 20, 2010 at 2:47 PM, Brian Williams wrote:
>>> On Tue, Jul 20, 2010 at 8:30 AM, Tuncer Ayaz wrote:
>>>> On Tue, Jul 20, 2010 at 2:26 PM, Brian Williams wrote:
>>>>> On Mon, Jul 19, 2010 at 4:22 PM, Tuncer Ayaz wrote:
>>>>>> On Mon, Jul 19, 2010 at 1:24 PM, Brian Williams wrote:
>>>>>>>
>>>>>>> Where would I look for this dump?
>>>>>>
>>>>>> Default should be C:\Windows\minidumps and I think it's configurable.
>>>>>>
>>>>>
>>>>> That directory doesn't exist. I guess I have to configure it in
>>>>> Windows somewhere? I don't know where to do that.
>>>>
>>>> What about C:\Windows\minidump?
>>>>
>>>
>>> No. I should probably add that this is a windows 7 box. Is that
>>> location determined by the OS when it detects the crash, or by werl
>>> before it dies?
>>
>> It is determined by the crash handler configured in the OS settings
>> and possible that no crash dump has been written or that it's in a
>> different directory. I don't have a Windows install to check. You
>> might want to read the docs about configuring user-mode minidumps and
>> enabling crash dumps. Have a look in the MSDN.
>>
>> You can also install windbg as the postmortem debugger and have it
>> spawned on each unhandled crash if you don't want to configure crash
>> dump settings. Also some applications like popular web browsers have
>> their own crash handler to collect and submit crash info to their
>> online database. These may not trigger a system level debugger at all
>> if their crash handler is not disabled.
>>
>
> Looks like in windows 7, after turning mini dumps on in advanced
> settings, they go to:
>
> C:\Users\<username>\AppData\Local\CrashDumps
>
>
> --
> Brian E. Williams
> mixolyde@REDACTED
> http://www.techhouse.us/wordpress-mu/brianw
>
> "Never attribute to malice that which can be adequately
> explained by stupidity." - Hanlon's Razor
>



-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From jilani@REDACTED  Fri Jul 23 13:15:10 2010
From: jilani@REDACTED (Jilani Khaldi)
Date: Fri, 23 Jul 2010 13:15:10 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz>
References: <4C482B47.6020004@cheapnet.it> <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz>
Message-ID: <4C4979BE.5050409@cheapnet.it>

> This says
>      for each X1 in L1 {
>          for each X2 in L2 {
>              include X1 - X2 in the result
>          }
>      }
>
>   ** sub(Xs, Ys) ->  [X-Y || X<- Xs&&  Y<- Ys]
I find this last one (not yet implemented in Erlang) the more natural 
and expressive solution to the question.

-- 
Jilani KHALDI
---------------------
http://www.iiiaugusta.com


From dmercer@REDACTED  Fri Jul 23 16:21:30 2010
From: dmercer@REDACTED (David Mercer)
Date: Fri, 23 Jul 2010 09:21:30 -0500
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4C4979BE.5050409@cheapnet.it>
References: <4C482B47.6020004@cheapnet.it> <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz> <4C4979BE.5050409@cheapnet.it>
Message-ID: <4FE640E4E5CD434187AE49D5946A4EBE@SSI.CORP>

Do any of y'all ever find yourself writing something like this when you want
to compute an intermediate value only once (in this case, the result of f(X)
is used twice but we only want to compute it once):

    [ {g(Y), h(Y)} || X <- L, Y <- [f(X)] ]

And is there a better way of writing that?  I don't really like having to
put the result f(X) into a single-element list just so it can be pulled out
again.

Cheers,

David


From vladdu55@REDACTED  Fri Jul 23 16:28:53 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Fri, 23 Jul 2010 16:28:53 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <4FE640E4E5CD434187AE49D5946A4EBE@SSI.CORP>
References: <4C482B47.6020004@cheapnet.it> <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz> 
	<4C4979BE.5050409@cheapnet.it> <4FE640E4E5CD434187AE49D5946A4EBE@SSI.CORP>
Message-ID: <AANLkTimcnhOoS4qDsatK25PWeiN27uw9pWxMebsO18N9@mail.gmail.com>

On Fri, Jul 23, 2010 at 16:21, David Mercer <dmercer@REDACTED> wrote:
> ? ?[ {g(Y), h(Y)} || X <- L, Y <- [f(X)] ]
>

Maybe
[ begin Y=f(X), {g(Y), h(Y)} end || X <- L ]

regards,
Vlad

From rvirding@REDACTED  Fri Jul 23 22:21:25 2010
From: rvirding@REDACTED (Robert Virding)
Date: Fri, 23 Jul 2010 22:21:25 +0200
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTimcnhOoS4qDsatK25PWeiN27uw9pWxMebsO18N9@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it> <9B4B9860-32B7-495B-B7E3-77A8BD3A068E@cs.otago.ac.nz> 
	<4C4979BE.5050409@cheapnet.it> <4FE640E4E5CD434187AE49D5946A4EBE@SSI.CORP> 
	<AANLkTimcnhOoS4qDsatK25PWeiN27uw9pWxMebsO18N9@mail.gmail.com>
Message-ID: <AANLkTin_Kxap_+4NCxkkWdjyXjGssMi1CVpvR3unk0JC@mail.gmail.com>

lists:map(fun (X) -> Y=f(X), {g(Y),h(Y)} end, L)

or

(lc ((<- x l)) (let ((y (f x)) (tuple (g y) (h y))))

Robert

On 23 July 2010 16:28, Vlad Dumitrescu <vladdu55@REDACTED> wrote:
> On Fri, Jul 23, 2010 at 16:21, David Mercer <dmercer@REDACTED> wrote:
>> ? ?[ {g(Y), h(Y)} || X <- L, Y <- [f(X)] ]
>>
>
> Maybe
> [ begin Y=f(X), {g(Y), h(Y)} end || X <- L ]
>
> regards,
> Vlad
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From tuncer.ayaz@REDACTED  Sat Jul 24 01:43:13 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Sat, 24 Jul 2010 01:43:13 +0200
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTi=gg3qgANJEeYc+DhfQhA1fkE984JVWbSN+DHQD@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com> 
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com> 
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com> 
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com> 
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com> 
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com> 
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com> 
	<AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com> 
	<AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com> 
	<AANLkTi=gg3qgANJEeYc+DhfQhA1fkE984JVWbSN+DHQD@mail.gmail.com>
Message-ID: <AANLkTinSK=vXzCd3G0UwaQE0uOrr3KH4YvvFqxyOJ59=@mail.gmail.com>

On Fri, Jul 23, 2010 at 3:42 PM, Brian Williams wrote:
> Interesting stuff from windbg on the crash dump:
> Symbol search path is: C:\Program
> Files\erl5.8\erts-5.8\bin;SRV*c:*http://msdl.microsoft.com/download/symbols

[...]

> beam_smp!ConDrawText+0x92:
> 0139c562 66893442 ? ? ? ?mov ? ? word ptr [edx+eax*2],si ?ds:0023:00000000=????
> 0:001> .lastevent

Does it also crash if you use erl.exe instead of werl.exe?

From tuncer.ayaz@REDACTED  Sat Jul 24 01:58:29 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Sat, 24 Jul 2010 01:58:29 +0200
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTinSK=vXzCd3G0UwaQE0uOrr3KH4YvvFqxyOJ59=@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com> 
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com> 
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com> 
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com> 
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com> 
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com> 
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com> 
	<AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com> 
	<AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com> 
	<AANLkTi=gg3qgANJEeYc+DhfQhA1fkE984JVWbSN+DHQD@mail.gmail.com> 
	<AANLkTinSK=vXzCd3G0UwaQE0uOrr3KH4YvvFqxyOJ59=@mail.gmail.com>
Message-ID: <AANLkTi=yL55rLUYGro=42aEMGeDiDm_HgcdJaYbormYf@mail.gmail.com>

call stacks of the three crash dumps:

werl.exe.9504.dmp

ChildEBP RetAddr  Args to Child
01a2d6ec 76fc5e4c 75386872 00000002 01a2d740 ntdll!KiFastSystemCallRet
01a2d6f0 75386872 00000002 01a2d740 00000001 ntdll!NtWaitForMultipleObjects+0xc
01a2d78c 759ef14a 01a2d740 01a2d7b4 00000000
KERNELBASE!WaitForMultipleObjectsEx+0x100
01a2d7d4 759ef2c2 00000002 7ffd4000 00000000
kernel32!WaitForMultipleObjectsExImplementation+0xe0
01a2d7f0 75a02f1d 00000002 01a2d824 00000000
kernel32!WaitForMultipleObjects+0x18
01a2d85c 75a02fba 01a2d93c 00000001 00000001
kernel32!WerpReportFaultInternal+0x186
01a2d870 75a02d48 01a2d93c 00000001 01a2d90c kernel32!WerpReportFault+0x70
01a2d880 75a02cc7 01a2d93c 00000001 4ba91c66 kernel32!BasepReportFault+0x20
01a2d90c 76ff5a74 00000000 76f9d950 00000000
kernel32!UnhandledExceptionFilter+0x1af
01a2d914 76f9d950 00000000 01a2ffd4 76fd0598 ntdll!__RtlUserThreadStart+0x62
01a2d928 76f9d7ec 00000000 00000000 00000000 ntdll!_EH4_CallFilterFunc+0x12
01a2d950 76fc65f9 fffffffe 01a2ffc4 01a2da58 ntdll!_except_handler4+0x8e
01a2d974 76fc65cb 01a2da3c 01a2ffc4 01a2da58 ntdll!ExecuteHandler2+0x26
01a2da24 76fc6457 00a2da3c 01a2da58 01a2da3c ntdll!ExecuteHandler+0x24
01a2da24 76fd1ffe 00a2da3c 01a2da58 01a2da3c ntdll!KiUserExceptionDispatcher+0xf
01a2dd70 76fd1faf 0180dee0 01830c98 01830858 ntdll!RtlpLowFragHeapFree+0x31
01a2dd88 759ef1cc 002f0000 00000000 0180dee0 ntdll!RtlFreeHeap+0x105
01a2dd9c 70ff4c39 002f0000 00000000 0180dee0 kernel32!HeapFree+0x14
01a2dde8 011ed4fc 0180dee0 009a0b24 0000028c msvcr80!free+0xcd
01a2de0c 011ed67d 009a0b24 01a2defc 00000005
beam_smp!reorganize_linebufs(struct HWND__ * hwnd = <Memory access
error>)+0x22c
01a2de6c 011ed7f1 009a0b24 00000000 0000029d
beam_smp!Client_OnSize(struct HWND__ * hwnd = 0x755d8876, unsigned int
state = 0x11ed7a0, int cx = 0n10095396, int cy = 0n5)+0xbd
01a2de80 755d86ef 009a0b24 00000005 00000000
beam_smp!ClientWndProc(struct HWND__ * hwnd = 0x755d8876, unsigned int
iMsg = 0x11ed7a0, unsigned int wParam = 0x9a0b24, long lParam =
0n5)+0x51
01a2deac 755d8876 011ed7a0 009a0b24 00000005 user32!InternalCallWinProc+0x23
01a2df24 755d1945 00000000 011ed7a0 009a0b24
user32!UserCallWinProcCheckWow+0x14b
01a2dfac 755d7308 009a0b24 011ed7a0 009a0b24
user32!RealDefWindowProcWorker+0x50c
01a2dfc8 73d81e60 009a0b24 00000047 00000000 user32!RealDefWindowProcW+0x47
01a2e024 73d81f20 00000000 00000000 00000000 uxtheme!_ThemeDefWindowProc+0x197
01a2e040 755d79f0 009a0b24 00000047 00000000 uxtheme!ThemeDefWindowProcW+0x18
01a2e088 755d86ef 009a0b24 00000047 00000000 user32!DefWindowProcW+0x68
01a2e0b4 755d79cc 011ed7a0 009a0b24 00000047 user32!InternalCallWinProc+0x23
01a2e12c 755d70f4 00000000 011ed7a0 009a0b24 user32!UserCallWinProcCheckWow+0xe0
01a2e188 755d184e 00596f80 00000047 00000000 user32!DispatchClientMessage+0xda
01a2e1b0 76fc642e 01a2e1c8 00000030 01a2e27c user32!__fnINLPWINDOWPOS+0x25
01a2e1f4 755d66ca 73d8cb9d 009a0b24 00000000 ntdll!KiUserCallbackDispatcher+0x2e
01a2e1f8 73d8cb9d 009a0b24 00000000 01a2e2a8 user32!NtUserSetScrollInfo+0xc
01a2e244 755d6672 009a0b24 00000000 01a2e2a8 uxtheme!ThemeSetScrollInfoProc+0x70
01a2e28c 011eaaff 009a0b24 00000000 01a2e2a8 user32!SetScrollInfo+0x57
01a2e2c0 011ed5e2 01a2e3ac 00000005 00000000
beam_smp!set_scroll_info(struct HWND__ * hwnd = 0x0180ded8)+0xaf
01a2e31c 011ed7f1 009a0b24 00000000 0000029d
beam_smp!Client_OnSize(struct HWND__ * hwnd = 0x755d8876, unsigned int
state = 0x11ed7a0, int cx = 0n10095396, int cy = 0n5)+0x22
01a2e330 755d86ef 009a0b24 00000005 00000000
beam_smp!ClientWndProc(struct HWND__ * hwnd = 0x755d8876, unsigned int
iMsg = 0x11ed7a0, unsigned int wParam = 0x9a0b24, long lParam =
0n5)+0x51
01a2e35c 755d8876 011ed7a0 009a0b24 00000005 user32!InternalCallWinProc+0x23
01a2e3d4 755d1945 00000000 011ed7a0 009a0b24
user32!UserCallWinProcCheckWow+0x14b
01a2e45c 755d7308 009a0b24 011ed7a0 009a0b24
user32!RealDefWindowProcWorker+0x50c
01a2e478 73d81e60 009a0b24 00000047 00000000 user32!RealDefWindowProcW+0x47
01a2e4d4 73d81f20 00000000 00000000 00000000 uxtheme!_ThemeDefWindowProc+0x197
01a2e4f0 755d79f0 009a0b24 00000047 00000000 uxtheme!ThemeDefWindowProcW+0x18
01a2e538 755d86ef 009a0b24 00000047 00000000 user32!DefWindowProcW+0x68
01a2e564 755d79cc 011ed7a0 009a0b24 00000047 user32!InternalCallWinProc+0x23
01a2e5dc 755d70f4 00000000 011ed7a0 009a0b24 user32!UserCallWinProcCheckWow+0xe0
01a2e638 755d184e 00596f80 00000047 00000000 user32!DispatchClientMessage+0xda
01a2e660 76fc642e 01a2e678 00000030 01a2ea84 user32!__fnINLPWINDOWPOS+0x25
01a2e6a4 755ca8d0 011ecab3 009a0b24 00000000 ntdll!KiUserCallbackDispatcher+0x2e
01a2e6a8 011ecab3 009a0b24 00000000 0000001c user32!NtUserMoveWindow+0xc
01a2e9f0 755d86ef 000807d2 00000005 00000000
beam_smp!FrameWndProc(struct HWND__ * hwnd = <Memory access error>,
unsigned int iMsg = <Memory access error>, unsigned int wParam =
<Memory access error>, long lParam = <Memory access error>)+0x133
01a2ea1c 755d8876 011ec980 000807d2 00000005 user32!InternalCallWinProc+0x23
01a2ea94 755d1945 00000000 011ec980 000807d2
user32!UserCallWinProcCheckWow+0x14b
01a2eb1c 755d7308 011ec980 011ec980 000807d2
user32!RealDefWindowProcWorker+0x50c
01a2eb38 73d81e60 000807d2 00000047 00000000 user32!RealDefWindowProcW+0x47
01a2eb94 73d81f20 00000000 00000000 00000000 uxtheme!_ThemeDefWindowProc+0x197
01a2ebb0 755d79f0 000807d2 00000047 00000000 uxtheme!ThemeDefWindowProcW+0x18

werl.exe.12616.dmp

ChildEBP RetAddr  Args to Child
01adf310 76fc5e4c 75386872 00000002 01adf364 ntdll!KiFastSystemCallRet
01adf314 75386872 00000002 01adf364 00000001 ntdll!NtWaitForMultipleObjects+0xc
01adf3b0 759ef14a 01adf364 01adf3d8 00000000
KERNELBASE!WaitForMultipleObjectsEx+0x100
01adf3f8 759ef2c2 00000002 7ffdd000 00000000
kernel32!WaitForMultipleObjectsExImplementation+0xe0
01adf414 75a02f1d 00000002 01adf448 00000000
kernel32!WaitForMultipleObjects+0x18
01adf480 75a02fba 01adf560 00000001 00000001
kernel32!WerpReportFaultInternal+0x186
01adf494 75a02d48 01adf560 00000001 01adf530 kernel32!WerpReportFault+0x70
01adf4a4 75a02cc7 01adf560 00000001 437b60c2 kernel32!BasepReportFault+0x20
01adf530 76ff5a74 00000000 76f9d950 00000000
kernel32!UnhandledExceptionFilter+0x1af
01adf538 76f9d950 00000000 01adffd4 76fd0598 ntdll!__RtlUserThreadStart+0x62
01adf54c 76f9d7ec 00000000 00000000 00000000 ntdll!_EH4_CallFilterFunc+0x12
01adf574 76fc65f9 fffffffe 01adffc4 01adf67c ntdll!_except_handler4+0x8e
01adf598 76fc65cb 01adf660 01adffc4 01adf67c ntdll!ExecuteHandler2+0x26
01adf648 76fc6457 00adf660 01adf67c 01adf660 ntdll!ExecuteHandler+0x24
01adf648 76f9f23e 00adf660 01adf67c 01adf660 ntdll!KiUserExceptionDispatcher+0xf
01adf98c 77007e3f 01887f00 01887f00 00000020 ntdll!RtlpDeCommitFreeBlock+0x146
01adfa74 76fd34ca 000000a2 000000b0 01887f02 ntdll!RtlpAllocateHeap+0x76b
01adfaf8 70ff4d83 006e0000 00000000 000000a2 ntdll!RtlAllocateHeap+0x23a
01adfb18 013bab33 000000a2 015c252a 755d7041 msvcr80!malloc+0x7a
01adfb28 013bc020 015c252a 013bc04f 013bc60d beam_smp!ConNewLine(void)+0x23
01adfb30 013bc04f 013bc60d 00000000 01adfbfc
beam_smp!ensure_line_below(void)+0x50
01adfb34 013bc60d 00000000 01adfbfc 00000401
beam_smp!ConCarriageFeed(int hard_newline = <Memory access error>)+0xf
01adfb78 013bd980 007c0eac 755d86ef 007c0eac
beam_smp!ConDrawText(struct HWND__ * hwnd = <Memory access
error>)+0x13d
01adfb80 755d86ef 007c0eac 00000401 00000000
beam_smp!ClientWndProc(struct HWND__ * hwnd = 0x755d8876, unsigned int
iMsg = 0x13bd7a0, unsigned int wParam = 0x7c0eac, long lParam =
0n1025)+0x1e0
01adfbac 755d8876 013bd7a0 007c0eac 00000401 user32!InternalCallWinProc+0x23
01adfc24 755d89b5 00000000 013bd7a0 007c0eac
user32!UserCallWinProcCheckWow+0x14b
01adfc84 755d8e9c 013bd7a0 00000000 00000000 user32!DispatchMessageWorker+0x35e
01adfc94 013bdc7d 01adfce4 00000000 00000000 user32!DispatchMessageW+0xf
01adff48 70ff29bb 00000000 43789f36 00000000
beam_smp!ConThreadInit(void * param = <Memory access error>)+0x2ed
01adff80 70ff2a47 00000000 759f1194 006e5258 msvcr80!_endthreadex+0x3b

werl.exe.14176.dmp

ChildEBP RetAddr  Args to Child
01b6f4f0 76fc5e4c 75386872 00000002 01b6f544 ntdll!KiFastSystemCallRet
01b6f4f4 75386872 00000002 01b6f544 00000001 ntdll!NtWaitForMultipleObjects+0xc
01b6f590 759ef14a 01b6f544 01b6f5b8 00000000
KERNELBASE!WaitForMultipleObjectsEx+0x100
01b6f5d8 759ef2c2 00000002 7ffdf000 00000000
kernel32!WaitForMultipleObjectsExImplementation+0xe0
01b6f5f4 75a02f1d 00000002 01b6f628 00000000
kernel32!WaitForMultipleObjects+0x18
01b6f660 75a02fba 01b6f740 00000001 00000001
kernel32!WerpReportFaultInternal+0x186
01b6f674 75a02d48 01b6f740 00000001 01b6f710 kernel32!WerpReportFault+0x70
01b6f684 75a02cc7 01b6f740 00000001 b1896c2b kernel32!BasepReportFault+0x20
01b6f710 76ff5a74 00000000 76f9d950 00000000
kernel32!UnhandledExceptionFilter+0x1af
01b6f718 76f9d950 00000000 01b6ffd4 76fd0598 ntdll!__RtlUserThreadStart+0x62
01b6f72c 76f9d7ec 00000000 00000000 00000000 ntdll!_EH4_CallFilterFunc+0x12
01b6f754 76fc65f9 fffffffe 01b6ffc4 01b6f85c ntdll!_except_handler4+0x8e
01b6f778 76fc65cb 01b6f840 01b6ffc4 01b6f85c ntdll!ExecuteHandler2+0x26
01b6f828 76fc6457 00b6f840 01b6f85c 01b6f840 ntdll!ExecuteHandler+0x24
01b6f828 0139c562 00b6f840 01b6f85c 01b6f840 ntdll!KiUserExceptionDispatcher+0xf
01b6fb78 0139d980 001a081c 755d86ef 001a081c
beam_smp!ConDrawText(struct HWND__ * hwnd = <Memory access
error>)+0x92
01b6fb80 755d86ef 001a081c 00000401 00000000
beam_smp!ClientWndProc(struct HWND__ * hwnd = 0x755d8876, unsigned int
iMsg = 0x139d7a0, unsigned int wParam = 0x1a081c, long lParam =
0n1025)+0x1e0
01b6fbac 755d8876 0139d7a0 001a081c 00000401 user32!InternalCallWinProc+0x23
01b6fc24 755d89b5 00000000 0139d7a0 001a081c
user32!UserCallWinProcCheckWow+0x14b
01b6fc84 755d8e9c 0139d7a0 00000000 00000000 user32!DispatchMessageWorker+0x35e
01b6fc94 0139dc7d 01b6fce4 00000000 00000000 user32!DispatchMessageW+0xf
01b6ff48 70ff29bb 00000000 b189c442 00000000
beam_smp!ConThreadInit(void * param = <Memory access error>)+0x2ed
01b6ff80 70ff2a47 00000000 759f1194 005b5258 msvcr80!_endthreadex+0x3b
01b6ff88 759f1194 005b5258 01b6ffd4 76fdb3f5 msvcr80!_endthreadex+0xc7
01b6ff94 76fdb3f5 005b5258 5e587bd5 00000000 kernel32!BaseThreadInitThunk+0xe
01b6ffd4 76fdb3c8 70ff29e1 005b5258 00000000 ntdll!__RtlUserThreadStart+0x70
01b6ffec 00000000 70ff29e1 005b5258 00000000 ntdll!_RtlUserThreadStart+0x1b

From g9414002.pccu.edu.tw@REDACTED  Sat Jul 24 20:40:48 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Sun, 25 Jul 2010 02:40:48 +0800
Subject: [erlang-questions] Question in Parser Implementation
Message-ID: <AANLkTik=t05tJOVquRYW9X8OdcLh_+Anx4YQZy3o39RE@mail.gmail.com>

Hey, guys. I tried implementing parsers guided by
Graham Hutton's paper: Higher-order Functions For Parsing.
( http://www.cs.nott.ac.uk/~gmh/bib.html#parsing )
Part code is listed below.

-module(parser).
-compile(export_all).

succeed(V, Inp) ->
    [{V, Inp}].

fail(_) ->
    [].

satisfy(_, []) ->
    fail([]);
satisfy(P, [X|Xs]) ->
    case erlang:apply(P, [X]) of
true ->
    succeed(X, Xs);
false ->
    fail(Xs)
    end.

literal(X, Inp) ->
    satisfy(fun(Y) -> X == Y end, Inp).

literal(X) ->
    fun(Inp) ->
    erlang:apply(?MODULE, literal, [X, Inp])
    end.

alt(P1, P2, Inp) ->
    erlang:apply(P1, [Inp]) ++ erlang:apply(P2, [Inp]).

The alt/3 is an implementation of alternation syntax (`` | '') in BNF,
that alt/3 takes two parsers and applies each to the input string.
Then I tested it using a query

    parser:alt(parser:fail, parser:literal($3), "345").

and found that it does not accept the syntax 'parser:fail' for
representing a function. The erl reports "Illegal expression" for
the query.

How to take a function name and apply anywhere?
Need the function `fail' be defined as a lambda function like

    fail() -> fun(Inp) -> [] end.

?

Best Regards.

From vladdu55@REDACTED  Sat Jul 24 21:10:25 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Sat, 24 Jul 2010 21:10:25 +0200
Subject: [erlang-questions] Question in Parser Implementation
In-Reply-To: <AANLkTik=t05tJOVquRYW9X8OdcLh_+Anx4YQZy3o39RE@mail.gmail.com>
References: <AANLkTik=t05tJOVquRYW9X8OdcLh_+Anx4YQZy3o39RE@mail.gmail.com>
Message-ID: <AANLkTikvcsaToEEGKV6iCt7ReG12qUEHMC=tRWs_-=Ed@mail.gmail.com>

2010/7/24 ??? (Yau-Hsien Huang) <g9414002.pccu.edu.tw@REDACTED>:
> Then I tested it using a query
>
> ? ?parser:alt(parser:fail, parser:literal($3), "345").
>
> and found that it does not accept the syntax 'parser:fail' for
> representing a function. The erl reports "Illegal expression" for
> the query.

Hi,

Try
parser:alt(fun parser:fail/1, parser:literal($3), "345").

http://www.erlang.org/doc/reference_manual/expressions.html#id2275688

regards,
Vlad

From dj3vande@REDACTED  Sat Jul 24 21:15:01 2010
From: dj3vande@REDACTED (Dave Vandervies)
Date: Sat, 24 Jul 2010 15:15:01 -0400
Subject: [erlang-questions] Erlang again!
In-Reply-To: <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
References: <4C482B47.6020004@cheapnet.it> <B42E68DE-F182-42A8-BCBF-67C91FCD17F5@masklinn.net> <AANLkTikPHhPhOqqE5Yz-gRUxb6w9RL0JuELLnutDg1hS@mail.gmail.com>
Message-ID: <20100724191500.GA15356@buttons.local>

Somebody claiming to be Boris M??hmer wrote:

> Well, I didn't know about zip or zipwith (still not inside the
> library), so my solution was like this:
> 
>     sub(L2,L1) ->
>         lists:reverse(sub(L2,L1,[])).
> 
>     sub([],[],List) ->
>         List;
>     sub([H2|T2],[H1|T1],List) ->
>         sub(T2,T1,[(H2-H1)|List]).
> 
> Ok, this is much longer than with zip or zipwith, but somehow this was
> much easier to "develop". Well, at the end of the documentation of
> zipwith there is almost a solution to the problem, but I wouldn't have
> found it, if zip or zipwith wasn't mentioned.
> 
> Is such a solution plain bad, or just a newbie mistake/error?

It's not bad, but there are two newbie mistakes/errors here.

Not knowing the library has already been mentioned, and it's the
lesser one; reimplementing library functions is almost always a
useful learning exercise, and reinventing it yourself before you
find it in the library gives you some insight into why it's in the
library and what you can use it for.

The bigger one is that if you build a list and then reverse it,
you're probably doing something wrong[1].  In particular, just
because you CAN write something tail-recursively doesn't mean you
SHOULD, and if the tail-recursive version ends up accumulating a
temporary that's the same size as the call stack would be that's a
pretty good sign you're not going to gain much.
(Tail recursion is a bigger win when you're accumulating into
something you can return directly or when the accumulator keeps a
constant size.)

In this case, the body-recursive version:
--------
sub([],[]) -> [];
sub([H1|T1],[H2|T2]) -> [H2-H1 | sub(T1,T2)].
--------
uses approximately the same working memory (both are linear in the
length of the list, and possibly with the same constant factor[2]),
avoids building a structure you're just going to throw away, and
is easier to read since the structure of the code matches what it's
actually doing more closely.


dave

[1] That's a "If you think you want to do this, you should consider
    alternatives first" wrong, not a "never do this" wrong.
[2] See entry 2.3 at <http://www.erlang.org/doc/efficiency_guide/myths.html>

-- 
Dave Vandervies
dj3vande@REDACTED / dj3vande@REDACTED

Plan your future!  Make God laugh!
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From luismarianoguerra@REDACTED  Sun Jul 25 19:56:04 2010
From: luismarianoguerra@REDACTED (Mariano Guerra)
Date: Sun, 25 Jul 2010 14:56:04 -0300
Subject: [ANN] efene 0.8 - a language for the erlang VM - released
Message-ID: <AANLkTimJdcVNuh9Qj1CWi4vh8kp0+iNvZnt-yexTp1B2@mail.gmail.com>

For the complete release notes with details on each item and examples see
the release notes here:
http://marianoguerra.com.ar/efene/docs/releases/oeight.html

About efene


efene is a programming language that runs on the erlang virtual machine.

The idea is to provide an alternative syntax to erlang that is most suitable
for people coming from languages like Java, C, C++, C#, Javascript.

The language is almost 100% compatible with erlang (and will be), the compiler
allows to translate an efene source file into a readable erlang one or compile
it directly to bytecode. It also adds some syntactic sugar in some places to
make some tasks easier.

Changes

    * spec expression support (EEP 8)
    * type expression support (EEP 8)
    * range statement .. to specify ranges like lists:seq
    * block statement to have full compatibility with erlang
    * allow parenthesis in for expression
    * allow typed record fields
    * meta programming similar to template haskell through [|?|], $(?)
and $[?] statements
    * parametrized module support
    * allow attribute manipulation and generation by efene code
          + objects, record, spec and type definitions are handled
using this technique

More information:

   * Download the latest snapshot:
        http://github.com/marianoguerra/efene/tarball/master
   * Website: http://marianoguerra.com.ar/efene
   * Documentation: http://marianoguerra.com.ar/efene/docs
   * Tutorial: http://marianoguerra.com.ar/efene/tutorial
   * Blog: http://efene.tumblr.com/
   * Central repo: http://github.com/marianoguerra/efene
   * Issue Tracker: http://github.com/marianoguerra/efene/issues

From mixolyde@REDACTED  Mon Jul 26 15:37:03 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Mon, 26 Jul 2010 09:37:03 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTinSK=vXzCd3G0UwaQE0uOrr3KH4YvvFqxyOJ59=@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>
	<AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com>
	<AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com>
	<AANLkTi=gg3qgANJEeYc+DhfQhA1fkE984JVWbSN+DHQD@mail.gmail.com>
	<AANLkTinSK=vXzCd3G0UwaQE0uOrr3KH4YvvFqxyOJ59=@mail.gmail.com>
Message-ID: <AANLkTim_nBYsSjuBrjHZ6NF0mvjMUzJ4PqKHh8aGXuQL@mail.gmail.com>

Haven't tried the command line, good suggestion.

On Fri, Jul 23, 2010 at 7:43 PM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
> On Fri, Jul 23, 2010 at 3:42 PM, Brian Williams wrote:
>> Interesting stuff from windbg on the crash dump:
>> Symbol search path is: C:\Program
>> Files\erl5.8\erts-5.8\bin;SRV*c:*http://msdl.microsoft.com/download/symbols
>
> [...]
>
>> beam_smp!ConDrawText+0x92:
>> 0139c562 66893442 ? ? ? ?mov ? ? word ptr [edx+eax*2],si ?ds:0023:00000000=????
>> 0:001> .lastevent
>
> Does it also crash if you use erl.exe instead of werl.exe?
>



-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From mixolyde@REDACTED  Mon Jul 26 16:27:02 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Mon, 26 Jul 2010 10:27:02 -0400
Subject: [erlang-questions] werl R14A on windows 7 frequently crashes 
	during file access
In-Reply-To: <AANLkTim_nBYsSjuBrjHZ6NF0mvjMUzJ4PqKHh8aGXuQL@mail.gmail.com>
References: <AANLkTikocpQPhGjQLzQZ9pd1eF-WvNy1xHo9vXnFvctv@mail.gmail.com>
	<AANLkTikP9P6dnV1P2IpVAXNkCTd1PtYnepz0tXZWwKxY@mail.gmail.com>
	<AANLkTiksDoZ3_R46a4SXJ8YmzYNbKivpw3HGvm6xNLSf@mail.gmail.com>
	<AANLkTil5nzVljI9FK-IL4Khl0e2jl2MHkRRaR2sWkWg9@mail.gmail.com>
	<AANLkTikxBzTyq6QY_Lt03cjJbTGiGQ5XIipYv49JURhf@mail.gmail.com>
	<AANLkTilCR4zkhN1cYOk_Xxt7LuDkbYTpU667z91gKWNi@mail.gmail.com>
	<AANLkTimiHjhh5_VmufOMR9yThG_I02WzZaORah9NVb89@mail.gmail.com>
	<AANLkTinW6j_87FOmsP5zhZDVwrBTap9cAeYpyr5UWgor@mail.gmail.com>
	<AANLkTilmQhGlwQr3dupZgIvW1VJEjSOgRFCEMWHJfdqJ@mail.gmail.com>
	<AANLkTi=gg3qgANJEeYc+DhfQhA1fkE984JVWbSN+DHQD@mail.gmail.com>
	<AANLkTinSK=vXzCd3G0UwaQE0uOrr3KH4YvvFqxyOJ59=@mail.gmail.com>
	<AANLkTim_nBYsSjuBrjHZ6NF0mvjMUzJ4PqKHh8aGXuQL@mail.gmail.com>
Message-ID: <AANLkTin6c6Y8P9Mi63k0UOxGs3jAFAw0+NTobTNmx3ud@mail.gmail.com>

Works perfectly from a command line shell. It may have to do with
rapidly spitting output to the werl GUI.

On Mon, Jul 26, 2010 at 9:37 AM, Brian Williams <mixolyde@REDACTED> wrote:
> Haven't tried the command line, good suggestion.
>
> On Fri, Jul 23, 2010 at 7:43 PM, Tuncer Ayaz <tuncer.ayaz@REDACTED> wrote:
>> On Fri, Jul 23, 2010 at 3:42 PM, Brian Williams wrote:
>>> Interesting stuff from windbg on the crash dump:
>>> Symbol search path is: C:\Program
>>> Files\erl5.8\erts-5.8\bin;SRV*c:*http://msdl.microsoft.com/download/symbols
>>
>> [...]
>>
>>> beam_smp!ConDrawText+0x92:
>>> 0139c562 66893442 ? ? ? ?mov ? ? word ptr [edx+eax*2],si ?ds:0023:00000000=????
>>> 0:001> .lastevent
>>
>> Does it also crash if you use erl.exe instead of werl.exe?
>>
>
>
>
> --
> Brian E. Williams
> mixolyde@REDACTED
> http://www.techhouse.us/wordpress-mu/brianw
>
> "Never attribute to malice that which can be adequately
> explained by stupidity." - Hanlon's Razor
>



-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From comptekki@REDACTED  Mon Jul 26 20:38:57 2010
From: comptekki@REDACTED (Wes James)
Date: Mon, 26 Jul 2010 12:38:57 -0600
Subject: increment in map
Message-ID: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com>

I have this code:

 map(fun(Row) ->
         	{table, [{style, "width:700px; margin:5px;
background-color:dddddd;"}],
         		[
         		thtd(Hdrs, [{td, [], massage(W,Ls)} || W <- vp(Vp,Row)])	
                ]}
			end, Rows)

and as I loop through the Row I would also like to send an increment
in the massage(W,LS,Inc) call, but I don't see how I can do that
within a list comprehension.  Any ideas on how I would do this?

thx,

-wes

From zeno490@REDACTED  Mon Jul 26 21:25:34 2010
From: zeno490@REDACTED (Nicholas Frechette)
Date: Mon, 26 Jul 2010 15:25:34 -0400
Subject: [erlang-questions] increment in map
In-Reply-To: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com>
References: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com>
Message-ID: <AANLkTimdzomO+JsRBknf4P4A5x0XdFW8OAKuKGGFm6QP@mail.gmail.com>

You could use 'foldl' instead of map:
foldl(fun(Row, Inc) ->
    ...
    Inc + 1 %% Return value is the new value of Inc for the next call
    end, Rows, 0).

You could also zip seq(0, numrows) with your rows and unzip them inside the
map (though if you have a lot of rows, the above will be faster and leaner).

Nicholas

On Mon, Jul 26, 2010 at 2:38 PM, Wes James <comptekki@REDACTED> wrote:

> I have this code:
>
>  map(fun(Row) ->
>                {table, [{style, "width:700px; margin:5px;
> background-color:dddddd;"}],
>                        [
>                        thtd(Hdrs, [{td, [], massage(W,Ls)} || W <-
> vp(Vp,Row)])
>                ]}
>                        end, Rows)
>
> and as I loop through the Row I would also like to send an increment
> in the massage(W,LS,Inc) call, but I don't see how I can do that
> within a list comprehension.  Any ideas on how I would do this?
>
> thx,
>
> -wes
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From comptekki@REDACTED  Mon Jul 26 21:43:24 2010
From: comptekki@REDACTED (Wes James)
Date: Mon, 26 Jul 2010 13:43:24 -0600
Subject: [erlang-questions] increment in map
In-Reply-To: <AANLkTimdzomO+JsRBknf4P4A5x0XdFW8OAKuKGGFm6QP@mail.gmail.com>
References: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com>
	<AANLkTimdzomO+JsRBknf4P4A5x0XdFW8OAKuKGGFm6QP@mail.gmail.com>
Message-ID: <AANLkTinoD4M5EzmVRB00PvLYvvLXgG6POMp5aLKUNnhw@mail.gmail.com>

Nicholas,

Thx - I realize I asked the question wrong.  The list comprehension

 [{td, [], massage(W,Ls)} || W <- vp(Vp,Row)]

will create a list in place, is there a way to create an increment
value within this structure?

I looked at a quick test with:

[{td, [],[W,X]} || W <- [1,2,3], X <- [1,2,3]]

but it creates:

[{td,[],[1,1]},
 {td,[],[1,2]},
 {td,[],[1,3]},
 {td,[],[2,1]},
 {td,[],[2,2]},
 {td,[],[2,3]},
 {td,[],[3,1]},
 {td,[],[3,2]},
 {td,[],[3,3]}]

whereas, I would like a one to one paring:

[{td,[],[1,1]},
 {td,[],[2,2]},
 {td,[],[3,3]}]


-wes

On Mon, Jul 26, 2010 at 1:25 PM, Nicholas Frechette <zeno490@REDACTED> wrote:
> You could use 'foldl' instead of map:
> foldl(fun(Row, Inc) ->
> ??? ...
> ??? Inc + 1 %% Return value is the new value of Inc for the next call
> ??? end, Rows, 0).
>
> You could also zip seq(0, numrows) with your rows and unzip them inside the
> map (though if you have a lot of rows, the above will be faster and leaner).
>
> Nicholas
>
> On Mon, Jul 26, 2010 at 2:38 PM, Wes James <comptekki@REDACTED> wrote:
>>
>> I have this code:
>>
>> ?map(fun(Row) ->
>> ? ? ? ? ? ? ? ?{table, [{style, "width:700px; margin:5px;
>> background-color:dddddd;"}],
>> ? ? ? ? ? ? ? ? ? ? ? ?[
>> ? ? ? ? ? ? ? ? ? ? ? ?thtd(Hdrs, [{td, [], massage(W,Ls)} || W <-
>> vp(Vp,Row)])
>> ? ? ? ? ? ? ? ?]}
>> ? ? ? ? ? ? ? ? ? ? ? ?end, Rows)
>>
>> and as I loop through the Row I would also like to send an increment
>> in the massage(W,LS,Inc) call, but I don't see how I can do that
>> within a list comprehension. ?Any ideas on how I would do this?
>>
>> thx,
>>
>> -wes
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>
>

From gleber.p@REDACTED  Mon Jul 26 21:51:45 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Mon, 26 Jul 2010 21:51:45 +0200
Subject: [erlang-questions] increment in map
In-Reply-To: <AANLkTinoD4M5EzmVRB00PvLYvvLXgG6POMp5aLKUNnhw@mail.gmail.com>
References: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com> 
	<AANLkTimdzomO+JsRBknf4P4A5x0XdFW8OAKuKGGFm6QP@mail.gmail.com> 
	<AANLkTinoD4M5EzmVRB00PvLYvvLXgG6POMp5aLKUNnhw@mail.gmail.com>
Message-ID: <AANLkTi=MKL5CufdqTTCy=q5KSLmTBSwYXkXkpFe6ogEC@mail.gmail.com>

[{td, [],[W,X]} || {W, X} <- lists:zip([1,2,3], [1,2,3])]

On Mon, Jul 26, 2010 at 21:43, Wes James <comptekki@REDACTED> wrote:
> Nicholas,
>
> Thx - I realize I asked the question wrong. ?The list comprehension
>
> ?[{td, [], massage(W,Ls)} || W <- vp(Vp,Row)]
>
> will create a list in place, is there a way to create an increment
> value within this structure?
>
> I looked at a quick test with:
>
> [{td, [],[W,X]} || W <- [1,2,3], X <- [1,2,3]]
>
> but it creates:
>
> [{td,[],[1,1]},
> ?{td,[],[1,2]},
> ?{td,[],[1,3]},
> ?{td,[],[2,1]},
> ?{td,[],[2,2]},
> ?{td,[],[2,3]},
> ?{td,[],[3,1]},
> ?{td,[],[3,2]},
> ?{td,[],[3,3]}]
>
> whereas, I would like a one to one paring:
>
> [{td,[],[1,1]},
> ?{td,[],[2,2]},
> ?{td,[],[3,3]}]
>
>
> -wes
>
> On Mon, Jul 26, 2010 at 1:25 PM, Nicholas Frechette <zeno490@REDACTED> wrote:
>> You could use 'foldl' instead of map:
>> foldl(fun(Row, Inc) ->
>> ??? ...
>> ??? Inc + 1 %% Return value is the new value of Inc for the next call
>> ??? end, Rows, 0).
>>
>> You could also zip seq(0, numrows) with your rows and unzip them inside the
>> map (though if you have a lot of rows, the above will be faster and leaner).
>>
>> Nicholas
>>
>> On Mon, Jul 26, 2010 at 2:38 PM, Wes James <comptekki@REDACTED> wrote:
>>>
>>> I have this code:
>>>
>>> ?map(fun(Row) ->
>>> ? ? ? ? ? ? ? ?{table, [{style, "width:700px; margin:5px;
>>> background-color:dddddd;"}],
>>> ? ? ? ? ? ? ? ? ? ? ? ?[
>>> ? ? ? ? ? ? ? ? ? ? ? ?thtd(Hdrs, [{td, [], massage(W,Ls)} || W <-
>>> vp(Vp,Row)])
>>> ? ? ? ? ? ? ? ?]}
>>> ? ? ? ? ? ? ? ? ? ? ? ?end, Rows)
>>>
>>> and as I loop through the Row I would also like to send an increment
>>> in the massage(W,LS,Inc) call, but I don't see how I can do that
>>> within a list comprehension. ?Any ideas on how I would do this?
>>>
>>> thx,
>>>
>>> -wes
>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>
>>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From comptekki@REDACTED  Mon Jul 26 22:36:11 2010
From: comptekki@REDACTED (Wes James)
Date: Mon, 26 Jul 2010 14:36:11 -0600
Subject: [erlang-questions] increment in map
In-Reply-To: <AANLkTi=MKL5CufdqTTCy=q5KSLmTBSwYXkXkpFe6ogEC@mail.gmail.com>
References: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com>
	<AANLkTimdzomO+JsRBknf4P4A5x0XdFW8OAKuKGGFm6QP@mail.gmail.com>
	<AANLkTinoD4M5EzmVRB00PvLYvvLXgG6POMp5aLKUNnhw@mail.gmail.com>
	<AANLkTi=MKL5CufdqTTCy=q5KSLmTBSwYXkXkpFe6ogEC@mail.gmail.com>
Message-ID: <AANLkTinoLix+YRVfKH6h4sL+NRH8QGhmOeHo-8drPmMB@mail.gmail.com>

Thanks.  That worked.  Didn't someone mention the other day on the
list that if we could remember the available BIFS and what they do,
we'd be set??

-wes

On Mon, Jul 26, 2010 at 1:51 PM, Gleb Peregud <gleber.p@REDACTED> wrote:
> [{td, [],[W,X]} || {W, X} <- lists:zip([1,2,3], [1,2,3])]
>
> On Mon, Jul 26, 2010 at 21:43, Wes James <comptekki@REDACTED> wrote:
>> Nicholas,
>>
>> Thx - I realize I asked the question wrong. ?The list comprehension
>>
>> ?[{td, [], massage(W,Ls)} || W <- vp(Vp,Row)]
>>
>> will create a list in place, is there a way to create an increment
>> value within this structure?
>>
>> I looked at a quick test with:
>>
>> [{td, [],[W,X]} || W <- [1,2,3], X <- [1,2,3]]
>>
>> but it creates:
>>
>> [{td,[],[1,1]},
>> ?{td,[],[1,2]},
>> ?{td,[],[1,3]},
>> ?{td,[],[2,1]},
>> ?{td,[],[2,2]},
>> ?{td,[],[2,3]},
>> ?{td,[],[3,1]},
>> ?{td,[],[3,2]},
>> ?{td,[],[3,3]}]
>>
>> whereas, I would like a one to one paring:
>>
>> [{td,[],[1,1]},
>> ?{td,[],[2,2]},
>> ?{td,[],[3,3]}]
>>
>>
>> -wes
>>
>> On Mon, Jul 26, 2010 at 1:25 PM, Nicholas Frechette <zeno490@REDACTED> wrote:
>>> You could use 'foldl' instead of map:
>>> foldl(fun(Row, Inc) ->
>>> ??? ...
>>> ??? Inc + 1 %% Return value is the new value of Inc for the next call
>>> ??? end, Rows, 0).
>>>
>>> You could also zip seq(0, numrows) with your rows and unzip them inside the
>>> map (though if you have a lot of rows, the above will be faster and leaner).
>>>
>>> Nicholas
>>>
>>> On Mon, Jul 26, 2010 at 2:38 PM, Wes James <comptekki@REDACTED> wrote:
>>>>
>>>> I have this code:
>>>>
>>>> ?map(fun(Row) ->
>>>> ? ? ? ? ? ? ? ?{table, [{style, "width:700px; margin:5px;
>>>> background-color:dddddd;"}],
>>>> ? ? ? ? ? ? ? ? ? ? ? ?[
>>>> ? ? ? ? ? ? ? ? ? ? ? ?thtd(Hdrs, [{td, [], massage(W,Ls)} || W <-
>>>> vp(Vp,Row)])
>>>> ? ? ? ? ? ? ? ?]}
>>>> ? ? ? ? ? ? ? ? ? ? ? ?end, Rows)
>>>>
>>>> and as I loop through the Row I would also like to send an increment
>>>> in the massage(W,LS,Inc) call, but I don't see how I can do that
>>>> within a list comprehension. ?Any ideas on how I would do this?
>>>>
>>>> thx,
>>>>
>>>> -wes
>>>>
>>>> ________________________________________________________________
>>>> erlang-questions (at) erlang.org mailing list.
>>>> See http://www.erlang.org/faq.html
>>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>>
>>>
>>>
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>

From g9414002.pccu.edu.tw@REDACTED  Tue Jul 27 06:00:53 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Tue, 27 Jul 2010 12:00:53 +0800
Subject: [erlang-questions] Question in Parser Implementation
In-Reply-To: <AANLkTikvcsaToEEGKV6iCt7ReG12qUEHMC=tRWs_-=Ed@mail.gmail.com>
References: <AANLkTik=t05tJOVquRYW9X8OdcLh_+Anx4YQZy3o39RE@mail.gmail.com>
	<AANLkTikvcsaToEEGKV6iCt7ReG12qUEHMC=tRWs_-=Ed@mail.gmail.com>
Message-ID: <AANLkTim5LbnWZpCF2zdByG=7Qv8L=6v37JXvm=s0KymD@mail.gmail.com>

2010/7/25 Vlad Dumitrescu <vladdu55@REDACTED>

> 2010/7/24 ??? (Yau-Hsien Huang) <g9414002.pccu.edu.tw@REDACTED>:
> > Then I tested it using a query
> >    parser:alt(parser:fail, parser:literal($3), "345").
> > and found that it does not accept the syntax 'parser:fail' for
> > representing a function. The erl reports "Illegal expression" for
> > the query.
> Hi,
>  Try
> parser:alt(fun parser:fail/1, parser:literal($3), "345").
> http://www.erlang.org/doc/reference_manual/expressions.html#id2275688
>  regards,
> Vlad
>

Thank you. And again, when implementing the parser tutored by Hutton's
paper, I was stuck  in mutual recursion of the grammar of a simple
expression.

Then I have a question. Do you know any debugging tools that
can reduce any function call or statement by expanding any
expression? And how to debug mutual recursions?

Best Regards.

And code is listed blow.

expn() ->
    parser:alt(parser:alt(
 parser:using(
   parser:then(simple:term()
       , parser:xthen(parser:literal($+)
      , simple:term()
     )
      )
   , simple:plus())
 , parser:using(parser:then(simple:term()
    , parser:xthen(
parser:literal($-)
, simple:term()
       )
   )
, simple:minus()
       )
)
       , simple:term()
      ).

term() ->
    parser:alt(parser:alt(
 parser:using(parser:then(simple:factor()
  , parser:xthen(
      parser:literal($*)
      , simple:factor()
     )
 )
      , simple:times())
 , parser:using(parser:then(simple:factor()
    , parser:xthen(
parser:literal($/)
, simple:factor()
       )
   ), simple:divide()
       )
)
       , simple:factor()
      ).

factor() ->
    parser:alt(parser:using(parser:number(), simple:value())
       , parser:xthen(parser:literal($()
      , parser:thenx(simple:expn()
     , parser:literal($))
    )
     )).

value() ->
    fun(Str)->
    case Str of
[_|_] -> {V,_} = string:to_integer(Str);
_ -> {V,_} = string:to_integer([Str])
    end,
    if
error == V -> parser:fail();
true -> V
    end
    end.

plus() -> fun({X,Y}) -> X + Y end.
minus() -> fun({X,Y}) -> X - Y end.
times() -> fun({X,Y}) -> X * Y end.
divide() -> fun({X,Y}) -> X / Y end.

From maruthavanan_s@REDACTED  Tue Jul 27 09:41:43 2010
From: maruthavanan_s@REDACTED (maruthavanan s)
Date: Tue, 27 Jul 2010 03:41:43 -0400
Subject: gen_tcp TCP Internals
Message-ID: <BLU138-W2513EA5C9613F86E08A497E3A70@phx.gbl>


Hi,

 

Is is possible to or delay the ACK of SYN using gen_tcp functions? Because I have scenario where when I get a connection request on the server which I need to validate and then only I should decide whether to send ACK or not.

 

Thanks,

Marutha

 
 		 	   		  

From attila.r.nohl@REDACTED  Tue Jul 27 11:10:06 2010
From: attila.r.nohl@REDACTED (Attila Rajmund Nohl)
Date: Tue, 27 Jul 2010 11:10:06 +0200
Subject: [erlang-questions] gen_tcp TCP Internals
In-Reply-To: <BLU138-W2513EA5C9613F86E08A497E3A70@phx.gbl>
References: <BLU138-W2513EA5C9613F86E08A497E3A70@phx.gbl>
Message-ID: <AANLkTi=zANaVVwF57doUDKSzRefdQ0BwJ5zySNYuiXna@mail.gmail.com>

2010/7/27, maruthavanan s <maruthavanan_s@REDACTED>:
>
> Hi,
>
>
>
> Is is possible to or delay the ACK of SYN using gen_tcp functions? Because I
> have scenario where when I get a connection request on the server which I
> need to validate and then only I should decide whether to send ACK or not.

I believe this is done on the operating system kernel level. I presume
you don't have much information about the incoming connection request,
except it's source IP address and TCP port, so you can configure your
firewall to reject connections based on this information.

From ffindermeister@REDACTED  Tue Jul 27 17:04:37 2010
From: ffindermeister@REDACTED (Roman Pelvetsky)
Date: Tue, 27 Jul 2010 08:04:37 -0700 (PDT)
Subject: efene for windows?
Message-ID: <e1f076cb-1d04-40b5-8ddf-1bebbc8233c1@h20g2000vbs.googlegroups.com>

Hello,
I was very interested by release of efene - new syntax for erlang,
especially the indented one.
( http://marianoguerra.com.ar/efene/#home ).
But is it supposed to run on Windows?
Are there some instructions how to compile and run it on windows box?

From comptekki@REDACTED  Tue Jul 27 19:15:20 2010
From: comptekki@REDACTED (Wes James)
Date: Tue, 27 Jul 2010 11:15:20 -0600
Subject: substr and sub_str ??
Message-ID: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>

I'm just curious as to why in:

http://www.erlang.org/doc/man/string.html

there is substr and sub_string - they look indentical?

thx,

-wes

From erik@REDACTED  Tue Jul 27 19:29:10 2010
From: erik@REDACTED (Erik Bogghed)
Date: Tue, 27 Jul 2010 19:29:10 +0200
Subject: [erlang-questions] substr and sub_str ??
In-Reply-To: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
References: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
Message-ID: <CF2DF9B3-32AB-43D4-AE0E-0B1545EC9C31@bogghed.se>


Well, they have a slightly different behavior as you can see in the documentation and in the example. At least that is 
what I can see :-). 

Erik

On 27 jul 2010, at 19.15, Wes James wrote:

> I'm just curious as to why in:
> 
> http://www.erlang.org/doc/man/string.html
> 
> there is substr and sub_string - they look indentical?
> 
> thx,
> 
> -wes
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 


From rvirding@REDACTED  Tue Jul 27 19:30:20 2010
From: rvirding@REDACTED (Robert Virding)
Date: Tue, 27 Jul 2010 19:30:20 +0200
Subject: [erlang-questions] substr and sub_str ??
In-Reply-To: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
References: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
Message-ID: <AANLkTi=-G2wUjD6JuGsWB7ewc3J8mNVs5L1A-_HFVgPK@mail.gmail.com>

Arguments are different:

substr(String, Start) -> SubString
substr(String, Start, Length) -> Substring

sub_string(String, Start) -> SubString
sub_string(String, Start, Stop) -> SubString

Two different philosophies.

Robert

On 27 July 2010 19:15, Wes James <comptekki@REDACTED> wrote:
> I'm just curious as to why in:
>
> http://www.erlang.org/doc/man/string.html
>
> there is substr and sub_string - they look indentical?
>
> thx,
>
> -wes
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From jesper.louis.andersen@REDACTED  Tue Jul 27 19:28:58 2010
From: jesper.louis.andersen@REDACTED (Jesper Louis Andersen)
Date: Tue, 27 Jul 2010 19:28:58 +0200
Subject: [erlang-questions] substr and sub_str ??
In-Reply-To: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
References: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
Message-ID: <AANLkTinF0kZ4Kw2sjyGmdxDebJA3hkvg7ce2UrN3kWjT@mail.gmail.com>

On Tue, Jul 27, 2010 at 7:15 PM, Wes James <comptekki@REDACTED> wrote:
> I'm just curious as to why in:
>
> http://www.erlang.org/doc/man/string.html
>
> there is substr and sub_string - they look indentical?

They are subtly different if given the 3rd argument. We have

substr(S, Start, Length)

and

sub_string(S, Start, Stop)

And the rule which governs their difference is that Stop = Start +
Length - 1 (If I can compute in my head). The examples in the
documentation tells more.

-- 
J.

From comptekki@REDACTED  Tue Jul 27 19:46:39 2010
From: comptekki@REDACTED (Wes James)
Date: Tue, 27 Jul 2010 11:46:39 -0600
Subject: [erlang-questions] substr and sub_str ??
In-Reply-To: <CF2DF9B3-32AB-43D4-AE0E-0B1545EC9C31@bogghed.se>
References: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
	<CF2DF9B3-32AB-43D4-AE0E-0B1545EC9C31@bogghed.se>
Message-ID: <AANLkTim+j++hDrR4FXJN0KmsaqNTeifuWfn5=4=ZaHhX@mail.gmail.com>

Yes - I see now as others pointed out also.

thx,

-wes


On Tue, Jul 27, 2010 at 11:29 AM, Erik Bogghed <erik@REDACTED> wrote:
>
> Well, they have a slightly different behavior as you can see in the documentation and in the example. At least that is
> what I can see :-).
>
> Erik
>
> On 27 jul 2010, at 19.15, Wes James wrote:
>
>> I'm just curious as to why in:
>>
>> http://www.erlang.org/doc/man/string.html
>>
>> there is substr and sub_string - they look indentical?
>>
>> thx,
>>
>> -wes
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>
>

From anders.nygren@REDACTED  Tue Jul 27 19:48:39 2010
From: anders.nygren@REDACTED (Anders Nygren)
Date: Tue, 27 Jul 2010 12:48:39 -0500
Subject: [erlang-questions] substr and sub_str ??
In-Reply-To: <AANLkTim+j++hDrR4FXJN0KmsaqNTeifuWfn5=4=ZaHhX@mail.gmail.com>
References: <AANLkTi=vKwPks6xBU6xyLLBndt2cudwspLLvmZT8xzNR@mail.gmail.com>
	<CF2DF9B3-32AB-43D4-AE0E-0B1545EC9C31@bogghed.se>
	<AANLkTim+j++hDrR4FXJN0KmsaqNTeifuWfn5=4=ZaHhX@mail.gmail.com>
Message-ID: <AANLkTimDESkvWJMpwfNv9KWZ+7D4PcYo-RjtcJibKhTu@mail.gmail.com>

On Tue, Jul 27, 2010 at 12:46 PM, Wes James <comptekki@REDACTED> wrote:
> Yes - I see now as others pointed out also.
>
> thx,

Also see the note at the end of the documentation

"Some of the general string functions may seem to overlap each other.
The reason for this is that this string package is the combination of
two earlier packages and all the functions of both packages have been
retained."

/Anders

>
> -wes
>
>
> On Tue, Jul 27, 2010 at 11:29 AM, Erik Bogghed <erik@REDACTED> wrote:
>>
>> Well, they have a slightly different behavior as you can see in the documentation and in the example. At least that is
>> what I can see :-).
>>
>> Erik
>>
>> On 27 jul 2010, at 19.15, Wes James wrote:
>>
>>> I'm just curious as to why in:
>>>
>>> http://www.erlang.org/doc/man/string.html
>>>
>>> there is substr and sub_string - they look indentical?
>>>
>>> thx,
>>>
>>> -wes
>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>
>>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From norton@REDACTED  Tue Jul 27 18:01:08 2010
From: norton@REDACTED (Joseph Wayne Norton)
Date: Wed, 28 Jul 2010 01:01:08 +0900
Subject: [ANN] Open Source Release of 'Hibari,' A Database for Big Data
Message-ID: <op.vgier6idhmvyvs@localhost.localdomain>


I wanted to share this announcement about the open sourcing of a  
non-relational, distributed database ... implemented in Erlang.


Gemini Mobile Technologies (?Gemini?) announced at ?Wireless
Japan 2010? in Tokyo that it will release Hibari (meaning
?Cloud Bird? in Japanese) as open source. Hibari is a database
optimized for the highly reliable, highly available storage of
massive data, so-called ?Big Data.?

Hibari is developed in Erlang, and is released under the Apache license.
Hibari provides highly-versatile APIs including Amazon S3,
JSON-RPC-RFC4627, Universal Binary Protocol, and soon-to-be-released
Thrift, Avro and Google's Protocol Buffers; Hibari supports Java, C/C++,
Python, Ruby, and Erlang. Gemini plans to provide Hadoop Map-Reduce
integration as well as a commercial license which includes updates and
support.


Resources:

Hibari download site - http://sourceforge.net/projects/hibari/
About Gemini Mobile Technologies - http://www.geminimobile.com/
About Hibari - http://www.geminimobile.com/technologies/technologiesDB.html


For the complete announcement, please see here:

http://www.prnewswire.com/news-releases/open-source-release-of-hibari-a-database-for-big-data-99300924.html

From mixolyde@REDACTED  Tue Jul 27 21:28:57 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Tue, 27 Jul 2010 15:28:57 -0400
Subject: Are recursive record definitions allowed?
Message-ID: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>

I'm working on some algorithm analysis and am trying to define a
fairly simple binary search tree with a record definition:
-record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
I get:
record btreenode undefined

Should I just not bother to specify the type of left and right and
just enforce the record type in code?


-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From cmcknight@REDACTED  Tue Jul 27 21:49:02 2010
From: cmcknight@REDACTED (cmcknight@REDACTED)
Date: Tue, 27 Jul 2010 12:49:02 -0700
Subject: EDoc inter-application links
Message-ID: <B9C25070-9D07-4825-9E03-E89CC682C33E@pheonic.com>

Hi All,

Is there a way to automatically create inter-application links in the EDoc generated HTML? The use case would be to fire off a script / makefile / etc. to call edoc against a directory, have it build the documentation files for each application in the directory but also allow those files to have links to other applications' documentation.

Thanks!

Chuck

From comptekki@REDACTED  Tue Jul 27 22:40:58 2010
From: comptekki@REDACTED (Wes James)
Date: Tue, 27 Jul 2010 14:40:58 -0600
Subject: escaping chars in re:replace
Message-ID: <AANLkTinSKD_3yiPONc_fi1PP2jZL0eGNmrPLCXX2TkB-@mail.gmail.com>

I'm replacing some values in some data.  It looks like when using

re:replace here:

http://www.erlang.org/doc/man/re.html

the RE parameter needs to have the chars *, [, (,) escaped to be used.

For example:

re:replace("this*", "*", "!", [{return,list}, global, caseless])

will error out with a bad argument error.  But this will work:

re:replace("this*", "\\*", "!", [{return,list}, global, caseless])


What other chars should I be looking for that need to be escaped?  The
RE value comes in as a variable, so I will need to change any of these
chars to escaped before using it in re:replace.

thx,

-wes

From comptekki@REDACTED  Tue Jul 27 22:53:24 2010
From: comptekki@REDACTED (Wes James)
Date: Tue, 27 Jul 2010 14:53:24 -0600
Subject: escaping values for re:replace
Message-ID: <AANLkTikBDkeZq=L4P-KzvTEYAyB86UQRTxUErTMSqqC7@mail.gmail.com>

I created a function:

escape(S) ->
	S2=re:replace(S, "\\*", "\\\\*", [{return,list}, global]),
	S3=re:replace(S2, "\\[", "\\\\[", [{return,list}, global]),
	S4=re:replace(S3, "\\(", "\\\\(", [{return,list}, global]),
	re:replace(S4, "\\)", "\\\\)", [{return,list}, global]).

to escape the values I know. Is there a more erlang way to do this?
I'm trying to replace all *, [, (, ) with the escaped values.

thx,

-wes

From hynek@REDACTED  Tue Jul 27 23:40:43 2010
From: hynek@REDACTED (Hynek Vychodil)
Date: Tue, 27 Jul 2010 23:40:43 +0200
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
Message-ID: <AANLkTik5Z67Df8nMx=8qK7aLOONMmo8aytVAB-sdM9y3@mail.gmail.com>

On Tue, Jul 27, 2010 at 9:28 PM, Brian Williams <mixolyde@REDACTED> wrote:
> I'm working on some algorithm analysis and am trying to define a
> fairly simple binary search tree with a record definition:
> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
> I get:
> record btreenode undefined
>
> Should I just not bother to specify the type of left and right and
> just enforce the record type in code?
>

Left term on = is default value. What should be done when you define
#btreenode{}? I think that even all memory available in the universe
will not suffice to declare this term ;-)
>
> --
> Brian E. Williams
> mixolyde@REDACTED
> http://www.techhouse.us/wordpress-mu/brianw
>
> "Never attribute to malice that which can be adequately
> explained by stupidity." - Hanlon's Razor
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
--Hynek (Pichi) Vychodil

Analyze your data in minutes. Share your insights instantly. Thrill
your boss.? Be a data hero!
Try GoodData now for free: www.gooddata.com

From mononcqc@REDACTED  Tue Jul 27 23:43:25 2010
From: mononcqc@REDACTED (Fred Hebert)
Date: Tue, 27 Jul 2010 17:43:25 -0400
Subject: [erlang-questions] escaping chars in re:replace
In-Reply-To: <AANLkTinSKD_3yiPONc_fi1PP2jZL0eGNmrPLCXX2TkB-@mail.gmail.com>
References: <AANLkTinSKD_3yiPONc_fi1PP2jZL0eGNmrPLCXX2TkB-@mail.gmail.com>
Message-ID: <AANLkTi=AvgDPjyx-VQ_SUhzN-qNB-uOAGq1nmq3+jTiB@mail.gmail.com>

There are many characters to escape:  ()[]{}\|*.+?:!$^<>= to name those I
can think of.

You have to be careful when accepting user-submitted regular expressions,
because it's possible to find pathological cases that will take a long time
to be ran. As far as I know, Erlang's re module is implemented as C code,
which could potentially lock your node (if anyone can confirm/deny).

It's generally a bad idea to run user-submitted regular expressions
server-side.

On Tue, Jul 27, 2010 at 4:40 PM, Wes James <comptekki@REDACTED> wrote:

> I'm replacing some values in some data.  It looks like when using
>
> re:replace here:
>
> http://www.erlang.org/doc/man/re.html
>
> the RE parameter needs to have the chars *, [, (,) escaped to be used.
>
> For example:
>
> re:replace("this*", "*", "!", [{return,list}, global, caseless])
>
> will error out with a bad argument error.  But this will work:
>
> re:replace("this*", "\\*", "!", [{return,list}, global, caseless])
>
>
> What other chars should I be looking for that need to be escaped?  The
> RE value comes in as a variable, so I will need to change any of these
> chars to escaped before using it in re:replace.
>
> thx,
>
> -wes
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From mononcqc@REDACTED  Tue Jul 27 23:49:09 2010
From: mononcqc@REDACTED (Fred Hebert)
Date: Tue, 27 Jul 2010 17:49:09 -0400
Subject: [erlang-questions] escaping values for re:replace
In-Reply-To: <AANLkTikBDkeZq=L4P-KzvTEYAyB86UQRTxUErTMSqqC7@mail.gmail.com>
References: <AANLkTikBDkeZq=L4P-KzvTEYAyB86UQRTxUErTMSqqC7@mail.gmail.com>
Message-ID: <AANLkTikp+MvrO9vya532S=_9=bFusXD3bfRzOrG8Yev=@mail.gmail.com>

Using a fold would be a bit cleaner. I used something like this to write a
quick (and not comprehensive) sluggifying function for French URLs. It
replaces accented characters by their normal counterpart, takes anything
that isn't a character or number and makes it a dash (-), then reduces
multiple dashes to a single one.

sluggify(Str) ->
   Patterns = [{"[????????]", "a"},
               {"[????????]", "e"},
               {"[????????]", "i"},
               {"[????????]", "o"},
               {"[????????]", "u"},
               {"[???]", "y"},
               {"[??]", "c"},
               {"[^\\w\\d_-]", "-"},
               {"[-]{2,}", "-"},
               {"(?:^-)|(?:-$)", ""}],
   Slug = lists:foldl(fun({Pat, Rep}, Slug) ->
       re:replace(Slug, Pat, Rep, [global, {return, binary}])
   end,
   Str,
   Patterns).

I guess you could use something like that.

On Tue, Jul 27, 2010 at 4:53 PM, Wes James <comptekki@REDACTED> wrote:

> I created a function:
>
> escape(S) ->
>        S2=re:replace(S, "\\*", "\\\\*", [{return,list}, global]),
>        S3=re:replace(S2, "\\[", "\\\\[", [{return,list}, global]),
>        S4=re:replace(S3, "\\(", "\\\\(", [{return,list}, global]),
>        re:replace(S4, "\\)", "\\\\)", [{return,list}, global]).
>
> to escape the values I know. Is there a more erlang way to do this?
> I'm trying to replace all *, [, (, ) with the escaped values.
>
> thx,
>
> -wes
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From hynek@REDACTED  Tue Jul 27 23:54:53 2010
From: hynek@REDACTED (Hynek Vychodil)
Date: Tue, 27 Jul 2010 23:54:53 +0200
Subject: [erlang-questions] escaping values for re:replace
In-Reply-To: <AANLkTikBDkeZq=L4P-KzvTEYAyB86UQRTxUErTMSqqC7@mail.gmail.com>
References: <AANLkTikBDkeZq=L4P-KzvTEYAyB86UQRTxUErTMSqqC7@mail.gmail.com>
Message-ID: <AANLkTin8v2-MXPpQk=qjtUmdUtPzwmW6L4zsDUa-9v26@mail.gmail.com>

Usual perlish idiom is to escape all non alphanumeric characters. I
think that use of re module for escaping is little bit overkill. I
would write:

escape([]) -> [];
escape([H|T]) when H>=$0, H=<$9; H>=$a, H=<$z; H>=$A, H=<$Z -> [H|escape(T)];
escape([H|T]) -> [$\\, H|escape(T)].

This should be way how quotemeta works in Perl but only for latin1.

On Tue, Jul 27, 2010 at 10:53 PM, Wes James <comptekki@REDACTED> wrote:
> I created a function:
>
> escape(S) ->
> ? ? ? ?S2=re:replace(S, "\\*", "\\\\*", [{return,list}, global]),
> ? ? ? ?S3=re:replace(S2, "\\[", "\\\\[", [{return,list}, global]),
> ? ? ? ?S4=re:replace(S3, "\\(", "\\\\(", [{return,list}, global]),
> ? ? ? ?re:replace(S4, "\\)", "\\\\)", [{return,list}, global]).
>
> to escape the values I know. Is there a more erlang way to do this?
> I'm trying to replace all *, [, (, ) with the escaped values.
>
> thx,
>
> -wes
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
--Hynek (Pichi) Vychodil

Analyze your data in minutes. Share your insights instantly. Thrill
your boss.? Be a data hero!
Try GoodData now for free: www.gooddata.com

From comptekki@REDACTED  Wed Jul 28 00:00:44 2010
From: comptekki@REDACTED (Wes James)
Date: Tue, 27 Jul 2010 16:00:44 -0600
Subject: [erlang-questions] escaping chars in re:replace
In-Reply-To: <AANLkTi=AvgDPjyx-VQ_SUhzN-qNB-uOAGq1nmq3+jTiB@mail.gmail.com>
References: <AANLkTinSKD_3yiPONc_fi1PP2jZL0eGNmrPLCXX2TkB-@mail.gmail.com>
	<AANLkTi=AvgDPjyx-VQ_SUhzN-qNB-uOAGq1nmq3+jTiB@mail.gmail.com>
Message-ID: <AANLkTi=eWdsci=AH+vE54BbWqSU6Nc63yQDy=AJkXKtg@mail.gmail.com>

What I'm doing is providing a search for site on book titles.  There
are *, [, (, ? chars in the data and I'm putting bold html around the
search text.  <b>search text</b>

I'm using re:replace on the the database return value.

Say a person types in "(b)", then on the page output this needs to be
changed to <b>(b)</b>.

Is there a better way to get the <b> around text with erlang other
than the re:replace?

thx,

-wes

On Tue, Jul 27, 2010 at 3:43 PM, Fred Hebert <mononcqc@REDACTED> wrote:
> There are many characters to escape: ?()[]{}\|*.+?:!$^<>= to name those I
> can think of.
>
> You have to be careful when accepting user-submitted regular expressions,
> because it's possible to find pathological cases that will take a long time
> to be ran. As far as I know, Erlang's re module is implemented as C code,
> which could potentially lock your node (if anyone can confirm/deny).
> It's generally a bad idea to run user-submitted regular expressions
> server-side.
> On Tue, Jul 27, 2010 at 4:40 PM, Wes James <comptekki@REDACTED> wrote:
>>
>> I'm replacing some values in some data. ?It looks like when using
>>
>> re:replace here:
>>
>> http://www.erlang.org/doc/man/re.html
>>
>> the RE parameter needs to have the chars *, [, (,) escaped to be used.
>>
>> For example:
>>
>> re:replace("this*", "*", "!", [{return,list}, global, caseless])
>>
>> will error out with a bad argument error. ?But this will work:
>>
>> re:replace("this*", "\\*", "!", [{return,list}, global, caseless])
>>
>>
>> What other chars should I be looking for that need to be escaped? ?The
>> RE value comes in as a variable, so I will need to change any of these
>> chars to escaped before using it in re:replace.
>>
>> thx,
>>
>> -wes
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>
>

From xma@REDACTED  Tue Jul 27 23:40:09 2010
From: xma@REDACTED (Xavier Maillard)
Date: Tue, 27 Jul 2010 23:40:09 +0200
Subject: erlang and web applications: which framework ?
Message-ID: <m2k4ogioxy.fsf@kcals.maillard.im>

Hi,

I am planning on developing a web application and I want it to be
written in erlang.

So, what is the set of possibilities on the framework side ? Which one
is recommended ?

Thank you very much

Xavier

From xma@REDACTED  Tue Jul 27 22:50:09 2010
From: xma@REDACTED (Xavier Maillard)
Date: Tue, 27 Jul 2010 22:50:09 +0200
Subject: erlang and web applications: which framework ?
Message-ID: <m2lj8wir9a.fsf@kcals.maillard.im>

Hi,

I am planning on developing a web application and I want it to be
written in erlang.

So, what is the set of possibilities on the framework side ? Which one
is recommended ?

Thank you very much

Xavier

From erik@REDACTED  Wed Jul 28 00:26:33 2010
From: erik@REDACTED (Erik Bogghed)
Date: Wed, 28 Jul 2010 00:26:33 +0200
Subject: [erlang-questions] erlang and web applications: which framework ?
In-Reply-To: <m2k4ogioxy.fsf@kcals.maillard.im>
References: <m2k4ogioxy.fsf@kcals.maillard.im>
Message-ID: <D1C6B6C0-2A9A-4D51-95E5-B272C9C18251@bogghed.se>


It depends on what you are looking for really. You have webmachine (REST toolkit, mochiweb), nitrogen (more complete, yaws), 
Zotonic (a CMS) and a few others I haven't looked at closely like Erlang Web, and Erlyweb. I have most likely missed mentioning 
quite a few.   

Erik 

On 27 jul 2010, at 23.40, Xavier Maillard wrote:

> Hi,
> 
> I am planning on developing a web application and I want it to be
> written in erlang.
> 
> So, what is the set of possibilities on the framework side ? Which one
> is recommended ?
> 
> Thank you very much
> 
> Xavier
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 


From tuncer.ayaz@REDACTED  Wed Jul 28 01:08:47 2010
From: tuncer.ayaz@REDACTED (Tuncer Ayaz)
Date: Wed, 28 Jul 2010 01:08:47 +0200
Subject: [erlang-questions] Distributed erlang not working after upgrading 
	to OSX Snow leopard
In-Reply-To: <AANLkTikt1OFT6ILhdMkLSCI-kE5wm9gY2q8c4lnHRyVB@mail.gmail.com>
References: <AANLkTik8wmCKZz5VyaRTH8bm9OhQ_LF0hGzdHy13dF7Y@mail.gmail.com> 
	<AANLkTilZ92XgSPk6OolAiI_YW7zW9odvxNXqJOvs20Ca@mail.gmail.com> 
	<AANLkTineyDdHF6TQ5LdyYnDkQF3K7mLBZk9Mwq6peGYC@mail.gmail.com> 
	<AANLkTikt1OFT6ILhdMkLSCI-kE5wm9gY2q8c4lnHRyVB@mail.gmail.com>
Message-ID: <AANLkTinQRYbX+eoWAGvmo3z22n=OTytPbqEPHJh-FFw9@mail.gmail.com>

On Thu, Jul 22, 2010 at 12:58 PM, Tuncer Ayaz wrote:
>
> On Wed, Jul 21, 2010 at 6:17 AM, Arun Suresh wrote:
> > Thanx michal..
> > that seems to have done the trick..
> >
> > On Wed, Jul 21, 2010 at 2:57 AM, Michal Zajda wrote:
> >
> >> Recompile your otp with --enable-darwin-64bit option to configure
> >> script. It is described in INSTALL.md file (in OTP sources).
>
> I have to admit I'm a little curious why using a 64bit emulator fixed
> the problem. I don't remember having issues with both 32bit and 64bit
> emulators on Linux or Darwin. Any detail I'm missing?

The only explanation is that a rebuild is required due to incompatible
changes from 10.5 to 10.6 and not that a 64-bit emu made distribution
work again.

From bengt.kleberg@REDACTED  Wed Jul 28 07:24:48 2010
From: bengt.kleberg@REDACTED (Bengt Kleberg)
Date: Wed, 28 Jul 2010 07:24:48 +0200
Subject: ot: Threads and Blocking I/O in Java
Message-ID: <1280294688.4903.2.camel@seasc1137>

Greetings,

A little information about Java I/O that might be relevant for Erlang
developers.
http://www.thebuzzmedia.com/java-io-faster-than-nio-old-is-new-again


bengt


From chaitanya.chalasani@REDACTED  Wed Jul 28 09:00:38 2010
From: chaitanya.chalasani@REDACTED (CHAITANYA CHALASANI)
Date: Wed, 28 Jul 2010 12:30:38 +0530
Subject: Installing multiple versions of erlang on a machine?
Message-ID: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>

Hi,

We have production systems running on R13B04. I want to evaluate our
programs on R14A meanwhile.
How can I install more than version of erlang on the same machine and
yet choose which one i want to use at the point of time?

Is there a direct solution for this? If not any workarounds?

-- 
Chaitanya Chalasani
Linux User: 410931

From rapsey@REDACTED  Wed Jul 28 09:23:10 2010
From: rapsey@REDACTED (Rapsey)
Date: Wed, 28 Jul 2010 09:23:10 +0200
Subject: [erlang-questions] Installing multiple versions of erlang on a 
	machine?
In-Reply-To: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
References: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
Message-ID: <AANLkTikQAW161k24KiG81RSuSF0ew1rp35qk_+8vk7WD@mail.gmail.com>

Of course. Just like any configure script, you can set prefix:
./configure --prefix=/opt
-> erl will be placed in /opt/bin, everything else in /opt/lib/erlang

So install in some path, call erl with full path (/opt/bin/erl) and that's
it.


Sergej

On Wed, Jul 28, 2010 at 9:00 AM, CHAITANYA CHALASANI <
chaitanya.chalasani@REDACTED> wrote:

> Hi,
>
> We have production systems running on R13B04. I want to evaluate our
> programs on R14A meanwhile.
> How can I install more than version of erlang on the same machine and
> yet choose which one i want to use at the point of time?
>
> Is there a direct solution for this? If not any workarounds?
>
> --
> Chaitanya Chalasani
> Linux User: 410931
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From boris.muehmer@REDACTED  Wed Jul 28 09:32:42 2010
From: boris.muehmer@REDACTED (=?UTF-8?Q?Boris_M=C3=BChmer?=)
Date: Wed, 28 Jul 2010 09:32:42 +0200
Subject: [erlang-questions] Installing multiple versions of erlang on a 
	machine?
In-Reply-To: <AANLkTikQAW161k24KiG81RSuSF0ew1rp35qk_+8vk7WD@mail.gmail.com>
References: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
	<AANLkTikQAW161k24KiG81RSuSF0ew1rp35qk_+8vk7WD@mail.gmail.com>
Message-ID: <AANLkTinhr-BCHuJ+F8vTBPjWFLC7d-q1ADHsdJk35krC@mail.gmail.com>

2010/7/28 Rapsey <rapsey@REDACTED>:
> Of course. Just like any configure script, you can set prefix:
> ./configure --prefix=/opt

I would add the version with the "--prefix" option,
like "--prefix=/opt/R13B04" or "--prefix=/opt/R14A".


  - boris

From mpalmer@REDACTED  Wed Jul 28 09:30:36 2010
From: mpalmer@REDACTED (Matthew Palmer)
Date: Wed, 28 Jul 2010 17:30:36 +1000
Subject: Installing multiple versions of erlang on a machine?
In-Reply-To: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
References: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
Message-ID: <20100728073036.GH4174@hezmatt.org>

On Wed, Jul 28, 2010 at 12:30:38PM +0530, CHAITANYA CHALASANI wrote:
> We have production systems running on R13B04. I want to evaluate our
> programs on R14A meanwhile.
> How can I install more than version of erlang on the same machine and
> yet choose which one i want to use at the point of time?
> 
> Is there a direct solution for this? If not any workarounds?

You can almost certainly build multiple versions of Erlang, with different
installation and library paths.  The hassle involved, the possibility of
bugs and things not working as you'd expect in production (due to different
paths for things), and the need to go outside what the package management
system lets you do, all make this a fairly painful exercise.

I just spin up new VMs using KVM when I need to test this sort of thing;
automated builds make creating a new machine a low-cost operation, and it
ensures that your test environment matches production as closely as possible
at all times.

- Matt

From mchris@REDACTED  Wed Jul 28 09:36:04 2010
From: mchris@REDACTED (Maria Christakis)
Date: Wed, 28 Jul 2010 10:36:04 +0300
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
Message-ID: <4C4FDDE4.20001@mail.ntua.gr>

On 07/27/2010 10:28 PM, Brian Williams wrote:
> I'm working on some algorithm analysis and am trying to define a
> fairly simple binary search tree with a record definition:
> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
> I get:
> record btreenode undefined
>
> Should I just not bother to specify the type of left and right and
> just enforce the record type in code?
>
>    
If, as you say, you are just trying "to specify the type of left and right"
and not assign an initial (default) value, then you should write your
record definition as follows:

-record(btreenode, {left :: #btreenode{}, right :: #btreenode{}, value}).

From chaitanya.chalasani@REDACTED  Wed Jul 28 10:02:49 2010
From: chaitanya.chalasani@REDACTED (CHAITANYA CHALASANI)
Date: Wed, 28 Jul 2010 13:32:49 +0530
Subject: [erlang-questions] Installing multiple versions of erlang on a 
	machine?
In-Reply-To: <AANLkTikQAW161k24KiG81RSuSF0ew1rp35qk_+8vk7WD@mail.gmail.com>
References: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
	<AANLkTikQAW161k24KiG81RSuSF0ew1rp35qk_+8vk7WD@mail.gmail.com>
Message-ID: <AANLkTikMFw7JGJnLduPEOZQmjrcECYnzZu21Yaq6U4nz@mail.gmail.com>

Thankyou I would try that.

On Wed, Jul 28, 2010 at 12:53 PM, Rapsey <rapsey@REDACTED> wrote:
> Of course. Just like any configure script, you can set prefix:
> ./configure --prefix=/opt
> -> erl will be placed in /opt/bin, everything else in /opt/lib/erlang
>
> So install in some path, call erl with full path (/opt/bin/erl) and that's
> it.
>
>
> Sergej
>
> On Wed, Jul 28, 2010 at 9:00 AM, CHAITANYA CHALASANI <
> chaitanya.chalasani@REDACTED> wrote:
>
>> Hi,
>>
>> We have production systems running on R13B04. I want to evaluate our
>> programs on R14A meanwhile.
>> How can I install more than version of erlang on the same machine and
>> yet choose which one i want to use at the point of time?
>>
>> Is there a direct solution for this? If not any workarounds?
>>
>> --
>> Chaitanya Chalasani
>> Linux User: 410931
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>



-- 
Chaitanya Chalasani
Linux User: 410931

From bartlomiej@REDACTED  Wed Jul 28 10:10:25 2010
From: bartlomiej@REDACTED (=?utf-8?Q?Bart=C5=82omiej_Puzo=C5=84?=)
Date: Wed, 28 Jul 2010 08:10:25 +0000 (GMT)
Subject: Reloading module
Message-ID: <1837107427.637501280304625454.JavaMail.root@zimbra>

Hi list,

Do you know any way to check if the module has been reloaded (the same module, not recompiled)?

Saludos,
-- 
Bart?omiej Puzo?
Erlang Solutions
bartlomiej.puzon@REDACTED

From bengt.kleberg@REDACTED  Wed Jul 28 10:46:35 2010
From: bengt.kleberg@REDACTED (Bengt Kleberg)
Date: Wed, 28 Jul 2010 10:46:35 +0200
Subject: [erlang-questions] Reloading module
In-Reply-To: <1837107427.637501280304625454.JavaMail.root@zimbra>
References: <1837107427.637501280304625454.JavaMail.root@zimbra>
Message-ID: <1280306795.4903.14.camel@seasc1137>

Greetings,

If you mean the exact same module, with no changes, I would like to know
why you want to check this, please?


ebngt

On Wed, 2010-07-28 at 10:10 +0200, Bart?omiej Puzo? wrote:
> Hi list,
> 
> Do you know any way to check if the module has been reloaded (the same module, not recompiled)?
> 
> Saludos,


From bartlomiej@REDACTED  Wed Jul 28 13:19:11 2010
From: bartlomiej@REDACTED (=?utf-8?Q?Bart=C5=82omiej_Puzo=C5=84?=)
Date: Wed, 28 Jul 2010 11:19:11 +0000 (GMT)
Subject: Fwd: [erlang-questions] Reloading module
In-Reply-To: <1237822775.637901280307543755.JavaMail.root@zimbra>
Message-ID: <658635322.638451280315951895.JavaMail.root@zimbra>


----- Mensaje reenviado -----
De: "Bart?omiej Puzo?" <bartlomiej.puzon@REDACTED>
Para: "bengt kleberg" <bengt.kleberg@REDACTED>
Enviados: Mi?rcoles, 28 de Julio 2010 10:59:03 GMT +01:00 Amsterdam / Berl?n / Berna / Roma / Estocolmo / Viena
Asunto: Re: [erlang-questions] Reloading module

Yes, the exact same module. It seems (in R13B04) that relolading a module disables tracing patterns set on that module. I wanted to keep track on active tracing patterns.


----- "Bengt Kleberg" <bengt.kleberg@REDACTED> escribi?:

> Greetings,
> 
> If you mean the exact same module, with no changes, I would like to
> know
> why you want to check this, please?
> 
> 
> ebngt
> 
> On Wed, 2010-07-28 at 10:10 +0200, Bart?omiej Puzo? wrote:
> > Hi list,
> > 
> > Do you know any way to check if the module has been reloaded (the
> same module, not recompiled)?
> > 
> > Saludos,
> 
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED

Saludos,
-- 
Bart?omiej Puzo?
Erlang Solutions

-- 
Bart?omiej Puzo?
Erlang Solutions
bartlomiej.puzon@REDACTED

From antoine.koener@REDACTED  Wed Jul 28 13:48:30 2010
From: antoine.koener@REDACTED (Antoine Koener)
Date: Wed, 28 Jul 2010 13:48:30 +0200
Subject: [erlang-questions] escaping chars in re:replace
In-Reply-To: <AANLkTi=eWdsci=AH+vE54BbWqSU6Nc63yQDy=AJkXKtg@mail.gmail.com>
References: <AANLkTinSKD_3yiPONc_fi1PP2jZL0eGNmrPLCXX2TkB-@mail.gmail.com>
	<AANLkTi=AvgDPjyx-VQ_SUhzN-qNB-uOAGq1nmq3+jTiB@mail.gmail.com>
	<AANLkTi=eWdsci=AH+vE54BbWqSU6Nc63yQDy=AJkXKtg@mail.gmail.com>
Message-ID: <AANLkTinAhi16nKpnUz6E2R+G5SjgY0WzR2vJ3M9_0Ubp@mail.gmail.com>

On Wed, Jul 28, 2010 at 12:00 AM, Wes James <comptekki@REDACTED> wrote:

> What I'm doing is providing a search for site on book titles.  There
> are *, [, (, ? chars in the data and I'm putting bold html around the
> search text.  <b>search text</b>
>
> I'm using re:replace on the the database return value.
>
> Say a person types in "(b)", then on the page output this needs to be
> changed to <b>(b)</b>.
>
> Is there a better way to get the <b> around text with erlang other
> than the re:replace?
>

Result = [ <<"<b>">>, WhatUserHasTyped, <<"</b>">> ],
gen_tcp:send(Socket, Result),

May be ?



>
> thx,
>
> -wes
>
> On Tue, Jul 27, 2010 at 3:43 PM, Fred Hebert <mononcqc@REDACTED> wrote:
> > There are many characters to escape:  ()[]{}\|*.+?:!$^<>= to name those I
> > can think of.
> >
> > You have to be careful when accepting user-submitted regular expressions,
> > because it's possible to find pathological cases that will take a long
> time
> > to be ran. As far as I know, Erlang's re module is implemented as C code,
> > which could potentially lock your node (if anyone can confirm/deny).
> > It's generally a bad idea to run user-submitted regular expressions
> > server-side.
> > On Tue, Jul 27, 2010 at 4:40 PM, Wes James <comptekki@REDACTED> wrote:
> >>
> >> I'm replacing some values in some data.  It looks like when using
> >>
> >> re:replace here:
> >>
> >> http://www.erlang.org/doc/man/re.html
> >>
> >> the RE parameter needs to have the chars *, [, (,) escaped to be used.
> >>
> >> For example:
> >>
> >> re:replace("this*", "*", "!", [{return,list}, global, caseless])
> >>
> >> will error out with a bad argument error.  But this will work:
> >>
> >> re:replace("this*", "\\*", "!", [{return,list}, global, caseless])
> >>
> >>
> >> What other chars should I be looking for that need to be escaped?  The
> >> RE value comes in as a variable, so I will need to change any of these
> >> chars to escaped before using it in re:replace.
> >>
> >> thx,
> >>
> >> -wes
> >>
> >> ________________________________________________________________
> >> erlang-questions (at) erlang.org mailing list.
> >> See http://www.erlang.org/faq.html
> >> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >>
> >
> >
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From michael.eugene.turner@REDACTED  Wed Jul 28 16:46:57 2010
From: michael.eugene.turner@REDACTED (Michael Turner)
Date: Wed, 28 Jul 2010 23:46:57 +0900
Subject: [erlang-questions] increment in map
In-Reply-To: <AANLkTi=MKL5CufdqTTCy=q5KSLmTBSwYXkXkpFe6ogEC@mail.gmail.com>
References: <AANLkTi=tj0pbU1anq05Fkj_5M19_v7j-qCv8b6QvqTJM@mail.gmail.com>
	<AANLkTimdzomO+JsRBknf4P4A5x0XdFW8OAKuKGGFm6QP@mail.gmail.com>
	<AANLkTinoD4M5EzmVRB00PvLYvvLXgG6POMp5aLKUNnhw@mail.gmail.com>
	<AANLkTi=MKL5CufdqTTCy=q5KSLmTBSwYXkXkpFe6ogEC@mail.gmail.com>
Message-ID: <AANLkTik0bx=T=JdbQUS4Uy9gMJ3VraY0XL9wvfbSKRig@mail.gmail.com>

On Tue, Jul 27, 2010 at 4:51 AM, Gleb Peregud <gleber.p@REDACTED> wrote:

> [{td, [],[W,X]} || {W, X} <- lists:zip([1,2,3], [1,2,3])]



[{td,[],[X,X]} || X <- lists:seq(1,3)].

-michael ("terser than thou") turner

From g9414002.pccu.edu.tw@REDACTED  Wed Jul 28 19:15:30 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Thu, 29 Jul 2010 01:15:30 +0800
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
Message-ID: <AANLkTikc1xx+swG5O5ZpNr_-qgB6G_DtTGtJBep9ewbH@mail.gmail.com>

On Wed, Jul 28, 2010 at 3:28 AM, Brian Williams <mixolyde@REDACTED> wrote:

> I'm working on some algorithm analysis and am trying to define a
> fairly simple binary search tree with a record definition:
> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
> I get:
> record btreenode undefined
>
> Should I just not bother to specify the type of left and right and
> just enforce the record type in code?
>

Although it's comprehensible in Haskell, I'd never seen any tree
definition in Erlang in this style. The `record' syntax is not to
define types with a type constructor and its data constructors.
It's just a record with fields about some data.

Thus, to define the tree structure, it is like

    -record(btree, {value, ltree, rtree}).

And fill data into those field: for example, a blind tree

    tree([]) ->
        nil;
    tree([X|Xs]) ->
        T = tree(Xs),
        #btree{value=X,ltree=T,rtree=T}.

> test:tree([1,2,3]).
{btree,1,
       {btree,2,{btree,3,nil,nil},{btree,3,nil,nil}},
       {btree,2,{btree,3,nil,nil},{btree,3,nil,nil}}}

From tony.arcieri@REDACTED  Wed Jul 28 19:39:52 2010
From: tony.arcieri@REDACTED (Tony Arcieri)
Date: Wed, 28 Jul 2010 11:39:52 -0600
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
Message-ID: <AANLkTin5Ef2=vCmHS4AP7Fgo7_OcmS7212yGdupUSKwK@mail.gmail.com>

On Tue, Jul 27, 2010 at 1:28 PM, Brian Williams <mixolyde@REDACTED> wrote:

> I'm working on some algorithm analysis and am trying to define a
> fairly simple binary search tree with a record definition:
> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).


Wouldn't you want the defaults to be for the leaf nodes, and if so,
shouldn't they be some sort of nil/null/void atom to indicate there are no
left/right branches?

-- 
Tony Arcieri
Medioh! A Kudelski Brand

From luismarianoguerra@REDACTED  Wed Jul 28 22:19:21 2010
From: luismarianoguerra@REDACTED (Mariano Guerra)
Date: Wed, 28 Jul 2010 17:19:21 -0300
Subject: [erlang-questions] efene for windows?
In-Reply-To: <e1f076cb-1d04-40b5-8ddf-1bebbc8233c1@h20g2000vbs.googlegroups.com>
References: <e1f076cb-1d04-40b5-8ddf-1bebbc8233c1@h20g2000vbs.googlegroups.com>
Message-ID: <AANLkTimvUAvMbA-GNTjZLZg6hvkRatQvPXM22Evzr_ii@mail.gmail.com>

On Tue, Jul 27, 2010 at 12:04 PM, Roman Pelvetsky
<ffindermeister@REDACTED> wrote:
> Hello,
> I was very interested by release of efene - new syntax for erlang,
> especially the indented one.
> ( http://marianoguerra.com.ar/efene/#home ).
> But is it supposed to run on Windows?
> Are there some instructions how to compile and run it on windows box?
>

I will install a windows VM to make the build scripts for windows as
soon as I can.

other than that it should be straightforward to install it, look at
the build.sh scripts in src and lib, you can run those commands and it
should work.

From vinoski@REDACTED  Wed Jul 28 22:29:44 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Wed, 28 Jul 2010 16:29:44 -0400
Subject: VM silently exits
Message-ID: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>

With R13B04 running on Montavista Linux, I've seen a few cases
recently where the Erlang VM simply exits without any log messages,
crash dumps, or coredumps. It appears to happen only after days of
running under load, making it hard to reproduce and investigate. It
may be related to memory consumption, but I'm not sure. External
programs like heart and memsup simply report "Erlang has closed,"
which according to the source code means they each got a return value
of 0 from read() on their connection to the VM, which in turn would
seem to indicate that the VM side of the connection was simply closed.
This would all seem to indicate that the VM was either killed by
another process or that it called exit() itself. The Linux "OOM
killer" is disabled on this system, and I don't know of any other
process that would be killing the VM. There are no alarms in the logs
about hitting memory high watermarks or anything like that, and we
aren't using any options to change allocators or anything like that.

Anybody ever seen anything like this?

I've found a few places in the VM C source code where exit() is called
without logging anything. Some of these are normal exits, like when
you exit an Erlang shell, where no logging is needed. But others seem
to be error conditions, and there should be logging for those. I think
I'll probably have to patch my system to add logging to those cases to
try to track down this problem -- is there still time to get a patch
like this into R14B? If this issue is memory-related, I suppose it's
possible that a sudden increase in memory consumption could cause the
VM to exit between alarm checks, explaining why things like memsup
don't seem to notice, so it would seem to be fairly critical that
something is logged by the VM itself for such cases.

thanks,
--steve

From vladdu55@REDACTED  Wed Jul 28 22:42:16 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Wed, 28 Jul 2010 22:42:16 +0200
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
Message-ID: <AANLkTikYGS0yB9qnceK9BZ1u6_ydM2XfZUoonjLZ5FMN@mail.gmail.com>

On Wed, Jul 28, 2010 at 22:29, Steve Vinoski <vinoski@REDACTED> wrote:
> With R13B04 running on Montavista Linux, I've seen a few cases
> recently where the Erlang VM simply exits without any log messages,
> crash dumps, or coredumps.

Hi,

I got something similar a while ago, with SuSe, but the lack of a
coredump was caused by some weird setting that I don't remember right
now (it worked for some programs but not all, notably not erlang). Are
you sure that core dumps are enabled properly on your system? You can
try to kill the VM manually, to see if there is a core dump or not.
(BTW, in my case it was a memory problem).

regards,
Vlad

From vinoski@REDACTED  Wed Jul 28 22:50:15 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Wed, 28 Jul 2010 16:50:15 -0400
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTikYGS0yB9qnceK9BZ1u6_ydM2XfZUoonjLZ5FMN@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
	<AANLkTikYGS0yB9qnceK9BZ1u6_ydM2XfZUoonjLZ5FMN@mail.gmail.com>
Message-ID: <AANLkTim3Pj=E3BsHMw9B9HBKCdowVF_gMsnXqA-=42FT@mail.gmail.com>

On Wed, Jul 28, 2010 at 4:42 PM, Vlad Dumitrescu <vladdu55@REDACTED> wrote:
> On Wed, Jul 28, 2010 at 22:29, Steve Vinoski <vinoski@REDACTED> wrote:
>> With R13B04 running on Montavista Linux, I've seen a few cases
>> recently where the Erlang VM simply exits without any log messages,
>> crash dumps, or coredumps.
>
> Hi,
>
> I got something similar a while ago, with SuSe, but the lack of a
> coredump was caused by some weird setting that I don't remember right
> now (it worked for some programs but not all, notably not erlang). Are
> you sure that core dumps are enabled properly on your system? You can
> try to kill the VM manually, to see if there is a core dump or not.
> (BTW, in my case it was a memory problem).

Hi Vlad, yes, core dumping is definitely enabled and working properly.

thanks,
--steve

From soroker@REDACTED  Thu Jul 29 00:54:19 2010
From: soroker@REDACTED (Andrei Soroker)
Date: Wed, 28 Jul 2010 15:54:19 -0700
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
Message-ID: <AANLkTim0P6Ozhgq7nVZgBAdy5=Cis1DvbnP5hmpAj5ob@mail.gmail.com>

On Wed, Jul 28, 2010 at 1:29 PM, Steve Vinoski <vinoski@REDACTED> wrote:
> With R13B04 running on Montavista Linux, I've seen a few cases
> recently where the Erlang VM simply exits without any log messages,
> crash dumps, or coredumps. It appears to happen only after days of
> running under load, making it hard to reproduce and investigate.

We've seen something similar once when we hit the atom table limit.
The fact that the exit occurs after some time of happy running might
be indicative of a hard limit being reached, and as far as I remember,
the nature of that kind of exit could be somewhat ungallant.

Andrei

From chaitanya.chalasani@REDACTED  Thu Jul 29 03:39:24 2010
From: chaitanya.chalasani@REDACTED (CHAITANYA CHALASANI)
Date: Thu, 29 Jul 2010 07:09:24 +0530
Subject: [erlang-questions] Installing multiple versions of erlang on a 
	machine?
In-Reply-To: <AANLkTikMFw7JGJnLduPEOZQmjrcECYnzZu21Yaq6U4nz@mail.gmail.com>
References: <AANLkTi=fN8X+GPzosZq6ZzV9UxFv2jc=t3h6E7sV+vvT@mail.gmail.com>
	<AANLkTikQAW161k24KiG81RSuSF0ew1rp35qk_+8vk7WD@mail.gmail.com>
	<AANLkTikMFw7JGJnLduPEOZQmjrcECYnzZu21Yaq6U4nz@mail.gmail.com>
Message-ID: <AANLkTinyPZNi0Jg6UjB=A-M2SyBHGUXrJrRju93rSs4C@mail.gmail.com>

That worked for me. Thanks a lot

On Wed, Jul 28, 2010 at 1:32 PM, CHAITANYA CHALASANI
<chaitanya.chalasani@REDACTED> wrote:
> Thankyou I would try that.
>
> On Wed, Jul 28, 2010 at 12:53 PM, Rapsey <rapsey@REDACTED> wrote:
>> Of course. Just like any configure script, you can set prefix:
>> ./configure --prefix=/opt
>> -> erl will be placed in /opt/bin, everything else in /opt/lib/erlang
>>
>> So install in some path, call erl with full path (/opt/bin/erl) and that's
>> it.
>>
>>
>> Sergej
>>
>> On Wed, Jul 28, 2010 at 9:00 AM, CHAITANYA CHALASANI <
>> chaitanya.chalasani@REDACTED> wrote:
>>
>>> Hi,
>>>
>>> We have production systems running on R13B04. I want to evaluate our
>>> programs on R14A meanwhile.
>>> How can I install more than version of erlang on the same machine and
>>> yet choose which one i want to use at the point of time?
>>>
>>> Is there a direct solution for this? If not any workarounds?
>>>
>>> --
>>> Chaitanya Chalasani
>>> Linux User: 410931
>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>>
>>
>
>
>
> --
> Chaitanya Chalasani
> Linux User: 410931
>



-- 
Chaitanya Chalasani
Linux User: 410931

From vinayakapawar@REDACTED  Thu Jul 29 04:04:04 2010
From: vinayakapawar@REDACTED (Vinayak Pawar)
Date: Thu, 29 Jul 2010 07:34:04 +0530
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
Message-ID: <AANLkTim-7QXaAL4bFcyz9byB=g4MmwtxsXfYcjqu6KV8@mail.gmail.com>

> With R13B04 running on Montavista Linux, I've seen a few cases
> recently where the Erlang VM simply exits without any log messages,
> crash dumps, or coredumps. It appears to happen only after days of
> running under load, making it hard to reproduce and investigate. It
> may be related to memory consumption, but I'm not sure. External
> programs like heart and memsup simply report "Erlang has closed,"
> which according to the source code means they each got a return value
> of 0 from read() on their connection to the VM, which in turn would
> seem to indicate that the VM side of the connection was simply closed.
> This would all seem to indicate that the VM was either killed by
> another process or that it called exit() itself. The Linux "OOM
> killer" is disabled on this system, and I don't know of any other
> process that would be killing the VM. There are no alarms in the logs
> about hitting memory high watermarks or anything like that, and we
> aren't using any options to change allocators or anything like that.
>
> Anybody ever seen anything like this?
>
> Hi Steve,

Yes, we've noticed this silent exit behaviour of Erlang VM (R13B04) on
Fedora 12. In our case, about ~12K YAWS/HTTP processes were in contention to
get lock for compiling same YAWS page. We changed YAWS cache refresh
interval to some very high figure and got rid of this problem.

Regards,
Vinayak

From serge@REDACTED  Thu Jul 29 05:38:04 2010
From: serge@REDACTED (Serge Aleynikov)
Date: Wed, 28 Jul 2010 23:38:04 -0400
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
Message-ID: <4C50F79C.2030802@aleynikov.org>

Steve,

I've seen something like this that was memory related.  Adjusting 
'fullsweep_after' option or setting ERL_FULLSWEEP_AFTER environment 
variable (http://www.erlang.org/doc/man/erlang.html#system_flag-2) 
helped in our case.

Perhaps you should set up a separate watchdog OS process that would 
monitor memory consumption of VM by reading the /proc/PID/stat and 
logging it every N seconds.

Serge

On 7/28/2010 4:29 PM, Steve Vinoski wrote:
> With R13B04 running on Montavista Linux, I've seen a few cases
> recently where the Erlang VM simply exits without any log messages,
> crash dumps, or coredumps. It appears to happen only after days of
> running under load, making it hard to reproduce and investigate. It
> may be related to memory consumption, but I'm not sure. External
> programs like heart and memsup simply report "Erlang has closed,"
> which according to the source code means they each got a return value
> of 0 from read() on their connection to the VM, which in turn would
> seem to indicate that the VM side of the connection was simply closed.
> This would all seem to indicate that the VM was either killed by
> another process or that it called exit() itself. The Linux "OOM
> killer" is disabled on this system, and I don't know of any other
> process that would be killing the VM. There are no alarms in the logs
> about hitting memory high watermarks or anything like that, and we
> aren't using any options to change allocators or anything like that.
>
> Anybody ever seen anything like this?
>
> I've found a few places in the VM C source code where exit() is called
> without logging anything. Some of these are normal exits, like when
> you exit an Erlang shell, where no logging is needed. But others seem
> to be error conditions, and there should be logging for those. I think
> I'll probably have to patch my system to add logging to those cases to
> try to track down this problem -- is there still time to get a patch
> like this into R14B? If this issue is memory-related, I suppose it's
> possible that a sudden increase in memory consumption could cause the
> VM to exit between alarm checks, explaining why things like memsup
> don't seem to notice, so it would seem to be fairly critical that
> something is logged by the VM itself for such cases.
>
> thanks,
> --steve
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>

From vinoski@REDACTED  Thu Jul 29 06:42:27 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Thu, 29 Jul 2010 00:42:27 -0400
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTim0P6Ozhgq7nVZgBAdy5=Cis1DvbnP5hmpAj5ob@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
	<AANLkTim0P6Ozhgq7nVZgBAdy5=Cis1DvbnP5hmpAj5ob@mail.gmail.com>
Message-ID: <AANLkTi=btevz-WhHR9Uy4MGdqG5McXZEHDbbV4Kgu9Eh@mail.gmail.com>

On Wed, Jul 28, 2010 at 6:54 PM, Andrei Soroker <soroker@REDACTED> wrote:
> On Wed, Jul 28, 2010 at 1:29 PM, Steve Vinoski <vinoski@REDACTED> wrote:
>> With R13B04 running on Montavista Linux, I've seen a few cases
>> recently where the Erlang VM simply exits without any log messages,
>> crash dumps, or coredumps. It appears to happen only after days of
>> running under load, making it hard to reproduce and investigate.
>
> We've seen something similar once when we hit the atom table limit.
> The fact that the exit occurs after some time of happy running might
> be indicative of a hard limit being reached, and as far as I remember,
> the nature of that kind of exit could be somewhat ungallant.

Good idea, I'll try to check for this sort of thing.

thanks,
--steve

From vinoski@REDACTED  Thu Jul 29 06:49:25 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Thu, 29 Jul 2010 00:49:25 -0400
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTim-7QXaAL4bFcyz9byB=g4MmwtxsXfYcjqu6KV8@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
	<AANLkTim-7QXaAL4bFcyz9byB=g4MmwtxsXfYcjqu6KV8@mail.gmail.com>
Message-ID: <AANLkTi=uOAx7Cfm=9j1y9TWyddWg447ET+DtQN2xBG6r@mail.gmail.com>

On Wed, Jul 28, 2010 at 10:04 PM, Vinayak Pawar <vinayakapawar@REDACTED> wrote:
>
>> With R13B04 running on Montavista Linux, I've seen a few cases
>> recently where the Erlang VM simply exits without any log messages,
>> crash dumps, or coredumps. It appears to happen only after days of
>> running under load, making it hard to reproduce and investigate. It
>> may be related to memory consumption, but I'm not sure. External
>> programs like heart and memsup simply report "Erlang has closed,"
>> which according to the source code means they each got a return value
>> of 0 from read() on their connection to the VM, which in turn would
>> seem to indicate that the VM side of the connection was simply closed.
>> This would all seem to indicate that the VM was either killed by
>> another process or that it called exit() itself. The Linux "OOM
>> killer" is disabled on this system, and I don't know of any other
>> process that would be killing the VM. There are no alarms in the logs
>> about hitting memory high watermarks or anything like that, and we
>> aren't using any options to change allocators or anything like that.
>>
>> Anybody ever seen anything like this?
>>
> Hi Steve,
>
> Yes, we've noticed this silent exit behaviour of Erlang VM (R13B04) on
> Fedora 12. In our case, about ~12K YAWS/HTTP processes were in contention to
> get lock for compiling same YAWS page. We changed YAWS cache refresh
> interval to some very high figure and got rid of this problem.

Yaws isn't doing that sort of thing in my case, but generally, this is
good info since it's certainly possible some process queue is getting
backed up which of course just worsens over time. We're now running a
periodic check for such things but we haven't caught anything yet
(we're between failures at the moment).

thanks,
--steve

From vinoski@REDACTED  Thu Jul 29 06:53:30 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Thu, 29 Jul 2010 00:53:30 -0400
Subject: [erlang-questions] VM silently exits
In-Reply-To: <4C50F79C.2030802@aleynikov.org>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
	<4C50F79C.2030802@aleynikov.org>
Message-ID: <AANLkTinp4jtu_vP7+NUVMjMs-h+K62hW2w58DqDkObY+@mail.gmail.com>

On Wed, Jul 28, 2010 at 11:38 PM, Serge Aleynikov <serge@REDACTED> wrote:
> Steve,
>
> I've seen something like this that was memory related. ?Adjusting
> 'fullsweep_after' option or setting ERL_FULLSWEEP_AFTER environment variable
> (http://www.erlang.org/doc/man/erlang.html#system_flag-2) helped in our
> case.

Thanks, this is good advice that I hadn't considered.

> Perhaps you should set up a separate watchdog OS process that would monitor
> memory consumption of VM by reading the /proc/PID/stat and logging it every
> N seconds.

Yep, I started something exactly like this running on a testbed yesterday.

thanks,
--steve

From anthonym@REDACTED  Thu Jul 29 07:25:43 2010
From: anthonym@REDACTED (Anthony Molinaro)
Date: Wed, 28 Jul 2010 22:25:43 -0700
Subject: [erlang-questions] erlang and web applications: which framework ?
In-Reply-To: <m2lj8wir9a.fsf@kcals.maillard.im>
References: <m2lj8wir9a.fsf@kcals.maillard.im>
Message-ID: <20100729052543.GA23077@alumni.caltech.edu>

Hi Xavier,

   It probably depends on what you want to do, a few you can check out
are

http://webmachine.basho.com/
http://nitrogenproject.com/
http://www.erlang-web.org/
http://www.chicagoboss.org/

plus probably a few dozen more if you hunt around

http://projects.trapexit.org/

I've used webmachine (for REST web services) and nitrogen (for web ui's),
and like both of them.  Others seem to concentrate on different things
so you'll have to check out their feature sets and compare it to what you
want to do.

Good Luck,

-Anthony

On Tue, Jul 27, 2010 at 10:50:09PM +0200, Xavier Maillard wrote:
> Hi,
> 
> I am planning on developing a web application and I want it to be
> written in erlang.
> 
> So, what is the set of possibilities on the framework side ? Which one
> is recommended ?
> 
> Thank you very much
> 
> Xavier
> 
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> 

-- 
------------------------------------------------------------------------
Anthony Molinaro                           <anthonym@REDACTED>

From sacha@REDACTED  Thu Jul 29 11:01:24 2010
From: sacha@REDACTED (Alexander Kotelnikov)
Date: Thu, 29 Jul 2010 13:01:24 +0400
Subject: Which Erlang JSON parser?
Message-ID: <87eiemmzkr.fsf@benington.loc>

Hello.

It is a terrible story. I needed a JSON parcer to deal with JSON data in
my Erlang programm.

At first I picked json_eep
(http://github.com/jchris/erlang-json-eep-parser.git) which worked quite
fine, but later I found out that it is not able to parse (some!) escaped
unicode characters:
28> json_eep:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
** exception error: bad argument
     in function  list_to_binary/1
        called as list_to_binary([1075,1086,1088,1086,1076])
     in call from json_grammar:yeccpars2_9/7
     in call from json_grammar:yeccpars0/2
     in call from json_eep:json_to_term/1

My guess is that just a little change near list_to_binary should fix the
problem.


Then I start investigation of other parsers. I found around 7. Most of
them not eep0018 parsers. So I tried
http://github.com/davisp/eep0018.git
and
http://github.com/dizzyd/eep0018.git (both are based on yajl).

The former did not build for me because of some rebar issues. The latter
did after some changes to Makefiles. A little problem with it is that I
do not understand, how it decodes unicode:
1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
<<208,179,208,190,209,128,208,190,208,180>>

Probably authors of these modules read this list and will clarify and/or
fix if there is something to fix. 

Thanks, A.

PS And, just in case if anyone cares, none of these parsers implements
json_to_term/2.

From soroker@REDACTED  Thu Jul 29 11:17:53 2010
From: soroker@REDACTED (Andrei Soroker)
Date: Thu, 29 Jul 2010 02:17:53 -0700
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <87eiemmzkr.fsf@benington.loc>
References: <87eiemmzkr.fsf@benington.loc>
Message-ID: <AANLkTin4o=JYr3KBMLxab3HpNEP5Q7emx0Am=FBqa0Xe@mail.gmail.com>

On Thu, Jul 29, 2010 at 2:01 AM, Alexander Kotelnikov <sacha@REDACTED> wrote:
> Hello.
>
> It is a terrible story. I needed a JSON parcer to deal with JSON data in
> my Erlang programm.

Try json.erl form Yaws: http://github.com/klacke/yaws/blob/master/src/json.erl

I've used it successfully to encode/decode some Russian text.

Andrei

From bgustavsson@REDACTED  Thu Jul 29 11:44:31 2010
From: bgustavsson@REDACTED (=?UTF-8?Q?Bj=C3=B6rn_Gustavsson?=)
Date: Thu, 29 Jul 2010 11:44:31 +0200
Subject: [erlang-questions] VM silently exits
In-Reply-To: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
References: <AANLkTikX1rj_XK5NHpnzbLn38xW1Z-uuK=eFQqhqJv=t@mail.gmail.com>
Message-ID: <AANLkTikojztC+MZKdDdks183chx=6bJfG7VkAgrU8Nh=@mail.gmail.com>

On Wed, Jul 28, 2010 at 10:29 PM, Steve Vinoski <vinoski@REDACTED> wrote:
> I've found a few places in the VM C source code where exit() is called
> without logging anything. Some of these are normal exits, like when
> you exit an Erlang shell, where no logging is needed. But others seem
> to be error conditions, and there should be logging for those. I think
> I'll probably have to patch my system to add logging to those cases to
> try to track down this problem -- is there still time to get a patch
> like this into R14B?

Yes, there should still be time. The issue seems important enough
to fix in R14B.

-- 
Bj?rn Gustavsson, Erlang/OTP, Ericsson AB

From gleber.p@REDACTED  Thu Jul 29 12:30:03 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Thu, 29 Jul 2010 12:30:03 +0200
Subject: Edoc crashes when called from command line
Message-ID: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com>

Hello

Edoc crashes when called from command line, though it works well when
called from shell, as shown below:

~/test$ cat a.erl
-module(a).

-compile(export_all).

a() ->
        ok.

~/test$ erlc a.erl

~/test$ erl
Erlang R14A (erts-5.8) [source] [smp:2:2] [rq:2] [async-threads:0]
[kernel-poll:false]

Eshell V5.8  (abort with ^G)
1> edoc:file("a.erl").
ok
2> q().
ok
3>

~/test$ erl -noinput -run edoc file a.erl
{"init terminating in do_boot",error}

Crash dump was written to: erl_crash.dump
init terminating in do_boot (error)

~/test$ erl -noinput -s edoc file a.erl
{"init terminating in do_boot",error}

Crash dump was written to: erl_crash.dump
init terminating in do_boot (error)


It happens on Ubuntu Lucid 10.4 with Erlang packages (v 1:14.a-dfsg-1)
from Debian repositories.

Have anyone encountered this issue before? How can I debug this? Any
ideas on a reason?

Best regards,
Gleb Peregud

From ivan@REDACTED  Thu Jul 29 11:10:28 2010
From: ivan@REDACTED (Ivan Uemlianin)
Date: Thu, 29 Jul 2010 10:10:28 +0100
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <87eiemmzkr.fsf@benington.loc>
References: <87eiemmzkr.fsf@benington.loc>
Message-ID: <4C514584.2090104@llaisdy.com>

Dear Alexander

Have you tried mochijson or mochijson2 from mochiweb?

     http://stackoverflow.com/questions/1562235/mochijson2-or-mochijson

Best wishes

Ivan


On 29/07/2010 10:01, Alexander Kotelnikov wrote:
> Hello.
>
> It is a terrible story. I needed a JSON parcer to deal with JSON data in
> my Erlang programm.
>
> At first I picked json_eep
> (http://github.com/jchris/erlang-json-eep-parser.git) which worked quite
> fine, but later I found out that it is not able to parse (some!) escaped
> unicode characters:
> 28>  json_eep:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> ** exception error: bad argument
>       in function  list_to_binary/1
>          called as list_to_binary([1075,1086,1088,1086,1076])
>       in call from json_grammar:yeccpars2_9/7
>       in call from json_grammar:yeccpars0/2
>       in call from json_eep:json_to_term/1
>
> My guess is that just a little change near list_to_binary should fix the
> problem.
>
>
> Then I start investigation of other parsers. I found around 7. Most of
> them not eep0018 parsers. So I tried
> http://github.com/davisp/eep0018.git
> and
> http://github.com/dizzyd/eep0018.git (both are based on yajl).
>
> The former did not build for me because of some rebar issues. The latter
> did after some changes to Makefiles. A little problem with it is that I
> do not understand, how it decodes unicode:
> 1>  eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> <<208,179,208,190,209,128,208,190,208,180>>
>
> Probably authors of these modules read this list and will clarify and/or
> fix if there is something to fix.
>
> Thanks, A.
>
> PS And, just in case if anyone cares, none of these parsers implements
> json_to_term/2.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>    


-- 
============================================================
Ivan A. Uemlianin
Speech Technology Research and Development

                     ivan@REDACTED
                      www.llaisdy.com
                          llaisdy.wordpress.com
                      www.linkedin.com/in/ivanuemlianin

     "Froh, froh! Wie seine Sonnen, seine Sonnen fliegen"
                      (Schiller, Beethoven)
============================================================


From vladdu55@REDACTED  Thu Jul 29 12:41:48 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Thu, 29 Jul 2010 12:41:48 +0200
Subject: [erlang-questions] Edoc crashes when called from command line
In-Reply-To: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com>
References: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com>
Message-ID: <AANLkTim4X=sWJVfu1_e4rKckRSTWJYwHWoh2iQK7-CBY@mail.gmail.com>

On Thu, Jul 29, 2010 at 12:30, Gleb Peregud <gleber.p@REDACTED> wrote:
> ~/test$ erl -noinput -s edoc file a.erl
> {"init terminating in do_boot",error}

Hi,

Could it be because the argument a.erl is sent to edoc:file as an atom?

regards,
Vlad

From gleber.p@REDACTED  Thu Jul 29 12:58:01 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Thu, 29 Jul 2010 12:58:01 +0200
Subject: [erlang-questions] Edoc crashes when called from command line
In-Reply-To: <AANLkTim4X=sWJVfu1_e4rKckRSTWJYwHWoh2iQK7-CBY@mail.gmail.com>
References: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com> 
	<AANLkTim4X=sWJVfu1_e4rKckRSTWJYwHWoh2iQK7-CBY@mail.gmail.com>
Message-ID: <AANLkTik3xfa-GVJfQOxxhcGi7+LUQhQs-qivsGBx=3w=@mail.gmail.com>

On Thu, Jul 29, 2010 at 12:41, Vlad Dumitrescu <vladdu55@REDACTED> wrote:
> On Thu, Jul 29, 2010 at 12:30, Gleb Peregud <gleber.p@REDACTED> wrote:
>> ~/test$ erl -noinput -s edoc file a.erl
> Could it be because the argument a.erl is sent to edoc:file as an atom?

According to erl(3) if using -run arguments are passed as strings and
this does not work neither as shown in the first message. And it was
working with -run in R12 and R13 well.

Best,
Gleb

From vladdu55@REDACTED  Thu Jul 29 13:05:41 2010
From: vladdu55@REDACTED (Vlad Dumitrescu)
Date: Thu, 29 Jul 2010 13:05:41 +0200
Subject: Fwd: [erlang-questions] Edoc crashes when called from command line
In-Reply-To: <AANLkTi=2gxcFfji9ZrRQx3vWm9POqxxH0FJuLTy4g3Nb@mail.gmail.com>
References: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com> 
	<AANLkTim4X=sWJVfu1_e4rKckRSTWJYwHWoh2iQK7-CBY@mail.gmail.com> 
	<AANLkTik3xfa-GVJfQOxxhcGi7+LUQhQs-qivsGBx=3w=@mail.gmail.com> 
	<AANLkTi=2gxcFfji9ZrRQx3vWm9POqxxH0FJuLTy4g3Nb@mail.gmail.com>
Message-ID: <AANLkTi=f28jQA-Yt+T++jOr+MC+4n_LJyXaWPXZ_euXA@mail.gmail.com>

On Thu, Jul 29, 2010 at 12:58, Gleb Peregud <gleber.p@REDACTED> wrote:
> On Thu, Jul 29, 2010 at 12:41, Vlad Dumitrescu <vladdu55@REDACTED> wrote:
>> On Thu, Jul 29, 2010 at 12:30, Gleb Peregud <gleber.p@REDACTED> wrote:
>>> ~/test$ erl -noinput -s edoc file a.erl
>> Could it be because the argument a.erl is sent to edoc:file as an atom?
>
> According to erl(3) if using -run arguments are passed as strings and
> this does not work neither as shown in the first message. And it was
> working with -run in R12 and R13 well.

Yes, but the docs say that the specified function "is assumed to be of
arity 1, taking the list [Arg1,Arg2,...] as argument", so you get
? ? ?edoc:file(["a.erl"])
instead of
? ? ?edoc:file("a.erl")

regards,
Vlad

From sedrik@REDACTED  Thu Jul 29 13:17:34 2010
From: sedrik@REDACTED (Fredrik Andersson)
Date: Thu, 29 Jul 2010 13:17:34 +0200
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTin5Ef2=vCmHS4AP7Fgo7_OcmS7212yGdupUSKwK@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
	<AANLkTin5Ef2=vCmHS4AP7Fgo7_OcmS7212yGdupUSKwK@mail.gmail.com>
Message-ID: <AANLkTimtAVD4O8pvMdfQ41oN7GQzvQKqpS63=GsJif8h@mail.gmail.com>

On Wed, Jul 28, 2010 at 7:39 PM, Tony Arcieri <tony.arcieri@REDACTED> wrote:
> On Tue, Jul 27, 2010 at 1:28 PM, Brian Williams <mixolyde@REDACTED> wrote:
>
>> I'm working on some algorithm analysis and am trying to define a
>> fairly simple binary search tree with a record definition:
>> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
>
>
> Wouldn't you want the defaults to be for the leaf nodes, and if so,
> shouldn't they be some sort of nil/null/void atom to indicate there are no
> left/right branches?
>
> --
> Tony Arcieri
> Medioh! A Kudelski Brand
>

Why not even make them the atom leaf? :)

From gleber.p@REDACTED  Thu Jul 29 13:18:48 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Thu, 29 Jul 2010 13:18:48 +0200
Subject: [erlang-questions] Edoc crashes when called from command line
In-Reply-To: <AANLkTi=f28jQA-Yt+T++jOr+MC+4n_LJyXaWPXZ_euXA@mail.gmail.com>
References: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com> 
	<AANLkTim4X=sWJVfu1_e4rKckRSTWJYwHWoh2iQK7-CBY@mail.gmail.com> 
	<AANLkTik3xfa-GVJfQOxxhcGi7+LUQhQs-qivsGBx=3w=@mail.gmail.com> 
	<AANLkTi=2gxcFfji9ZrRQx3vWm9POqxxH0FJuLTy4g3Nb@mail.gmail.com> 
	<AANLkTi=f28jQA-Yt+T++jOr+MC+4n_LJyXaWPXZ_euXA@mail.gmail.com>
Message-ID: <AANLkTindUmdQz4tBPmK38NSue_e2J5Ese_HAag9Jzbuq@mail.gmail.com>

On Thu, Jul 29, 2010 at 13:05, Vlad Dumitrescu <vladdu55@REDACTED> wrote:
> Yes, but the docs say that the specified function "is assumed to be of
> arity 1, taking the list [Arg1,Arg2,...] as argument", so you get
> ? ? ?edoc:file(["a.erl"])
> instead of
> ? ? ?edoc:file("a.erl")

Yes, you are right. I've missed this (RTM FTW). But it looks like
either edoc:file/1 definition has changed or 'erl -run' behaviour has
changed, since it was working previously for me.

A quick and easy solution is to use:

    erl -run edoc files a.erl


Vlad, thanks for pointing this out.

Best,
Gleb

From mixolyde@REDACTED  Thu Jul 29 14:22:10 2010
From: mixolyde@REDACTED (Brian Williams)
Date: Thu, 29 Jul 2010 08:22:10 -0400
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTimtAVD4O8pvMdfQ41oN7GQzvQKqpS63=GsJif8h@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
	<AANLkTin5Ef2=vCmHS4AP7Fgo7_OcmS7212yGdupUSKwK@mail.gmail.com>
	<AANLkTimtAVD4O8pvMdfQ41oN7GQzvQKqpS63=GsJif8h@mail.gmail.com>
Message-ID: <AANLkTinTp=AFRckuyb+5=kVpy+oiXXDKgY_xwwQW+7EM@mail.gmail.com>

This is essentially what I'm doing, but using the undefined atom. Leaf
technically is a node that has a value, but no children. it's not
really the name of an empty left or right node pointer. Here, new_node
generates a leaf.

new_node(Value) ->
    #btreenode{left = undefined, right = undefined, value = Value}.

insert([], Tree) -> Tree;
insert([Head | Tail], Tree) -> insert(Tail, insert(Head, Tree));
insert(Value, undefined) -> new_node(Value);
insert(Value, Tree = #btreenode{value = Value}) -> Tree;
insert(Value, #btreenode{left = Left, right = Right, value = CurrentValue})
    when Value < CurrentValue ->
        #btreenode{left = insert(Value, Left), right = Right, value =
CurrentValue};
insert(Value, #btreenode{left = Left, right = Right, value = CurrentValue})
    when Value > CurrentValue ->
        #btreenode{left = Left, right = insert(Value, Right), value =
CurrentValue}.

Writing somre more complicated operations and homework assignments
next. I have found rewriting old homework assignments from Algorithms
and AI classes to be very helpful in teaching myself the language.

On Thu, Jul 29, 2010 at 7:17 AM, Fredrik Andersson <sedrik@REDACTED> wrote:
> On Wed, Jul 28, 2010 at 7:39 PM, Tony Arcieri <tony.arcieri@REDACTED> wrote:
>> On Tue, Jul 27, 2010 at 1:28 PM, Brian Williams <mixolyde@REDACTED> wrote:
>>
>>> I'm working on some algorithm analysis and am trying to define a
>>> fairly simple binary search tree with a record definition:
>>> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
>>
>>
>> Wouldn't you want the defaults to be for the leaf nodes, and if so,
>> shouldn't they be some sort of nil/null/void atom to indicate there are no
>> left/right branches?
>>
>> --
>> Tony Arcieri
>> Medioh! A Kudelski Brand
>>
>
> Why not even make them the atom leaf? :)
>



-- 
Brian E. Williams
mixolyde@REDACTED
http://www.techhouse.us/wordpress-mu/brianw

"Never attribute to malice that which can be adequately
explained by stupidity." - Hanlon's Razor

From max.lapshin@REDACTED  Thu Jul 29 16:04:26 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Thu, 29 Jul 2010 18:04:26 +0400
Subject: postgresql driver rewrite
Message-ID: <AANLkTimbt+kdOfFNXv9P24bRitC0WF7+=LLC6T_9DonN@mail.gmail.com>

Hi. I was using pgsql driver, but found that it is absolutely non-OTP.

I've started adding supervisors in it and now I'm in process of
rewriting protocol to gen_fsm.

Maybe there is already supported code, that doesn't require so many work?

From rvirding@REDACTED  Thu Jul 29 16:05:56 2010
From: rvirding@REDACTED (Robert Virding)
Date: Thu, 29 Jul 2010 16:05:56 +0200
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <87eiemmzkr.fsf@benington.loc>
References: <87eiemmzkr.fsf@benington.loc>
Message-ID: <AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com>

Hi,

I am afraid I can't help you by suggesting a better JSON parser, but I
can explain what you are seeing. The basic to remember that a binary
internally is a sequence of bytes/bits, there is no extra information
saying how to interpret these bytes/bits. All interpretation is done
when you create or access the binary, it then you say whether it is a
32 bit float, or 3 bit integer, or a utf-8 encoded character. That
means that there is nothing to stop you from creating a binary of
utf-8 characters and then decoding it as 5 bit integers. Not useful
perhaps but perfectly legal.

So:

On 29 July 2010 11:01, Alexander Kotelnikov <sacha@REDACTED> wrote:
> Hello.
>
> It is a terrible story. I needed a JSON parcer to deal with JSON data in
> my Erlang programm.
>
> At first I picked json_eep
> (http://github.com/jchris/erlang-json-eep-parser.git) which worked quite
> fine, but later I found out that it is not able to parse (some!) escaped
> unicode characters:
> 28> json_eep:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> ** exception error: bad argument
> ? ? in function ?list_to_binary/1
> ? ? ? ?called as list_to_binary([1075,1086,1088,1086,1076])
> ? ? in call from json_grammar:yeccpars2_9/7
> ? ? in call from json_grammar:yeccpars0/2
> ? ? in call from json_eep:json_to_term/1
>
> My guess is that just a little change near list_to_binary should fix the
> problem.

You are right in that the problem is the call to list_to_binary.
List_to_binary is a very low-level function as it expects its input to
be a, possibly nested, list of byte values, 0 - 255. Here, obviously,
this has not been done properly and the code is trying to call
list_to_binary with a list of the unicode codepoint values.

> Then I start investigation of other parsers. I found around 7. Most of
> them not eep0018 parsers. So I tried
> http://github.com/davisp/eep0018.git
> and
> http://github.com/dizzyd/eep0018.git (both are based on yajl).
>
> The former did not build for me because of some rebar issues. The latter
> did after some changes to Makefiles. A little problem with it is that I
> do not understand, how it decodes unicode:
> 1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> <<208,179,208,190,209,128,208,190,208,180>>

As I said earlier a binary is a sequence of bytes without any other
internal information and when you print a binary this is what you see,
the *bytes* of which it is composed. In this case each of the utf-8
encoded characters uses 2 bytes in big endian order, which is what you
see. Apparently it works as it should.

> PS And, just in case if anyone cares, none of these parsers implements
> json_to_term/2.

As yet there is no "standard" JSON parser and converter. Hopefully we
will see one soon, using NIFs it should be possible to do an efficient
one. If we can agree to the erlang representation. :-)

Robert

From doug.fort@REDACTED  Thu Jul 29 16:15:40 2010
From: doug.fort@REDACTED (Doug Fort)
Date: Thu, 29 Jul 2010 10:15:40 -0400
Subject: [erlang-questions] postgresql driver rewrite
In-Reply-To: <AANLkTimbt+kdOfFNXv9P24bRitC0WF7+=LLC6T_9DonN@mail.gmail.com>
References: <AANLkTimbt+kdOfFNXv9P24bRitC0WF7+=LLC6T_9DonN@mail.gmail.com>
Message-ID: <AANLkTimJB110hn9XF3uLdGSqtnQtKMgRiL1gQdLqg3Uw@mail.gmail.com>

On Thu, Jul 29, 2010 at 10:04 AM, Max Lapshin <max.lapshin@REDACTED> wrote:
> Hi. I was using pgsql driver, but found that it is absolutely non-OTP.
>
> I've started adding supervisors in it and now I'm in process of
> rewriting protocol to gen_fsm.
>
> Maybe there is already supported code, that doesn't require so many work?
>

Hi,

At SpiderOak we use epgsql. It seems plenty OTP to me.
http://github.com/wg/epgsql


> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>



-- 
Doug Fort, Consulting Programmer
http://www.dougfort.com

From juanjo@REDACTED  Thu Jul 29 17:15:31 2010
From: juanjo@REDACTED (Juan Jose Comellas)
Date: Thu, 29 Jul 2010 12:15:31 -0300
Subject: Reinserting a message into a gen_server's mailbox
Message-ID: <AANLkTimRAKSgmYvwW8B6qhQkyMK_NgzqF42NOSi+uahv@mail.gmail.com>

I have a situation where for one specific gen_server:call/2 invocation I
have to perform an action that may take a few seconds (e.g. reading from a
DB; reading from external files). I don't want to block the gen_server
process while I do this, so I want to spawn a helper process that takes care
of reading the data I need. The problem is that I can receive several
gen_server:call/2 invocations that depend on this data being present at the
same time and I don't want to have them fail because the data is not yet
ready. I've thought of two ways of solving this problem:

1) The "correct" one: keep the list of requests that come in while the data
is not ready and once I have the data in the helper process, notify the
gen_server process and do a gen_server:reply/2 with the response for each of
the pending requests.

2) The easy (non-kosher) one: while the data is not ready reinsert all the
requests (that depend on the data) that come into the gen_server process
back into its own mailbox (maybe with a little delay) and hope that when
they are processed again the data will be ready.

Does anybody see a problem with option 2? As far as I've seen, reinserting a
gen_server:call/2 request into the process' mailbox would be kind of a hack,
because according to the gen module, these messages have the following
format:

{'$gen_call', {pid(), ref()}, Request :: any()}

Does this format ever change? Can I rely on it not to change in the future?

Thanks,

Juanjo.

From gleber.p@REDACTED  Thu Jul 29 17:22:28 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Thu, 29 Jul 2010 17:22:28 +0200
Subject: [erlang-questions] postgresql driver rewrite
In-Reply-To: <AANLkTimJB110hn9XF3uLdGSqtnQtKMgRiL1gQdLqg3Uw@mail.gmail.com>
References: <AANLkTimbt+kdOfFNXv9P24bRitC0WF7+=LLC6T_9DonN@mail.gmail.com> 
	<AANLkTimJB110hn9XF3uLdGSqtnQtKMgRiL1gQdLqg3Uw@mail.gmail.com>
Message-ID: <AANLkTi=Y7m-ZYcN0PqmegRMO8iRH-aD5Q=vYfLVMshHQ@mail.gmail.com>

> At SpiderOak we use epgsql. It seems plenty OTP to me.
> http://github.com/wg/epgsql

We use this driver too in our company. Works really well

Best,
Gleb Peregud

From ngreco@REDACTED  Thu Jul 29 17:42:02 2010
From: ngreco@REDACTED (Nahuel Greco)
Date: Thu, 29 Jul 2010 12:42:02 -0300
Subject: Closures across module reloads, undocumented behavior?
Message-ID: <AANLkTi=NTu-c4OqNgT+5D28_5apuWc1VERpa=+86ZA=4@mail.gmail.com>

I found an strange behavior, probably undocumented:

1- Load a 'm' module (first version).
2- Start a process P1 whose initial function is m:a/1, this function
creates a closure that calls m:version/0 directly (not fully
qualified).
3- The closure is executed once, shows it calls the first version of
m:version/0, and is keep in memory by P1.
4- The source code of m is modified, m is compiled and the new version
is loaded.

Now, the strange thing is:

5- The same closure instance of step 3 is executed again by P1, but
what version of m:version/0 is called _depends on the changes_ made in
step 4. Also, I found you can change the bound values of the closure.

Detailing (see attached files):

Test 2:
- step 4: the m:version/0 function body is changed.
- step 5: then the closure will use the _NEW_ version of m:version/0.

Test 3:
- step 4: the name of m:version/0 is redefined to m:another_version/0,
and the closure body is redefined to call another_version/0.
- step 5: then the closure will call the _OLD_ version of m:version/0.

Test 4:
- step 4: a literal is changed inside the closure body.
- step 5: then the closure will use the _OLD_ version of m:version/0.

Test 5:
- step 4: the value bound from the closure is changed
- step 5: then closure will use the _NEW_ version of m:/version/0 with
the _NEW_ value.

I don't find a clear semantic and I didn't found any documentation
about this. What are the defined semantics for closures across module
reloads?

I'm attaching a test.erl file, it compiles and loads/reloads the many
versions of 'm', executing the tests 2-5 detailed before. The original
m version loaded in step 1 is m__base.erl and the one loaded in step 4
is m__[2-5].erl.

Output:

Erlang R13B04 (erts-5.7.5) [source] [smp:2:2] [rq:2] [async-threads:0]
[kernel-poll:false]
Eshell V5.7.5  (abort with ^G)
1> c(test).
{ok,test}
2> test:start().

- Unloading m old and current
- Loading m__base and starting process
Started a() from version 1
>From closure, version() -> 1, B -> first
- Loaded m__2 , differences with base: Increments the version
- Continuing process
>From closure, version() -> 2, B -> first

- Unloading m old and current
- Loading m__base and starting process
Started a() from version 1
>From closure, version() -> 1, B -> first
- Loaded m__3 , differences with base: Increments the version,
version/0 changed to another_version/0
- Continuing process
>From closure, version() -> 1, B -> first

- Unloading m old and current
- Loading m__base and starting process
Started a() from version 1
>From closure, version() -> 1, B -> first
- Loaded m__4 , differences with base: Increments the version, changed
text literal in closure
- Continuing process
>From closure, version() -> 1, B -> first

- Unloading m old and current
- Loading m__base and starting process
Started a() from version 1
>From closure, version() -> 1, B -> first
- Loaded m__5 , differences with base: Increments the version, changed
B assigned atom to 'second'
- Continuing process
>From closure, version() -> 2, B -> second
[undef,undef,undef,undef]
3>


Saludos,
Nahuel Greco.
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From gleber.p@REDACTED  Thu Jul 29 17:55:28 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Thu, 29 Jul 2010 17:55:28 +0200
Subject: [erlang-questions] Reinserting a message into a gen_server's 
	mailbox
In-Reply-To: <AANLkTimRAKSgmYvwW8B6qhQkyMK_NgzqF42NOSi+uahv@mail.gmail.com>
References: <AANLkTimRAKSgmYvwW8B6qhQkyMK_NgzqF42NOSi+uahv@mail.gmail.com>
Message-ID: <AANLkTik5_VqivxKvFqWuZ5Yp0FGT9RR0zJ5s7QHMU+-c@mail.gmail.com>

On Thu, Jul 29, 2010 at 17:15, Juan Jose Comellas <juanjo@REDACTED> wrote:
> 1) The "correct" one: keep the list of requests that come in while the data
> is not ready and once I have the data in the helper process, notify the
> gen_server process and do a gen_server:reply/2 with the response for each of
> the pending requests.
AFAIK there is no need to do gen_server:reply/2 from the gen_server
itself - one can send reply from absolutely any process. So just
proc_lib:spawn_link/1 a worker process for long tasks and do
gen_server:reply/2 in it when it finishes the task. In fact there is
even no need to store a list of requests in gen_server.

> 2) The easy (non-kosher) one: while the data is not ready reinsert all the
> requests (that depend on the data) that come into the gen_server process
> back into its own mailbox (maybe with a little delay) and hope that when
> they are processed again the data will be ready.
This is a form of polling. Why do you want one? "Correct" solution is
much-much more elegant and efficient. I can't see a situation when
this solution would be better...

Best,
Gleb Peregud

From james.aimonetti@REDACTED  Thu Jul 29 18:00:59 2010
From: james.aimonetti@REDACTED (James Aimonetti)
Date: Thu, 29 Jul 2010 09:00:59 -0700
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTinTp=AFRckuyb+5=kVpy+oiXXDKgY_xwwQW+7EM@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
	<AANLkTin5Ef2=vCmHS4AP7Fgo7_OcmS7212yGdupUSKwK@mail.gmail.com>
	<AANLkTimtAVD4O8pvMdfQ41oN7GQzvQKqpS63=GsJif8h@mail.gmail.com>
	<AANLkTinTp=AFRckuyb+5=kVpy+oiXXDKgY_xwwQW+7EM@mail.gmail.com>
Message-ID: <AANLkTikGc21ZgCnYHsxmsTqzTiRcCY6eL4jyg5axSvBU@mail.gmail.com>

I found Chris Okasaki's Purely Functional Data Structures to be
helpful in expanding my Erlang, data structures (duh), and functional
programming skills as well. Sometimes the conversion from imperative
to functional doesn't match up and this book helped bridge the gap a
bit. I should probably dust it off and go through it again :)

On Thu, Jul 29, 2010 at 5:22 AM, Brian Williams <mixolyde@REDACTED> wrote:
> This is essentially what I'm doing, but using the undefined atom. Leaf
> technically is a node that has a value, but no children. it's not
> really the name of an empty left or right node pointer. Here, new_node
> generates a leaf.
>
> new_node(Value) ->
> ? ?#btreenode{left = undefined, right = undefined, value = Value}.
>
> insert([], Tree) -> Tree;
> insert([Head | Tail], Tree) -> insert(Tail, insert(Head, Tree));
> insert(Value, undefined) -> new_node(Value);
> insert(Value, Tree = #btreenode{value = Value}) -> Tree;
> insert(Value, #btreenode{left = Left, right = Right, value = CurrentValue})
> ? ?when Value < CurrentValue ->
> ? ? ? ?#btreenode{left = insert(Value, Left), right = Right, value =
> CurrentValue};
> insert(Value, #btreenode{left = Left, right = Right, value = CurrentValue})
> ? ?when Value > CurrentValue ->
> ? ? ? ?#btreenode{left = Left, right = insert(Value, Right), value =
> CurrentValue}.
>
> Writing somre more complicated operations and homework assignments
> next. I have found rewriting old homework assignments from Algorithms
> and AI classes to be very helpful in teaching myself the language.
>
> On Thu, Jul 29, 2010 at 7:17 AM, Fredrik Andersson <sedrik@REDACTED> wrote:
>> On Wed, Jul 28, 2010 at 7:39 PM, Tony Arcieri <tony.arcieri@REDACTED> wrote:
>>> On Tue, Jul 27, 2010 at 1:28 PM, Brian Williams <mixolyde@REDACTED> wrote:
>>>
>>>> I'm working on some algorithm analysis and am trying to define a
>>>> fairly simple binary search tree with a record definition:
>>>> -record(btreenode, {left = #btreenode{}, right = #btreenode{}, value}).
>>>
>>>
>>> Wouldn't you want the defaults to be for the leaf nodes, and if so,
>>> shouldn't they be some sort of nil/null/void atom to indicate there are no
>>> left/right branches?
>>>
>>> --
>>> Tony Arcieri
>>> Medioh! A Kudelski Brand
>>>
>>
>> Why not even make them the atom leaf? :)
>>
>
>
>
> --
> Brian E. Williams
> mixolyde@REDACTED
> http://www.techhouse.us/wordpress-mu/brianw
>
> "Never attribute to malice that which can be adequately
> explained by stupidity." - Hanlon's Razor
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From g9414002.pccu.edu.tw@REDACTED  Thu Jul 29 18:16:50 2010
From: g9414002.pccu.edu.tw@REDACTED (=?UTF-8?B?6buD6ICA6LOiIChZYXUtSHNpZW4gSHVhbmcp?=)
Date: Fri, 30 Jul 2010 00:16:50 +0800
Subject: [erlang-questions] Are recursive record definitions allowed?
In-Reply-To: <AANLkTikGc21ZgCnYHsxmsTqzTiRcCY6eL4jyg5axSvBU@mail.gmail.com>
References: <AANLkTimyXFKSUAm3fPhK5qR9-65d7NQnqKg_HPQw6Exw@mail.gmail.com>
	<AANLkTin5Ef2=vCmHS4AP7Fgo7_OcmS7212yGdupUSKwK@mail.gmail.com>
	<AANLkTimtAVD4O8pvMdfQ41oN7GQzvQKqpS63=GsJif8h@mail.gmail.com>
	<AANLkTinTp=AFRckuyb+5=kVpy+oiXXDKgY_xwwQW+7EM@mail.gmail.com>
	<AANLkTikGc21ZgCnYHsxmsTqzTiRcCY6eL4jyg5axSvBU@mail.gmail.com>
Message-ID: <AANLkTinGU=_d2KerPNNt2rUYUc7KuUgrkS-N9BmLOv1H@mail.gmail.com>

And you can try the book "Algorithms: A Functional Programming Approach."
Essential functional programming techniques.

On Fri, Jul 30, 2010 at 12:00 AM, James Aimonetti <james.aimonetti@REDACTED
> wrote:

> I found Chris Okasaki's Purely Functional Data Structures to be
> helpful in expanding my Erlang, data structures (duh), and functional
> programming skills as well. Sometimes the conversion from imperative
> to functional doesn't match up and this book helped bridge the gap a
> bit. I should probably dust it off and go through it again :)
>
> On Thu, Jul 29, 2010 at 5:22 AM, Brian Williams <mixolyde@REDACTED>
> wrote:
> > This is essentially what I'm doing, but using the undefined atom. Leaf
> > technically is a node that has a value, but no children. it's not
> > really the name of an empty left or right node pointer. Here, new_node
> > generates a leaf.
> >
> > new_node(Value) ->
> >    #btreenode{left = undefined, right = undefined, value = Value}.
> >
> > insert([], Tree) -> Tree;
> > insert([Head | Tail], Tree) -> insert(Tail, insert(Head, Tree));
> > insert(Value, undefined) -> new_node(Value);
> > insert(Value, Tree = #btreenode{value = Value}) -> Tree;
> > insert(Value, #btreenode{left = Left, right = Right, value =
> CurrentValue})
> >    when Value < CurrentValue ->
> >        #btreenode{left = insert(Value, Left), right = Right, value =
> > CurrentValue};
> > insert(Value, #btreenode{left = Left, right = Right, value =
> CurrentValue})
> >    when Value > CurrentValue ->
> >        #btreenode{left = Left, right = insert(Value, Right), value =
> > CurrentValue}.
> >
> > Writing somre more complicated operations and homework assignments
> > next. I have found rewriting old homework assignments from Algorithms
> > and AI classes to be very helpful in teaching myself the language.
> >
> > On Thu, Jul 29, 2010 at 7:17 AM, Fredrik Andersson <sedrik@REDACTED>
> wrote:
> >> On Wed, Jul 28, 2010 at 7:39 PM, Tony Arcieri <tony.arcieri@REDACTED>
> wrote:
> >>> On Tue, Jul 27, 2010 at 1:28 PM, Brian Williams <mixolyde@REDACTED>
> wrote:
> >>>
> >>>> I'm working on some algorithm analysis and am trying to define a
> >>>> fairly simple binary search tree with a record definition:
> >>>> -record(btreenode, {left = #btreenode{}, right = #btreenode{},
> value}).
> >>>
> >>>
> >>> Wouldn't you want the defaults to be for the leaf nodes, and if so,
> >>> shouldn't they be some sort of nil/null/void atom to indicate there are
> no
> >>> left/right branches?
> >>>
> >>> --
> >>> Tony Arcieri
> >>> Medioh! A Kudelski Brand
> >>>
> >>
> >> Why not even make them the atom leaf? :)
> >>
> >
> >
> >
> > --
> > Brian E. Williams
> > mixolyde@REDACTED
> > http://www.techhouse.us/wordpress-mu/brianw
> >
> > "Never attribute to malice that which can be adequately
> > explained by stupidity." - Hanlon's Razor
> >
> > ________________________________________________________________
> > erlang-questions (at) erlang.org mailing list.
> > See http://www.erlang.org/faq.html
> > To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
> >
> >
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From MARTIN.LOGAN@REDACTED  Thu Jul 29 18:22:06 2010
From: MARTIN.LOGAN@REDACTED (Logan, Martin)
Date: Thu, 29 Jul 2010 11:22:06 -0500
Subject: The most efficient way to make sure a remote process is alive
Message-ID: <C87714DE.3CDC%martin.logan@orbitz.com>

I am looking for the absolute most efficient way to make sure a process, referenced by a pid I have, is alive. The process my pid references could of course be local or remote. There are lots of ways but I want the most efficient and I can't assume any application level code - this must be generic. Thoughts?

Cheers,
Martin

From max.lapshin@REDACTED  Thu Jul 29 20:36:07 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Thu, 29 Jul 2010 22:36:07 +0400
Subject: [erlang-questions] postgresql driver rewrite
In-Reply-To: <AANLkTi=Y7m-ZYcN0PqmegRMO8iRH-aD5Q=vYfLVMshHQ@mail.gmail.com>
References: <AANLkTimbt+kdOfFNXv9P24bRitC0WF7+=LLC6T_9DonN@mail.gmail.com>
	<AANLkTimJB110hn9XF3uLdGSqtnQtKMgRiL1gQdLqg3Uw@mail.gmail.com>
	<AANLkTi=Y7m-ZYcN0PqmegRMO8iRH-aD5Q=vYfLVMshHQ@mail.gmail.com>
Message-ID: <AANLkTi=0hsX7fWk2x+Ux4rhYtY1uwF=V54KwYM97WezE@mail.gmail.com>

It seems to have api just like in pgsql and it is newer. Ok, thank you
and I will take a look at this driver.

From alisdairsullivan@REDACTED  Thu Jul 29 20:16:54 2010
From: alisdairsullivan@REDACTED (alisdair sullivan)
Date: Thu, 29 Jul 2010 11:16:54 -0700 (PDT)
Subject: Fw: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com>
References: <87eiemmzkr.fsf@benington.loc> <AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com>
Message-ID: <201597.67877.qm@web63605.mail.re1.yahoo.com>





----- Forwarded Message ----
From: alisdair sullivan <alisdairsullivan@REDACTED>
To: Robert Virding <rvirding@REDACTED>
Sent: Thu, July 29, 2010 11:15:44 AM
Subject: Re: [erlang-questions] Which Erlang JSON parser?


I have an (undocumented) json parser at http://github.com/talentdeficit/json. it 
implements the interface recommended in eep0018 with a few additions. it also 
parses naked json values (ie, 'true', 'false', '1', '"a string"') when passed 
the option {strict, false} (default true) and (c style, /* ... */) comments when 
passed the option {comments, true} (default false). the encoder will encode 
naked json values when passed the option {strict, false} also.

it relies on jsx (available at http://github.com/talentdeficit/jsx), my port of 
yajl to erlang.

to install jsx into ERL_LIBS, run 'make', './rebar install'. to install json, 
run  './rebar compile' then './rebar install'. (froom the roots of the 
respective projects).

I'm working on documentation, but I hadn't planned to 'go public' quite yet. I'm 
confident in the underlying jsx project, less so on json, though we've been 
using the decoder in production with no problems yet.


On 29 July 2010 11:01, Alexander Kotelnikov <sacha@REDACTED> wrote:
> Hello.
>
> It is a terrible story. I needed a JSON parcer to deal with JSON data in
> my Erlang programm.
>
> At first I picked json_eep
> (http://github.com/jchris/erlang-json-eep-parser.git) which worked quite
> fine,  but later I found out that it is not able to parse (some!) escaped
> unicode characters:
> 28> json_eep:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> ** exception error: bad argument
>     in function  list_to_binary/1
>        called as list_to_binary([1075,1086,1088,1086,1076])
>     in call from json_grammar:yeccpars2_9/7
>     in call from json_grammar:yeccpars0/2
>     in call from json_eep:json_to_term/1
>
> My guess is that just a little change near list_to_binary should fix the
> problem.

You are right in that the problem is the call to list_to_binary.
List_to_binary is a very low-level function as it expects its input to
be a, possibly nested, list of byte values, 0 - 255. Here, obviously,
this has not been done properly and the code is trying to call
list_to_binary with a list of  the unicode codepoint values.

> Then I start investigation of other parsers. I found around 7. Most of
> them not eep0018 parsers. So I tried
> http://github.com/davisp/eep0018.git
> and
> http://github.com/dizzyd/eep0018.git (both are based on yajl).
>
> The former did not build for me because of some rebar issues. The latter
> did after some changes to Makefiles. A little problem with it is that I
> do not understand, how it decodes unicode:
> 1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> <<208,179,208,190,209,128,208,190,208,180>>

As I said earlier a binary is a sequence of bytes without any other
internal information and when you print a binary this is what you see,
the *bytes* of which it is  composed. In this case each of the utf-8
encoded characters uses 2 bytes in big endian order, which is what you
see. Apparently it works as it should.

> PS And, just in case if anyone cares, none of these parsers implements
> json_to_term/2.

As yet there is no "standard" JSON parser and converter. Hopefully we
will see one soon, using NIFs it should be possible to do an efficient
one. If we can agree to the erlang representation. :-)

Robert

________________________________________________________________
erlang-questions (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED


From juanjo@REDACTED  Thu Jul 29 21:31:18 2010
From: juanjo@REDACTED (Juan Jose Comellas)
Date: Thu, 29 Jul 2010 16:31:18 -0300
Subject: [erlang-questions] Reinserting a message into a gen_server's 
	mailbox
In-Reply-To: <AANLkTik5_VqivxKvFqWuZ5Yp0FGT9RR0zJ5s7QHMU+-c@mail.gmail.com>
References: <AANLkTimRAKSgmYvwW8B6qhQkyMK_NgzqF42NOSi+uahv@mail.gmail.com>
	<AANLkTik5_VqivxKvFqWuZ5Yp0FGT9RR0zJ5s7QHMU+-c@mail.gmail.com>
Message-ID: <AANLkTikFbn=p3khCsF4t2w8+Quvdc9-ehMXfqkizTY+J@mail.gmail.com>

I'm aware that I can do a gen_server:reply/2 from any process, but I was
planning on issuing the gen_server:reply/2 calls from the gen_server process
because that's where I'll be queueing up the requests.

You're right, the second option is a form of polling, but it makes the code
simpler, and I only have to load the external data once from the gen_server
process, so it wouldn't have mattered that much.

Anyway, thanks for your comments, I'll probably end up doing it in the
correct way.

I'm still curious, though, does the format of these internal messages ever
change? What happens if I use two different Erlang/OTP versions in my nodes?
Does the newer VM/library still accept the old version of the messages?


On Thu, Jul 29, 2010 at 12:55 PM, Gleb Peregud <gleber.p@REDACTED> wrote:

> On Thu, Jul 29, 2010 at 17:15, Juan Jose Comellas <juanjo@REDACTED>
> wrote:
> > 1) The "correct" one: keep the list of requests that come in while the
> data
> > is not ready and once I have the data in the helper process, notify the
> > gen_server process and do a gen_server:reply/2 with the response for each
> of
> > the pending requests.
> AFAIK there is no need to do gen_server:reply/2 from the gen_server
> itself - one can send reply from absolutely any process. So just
> proc_lib:spawn_link/1 a worker process for long tasks and do
> gen_server:reply/2 in it when it finishes the task. In fact there is
> even no need to store a list of requests in gen_server.
>
> > 2) The easy (non-kosher) one: while the data is not ready reinsert all
> the
> > requests (that depend on the data) that come into the gen_server process
> > back into its own mailbox (maybe with a little delay) and hope that when
> > they are processed again the data will be ready.
> This is a form of polling. Why do you want one? "Correct" solution is
> much-much more elegant and efficient. I can't see a situation when
> this solution would be better...
>
> Best,
> Gleb Peregud
>

From gleber.p@REDACTED  Thu Jul 29 21:37:56 2010
From: gleber.p@REDACTED (Gleb Peregud)
Date: Thu, 29 Jul 2010 21:37:56 +0200
Subject: [erlang-questions] Reinserting a message into a gen_server's 
	mailbox
In-Reply-To: <AANLkTikFbn=p3khCsF4t2w8+Quvdc9-ehMXfqkizTY+J@mail.gmail.com>
References: <AANLkTimRAKSgmYvwW8B6qhQkyMK_NgzqF42NOSi+uahv@mail.gmail.com> 
	<AANLkTik5_VqivxKvFqWuZ5Yp0FGT9RR0zJ5s7QHMU+-c@mail.gmail.com> 
	<AANLkTikFbn=p3khCsF4t2w8+Quvdc9-ehMXfqkizTY+J@mail.gmail.com>
Message-ID: <AANLkTimqhjT36E0eJ0=fYuzp5g05YYixv_gBpExyeL=z@mail.gmail.com>

On Thu, Jul 29, 2010 at 21:31, Juan Jose Comellas <juanjo@REDACTED> wrote:
> I'm aware that I can do a gen_server:reply/2 from any process, but I was
> planning on issuing the gen_server:reply/2 calls from the gen_server process
> because that's where I'll be queueing up the requests.

Do you need this for doing some kind of throttling? Or to make sure
that these requests are processed one by one serially?

> I'm still curious, though, does the format of these internal messages ever
> change? What happens if I use two different Erlang/OTP versions in my nodes?
> Does the newer VM/library still accept the old version of the messages?

gen_* message format is not documented. So there are no guarantees
that they will not change, so you shouldn't rely on them unless you
are ready to take the risk. AFAIR there's a promise that nodes which
major version differ by one will work together in a cluster (e.g. R13
would work with R14).

Best,
Gleb Peregud

From sacha@REDACTED  Thu Jul 29 21:07:15 2010
From: sacha@REDACTED (Alexander Kotelnikov)
Date: Thu, 29 Jul 2010 23:07:15 +0400
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com> (Robert
 Virding's message of "Thu, 29 Jul 2010 16:05:56 +0200")
References: <87eiemmzkr.fsf@benington.loc>
	<AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com>
Message-ID: <85eiemjee4.fsf@myxomop.com>

>>>>> On Thu, 29 Jul 2010 16:05:56 +0200
>>>>> "RV" == Robert Virding <rvirding@REDACTED> wrote:
RV> 
>> The former did not build for me because of some rebar issues. The latter
>> did after some changes to Makefiles. A little problem with it is that I
>> do not understand, how it decodes unicode:
1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
>> <<208,179,208,190,209,128,208,190,208,180>>
RV> 
RV> As I said earlier a binary is a sequence of bytes without any other
RV> internal information and when you print a binary this is what you see,
RV> the *bytes* of which it is composed. In this case each of the utf-8
RV> encoded characters uses 2 bytes in big endian order, which is what you
RV> see. Apparently it works as it should.

Really?

5> (208 bsl 8) + 179.
53427
6> 16#433.
1075

I guess, something is wrong.

From sacha@REDACTED  Thu Jul 29 21:11:39 2010
From: sacha@REDACTED (Alexander Kotelnikov)
Date: Thu, 29 Jul 2010 23:11:39 +0400
Subject: Fw: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <201597.67877.qm@web63605.mail.re1.yahoo.com> (alisdair
 sullivan's message of "Thu, 29 Jul 2010 11:16:54 -0700 (PDT)")
References: <87eiemmzkr.fsf@benington.loc>
	<AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com>
	<201597.67877.qm@web63605.mail.re1.yahoo.com>
Message-ID: <857hkeje6s.fsf@myxomop.com>

>>>>> On Thu, 29 Jul 2010 11:16:54 -0700 (PDT)
>>>>> "as" == alisdair sullivan <alisdairsullivan@REDACTED> wrote:
as> 
as> it relies on jsx (available at http://github.com/talentdeficit/jsx), my port of 
as> yajl to erlang.

So it tends to be at least fourth eep-0018 parser, third based on
yajl.


From paul.joseph.davis@REDACTED  Thu Jul 29 22:19:43 2010
From: paul.joseph.davis@REDACTED (Paul Davis)
Date: Thu, 29 Jul 2010 16:19:43 -0400
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <87eiemmzkr.fsf@benington.loc>
References: <87eiemmzkr.fsf@benington.loc>
Message-ID: <AANLkTi=wQND84+tUmZ-cx+gNZaBTT7OQL3CPO=3rptgj@mail.gmail.com>

On Thu, Jul 29, 2010 at 5:01 AM, Alexander Kotelnikov <sacha@REDACTED> wrote:
> Hello.
>
> It is a terrible story. I needed a JSON parcer to deal with JSON data in
> my Erlang programm.
>
> At first I picked json_eep
> (http://github.com/jchris/erlang-json-eep-parser.git) which worked quite
> fine, but later I found out that it is not able to parse (some!) escaped
> unicode characters:
> 28> json_eep:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> ** exception error: bad argument
> ? ? in function ?list_to_binary/1
> ? ? ? ?called as list_to_binary([1075,1086,1088,1086,1076])
> ? ? in call from json_grammar:yeccpars2_9/7
> ? ? in call from json_grammar:yeccpars0/2
> ? ? in call from json_eep:json_to_term/1
>
> My guess is that just a little change near list_to_binary should fix the
> problem.
>
>
> Then I start investigation of other parsers. I found around 7. Most of
> them not eep0018 parsers. So I tried
> http://github.com/davisp/eep0018.git
> and
> http://github.com/dizzyd/eep0018.git (both are based on yajl).
>
> The former did not build for me because of some rebar issues. The latter
> did after some changes to Makefiles. A little problem with it is that I
> do not understand, how it decodes unicode:
> 1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> <<208,179,208,190,209,128,208,190,208,180>>
>
> Probably authors of these modules read this list and will clarify and/or
> fix if there is something to fix.
>
> Thanks, A.
>
> PS And, just in case if anyone cares, none of these parsers implements
> json_to_term/2.
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

Alexander,

I'm the author of http://github.com/davisp/eep0018.git If you send me
any of the rebar errors you had while building I can take a look. I
haven't heard of anyone having issues with it, but my first guess is
that its an issue with which version of Erlang you're using. If memory
serves, that version requires R13B and hasn't been upgraded to R14 NIF
api yet.

I think the issue you're having with the unicode decoding is that most
decoders are going to return a UTF-8 encoded string by default. To get
a list of unicode code points you'll need to do something like:

{ok, Bin} = json:decode("\"\\u0433\\u043e\\u0440\\u043e\\u0434\""),
CodePoints = xmerl_ucs:from_utf8(Bin).


As to EEP0018 parsers, I don't really think there's a single parser
that you can point to as most compliant. The EEP itself is mostly a
collection of all the various points of disagreement in the
implementations that existed at the time. Until someone's parser
either gets included in the standard library, or just gains enough
common usage I doubt there will ever be a finalized version of what's
EEP compliant and what's not.

If you're looking for a good JSON parser, I would recommend either the
mochijson2.erl parser or one of the C implementations. mochijson2 is
pretty solid and has been tested extensively. The C based ones can
give some pretty good speedups for large decoding operatiosn though,
so that might be a motivaton against. And IIRC, Alisdair's latest
decoder is stream based so you can use it for incremental parsing if
you need that.

HTH,
Paul

From juanjo@REDACTED  Thu Jul 29 23:04:19 2010
From: juanjo@REDACTED (Juan Jose Comellas)
Date: Thu, 29 Jul 2010 18:04:19 -0300
Subject: [erlang-questions] Reinserting a message into a gen_server's 
	mailbox
In-Reply-To: <AANLkTimqhjT36E0eJ0=fYuzp5g05YYixv_gBpExyeL=z@mail.gmail.com>
References: <AANLkTimRAKSgmYvwW8B6qhQkyMK_NgzqF42NOSi+uahv@mail.gmail.com>
	<AANLkTik5_VqivxKvFqWuZ5Yp0FGT9RR0zJ5s7QHMU+-c@mail.gmail.com>
	<AANLkTikFbn=p3khCsF4t2w8+Quvdc9-ehMXfqkizTY+J@mail.gmail.com>
	<AANLkTimqhjT36E0eJ0=fYuzp5g05YYixv_gBpExyeL=z@mail.gmail.com>
Message-ID: <AANLkTinvSzHOtRZ0uOEDjJn18VTW=Yt0phvP8otiSVa4@mail.gmail.com>

On Thu, Jul 29, 2010 at 4:37 PM, Gleb Peregud <gleber.p@REDACTED> wrote:

> On Thu, Jul 29, 2010 at 21:31, Juan Jose Comellas <juanjo@REDACTED>
> wrote:
> > I'm aware that I can do a gen_server:reply/2 from any process, but I was
> > planning on issuing the gen_server:reply/2 calls from the gen_server
> process
> > because that's where I'll be queueing up the requests.
>
> Do you need this for doing some kind of throttling? Or to make sure
> that these requests are processed one by one serially?
>

Just to make sure that the requests are processed sequentially in the order
they were received.



> > I'm still curious, though, does the format of these internal messages
> ever
> > change? What happens if I use two different Erlang/OTP versions in my
> nodes?
> > Does the newer VM/library still accept the old version of the messages?
>
> gen_* message format is not documented. So there are no guarantees
> that they will not change, so you shouldn't rely on them unless you
> are ready to take the risk. AFAIR there's a promise that nodes which
> major version differ by one will work together in a cluster (e.g. R13
> would work with R14).
>

Have you seen this "promise" documented anywhere? I've always been hesitant
to have different Erlang versions in the nodes that run as a single system
specifically because I was not sure which versions were compatible at the
message format level.


Best,
> Gleb Peregud
>


Juanjo.

From vinoski@REDACTED  Thu Jul 29 23:10:50 2010
From: vinoski@REDACTED (Steve Vinoski)
Date: Thu, 29 Jul 2010 17:10:50 -0400
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <85eiemjee4.fsf@myxomop.com>
References: <87eiemmzkr.fsf@benington.loc>
	<AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com>
	<85eiemjee4.fsf@myxomop.com>
Message-ID: <AANLkTi=s3vubwQ6iognY5f=pxgJk8T4Me5xQ8RL2B7Yj@mail.gmail.com>

On Thu, Jul 29, 2010 at 3:07 PM, Alexander Kotelnikov <sacha@REDACTED> wrote:
>>>>>> On Thu, 29 Jul 2010 16:05:56 +0200
>>>>>> "RV" == Robert Virding <rvirding@REDACTED> wrote:
> RV>
>>> The former did not build for me because of some rebar issues. The latter
>>> did after some changes to Makefiles. A little problem with it is that I
>>> do not understand, how it decodes unicode:
> 1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
>>> <<208,179,208,190,209,128,208,190,208,180>>
> RV>
> RV> As I said earlier a binary is a sequence of bytes without any other
> RV> internal information and when you print a binary this is what you see,
> RV> the *bytes* of which it is composed. In this case each of the utf-8
> RV> encoded characters uses 2 bytes in big endian order, which is what you
> RV> see. Apparently it works as it should.
>
> Really?
>
> 5> (208 bsl 8) + 179.
> 53427
> 6> 16#433.
> 1075
>
> I guess, something is wrong.

These calculations don't reflect how character U+0433 is properly
UTF-8 encoded. The two bytes required for this character can be
calculated as follows:

1> ((16#433 bsr 6) band 16#1F) bor 16#C0.
208
2> (16#433 band 16#3F) bor 16#80.
179

which is what the binary from json_to_term above contains. See
<http://en.wikipedia.org/wiki/UTF-8> for details.

--steve

From MARTIN.LOGAN@REDACTED  Fri Jul 30 00:11:41 2010
From: MARTIN.LOGAN@REDACTED (Logan, Martin)
Date: Thu, 29 Jul 2010 17:11:41 -0500
Subject: [erlang-questions] The most efficient way to make sure a remote
 process is alive
In-Reply-To: <2CA18EC0-331D-4EFB-8812-B7CE9377F268@alertlogic.com>
Message-ID: <C87766CD.3D3A%martin.logan@orbitz.com>

Agreed on that count but I don't have that option.  is_process_alive is nice but only for local processes. I was thinking the function would use that first to determine if the process is alive and local, if that fails then some more time consuming check would be needed.  I can use node/1 to figure out what node it is on and then check to see if that node is within nodes() and if it is not, then I know the process is dead.  Provided that all those checks pass though then what am I left with - needing to do an rpc call on is_process_alive?  Any clever ideas, some interface I don't know of?


On 7/29/10 11:46 AM, "Paul Fisher" <pfisher@REDACTED> wrote:

The best way i have found is to create a relay process locally, that monitors the remote one, forwards messages, and exits on DOWN.   Then u can use erlang:is_process_alive/1 on the local one.  Still a race when it is dying, but that is there for local processes too.

On Jul 29, 2010, at 11:22 AM, Logan, Martin wrote:

> I am looking for the absolute most efficient way to make sure a process, referenced by a pid I have, is alive. The process my pid references could of course be local or remote. There are lots of ways but I want the most efficient and I can't assume any application level code - this must be generic. Thoughts?
>
> Cheers,
> Martin

--
paul



From MARTIN.LOGAN@REDACTED  Fri Jul 30 00:13:55 2010
From: MARTIN.LOGAN@REDACTED (Logan, Martin)
Date: Thu, 29 Jul 2010 17:13:55 -0500
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <201597.67877.qm@web63605.mail.re1.yahoo.com>
Message-ID: <C8776753.3D3C%martin.logan@orbitz.com>

Ktuo is a really good one. Either the latest incarnation or the very next one will support either native erlang parsing logic or when present highly optimized C logic. This makes it very flexible. The interface is quite simple and the app is easily installable with faxien which you can get from erlware.org..

Cheers,
Martin


On 7/29/10 1:16 PM, "alisdair sullivan" <alisdairsullivan@REDACTED> wrote:






----- Forwarded Message ----
From: alisdair sullivan <alisdairsullivan@REDACTED>
To: Robert Virding <rvirding@REDACTED>
Sent: Thu, July 29, 2010 11:15:44 AM
Subject: Re: [erlang-questions] Which Erlang JSON parser?


I have an (undocumented) json parser at http://github.com/talentdeficit/json. it
implements the interface recommended in eep0018 with a few additions. it also
parses naked json values (ie, 'true', 'false', '1', '"a string"') when passed
the option {strict, false} (default true) and (c style, /* ... */) comments when
passed the option {comments, true} (default false). the encoder will encode
naked json values when passed the option {strict, false} also.

it relies on jsx (available at http://github.com/talentdeficit/jsx), my port of
yajl to erlang.

to install jsx into ERL_LIBS, run 'make', './rebar install'. to install json,
run  './rebar compile' then './rebar install'. (froom the roots of the
respective projects).

I'm working on documentation, but I hadn't planned to 'go public' quite yet. I'm
confident in the underlying jsx project, less so on json, though we've been
using the decoder in production with no problems yet.


On 29 July 2010 11:01, Alexander Kotelnikov <sacha@REDACTED> wrote:
> Hello.
>
> It is a terrible story. I needed a JSON parcer to deal with JSON data in
> my Erlang programm.
>
> At first I picked json_eep
> (http://github.com/jchris/erlang-json-eep-parser.git) which worked quite
> fine,  but later I found out that it is not able to parse (some!) escaped
> unicode characters:
> 28> json_eep:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> ** exception error: bad argument
>     in function  list_to_binary/1
>        called as list_to_binary([1075,1086,1088,1086,1076])
>     in call from json_grammar:yeccpars2_9/7
>     in call from json_grammar:yeccpars0/2
>     in call from json_eep:json_to_term/1
>
> My guess is that just a little change near list_to_binary should fix the
> problem.

You are right in that the problem is the call to list_to_binary.
List_to_binary is a very low-level function as it expects its input to
be a, possibly nested, list of byte values, 0 - 255. Here, obviously,
this has not been done properly and the code is trying to call
list_to_binary with a list of  the unicode codepoint values.

> Then I start investigation of other parsers. I found around 7. Most of
> them not eep0018 parsers. So I tried
> http://github.com/davisp/eep0018.git
> and
> http://github.com/dizzyd/eep0018.git (both are based on yajl).
>
> The former did not build for me because of some rebar issues. The latter
> did after some changes to Makefiles. A little problem with it is that I
> do not understand, how it decodes unicode:
> 1> eep0018:json_to_term("\"\\u0433\\u043e\\u0440\\u043e\\u0434\"").
> <<208,179,208,190,209,128,208,190,208,180>>

As I said earlier a binary is a sequence of bytes without any other
internal information and when you print a binary this is what you see,
the *bytes* of which it is  composed. In this case each of the utf-8
encoded characters uses 2 bytes in big endian order, which is what you
see. Apparently it works as it should.

> PS And, just in case if anyone cares, none of these parsers implements
> json_to_term/2.

As yet there is no "standard" JSON parser and converter. Hopefully we
will see one soon, using NIFs it should be possible to do an efficient
one. If we can agree to the erlang representation. :-)

Robert

________________________________________________________________
erlang-questions (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED



From woody.peterson@REDACTED  Fri Jul 30 03:19:04 2010
From: woody.peterson@REDACTED (Woody Peterson)
Date: Thu, 29 Jul 2010 18:19:04 -0700
Subject: erlang's binary representation of 7 compared to other languages
Message-ID: <58EA5255-7662-44C0-BCF7-AF7185DA2970@gmail.com>

I have a problem that's on the borders of ruby and erlang, and I  
figured the erlang list would generally be more familiar with binary  
issues. And forgive me for my haziness with the terminology here...

The basic problem is that ruby encodes the integer 7 as "\a", while  
erlang only decodes it as "\007". Ruby *will* decode both "\007" and  
"\a" into 7, which makes me think there's more than one opinion about  
how it should be encoded.

The bigger problem is I'm trying to send data from ruby to erlang via  
BERT, and turns out it can't handle data (broadly defined) of length 7.

Here's some code examples:

ruby:

     [7].pack("C") # => "\a"
     "\a".unpack("C") # => 7
     "\007".unpack("C") # => 7

erlang:

     <<"\a">>. % => <<a>>
     <<"\007">>. % => <<7>>

That's all I've got. Not sure exactly what to google here, "erlang OR  
ruby binary 007" doesn't really get me anywhere (suprise!), plus I'm  
not sure what exactly this encoding/decoding specification is called.

Any help is appreciated, even google terms :p

-Woody

From mjtruog@REDACTED  Fri Jul 30 03:36:10 2010
From: mjtruog@REDACTED (Michael Truog)
Date: Thu, 29 Jul 2010 18:36:10 -0700
Subject: [erlang-questions] erlang's binary representation of 7 compared
 to other languages
In-Reply-To: <58EA5255-7662-44C0-BCF7-AF7185DA2970@gmail.com>
References: <58EA5255-7662-44C0-BCF7-AF7185DA2970@gmail.com>
Message-ID: <4C522C8A.2040303@gmail.com>

I think this is just because Erlang does not recognize the "\a" encoding
and instead just recognizes "a" ("\07" seems best in this case, and is
equivalent to "\a"):
4> <<"\n">>.
<<"\n">>
5> <<"\a">>.
<<"a">>
6> <<"\07">>.
<<7>>
7>

- Michael

On 07/29/2010 06:19 PM, Woody Peterson wrote:
> I have a problem that's on the borders of ruby and erlang, and I
> figured the erlang list would generally be more familiar with binary
> issues. And forgive me for my haziness with the terminology here...
>
> The basic problem is that ruby encodes the integer 7 as "\a", while
> erlang only decodes it as "\007". Ruby *will* decode both "\007" and
> "\a" into 7, which makes me think there's more than one opinion about
> how it should be encoded.
>
> The bigger problem is I'm trying to send data from ruby to erlang via
> BERT, and turns out it can't handle data (broadly defined) of length 7.
>
> Here's some code examples:
>
> ruby:
>
>     [7].pack("C") # => "\a"
>     "\a".unpack("C") # => 7
>     "\007".unpack("C") # => 7
>
> erlang:
>
>     <<"\a">>. % => <<a>>
>     <<"\007">>. % => <<7>>
>
> That's all I've got. Not sure exactly what to google here, "erlang OR
> ruby binary 007" doesn't really get me anywhere (suprise!), plus I'm
> not sure what exactly this encoding/decoding specification is called.
>
> Any help is appreciated, even google terms :p
>
> -Woody
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>


From woody.peterson@REDACTED  Fri Jul 30 03:51:40 2010
From: woody.peterson@REDACTED (Woody Peterson)
Date: Thu, 29 Jul 2010 18:51:40 -0700
Subject: [erlang-questions] erlang's binary representation of 7 compared to other languages
In-Reply-To: <4C522C8A.2040303@gmail.com>
References: <58EA5255-7662-44C0-BCF7-AF7185DA2970@gmail.com> <4C522C8A.2040303@gmail.com>
Message-ID: <0933BE87-4B3E-4FCD-8C73-354AE4AC7794@gmail.com>

Thanks for the quick reply! So you're saying erlang can't be made to  
recognize "\a"; any idea why "\07" and "\a" are considered equivalent,  
but the two languages chose incompatible representations? Or, if  
erlang can't parse "\a" (I was hoping for an option a la http://www.erlang.org/doc/programming_examples/bit_syntax.html#id2261157) 
, I guess the simplest answer is how to get ruby to output "\07",  
which isn't on topic here.

I'm always down for a quick fix, so I'll see if any rubyists know how  
to accomplish the latter, but I'm going to lose sleep if I don't know  
why the opposing designs exist in the first place :)

On Jul 29, 2010, at 6:36 PM, Michael Truog wrote:

> I think this is just because Erlang does not recognize the "\a"  
> encoding
> and instead just recognizes "a" ("\07" seems best in this case, and is
> equivalent to "\a"):
> 4> <<"\n">>.
> <<"\n">>
> 5> <<"\a">>.
> <<"a">>
> 6> <<"\07">>.
> <<7>>
> 7>
>
> - Michael
>
> On 07/29/2010 06:19 PM, Woody Peterson wrote:
>> I have a problem that's on the borders of ruby and erlang, and I
>> figured the erlang list would generally be more familiar with binary
>> issues. And forgive me for my haziness with the terminology here...
>>
>> The basic problem is that ruby encodes the integer 7 as "\a", while
>> erlang only decodes it as "\007". Ruby *will* decode both "\007" and
>> "\a" into 7, which makes me think there's more than one opinion about
>> how it should be encoded.
>>
>> The bigger problem is I'm trying to send data from ruby to erlang via
>> BERT, and turns out it can't handle data (broadly defined) of  
>> length 7.
>>
>> Here's some code examples:
>>
>> ruby:
>>
>>    [7].pack("C") # => "\a"
>>    "\a".unpack("C") # => 7
>>    "\007".unpack("C") # => 7
>>
>> erlang:
>>
>>    <<"\a">>. % => <<a>>
>>    <<"\007">>. % => <<7>>
>>
>> That's all I've got. Not sure exactly what to google here, "erlang OR
>> ruby binary 007" doesn't really get me anywhere (suprise!), plus I'm
>> not sure what exactly this encoding/decoding specification is called.
>>
>> Any help is appreciated, even google terms :p
>>
>> -Woody
>>
>> ________________________________________________________________
>> erlang-questions (at) erlang.org mailing list.
>> See http://www.erlang.org/faq.html
>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>
>>
>


From rvirding@REDACTED  Fri Jul 30 04:29:46 2010
From: rvirding@REDACTED (Robert Virding)
Date: Fri, 30 Jul 2010 04:29:46 +0200
Subject: [erlang-questions] erlang's binary representation of 7 compared 
	to other languages
In-Reply-To: <0933BE87-4B3E-4FCD-8C73-354AE4AC7794@gmail.com>
References: <58EA5255-7662-44C0-BCF7-AF7185DA2970@gmail.com> 
	<4C522C8A.2040303@gmail.com> <0933BE87-4B3E-4FCD-8C73-354AE4AC7794@gmail.com>
Message-ID: <AANLkTi==sfCMFT7erkQow8LVFm2hJQ3bqDv-rZW4zDmr@mail.gmail.com>

The reason why Erlang doesn't specially recognise \a as 7 is that when
we added character escaping we tool the basic C set and used that.
IIRC \a wasn't in that set. To do it now would be to introduce
something which in not backwards compatible so not without its
problems. Although I think very few would be affected by it. Btw the 7
is BEL in the ascii characters, unfortunately \b is already taken.

Robert

On 30 July 2010 03:51, Woody Peterson <woody.peterson@REDACTED> wrote:
> Thanks for the quick reply! So you're saying erlang can't be made to
> recognize "\a"; any idea why "\07" and "\a" are considered equivalent, but
> the two languages chose incompatible representations? Or, if erlang can't
> parse "\a" (I was hoping for an option a la
> http://www.erlang.org/doc/programming_examples/bit_syntax.html#id2261157), I
> guess the simplest answer is how to get ruby to output "\07", which isn't on
> topic here.
>
> I'm always down for a quick fix, so I'll see if any rubyists know how to
> accomplish the latter, but I'm going to lose sleep if I don't know why the
> opposing designs exist in the first place :)
>
> On Jul 29, 2010, at 6:36 PM, Michael Truog wrote:
>
>> I think this is just because Erlang does not recognize the "\a" encoding
>> and instead just recognizes "a" ("\07" seems best in this case, and is
>> equivalent to "\a"):
>> 4> <<"\n">>.
>> <<"\n">>
>> 5> <<"\a">>.
>> <<"a">>
>> 6> <<"\07">>.
>> <<7>>
>> 7>
>>
>> - Michael
>>
>> On 07/29/2010 06:19 PM, Woody Peterson wrote:
>>>
>>> I have a problem that's on the borders of ruby and erlang, and I
>>> figured the erlang list would generally be more familiar with binary
>>> issues. And forgive me for my haziness with the terminology here...
>>>
>>> The basic problem is that ruby encodes the integer 7 as "\a", while
>>> erlang only decodes it as "\007". Ruby *will* decode both "\007" and
>>> "\a" into 7, which makes me think there's more than one opinion about
>>> how it should be encoded.
>>>
>>> The bigger problem is I'm trying to send data from ruby to erlang via
>>> BERT, and turns out it can't handle data (broadly defined) of length 7.
>>>
>>> Here's some code examples:
>>>
>>> ruby:
>>>
>>> ? [7].pack("C") # => "\a"
>>> ? "\a".unpack("C") # => 7
>>> ? "\007".unpack("C") # => 7
>>>
>>> erlang:
>>>
>>> ? <<"\a">>. % => <<a>>
>>> ? <<"\007">>. % => <<7>>
>>>
>>> That's all I've got. Not sure exactly what to google here, "erlang OR
>>> ruby binary 007" doesn't really get me anywhere (suprise!), plus I'm
>>> not sure what exactly this encoding/decoding specification is called.
>>>
>>> Any help is appreciated, even google terms :p
>>>
>>> -Woody
>>>
>>> ________________________________________________________________
>>> erlang-questions (at) erlang.org mailing list.
>>> See http://www.erlang.org/faq.html
>>> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>>>
>>>
>>
>
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From tanduy.vo@REDACTED  Fri Jul 30 04:44:40 2010
From: tanduy.vo@REDACTED (tanduy)
Date: Thu, 29 Jul 2010 19:44:40 -0700 (PDT)
Subject: Edoc crashes when called from command line
In-Reply-To: <AANLkTindUmdQz4tBPmK38NSue_e2J5Ese_HAag9Jzbuq@mail.gmail.com>
References: <AANLkTin9paKHXobMqyKaGfeCcKO3w9TWBLYv51rJrLkz@mail.gmail.com> 
	<AANLkTim4X=sWJVfu1_e4rKckRSTWJYwHWoh2iQK7-CBY@mail.gmail.com> 
	<AANLkTik3xfa-GVJfQOxxhcGi7+LUQhQs-qivsGBx=3w=@mail.gmail.com> 
	<AANLkTi=2gxcFfji9ZrRQx3vWm9POqxxH0FJuLTy4g3Nb@mail.gmail.com> 
	<AANLkTi=f28jQA-Yt+T++jOr+MC+4n_LJyXaWPXZ_euXA@mail.gmail.com> 
	<AANLkTindUmdQz4tBPmK38NSue_e2J5Ese_HAag9Jzbuq@mail.gmail.com>
Message-ID: <7f642331-fca5-486d-a99e-2121aa911f9e@p22g2000pre.googlegroups.com>

> A quick and easy solution is to use:
> erl -run edoc files a.erl

Hi Gleb Peregud.

In module a.erl change function a/0 to a/1 like this to test: a(Arg) -
> io:format("~p",[Arg]).
    1. erl -noinput -run a a a.erl b.erl -s init stop
        -> Arg = ["a.erl","b.erl"]
    2. erl -noinput -s a a a.erl b.erl -s init stop
        -> Arg = ['a.erl','b.erl']

if you run command:
    erl -run edoc files a.erl many html files are created.

So you can use this command:
    1. Document only come from module a.erl: erl -noinput -eval
'edoc:file("a.erl")' -s init stop
    2. Document come from overview.edoc and a.erl: erl -noinput -eval
'edoc:files(["a.erl"])' -s init stop

regards,
Duy.


> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> Seehttp://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscr...@REDACTED

From xramtsov@REDACTED  Fri Jul 30 06:02:03 2010
From: xramtsov@REDACTED (Evgeniy Khramtsov)
Date: Fri, 30 Jul 2010 14:02:03 +1000
Subject: [erlang-questions] The most efficient way to make sure a remote
 process is alive
In-Reply-To: <C87714DE.3CDC%martin.logan@orbitz.com>
References: <C87714DE.3CDC%martin.logan@orbitz.com>
Message-ID: <4C524EBB.5010306@gmail.com>

30.07.2010 02:22, Logan, Martin wrote:
> I am looking for the absolute most efficient way to make sure a process, referenced by a pid I have, is alive. The process my pid references could of course be local or remote. There are lots of ways but I want the most efficient and I can't assume any application level code - this must be generic. Thoughts?
>
> Cheers,
> Martin
>
>    

rpc:pinfo/1,2. If the pid is local, rpc transforms into apply/3, so it 
is pretty efficient.

-- 
Regards,
Evgeniy Khramtsov, ProcessOne.
xmpp:xram@REDACTED


From james.aimonetti@REDACTED  Fri Jul 30 06:57:45 2010
From: james.aimonetti@REDACTED (James Aimonetti)
Date: Thu, 29 Jul 2010 21:57:45 -0700
Subject: Experience with gen_bunny or other RabbitMQ clients?
Message-ID: <AANLkTikyr4VJSiUPvaP9OZs154eCrhbAwh75dZYHoi+m@mail.gmail.com>

List,

Has anyone been using gen_bunny besides the two folks contributing to
the code? What about other AMQP erlang clients (besides the
rabbitmq-erlang-client)?

Thanks for any suggestions/experiences.

James

From max.lapshin@REDACTED  Fri Jul 30 08:32:50 2010
From: max.lapshin@REDACTED (Max Lapshin)
Date: Fri, 30 Jul 2010 10:32:50 +0400
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <C8776753.3D3C%martin.logan@orbitz.com>
References: <201597.67877.qm@web63605.mail.re1.yahoo.com>
	<C8776753.3D3C%martin.logan@orbitz.com>
Message-ID: <AANLkTinwF=Yzs626zr-NHfP98NDZ0n_4T9unL=YFFpgw@mail.gmail.com>

I've just tested http://github.com/lambder/jsonerl
It has cool macros  ?record_to_json

From alisdairsullivan@REDACTED  Fri Jul 30 08:07:09 2010
From: alisdairsullivan@REDACTED (Alisdair Sullivan)
Date: Thu, 29 Jul 2010 23:07:09 -0700
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <857hkeje6s.fsf@myxomop.com>
References: <87eiemmzkr.fsf@benington.loc> <AANLkTinmtrR=GDJC_0HaQ+4L0Kh+-ixqNs84rPE=6+KP@mail.gmail.com> <201597.67877.qm@web63605.mail.re1.yahoo.com> <857hkeje6s.fsf@myxomop.com>
Message-ID: <B44D9C27-B7DF-425B-BE63-A61C462A0B39@yahoo.ca>


On 2010-07-29, at 12:11 PM, Alexander Kotelnikov wrote:

>>>>>> On Thu, 29 Jul 2010 11:16:54 -0700 (PDT)
>>>>>> "as" == alisdair sullivan <alisdairsullivan@REDACTED> wrote:
> as> 
> as> it relies on jsx (available at http://github.com/talentdeficit/jsx), my port of 
> as> yajl to erlang.
> 
> So it tends to be at least fourth eep-0018 parser, third based on
> yajl.

jsx is an erlang native port of yajl, not another port or nif. none of the other yajl based projects expose yajl's full interface (or anything close to it, as far as I know). I've added a readme with a couple of examples and some documentation to http://github.com/talentdeficit/jsx. the eep0018 implementation was meant more as an example of what jsx can do.

From sacha@REDACTED  Fri Jul 30 11:59:49 2010
From: sacha@REDACTED (Alexander Kotelnikov)
Date: Fri, 30 Jul 2010 13:59:49 +0400
Subject: [erlang-questions] Which Erlang JSON parser?
In-Reply-To: <AANLkTi=wQND84+tUmZ-cx+gNZaBTT7OQL3CPO=3rptgj@mail.gmail.com>
	(Paul Davis's message of "Thu, 29 Jul 2010 16:19:43 -0400")
References: <87eiemmzkr.fsf@benington.loc>
	<AANLkTi=wQND84+tUmZ-cx+gNZaBTT7OQL3CPO=3rptgj@mail.gmail.com>
Message-ID: <877hkdmgru.fsf@benington.loc>

>>>>> On Thu, 29 Jul 2010 16:19:43 -0400
>>>>> "PD" == Paul Davis <paul.joseph.davis@REDACTED> wrote:
PD> 
PD> I'm the author of http://github.com/davisp/eep0018.git If you send me
PD> any of the rebar errors you had while building I can take a look. I
PD> haven't heard of anyone having issues with it, but my first guess is
PD> that its an issue with which version of Erlang you're using. If memory
PD> serves, that version requires R13B and hasn't been upgraded to R14 NIF
PD> api yet.

Then I believe that problem is that I am running R12B.

Also my personal feeling is that it is evil to distribute binary build
tools.

PD> If you're looking for a good JSON parser, I would recommend either the
PD> mochijson2.erl parser or one of the C implementations. mochijson2 is
PD> pretty solid and has been tested extensively. The C based ones can
PD> give some pretty good speedups for large decoding operatiosn though,
PD> so that might be a motivaton against. And IIRC, Alisdair's latest
PD> decoder is stream based so you can use it for incremental parsing if
PD> you need that.

My expectation was that parser written after a standard might be
more... predictable. Also, if you find that one is buggy you can switch
to another relatively easily. Probably I will have a look at
mochijson/mochijson2 now. Thanks

From ttom.kelly@REDACTED  Fri Jul 30 16:55:25 2010
From: ttom.kelly@REDACTED (tom kelly)
Date: Fri, 30 Jul 2010 15:55:25 +0100
Subject: [erlang-questions] heart restarting erlang node
In-Reply-To: <AANLkTimBODn3AKIZ_R9fzT1hSn7bFOVHxTB__15x6Vxc@mail.gmail.com>
References: <AANLkTil1ent_SJYuC6Nnf2abra_KjiukjpovSh2ssMwl@mail.gmail.com>
	<1304.1277505431@snookles.snookles.com>
	<AANLkTimBODn3AKIZ_R9fzT1hSn7bFOVHxTB__15x6Vxc@mail.gmail.com>
Message-ID: <AANLkTi=t1SWRCUW-D6Y=nXdNSQE6o9U=uCkTTurY661L@mail.gmail.com>

Hi List,

Sorry if this is noise, just finishing off this thread in case it comes up
in anyones google search in the future.

This problem appears to have fixed itself when we convinced our customer to
go for a hardware reboot. We also changed the +A attribute from 256 to 128
but we can't say that's what caused this to go away. Previously it was
restarting approx every 1.5 days but has now been up for 22.

Not being able to reproduce this on our test site we didn't have an
opportunity to chase it down and find a definitive cause and solution. For
anyone reading this who has a node inexplicably restarting on a customers
site, I sympathise! Ask them to reboot the HW if it doesn't make you look
like you're clutching at straws! ;-)

//Tom.



On Sun, Jun 27, 2010 at 5:14 PM, tom kelly <ttom.kelly@REDACTED> wrote:

> Hi Scott,
> Thanks for your very useful answers!
> We found some segmentation errors reported by the OS so we were starting to
> think that heart wasn't the problem after all.
> This is proving difficult to pin down as it's on a customers site and
> happens at very irregular intervals.
> For anyone else experiencing similar problems we'll inform the list if we
> find a definitive solution.
> //Tom.
>
>
>
> On Sat, Jun 26, 2010 at 12:37 AM, Scott Lystig Fritchie <
> fritchie@REDACTED> wrote:
>
>> tom kelly <ttom.kelly@REDACTED> wrote:
>>
>> tk> We've found this post from Serge Aleynikov which we're
>> tk> investigating:
>> tk>
>> http://www.erlang.org/pipermail/erlang-questions/2006-December/024365.html
>>
>> tk> But I'm not yet sure it's the same issue. This can cause heart to
>> tk> restart our system but only after memory usage was sustained around
>> tk> 90% for 5-10 minutes which wasn't the case for all of our restarts.
>>
>> Tom, if your Erlang process is causing your OS to page VM to/from disk,
>> then all expectations of soft realtime performance will be thrown out
>> the window.  If the VM tries to do something simple like "char foo =
>> *(some_pointer)", and if some_pointer points to a page that isn't
>> resident in RAM, that thread will wait a *long* time before progress can
>> be made again.  Typically you've got 1 scheduler thread per CPU, but if
>> your working set isn't resident in RAM, you'll quickly block all
>> scheduler threads...
>>
>> ... and then when it comes time to answer a heartbeat, you won't do it
>> in time, and you'll be killed because you're too !@#$! slow.
>>
>> If you're using Linux, crank the /proc/vm/*swappiness* (I forget the
>> exact path) down to 0.  Many kernels (RedHat comes to mind) use 60,
>> which is not what you want a snappy server to do.
>>
>> If you can't blame your OS for moving your VM's pages to RAM, you'll
>> have to blame yourself: use less data or buy more RAM.  :-)
>>
>> -Scott
>>
>
>

From andre@REDACTED  Fri Jul 30 16:58:17 2010
From: andre@REDACTED (Andre Nathan)
Date: Fri, 30 Jul 2010 11:58:17 -0300
Subject: gen_tcp under gen_server design
Message-ID: <1280501897.24093.28.camel@andre.mz.digirati.com.br>

Hello

I'm building my first OTP application. It's a network server that deals
with a binary protocol. My question is about the design I came up to fit
a gen_tcp server into the gen_server behaviour.

The idea is to have a server process (a gen_server) which listens on a
given port and spawns an acceptor process. This process is created with
proc_lib:spawn_link and the listening socket is passed to it with
gen_tcp:controlling_process; it doesn't implement any OTP behavior.

The acceptor process calls gen_tcp:accept, and when the call returns, a
new process responsible for handling the data is spawned. The client
socket is given to this process via gen_tcp:controlling_process, and the
acceptor calls gen_tcp:accept again waiting for new connections.

I call the process created by the acceptor the "packager" process. It's
a simple gen_fsm that reads binary data from the socket and packages it
into binaries of the appropriate size, according to the protocol, parses
them and generate the appropriate events on the worker process that
implements the protocol FSM. The packager process receives tcp data in
the handle_info callback, which sets the socket to {active, once} each
time it is called and calls the function corresponding to the current
gen_fsm state, generating a "data" event.

Is this a reasonable design for this kind of server? Is there anything I
could do to improve its reliability and/or efficiency? Would it be
better to, for example, have multiple acceptor processes and let them do
the binary processing that the packager processes do in my case by
themselves?

Thanks in advance,
Andre


From MARTIN.LOGAN@REDACTED  Fri Jul 30 18:42:24 2010
From: MARTIN.LOGAN@REDACTED (Logan, Martin)
Date: Fri, 30 Jul 2010 11:42:24 -0500
Subject: [erlang-questions] gen_tcp under gen_server design
In-Reply-To: <1280501897.24093.28.camel@andre.mz.digirati.com.br>
Message-ID: <C8786B20.3D8D%martin.logan@orbitz.com>

Chapter 3 and Chapter 11 of our book with Manning http://manning.com/logan will show you exactly how to do what you want.

Cheers,
Martin


On 7/30/10 9:58 AM, "Andre Nathan" <andre@REDACTED> wrote:

Hello

I'm building my first OTP application. It's a network server that deals
with a binary protocol. My question is about the design I came up to fit
a gen_tcp server into the gen_server behaviour.

The idea is to have a server process (a gen_server) which listens on a
given port and spawns an acceptor process. This process is created with
proc_lib:spawn_link and the listening socket is passed to it with
gen_tcp:controlling_process; it doesn't implement any OTP behavior.

The acceptor process calls gen_tcp:accept, and when the call returns, a
new process responsible for handling the data is spawned. The client
socket is given to this process via gen_tcp:controlling_process, and the
acceptor calls gen_tcp:accept again waiting for new connections.

I call the process created by the acceptor the "packager" process. It's
a simple gen_fsm that reads binary data from the socket and packages it
into binaries of the appropriate size, according to the protocol, parses
them and generate the appropriate events on the worker process that
implements the protocol FSM. The packager process receives tcp data in
the handle_info callback, which sets the socket to {active, once} each
time it is called and calls the function corresponding to the current
gen_fsm state, generating a "data" event.

Is this a reasonable design for this kind of server? Is there anything I
could do to improve its reliability and/or efficiency? Would it be
better to, for example, have multiple acceptor processes and let them do
the binary processing that the packager processes do in my case by
themselves?

Thanks in advance,
Andre


________________________________________________________________
erlang-questions (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED



From MARTIN.LOGAN@REDACTED  Fri Jul 30 18:57:42 2010
From: MARTIN.LOGAN@REDACTED (Logan, Martin)
Date: Fri, 30 Jul 2010 11:57:42 -0500
Subject: [erlang-questions] gen_tcp under gen_server design
In-Reply-To: <1280501897.24093.28.camel@andre.mz.digirati.com.br>
Message-ID: <C8786EB6.3D93%martin.logan@orbitz.com>

Andrew, BTW - you should not have to use controlling process. Have the listen sock spawned in your application behaviour implementation module, then pass it through to each acceptor which blocks on accept in the handle_info(timeout clause which is prompted by using a timeout of 0 out of init/1. Once you accept call into the simple_one_for_one supervisor that is  responsible for spawning off your acceptors and have it spawn another one to wait for the next connection while the first chugs along processing on a socket it already owns by virtue of the fact that it accepted it. There is no worry here between accepting one connection and spawning another to accept the next because the OS queues up pending connections of which the call to accept/1 only pulls off the first one.

Hope that helps.

Cheers,
Martin


On 7/30/10 9:58 AM, "Andre Nathan" <andre@REDACTED> wrote:

Hello

I'm building my first OTP application. It's a network server that deals
with a binary protocol. My question is about the design I came up to fit
a gen_tcp server into the gen_server behaviour.

The idea is to have a server process (a gen_server) which listens on a
given port and spawns an acceptor process. This process is created with
proc_lib:spawn_link and the listening socket is passed to it with
gen_tcp:controlling_process; it doesn't implement any OTP behavior.

The acceptor process calls gen_tcp:accept, and when the call returns, a
new process responsible for handling the data is spawned. The client
socket is given to this process via gen_tcp:controlling_process, and the
acceptor calls gen_tcp:accept again waiting for new connections.

I call the process created by the acceptor the "packager" process. It's
a simple gen_fsm that reads binary data from the socket and packages it
into binaries of the appropriate size, according to the protocol, parses
them and generate the appropriate events on the worker process that
implements the protocol FSM. The packager process receives tcp data in
the handle_info callback, which sets the socket to {active, once} each
time it is called and calls the function corresponding to the current
gen_fsm state, generating a "data" event.

Is this a reasonable design for this kind of server? Is there anything I
could do to improve its reliability and/or efficiency? Would it be
better to, for example, have multiple acceptor processes and let them do
the binary processing that the packager processes do in my case by
themselves?

Thanks in advance,
Andre


________________________________________________________________
erlang-questions (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED



From woody.peterson@REDACTED  Fri Jul 30 19:50:41 2010
From: woody.peterson@REDACTED (Woody Peterson)
Date: Fri, 30 Jul 2010 10:50:41 -0700
Subject: [erlang-questions] erlang's binary representation of 7 compared to other languages
In-Reply-To: <alpine.LSU.2.00.1007301503310.12262@hermes-2.csi.cam.ac.uk>
References: <58EA5255-7662-44C0-BCF7-AF7185DA2970@gmail.com>  <4C522C8A.2040303@gmail.com> <0933BE87-4B3E-4FCD-8C73-354AE4AC7794@gmail.com> <AANLkTi==sfCMFT7erkQow8LVFm2hJQ3bqDv-rZW4zDmr@mail.gmail.com> <alpine.LSU.2.00.1007301503310.12262@hermes-2.csi.cam.ac.uk>
Message-ID: <89E89C1B-FFDC-4E8A-BE52-823DF7EB9971@gmail.com>


> Btw the 7
> is BEL in the ascii characters, unfortunately \b is already taken.


> AFAICT from a quick search, \a was added in ANSI C.

Thanks, and I found out what the problem was, btw. Through a misuse of  
the ruby library, bert, my test was encoding bert's binary output to C  
escape sequences. Since erlang can *almost* decode those to the same  
binary representation, I thought that was the intended behavior (which  
is silly). Your "btw" comments and a couple side conversations nudged  
me to realize this sillyness... much appreciated

From fernandochucre@REDACTED  Fri Jul 30 20:44:14 2010
From: fernandochucre@REDACTED (Fernando Chucre)
Date: Fri, 30 Jul 2010 15:44:14 -0300
Subject: [OFF-TOPIC] invite to Web Dev Summit
Message-ID: <AANLkTikuq3KM4U5edeLUhXbQipmuYScOno915+P362C3@mail.gmail.com>

Hi,

My name is Fernando Chucre, and I with other comunity leaders will realize
in Fortaleza/Brazil a big event.

Web Dev Summit is an event that embraces all technologies and platforms for
the web. Our intention is to bring together in one place the largest possible
amount of knowledge and experience, creating a fertile and binder
 environment.

The first edition will take place in Fortaleza, Brazil, a city with great
structure for events. In 2011 we will open 3000 places for students,
professionals and academics area.

In the event we will have space for companies to recruit professionals and
present their products for the web. In this first edition, we focus on
APIs integration
between services.

To add more than talk, we will offer mini-courses for professionals in the
event, always with much diversity.

We count on you in Fortaleza, the Web Dev Summit.

Fernando Chucre

From MARTIN.LOGAN@REDACTED  Fri Jul 30 23:17:05 2010
From: MARTIN.LOGAN@REDACTED (Logan, Martin)
Date: Fri, 30 Jul 2010 16:17:05 -0500
Subject: [erlang-questions] The most efficient way to make sure a remote
 process is alive
In-Reply-To: <4C524EBB.5010306@gmail.com>
References: <C87714DE.3CDC%martin.logan@orbitz.com>
 <4C524EBB.5010306@gmail.com>
Message-ID: <ED99F931720BED42B9F579D90361667C0BE2664C@EGEXCMB01.oww.root.lcl>

NICE! That is what I was looking for. I thought I had the RPC module memorized and so I never even looked for this function. Thanks. 

-----Original Message-----
From: erlang-questions@REDACTED [mailto:erlang-questions@REDACTED] On Behalf Of Evgeniy Khramtsov
Sent: Thursday, July 29, 2010 11:02 PM
To: erlang-questions@REDACTED
Subject: Re: [erlang-questions] The most efficient way to make sure a remote process is alive

30.07.2010 02:22, Logan, Martin wrote:
> I am looking for the absolute most efficient way to make sure a process, referenced by a pid I have, is alive. The process my pid references could of course be local or remote. There are lots of ways but I want the most efficient and I can't assume any application level code - this must be generic. Thoughts?
>
> Cheers,
> Martin
>
>    

rpc:pinfo/1,2. If the pid is local, rpc transforms into apply/3, so it 
is pretty efficient.

-- 
Regards,
Evgeniy Khramtsov, ProcessOne.
xmpp:xram@REDACTED


________________________________________________________________
erlang-questions (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED


From james.aimonetti@REDACTED  Sat Jul 31 00:59:40 2010
From: james.aimonetti@REDACTED (James Aimonetti)
Date: Fri, 30 Jul 2010 15:59:40 -0700
Subject: Binaries in records syntax error
Message-ID: <AANLkTikLW=i=06Re13vYBcxcL5cZUyix58TDFmcpybb5@mail.gmail.com>

If setting raw binaries into records, a space is important between the
binding and the start of the binary.

#foo{bar=<<"something">>} causes a "syntax error before: '=<' " during
compilation.

#foo{bar= <<"something">>} is fine.

Caught me by surprise. FYI

James

From rvirding@REDACTED  Sat Jul 31 03:22:18 2010
From: rvirding@REDACTED (Robert Virding)
Date: Sat, 31 Jul 2010 03:22:18 +0200
Subject: [erlang-questions] Binaries in records syntax error
In-Reply-To: <AANLkTikLW=i=06Re13vYBcxcL5cZUyix58TDFmcpybb5@mail.gmail.com>
References: <AANLkTikLW=i=06Re13vYBcxcL5cZUyix58TDFmcpybb5@mail.gmail.com>
Message-ID: <AANLkTinWKK6A9NDbw4OYYyHxn6+ZCXjK=L+9hq3qbhg8@mail.gmail.com>

It's not just setting binaries in records, you always need a space
between an '=' and the << otherwise the parser groups them
incorrectly. So:

X=<<1,2,3>>,                 %This is BAD

will cause the same error. You need to write:

X = <<1,2,3>>

There is nothing really which can be done about this as you scan from
left-to-right.

Robert

On 31 July 2010 00:59, James Aimonetti <james.aimonetti@REDACTED> wrote:
> If setting raw binaries into records, a space is important between the
> binding and the start of the binary.
>
> #foo{bar=<<"something">>} causes a "syntax error before: '=<' " during
> compilation.
>
> #foo{bar= <<"something">>} is fine.
>
> Caught me by surprise. FYI
>
> James
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-questions-unsubscribe@REDACTED
>
>

From dj3vande@REDACTED  Sat Jul 31 15:53:24 2010
From: dj3vande@REDACTED (Dave Vandervies)
Date: Sat, 31 Jul 2010 09:53:24 -0400
Subject: [erlang-questions] Binaries in records syntax error
In-Reply-To: <AANLkTinWKK6A9NDbw4OYYyHxn6+ZCXjK=L+9hq3qbhg8@mail.gmail.com>
References: <AANLkTikLW=i=06Re13vYBcxcL5cZUyix58TDFmcpybb5@mail.gmail.com> <AANLkTinWKK6A9NDbw4OYYyHxn6+ZCXjK=L+9hq3qbhg8@mail.gmail.com>
Message-ID: <20100731135324.GA9274@buttons.local>

Somebody claiming to be Robert Virding wrote:
> It's not just setting binaries in records, you always need a space
> between an '=' and the << otherwise the parser groups them
> incorrectly.

This is a general principle that applies to other operators and
other languages as well.
In a typical two-stage lex-and-parse language implementation it
happens in the lexer, before the parser sees it; the lexer will
identify the longest prefix of the input that forms a legal token
and convert that into the next token it gives the parser (the
"maximal munch" rule).


> There is nothing really which can be done about this as you scan from
> left-to-right.

This kind of surprise is why starting with the second language I
learned I got in the habit of putting spaces around all the operators.

It might be an interesting experiment to try building a parser that
can recognize problems of this sort and ask the lexer to rescan
with a non-maximal munch, but I suspect getting something like that
to behave predictably would be harder than just forcing programmers
to use whitespace to help the lexer.


dave

-- 
Dave Vandervies
dj3vande@REDACTED / dj3vande@REDACTED

Plan your future!  Make God laugh!
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From xma@REDACTED  Sat Jul 31 23:11:54 2010
From: xma@REDACTED (Xavier Maillard)
Date: Sat, 31 Jul 2010 23:11:54 +0200
Subject: erlang and web applications: which framework ?
Message-ID: <m2iq3vicf9.fsf@kcals.maillard.im>

Hi,

I am planning on developing a web application and I want it to be
written in erlang.

So, what is the set of possibilities on the framework side ? Which one
is recommended ?

Thank you very much

Xavier