[erlang-questions] erlang sucks

Richard A. O'Keefe ok@REDACTED
Tue Mar 11 02:14:14 CET 2008

My take on the separators issue:

(1) I'm used to the Prolog approach, where every clause ends with a  
full stop.
     I'm also used to SML and Haskell and Clean, where again every  
clause ends
     the same way (with nothing).  If Prolog and Haskell can figure  
out that
     adjacent clauses defining the same thing belong to the same  
definition, it
     isn't clear to me why Erlang can't.  I once wrote a functional  
     for Prolog where I could write
	append([], Ys) = Ys.
	append([X|Xs], Ys) = [X | append(Xs, Ys)].
     and the use of a dot at the end of every function clause was no  
trouble at
     all.  Nor is it any trouble in Mercury.

     I generally don't accept arguments about re-ordering definition  
     because if you know what you are doing it is pretty rare.  But I  
     accept arguments about *adding* clauses when you revise a data  
type, so
     I wish that Erlang would allow all function clauses to end with a  

(2) Again, I generally don't accept arguments about re-ordering function
     calls in a body.  I don't find that to be a common mistake.  Oh,  
I do
     make mistakes in Erlang.  I make mistakes all the time in all  
sorts of
     languages.  One mistake I do make in Erlang and in C is to get  
the order
     of arguments wrong.  So why isn't Mr "Erlang sucks" complaining  
     about how C and Java use different terminators after the last  
argument ")"
     and all the others ",", making it hard to swap arguments?   
Presumably he
     isn't complaining about that BECAUSE C and Java do the same  
thing, so he
     hasn't noticed it.

(3) For what it's worth, my text editor, modelled on Emacs, but  
     small enough to fit comfortably on a PDP-11, has a "swap terms"  
     that interchanges the closed terms on either side of the cursor.   

	foo(X) ->

     with the cursor where the ^ is, Ctrl-X t will convert this to

	foo(X) ->

     with no trouble at all.  More generally, the DEdit editor in  
     had a nice facility:  you could build up a stack of selections  
and then
     choose an operation, so you could
	select thing one (except for its terminator)
	select thing two (except for its terminator)
	swap top selections
     Gosh, I miss the ability to have multiple selections.

     So this is arguably an EDITOR problem, not a LANGUAGE problem,  
and it
     can be addressed by more/better editor support.  (Is there an XCode
     plugin for Erlang?)

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