[erlang-questions] Generating Core Erlang -- Re: Dangers of generating a large erlang module
Sun Sep 29 20:59:22 CEST 2013
On 09/29/2013 08:24 PM, Ivan uemlianin wrote:
> That's what I've just done :D Core Erlang looks very verbose but quite
> regular & probably not difficult to generate.
> My questions now are:
> - are there any libraries "out there" for generating Core Erlang, or do
> we all roll our own?
Look at the cerl module. It's just a matter of generating the proper
structure using those functions.
> - how would one use compile:file or compile:forms with core erlang? I
> haven't been able to find any documentation (haven't read Richard
> Carlsson's Introduction paper yet).
Do read it. But to answer that question, compile:forms with from_core
> Many thanks
> festina lente
> On 29 Sep 2013, at 18:36, Erik Søe Sørensen <
> <mailto:>> wrote:
>> Core Erlang is an intermediate representation in the Erlang compiler
>> - but also (afaik) a fairly well-defined/public one and one that is
>> I don't think you'll find much in the vein of tutorials. Try getting
>> erlc to output the intermediate format, though, for a small program
>> similar to what you'll be using it for.
>> Den 29/09/2013 19.20 skrev "Ivan uemlianin" <
>> Thanks! I think I'll try and head in that direction. I've had a
>> few goes at other methods (db lookup etc) and they're much slower
>> than this "dynamic hardcoding"). I'll sniff around for Core Erlang
>> Best wishes
>> festina lente
>> On 29 Sep 2013, at 17:48, Erik Søe Sørensen <
>> <mailto:>> wrote:
>>> A thing which I discovered recently (in connection with
>>> mochiglobal) is that compiling code containing large binaries, or
>>> large amounts of binaries, is quite memory-intensive. As I
>>> recall it, the numbers were ~64 bytes of RAM per byte in a binary
>>> metal; twice as much if on a 64 bit emulator.
>>> Which means that if you want to compile modules containing (in
>>> sum) multimegabyte binaries, doing so from Erlang source or from
>>> full Erlang AST is a no-go. Iirc, it is feasible if starting
>>> from Core Erlang.
>>> Den 29/09/2013 12.50 skrev "Ivan Uemlianin" <
>>> Dear Anthony
>>> Thanks for your comment.
>>> Yes, that's exactly what the generated module is doing. The
>>> generated module has a single function with many clauses like
>>> f(<<"trigger", Rest/binary) -> ...
>>> This is why (as far as I can work out) the generated code has
>>> to be so big.
>>> I prefer the idea of generating and loading code to, say,
>>> updating a database table, because it seems faster and less
>>> likely to lead to bottlenecks.
>>> Best wishes
>>> On 29/09/2013 11:38, Anthony Ramine wrote:
>>> Hello Ivan,
>>> Out of curiosity, what does it look like?
>>> Pattern matching on literal values in Erlang is done with
>>> a binary search over the sorted list of patterns, I am
>>> not sure this would play well with your use case even if
>>> the compilation didn't bring the VM down.
>>> Le 29 sept. 2013 à 11:29, Ivan Uemlianin a écrit :
>>> All goes well on small test files, but the files I
>>> want to use IRL are relatively large --- around
>>> 120,000 lines.
>>> Ivan A. Uemlianin PhD
>>> Speech Technology Research and Development
>>> www.llaisdy.com <http://www.llaisdy.com>
>>> llaisdy.wordpress.com <http://llaisdy.wordpress.com>
>>> github.com/llaisdy <http://github.com/llaisdy>
>>> festina lente
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