Re: [Caml-list] Accelerating compilation

[Francois Berenger <berenger@riken.jp>]

On 09/09/2013 05:15 PM, Romain Bardou wrote:
> Le 06/09/2013 20:45, Martin Jambon a écrit :
>> On 09/06/2013 06:56 AM, Romain Bardou wrote:
>>> Hello list,
>>>
>>> As my project grows bigger, it is becoming much less efficient to use
>>> the type-checker to quickly find places in my code which must be updated
>>> (e.g. pattern-matching). Here is a wishlist for improvements.
>>>
>>> 1) Separate typing and code generation, in ocamlc and in ocamlopt
>>>
>>> For instance, provide an option -typing-only which would mean "only
>>> produce the .cmi but do not produce the .cmo or the .cmx". The compiler
>>> would only need the .cmi of the dependencies, not their .cmo or .cmx.
>>> This would make it possible to have a Makefile target, or an Ocamlbuild
>>> option, to just type.
>>>
>>> Also, provide an option -do-not-retype which would mean "if the .cmi
>>> exists, load it instead of type-checking again". This would allow the
>>> build process to first type-check (using -typing-only) and then generate
>>> the code without type-checking again (using -do-not-retype). Of course
>>> the build system should be very careful to ensure the .cmi is
>>> up-to-date. This option could also help when compiling both in bytecode
>>> and in native code. This option is not necessary to just find errors
>>> quickly, though.
>>>
>>> 2) Be able to disable Ocamlbuild's digest mechanism and use dates and
>>> file sizes instead
>>>
>>> If I am not mistaken, this is one of the main reasons why Ocamlbuild is
>>> slower that make.
>>
>> It would be interesting to know the size of your project and the time it
>> takes to build it.
>
> There are about 30K lines of code in the core of the project, which is
> well-split in a rather large number of files (Ocamlbuild reports about
> 400 targets). It takes about 30s to compile in native mode using the
> native compilers.
>
> It might seem very small compared to say, Coq :) But still, having to
> wait ~10s just to find the next pattern-matching to fix is already
> annoying and it will only get worse.

Isn't the merlin tool able to do that: show compilation errors as you type?

I don't use merlin that much but thought it was.