Re: [Caml-list] META file standards for ppx extensions

[Drup <drupyog+caml@zoho.com>]

I'm not fond of b). ppx_deriving et ppx_import don't follow this scheme, 
and that's rather understandable given the absence of runtime library.

Otherwise yes. lwt, js_of_ocaml follow that and it was widely adopted 
for camlp4, so it shouldn't be an issue.

Le 08/04/2015 20:20, Dario Teixeira a écrit :
> Hi,
>
> I think we need to standardise the naming and structure of META
> files associated with ppx extensions.  Case in point: I was hoping
> to start using sedlex instead of ulex, because the latter has been
> deprecated for a while now and all the cool kids are switching to
> the former.  However, sedlex currently ships with a broken META
> file that severely restricts its usefulness [1].  Therefore, in
> order to avoid similar problems with other ppx extensions and to
> foster some uniformity in the ecosystem, here's what I suggest:
>
> a) Suppose you have a ppx extension called 'foobar' that relies
>    on a runtime library foobar.cma (and native code counterparts,
>    which I'll omit from now on).  The top-level declarations in
>    foobar's META should reference foobar.cma, but should *not*
>    include a ppx declaration.  The ppx declaration should be
>    part of a 'ppx' sub-package.
>
> b) If the ppx extension 'foobar' does not have a runtime library,
>    then the top-level declarations in the META file should consist
>    only of generic version and description information.  The actual
>    ppx declaration should be part of a 'ppx' sub-package, as in a).
>
> There is obviously an alternative approach where the ppx invocations
> are located at the top-level and any potential runtime libraries
> are moved into a 'lib' sub-package.  I prefer the approach outlined
> above, however, as it makes ppx invocations explicit and follows the
> 'syntax' sub-package tradition from Camlp4's glory days.
>
> Thoughts or suggestions?
>
> Best regards,
> Dario Teixeira
>
> [1] https://github.com/alainfrisch/sedlex/issues/22
>
>