Re: [Caml-list] automatic extaction of the .mli (and a little more) from the .ml

[Francois Berenger <berenger@riken.jp>]

On 05/31/2013 06:10 PM, Romain Bardou wrote:
> I also used to believe the .mli file should be somehow included in the
> .ml file. Now I don't.
>
> But if you design such a tool, here are some things to consider.
>
> - Using numbers to order stuff creates some issues of scalability. In
> particular, inserting a declaration between #3 and #4 may require you to
> move #4 to #5, #5 to #6 and so on, which (in particular if everything is
> not in the right order in the implementation) can prove more annoying
> than reordering stuff in an .mli.

This is trivial to solve.

> - Even without numbers it will be harder to get the big picture from a
> module.

I just propose to generate the .mli automatically (for my projects).
Not to get rid of them.

 > An approach I like about this is Pascal units, with an interface
> section and an implementation section, in the same file. But it does not
> solve the duplication issue.
>
> - You need a way to specify abstraction. For instance:
>    * specify that a type should be exported as "type t" instead of "type
> t = A | B";
>    * specify that a type should be exported as "type t = private A | B"
> instead of "type t = A | B";
>    * specify that a value should be exported as "val f: t -> t" instead
> of "val f: int -> int"
>    * specify that a value should be exported as "val f: int -> t" instead
> of "val f: 'a -> 'a"

I did not think about this yet.

> Often, people who want automatic .mli generation do not use abstraction,
> which is the main point of interfaces.
>
> - Don't forget that you need to take into account the whole OCaml
> language, including objects, modules, polymorphic variants… It may be
> more work than expected. And this project will need to be maintained and
> follow the changes to the language.

I cannot provide any guarantee, on any of these.

Regards,
F.