Re: [Caml-list] Why should I use .mli files?

[Alain Frisch <alain@frisch.fr>]

On 10/30/2012 01:43 AM, Francois Berenger wrote:
> Here is my stupid question of the day:
> what's the use of those .mli files?

An argument which I haven't seen mentioned (but I did not read all the 
thread) is that providing an explicit .mli file give the compiler a 
chance to detect unused declarations (types, values) in your module 
(declarations which are not used internally and not exported).

FWIW, we have a tiny parser extension which allows us to put an 
interface on top of the current unit, without having to provide a proper 
.mli file.  This is used in our "addins", which typically register 
themselves into some kind of registry but don't export too many values 
otherwise (most often, none).  We can write:

   sig ... end
   .......

which is just sugar for:

include (.......  : sig ... end)


(without this extension, we would end up with many empty .mli files)


Alain