Re: [Caml-list] Quizz

[Jacques Garrigue <garrigue@math.nagoya-u.ac.jp>]

On 2015/01/15 02:24, Leo White wrote:
> 
> Milan Stanojević <milanst@gmail.com> writes:
> 
>>> The main problem is not so much syntax, as the fact it would require to make
>>> all definitions in the Types module mutually recursive. Not only that, but
>>> operations like path substitution need to be mutually recursive in the same
>>> way. So the question is whether the small gain in flexibility is worth making the
>>> implementation more complex.
>>> (Note that an extra gain is that it becomes possible to expand a module type
>>> definition when leaving its scope)
>> 
>> In my work I mostly just wanted to be able to just do something like
>> (module M : Intable with type t = t), i.e just specializing existing
>> module type with "with type =" or "with type :=".
>> Is this special case any easier to implement?
> 
> "with type t =" already works. I'm not sure, but I think that "with type
> t :=" could indeed be implemented without the increased implementation
> complexity that Jacques was referring to.


Indeed it could.
Module type names + non-parameterized constraints are ok, because you only have
to recurse on types, not concrete signatures.

	Jacques