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Module type of a structure returned by functor
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Date: 2010-04-26 (16:33)
From: Dawid Toton <d0@w...>
Subject: Re: Module type of a structure returned by functor
I've found that I have more fundamental problem. What is the exact 
meaning of the following line?

module type Foo = functor (X:X) -> sig val foo : X.t end

(1) Foo is not a functor, but it is a type of some functors that map 
modules to modules
(2) Foo is a mapping from modules to module types

Currently I think that it (1) is true and (2) is false. Let me know if 
I'm wrong.

It means that there is no easy way to get module type of what results 
from functor application. I think that the solution is to separately 
define signature of results of the functor and use "with type" clauses 
to recreate all result module types that are needed.

This is not very bad, but I'm still wondering if "module type of..." of 
3.12 will provide elegant solution for this.