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Re: [Caml-list] Polymorphic Variants and Number Parameterized Typ es
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Date: -- (:)
From: Francois Pottier <francois.pottier@i...>
Subject: Re: [Caml-list] Re: Encoding "abstract" signatures

Andreas,

> So you cannot simply `reuse' T's quantifier.

You're right -- it seems difficult to obtain a compositional encoding of
O'Caml's module system. We would need, in the target system, one universal
quantification over a type of record kind to be somehow equivalent to a series
of universal quantifications over types of base kind. I guess that's what you
were saying from the very start, but it took me a while to see the problem.
It would be interesting to devise a type system that has this property. Didier
Rémy noticed the need for such a feature back in 1994 when writing `Dynamic
typing in polymorphic languages' (see section 4.2 of the SRC tech report). I
don't think he has a polished solution, though.

-- 
François Pottier
Francois.Pottier@inria.fr
http://pauillac.inria.fr/~fpottier/
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