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GADT constructor syntax
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Date: -- (:)
From: Jacques Le Normand <rathereasy@g...>
Subject: Re: [Caml-list] GADT constructor syntax
you may want to name your type parameters because you can mix GADT
constructors with normal constructors. consider:

type 'a term =
     | Ignore of 'a term : int term
     | Embed of 'a

I don't think propagating type parameters is a good idea. The current
rule is: ignore type parameters in GADT constructors. This is simpler
than unifying the type parameters with the arguments of the return
type of the constructor.

On Sat, Dec 4, 2010 at 3:22 PM, Lukasz Stafiniak <> wrote:
> On Sat, Dec 4, 2010 at 9:14 PM, Jacques Le Normand <> wrote:
>> having
>> type 'a t = Foo of 'a : 'b t
>> creating a constructor of type forall 'a. 'a -> 'a t is really
>> confusing since the user explicitly gave the return type of the
>> constructor as 'b t.
> But why would the user have named 'a in the first place then. In the
> context of Foo, it should be assumed that
> 'a t = 'b t