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From: Jacques Le Normand <rathereasy@gmail.com>
To: Lukasz Stafiniak <lukstafi@gmail.com>
Cc: caml-list caml-list <caml-list@yquem.inria.fr>
Subject: Re: [Caml-list] GADT constructor syntax
Date: Sat, 4 Dec 2010 15:54:20 -0500	[thread overview]
Message-ID: <AANLkTin9Bdea8CZjx3OR1NsFFawSu7G8KGD_ZiTvGr1S@mail.gmail.com> (raw)
In-Reply-To: <AANLkTi=brs65VkfeM0qt+fLFVd=Vc7PMm809VstVN=Q-@mail.gmail.com>

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 <lukstafi@gmail.com> wrote:
> On Sat, Dec 4, 2010 at 9:14 PM, Jacques Le Normand <rathereasy@gmail.com> 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
>


  reply	other threads:[~2010-12-04 20:54 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-04 19:25 Jacques Le Normand
2010-12-04 19:36 ` [Caml-list] " gasche
2010-12-04 19:39 ` Basile Starynkevitch
2010-12-04 19:41 ` Lukasz Stafiniak
2010-12-04 20:14   ` Jacques Le Normand
2010-12-04 20:22     ` Lukasz Stafiniak
2010-12-04 20:54       ` Jacques Le Normand [this message]
2010-12-04 21:00         ` Lukasz Stafiniak
2010-12-04 21:06           ` Jacques Le Normand
2010-12-05  8:10             ` Lukasz Stafiniak
2010-12-05  8:16               ` Lukasz Stafiniak
2010-12-05  8:25               ` Lukasz Stafiniak
2010-12-05  8:35                 ` bluestorm
2010-12-06  0:21                   ` Jacques Garrigue
     [not found] <1245532236.1431213.1291490707868.JavaMail.root@zmbs3.inria.fr>
2010-12-06  9:11 ` Daniel de Rauglaudre

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