From: nakata keiko <keiko@kaba.or.jp>
To: garrigue@math.nagoya-u.ac.jp
Cc: caml-list@inria.fr
Subject: Re: [Caml-list] Type constraints
Date: Thu, 09 Dec 2004 09:56:02 +0900 (JST) [thread overview]
Message-ID: <20041209.095602.74680404.keiko@kaba.or.jp> (raw)
In-Reply-To: <8002B033-4906-11D9-8195-000D9345235C@inria.fr>
Damien Doligez wrote:
> On 8 Dec 2004, at 04:30, nakata keiko wrote:
>
> > This does not answer to me why this works,
> >
> > #type t = { t : 'a. 'a -> 'a}
> >
> > #let v = let module M = struct let t x = x end in {t = M.t} in (v.t 5,
> > v.t true)
>
> You'll have to ask Jacques about this. He's the one who added
> polymorphic
> methods and polymorphic record labels to the language, and I'm not sure
> I understand all the implications.
I have the impression that if the above code is type checked,
then, something like the following code could be type checked.
What is the differences?
> > However, if I can write something like
> >
> > #let v : 'a. 'a -> 'a = let module M = struct let t x = x end in M.t
> > in (v 5, v true)
> >
> > then, it would be type checked ?
>
> I doubt it. For the moment, a type constraint can only specialize the
> type of an expression. You're asking for a generalization constraint.
> I have no idea whether that can be implemented, but I think it would
> require some big changes to the typechecker.
Regards,
Keiko.
next prev parent reply other threads:[~2004-12-09 0:56 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-06 19:55 Jim Farrand
2004-12-07 7:12 ` [Caml-list] " Alain Frisch
2004-12-07 13:43 ` Damien Doligez
2004-12-07 14:57 ` Andreas Rossberg
2004-12-07 17:44 ` Damien Doligez
2004-12-07 18:08 ` Alain Frisch
2004-12-07 21:04 ` Damien Doligez
2004-12-07 21:43 ` Alain Frisch
2004-12-08 3:30 ` nakata keiko
[not found] ` <8002B033-4906-11D9-8195-000D9345235C@inria.fr>
2004-12-09 0:56 ` nakata keiko [this message]
2004-12-09 1:27 ` Jacques Garrigue
2004-12-08 10:53 ` Damien Doligez
2004-12-08 12:39 ` Alain Frisch
2004-12-08 14:23 ` Jacques Garrigue
2004-12-09 3:07 ` skaller
2004-12-09 4:53 ` Jacques Garrigue
2004-12-08 16:10 ` Xavier Leroy
2004-12-07 18:13 ` William Lovas
2004-12-08 0:27 ` Jacques Garrigue
2004-12-07 18:41 ` Boris Yakobowski
2004-12-07 19:38 ` Jim Farrand
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