From: Alain Frisch <Alain.Frisch@inria.fr>
To: Damien Doligez <damien.doligez@inria.fr>
Cc: caml users <caml-list@inria.fr>
Subject: Re: [Caml-list] Type constraints
Date: Tue, 07 Dec 2004 19:08:50 +0100 [thread overview]
Message-ID: <41B5F1B2.3000503@inria.fr> (raw)
In-Reply-To: <A940F6C2-4877-11D9-8195-000D9345235C@inria.fr>
Damien Doligez wrote:
> Yes, well I simplified it a bit too much. Try this instead:
>
> let module M = struct let v = ref [] end in M.v;;
I still don't understand. Compare:
# module M = struct let v = ref [] end;;
module M : sig val v : '_a list ref end
# module M : sig val v : 'a -> 'a end = struct let v x = x end;;
module M : sig val v : 'a -> 'a end
Of course, the type variable in the first example must not be
generalized, and it isn't. In the second example, there is no problem.
We get:
# M.v;;
- : 'a -> 'a = <fun>
So why not give the same type scheme to:
let module M : sig val v : 'a -> 'a end = struct let v x = x end in M.v
?
Alain
next prev parent reply other threads:[~2004-12-07 20:01 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 [this message]
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
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=41B5F1B2.3000503@inria.fr \
--to=alain.frisch@inria.fr \
--cc=caml-list@inria.fr \
--cc=damien.doligez@inria.fr \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).