From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <vincent.aravantinos@yahoo.fr>
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr
X-Spam-Level: 
X-Spam-Status: No, score=0.4 required=5.0 tests=AWL,DNS_FROM_RFC_ABUSE 
	autolearn=disabled version=3.1.3
X-Original-To: caml-list@yquem.inria.fr
Delivered-To: caml-list@yquem.inria.fr
Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39])
	by yquem.inria.fr (Postfix) with ESMTP id F266FBC6B
	for <caml-list@yquem.inria.fr>; Sat,  8 Sep 2007 13:39:08 +0200 (CEST)
Received: from smtp007.mail.ukl.yahoo.com (smtp007.mail.ukl.yahoo.com [217.12.11.96])
	by concorde.inria.fr (8.13.6/8.13.6) with SMTP id l88Bd8Nm017061
	for <caml-list@yquem.inria.fr>; Sat, 8 Sep 2007 13:39:08 +0200
Received: (qmail 17022 invoked from network); 8 Sep 2007 11:39:06 -0000
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
  s=s1024; d=yahoo.fr;
  h=Received:X-YMail-OSG:In-Reply-To:References:Mime-Version:Content-Type:Message-Id:Cc:Content-Transfer-Encoding:From:Subject:Date:To:X-Mailer;
  b=uYxbzyYb6mUCQEr1aN+uNPXjhVAzL1rzVxmPZKQ8/i6Q0i3UCaaZLg8wjIsxFqqsdC6jcKAFAQtIjcMCaLUbjxQ3mvNsR/5zY1zWmJ2LM89taxR7/Eek8TANBU6yswRP8/NXOOBOAgEcOSC7CbNeKQ6nhCnl8Ukn0GmiJJys8DA=  ;
Received: from unknown (HELO ?192.168.0.11?) (vincent.aravantinos@82.229.199.66 with plain)
  by smtp007.mail.ukl.yahoo.com with SMTP; 8 Sep 2007 11:39:06 -0000
X-YMail-OSG: 3oB4S2wVM1lo1UxELvuf9qzRW_cR3W4Y3gO8cBFZkZoa6RDzPWt39rnzUQBROXgZ2lx7hUMNGZgEmhU.Nmjwqbcket8AVOPh8oURGL2anucIoDyUzkknj7dhc8IIga9GcWE-
In-Reply-To: <002d01c7f1ed$77f31130$67d93390$@ac.kr>
References: <002d01c7f1ed$77f31130$67d93390$@ac.kr>
Mime-Version: 1.0 (Apple Message framework v752.2)
Content-Type: text/plain; charset=WINDOWS-1252; delsp=yes; format=flowed
Message-Id: <47BC498C-B6EA-443E-B990-991973A53179@yahoo.fr>
Cc: <caml-list@yquem.inria.fr>
Content-Transfer-Encoding: quoted-printable
From: Vincent Aravantinos <vincent.aravantinos@yahoo.fr>
Subject: Re: [Caml-list] A signature that cannot be inhabited by any structures
Date: Sat, 8 Sep 2007 13:39:04 +0200
To: "Hyeonseung Im" <genilhs@postech.ac.kr>
X-Mailer: Apple Mail (2.752.2)
X-Miltered: at concorde with ID 46E289DC.001 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)!
X-Spam: no; 0.00; ocaml:01 ocaml:01 sig:01 val:01 val:01 sig:01 bug:01 bug:01 sml:01 caml-list:01 caml-list:01 int:01 int:01 modules:02 caml:02 


Le 8 sept. 07 =E0 09:54, Hyeonseung Im a =E9crit :

> Hi all.
>
>
>
> I found something interesting. In the OCaml, the following =20
> signature is valid. (I tested it with the OCaml version 3.09.2 and =20
> 3.10.0.)
>
>
>
> (In the top-level)
>
> # module type S =3D sig val x : int val x : float end;;
>
> module type S =3D sig val x : int val x : float end
>
>
>
> But, this module type seems not to be inhabited by any structures. =20
> On the contrary, in the SML this sort of module types cannot be =20
> defined. (Actually, it raises an error: the duplication of variables.)
>
>
>
> I wonder if this is a feature of the OCaml (or maybe a bug in the =20
> implementation).
>
> I=92d appreciate any comment on it.
>
>
>
> Hyeonseung Im.
>

Hi,

apart from the question "is this a bug or a feature ?", I'd like to =20
say this is quite useful when you want to do some kind of inheritance =20=

between modules.
See http://caml.inria.fr/pub/ml-archives/caml-list/=20
2007/08/8f1e17b89b64d66ae406521947709aff.en.html for the different =20
situation for type replication.

Vincent=