From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by yquem.inria.fr (Postfix) with ESMTP id A5FD5BBC1 for ; Tue, 19 Feb 2008 14:41:19 +0100 (CET) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAExrukfAXQInh2dsb2JhbACQTQEBAQgKKZ1D X-IronPort-AV: E=Sophos;i="4.25,376,1199660400"; d="scan'208";a="9350829" Received: from concorde.inria.fr ([192.93.2.39]) by mail3-smtp-sop.national.inria.fr with ESMTP; 19 Feb 2008 14:41:19 +0100 Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id m1JDfIlC020432 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Tue, 19 Feb 2008 14:41:19 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ao8CACFqukeCNhAB/2dsb2JhbACuSg X-IronPort-AV: E=Sophos;i="4.25,376,1199660400"; d="scan'208";a="9350472" Received: from kurims.kurims.kyoto-u.ac.jp ([130.54.16.1]) by mail3-smtp-sop.national.inria.fr with ESMTP; 19 Feb 2008 14:38:03 +0100 Received: from localhost (orion [130.54.16.5]) by kurims.kurims.kyoto-u.ac.jp (8.13.8/8.13.8) with ESMTP id m1JDc0UQ004275; Tue, 19 Feb 2008 22:38:00 +0900 (JST) Date: Tue, 19 Feb 2008 22:37:59 +0900 (JST) Message-Id: <20080219.223759.125111280.keiko@kurims.kyoto-u.ac.jp> To: Julien.Signoles@lri.fr Cc: johannes.kanig@lri.fr, caml-list@inria.fr Subject: Re: [Caml-list] polymorphic variants and promotion From: Keiko Nakata In-Reply-To: References: <926565e50802190223r456d0ec2we4b8a4f51b134f42@mail.gmail.com> X-Mailer: Mew version 4.2 on Emacs 20.7 / Mule 4.1 (AOI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Miltered: at concorde with ID 47BADC7E.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; variants:01 coercions:01 polymorphic:01 caml-list:01 coercion:01 int:01 int:01 differences:06 indeed:07 kyoto-u:10 kurims:10 between:13 instead:14 double:16 double:16 Hello, indeed we need to use double coercion, instead of single: # ((`A 1 : [ `A of int ]) : [ `A of int ] :> [> `A of int ]);; - : [> `A of int ] = `A 1 # ((`A 1 : [ `A of int ]) :> [> `A of int ]);; - : [ `A of int ] = `A 1 This explains a little to me about the differences between double and single coercions. Thanks. With best, Keiko