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=3.1 required=5.0 tests=AWL,DNS_FROM_SECURITYSAGE, MAILTO_TO_SPAM_ADDR,SPF_FAIL autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by yquem.inria.fr (Postfix) with ESMTP id 7C552BB84 for ; Sat, 1 Nov 2008 14:01:34 +0100 (CET) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApMBAHjvC0lQW+UCe2dsb2JhbACUEQEBFiIEtVWDUQ X-IronPort-AV: E=Sophos;i="4.33,526,1220220000"; d="scan'208";a="16748052" Received: from discorde.inria.fr ([192.93.2.38]) by mail2-smtp-roc.national.inria.fr with ESMTP; 01 Nov 2008 14:01:34 +0100 Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by discorde.inria.fr (8.13.6/8.13.6) with ESMTP id mA1D1XE0002336 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Sat, 1 Nov 2008 14:01:34 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApMBAHjvC0lQW+UCe2dsb2JhbACUEQEBFiIEtVWDUQ X-IronPort-AV: E=Sophos;i="4.33,526,1220220000"; d="scan'208";a="16748050" Received: from main.gmane.org (HELO ciao.gmane.org) ([80.91.229.2]) by mail2-smtp-roc.national.inria.fr with ESMTP/TLS/AES256-SHA; 01 Nov 2008 14:01:33 +0100 Received: from list by ciao.gmane.org with local (Exim 4.43) id 1KwG6a-0006jy-Js for caml-list@inria.fr; Sat, 01 Nov 2008 13:01:28 +0000 Received: from ip-210.net-89-3-222.rev.numericable.fr ([89.3.222.210]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 01 Nov 2008 13:01:28 +0000 Received: from vanicat by ip-210.net-89-3-222.rev.numericable.fr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 01 Nov 2008 13:01:28 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: caml-list@inria.fr From: vanicat@debian.org (=?utf-8?Q?R=C3=A9mi?= Vanicat) Subject: Re: Private types Date: Sat, 01 Nov 2008 14:01:17 +0100 Organization: none Message-ID: <87ljw3iorm.dlv@maison.homelinux.org> References: <340C8DB35D244173AE527238DB359A19@countertenor> <04092D60-3BB6-49A6-8A04-0BFE3A2081BD@erratique.ch> <5687D906367C49F981398A97A5966E09@countertenor> <20081031.090842.254669920.garrigue@math.nagoya-u.ac.jp> <490BB657.5050301@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: ip-210.net-89-3-222.rev.numericable.fr Mail-Copy-To: never User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) Cancel-Lock: sha1:8dE2O0DkzyFN0jxH3q5VLHN8lHU= Sender: news X-Miltered: at discorde with ID 490C532D.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; subtyping:01 unification:01 compiler:01 edgar:98 wrote:01 coercion:01 writes:01 vanicat:01 vanicat:01 garrigue:03 jacques:03 let:03 debian:04 explicit:04 types:05 Edgar Friendly writes: > Jacques Garrigue wrote: > >> Your intuition is correct that it would theoretically be possible to >> try subtyping in place of unification in some cases. The trouble is >> that thoses cases are not easy to specify (so that it would be hard >> for the programmer to known when he can remove a coercion), > > Does the compiler really get any information from an explicit cast that > it can't figure out already? I can't come up with any example. you mean as in the following function ? let f x = (x : t :> t') -- Rémi Vanicat