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 nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by yquem.inria.fr (Postfix) with ESMTP id 13D1CBB83 for ; Thu, 24 Aug 2006 17:03:27 +0200 (CEST) Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35]) by nez-perce.inria.fr (8.13.6/8.13.6) with ESMTP id k7OF2uec014474 for ; Thu, 24 Aug 2006 17:03:26 +0200 Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id QAA23395 for ; Thu, 24 Aug 2006 16:52:11 +0200 (MET DST) Received: from mail.barettadeit.com (h213-255-109-130.albacom.net [213.255.109.130] (may be forged)) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id k7OEqBMU015114 for ; Thu, 24 Aug 2006 16:52:11 +0200 Received: from [10.0.0.10] (alex.barettalocal.com [10.0.0.10]) by mail.barettadeit.com (Postfix) with ESMTP id 9B07C19CD6E for ; Thu, 24 Aug 2006 16:55:33 +0200 (CEST) Message-ID: <44EDBD0D.1070502@studio.baretta.com> Date: Thu, 24 Aug 2006 16:51:57 +0200 From: Alessandro Baretta User-Agent: Thunderbird 1.5.0.4 (X11/20060713) MIME-Version: 1.0 To: Ocaml Subject: Re: [Caml-list] 'a & string unification issue References: <44EB38CA.8080800@studio.baretta.com> <20060823.082459.99830220.garrigue@math.nagoya-u.ac.jp> In-Reply-To: <20060823.082459.99830220.garrigue@math.nagoya-u.ac.jp> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Miltered: at nez-perce with ID 44EDBFA0.00B by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Miltered: at concorde with ID 44EDBD1B.001 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; baretta:01 baretta:01 unification:01 subtyping:01 mli:01 wrote:01 caml-list:01 constraint:01 inferred:02 string:02 garrigue:03 garrigue:03 alessandro:03 alessandro:03 jacques:03 Jacques Garrigue wrote: > From: Alessandro Baretta > Looks like your implementation contains at least `Options, while the > interface doesn't. Since it is in a contravariant position, you should > be able to remove it from the implementation by subtyping. > > Jacques Garrigue Ah, yes! The error message was so long that I missed the relevant spot, and the `&' sign tricked me into thinking that the issue was there. And, yes, the problem is the "> `Options" constraint, which appears in the inferred signature of the function, but not in the mli. Thank you very much. Alex