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=AWL autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by yquem.inria.fr (Postfix) with ESMTP id 0E0B2BBC1 for ; Wed, 23 Apr 2008 18:15:00 +0200 (CEST) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnABAMb9DkjAXQIniGdsb2JhbACRUgEBAQ8mm14 X-IronPort-AV: E=Sophos;i="4.25,700,1199660400"; d="scan'208";a="25403364" Received: from concorde.inria.fr ([192.93.2.39]) by mail4-smtp-sop.national.inria.fr with ESMTP; 23 Apr 2008 18:14:59 +0200 Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id m3NGEx17009538 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Wed, 23 Apr 2008 18:14:59 +0200 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnABAOr8DkjBL1AZiGdsb2JhbACRUgEBAQ8mm2M X-IronPort-AV: E=Sophos;i="4.25,700,1199660400"; d="scan'208";a="9972062" Received: from gw.exalead.com (HELO exalead.com) ([193.47.80.25]) by mail2-smtp-roc.national.inria.fr with ESMTP; 23 Apr 2008 18:14:59 +0200 Received: from [192.168.204.148] (madpc064.exalead.com [192.168.204.148]) (authenticated bits=0) by exalead.com (8.14.2/8.14.0) with ESMTP id m3NGEwE5010536; Wed, 23 Apr 2008 18:14:59 +0200 Message-ID: <480F6082.6030901@exalead.com> Date: Wed, 23 Apr 2008 18:14:58 +0200 From: Berke Durak User-Agent: Thunderbird 1.5.0.10 (X11/20070221) MIME-Version: 1.0 To: Christophe Raffalli Cc: Caml-list List Subject: Re: [Caml-list] How to make a value uncomparable References: <480F3E52.60300@exalead.com> <480F578F.9040403@univ-savoie.fr> In-Reply-To: <480F578F.9040403@univ-savoie.fr> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Miltered: at concorde with ID 480F6083.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; berke:01 durak:01 berke:01 durak:01 christophe:01 raffalli:01 sig:01 val:01 val:01 struct:01 structurally:01 sig:01 struct:01 equality:01 wrote:01 Christophe Raffalli wrote: >> =20 >> module Uncomparable : >> sig >> type 'a t >> val make : 'a -> 'a t >> val get : 'a t -> 'a >> end >> =3D >> struct >> type 'a t =3D unit -> 'a >> =20 >> let make x =3D fun _ -> x >> =20 >> let get x =3D x () >> end >> =20 Indeed, that's a much simpler solution! :) But there's one minor difference: physical equality works on Weak.t but not on functions. But that can be handled by using a ref to a function. module Structurally_uncomparable : sig type 'a t val make : 'a -> 'a t val get : 'a t -> 'a end = struct type 'a t = (unit -> 'a) ref let make x = ref (fun _ -> x) let get x = (!x)() end -- Berke DURAK