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 concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by yquem.inria.fr (Postfix) with ESMTP id 7269CBC69 for ; Fri, 4 May 2007 03:10:47 +0200 (CEST) Received: from ipmail01.adl2.internode.on.net (ipmail01.adl2.internode.on.net [203.16.214.140]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id l441AiDJ026448 for ; Fri, 4 May 2007 03:10:46 +0200 X-IronPort-AV: E=Sophos;i="4.14,487,1170595800"; d="scan'208";a="123129250" Received: from ppp8-148.lns1.syd7.internode.on.net (HELO [192.168.1.201]) ([59.167.8.148]) by ipmail01.adl2.internode.on.net with ESMTP; 04 May 2007 10:40:08 +0930 Subject: Re: [Caml-list] wrapping parameterized types From: skaller To: Chris King Cc: Christopher L Conway , caml-list@yquem.inria.fr In-Reply-To: <875c7e070705031616w50ca595m2e55bda049ba7aa6@mail.gmail.com> References: <4a051d930705031531m396e42e7i6212137e2fb9cd53@mail.gmail.com> <875c7e070705031616w50ca595m2e55bda049ba7aa6@mail.gmail.com> Content-Type: text/plain Date: Fri, 04 May 2007 11:10:03 +1000 Message-Id: <1178241003.7436.10.camel@rosella.wigram> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit X-Miltered: at concorde with ID 463A8814.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; existential:01 o'caml:01 existential:01 sourceforge:01 polymorphic:01 wrote:01 wrote:01 caml-list:01 confused:03 types:03 types:03 thu:05 chris:06 function:08 christopher:08 On Thu, 2007-05-03 at 19:16 -0400, Chris King wrote: > On 5/3/07, Christopher L Conway wrote: > The solution is to use existential types. In a record, you can tell > O'Caml that a particular function _must_ be polymorphic: > > type 'b mylistfun = { listfun: 'a. 'a list -> 'b } I'm still confused why this is called an existential, when clearly the quantification is universal. -- John Skaller Felix, successor to C++: http://felix.sf.net