From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id BAA23885; Thu, 21 Aug 2003 01:33:07 +0200 (MET DST) X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f 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 BAA25474 for ; Thu, 21 Aug 2003 01:33:06 +0200 (MET DST) Received: from kurims.kurims.kyoto-u.ac.jp (kurims.kurims.kyoto-u.ac.jp [130.54.16.1]) by concorde.inria.fr (8.11.1/8.11.1) with ESMTP id h7KNX4f02811 for ; Thu, 21 Aug 2003 01:33:04 +0200 (MET DST) Received: from localhost (suiren.kurims.kyoto-u.ac.jp [130.54.16.25]) by kurims.kurims.kyoto-u.ac.jp (8.9.3p2/3.7W) with ESMTP id IAA11216; Thu, 21 Aug 2003 08:32:58 +0900 (JST) To: carette@mcmaster.ca Cc: caml-list@inria.fr Subject: RE: [Caml-list] does class polymorphism need to be so complicated? In-Reply-To: <000f01c36740$1bfe14b0$1b447182@cas.mcmaster.ca> References: <000f01c36740$1bfe14b0$1b447182@cas.mcmaster.ca> X-Mailer: Mew version 1.94.2 on Emacs 21.2 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20030821083400B.garrigue@kurims.kyoto-u.ac.jp> Date: Thu, 21 Aug 2003 08:34:00 +0900 From: Jacques Garrigue X-Dispatcher: imput version 20000228(IM140) X-Loop: caml-list@inria.fr X-Spam: no; 0.00; jacques:01 caml-list:01 naively:01 unification:01 garrigue:01 coq:02 unit:03 classes:03 dependent:03 object:03 types:03 complicated:04 seems:05 mean:05 define:05 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk From: "Jacques Carette" > > The extension of Brian's code to rows with more than one field is obvious > > though, isn't it? > > Indeed - but that rather begs the question of why are classes and rows > different, as they (naively perhaps) seem so ripe for 'unification'. > > The work on dependent records in Coq seems highly related (and looks quite > successful, at least in the context of the FOC project). I'm not sure of what you mean by rows. At least, in the above examples, rows were used as a name for object types. And a class type is just an object type plus a bit more information. In that respect, I would say they are one and the same thing, and there is no unification needed. class type printable = object method print : unit end also defines the type type printable = < print : unit > Of course there could be a discussion on whether we really need class types, or whether classes should define a class type or not, etc... Jacques Garrigue ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners