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 RAA27019; Mon, 20 Sep 2004 17:43:10 +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 RAA28048 for ; Mon, 20 Sep 2004 17:43:09 +0200 (MET DST) Received: from smtp1.adl2.internode.on.net (smtp1.adl2.internode.on.net [203.16.214.181]) by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id i8KFh6Uq021820 for ; Mon, 20 Sep 2004 17:43:08 +0200 Received: from [192.168.1.200] (ppp202-133.lns1.syd3.internode.on.net [203.122.202.133]) by smtp1.adl2.internode.on.net (8.12.9/8.12.9) with ESMTP id i8KFh44Y068062; Tue, 21 Sep 2004 01:13:05 +0930 (CST) Subject: Re: [Caml-list] type var in functor instance? From: skaller Reply-To: skaller@users.sourceforge.net To: Jean-Christophe Filliatre Cc: caml-list In-Reply-To: <16718.50690.954027.644373@gargle.gargle.HOWL> References: <1095516867.2580.211.camel@pelican.wigram> <16718.50690.954027.644373@gargle.gargle.HOWL> Content-Type: text/plain Message-Id: <1095694982.2580.595.camel@pelican.wigram> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-4) Date: 21 Sep 2004 01:43:03 +1000 Content-Transfer-Encoding: 7bit X-Miltered: at concorde with ID 414EFA8B.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Loop: caml-list@inria.fr X-Spam: no; 0.00; caml-list:01 functor:01 sourceforge:01 2004:99 filliatre:01 instantiate:01 functor:01 pervasives:01 distro:01 hashtbl:01 hashtbl:01 9660:01 glebe:01 semantics:01 int:01 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk On Mon, 2004-09-20 at 21:58, Jean-Christophe Filliatre wrote: > skaller writes: > > Is it possible instantiate a functor with a module > > containing a type variable? I have a Set with t = int, > > and I now need 'a * int.. > Various unsatisfying solutions have been proposed, among which > > - to make a copy of Set with an additional type parameter eveywhere (I > attach such a module below. Beware: this is an old version of Set) Hmmm. I see. I think I understand why this is needed. Dependent typing problem? Set depends on element... > - to make an unfunctorized version of Set that uses Pervasives.compare, > thus polymorphic This is already in the standard distro for Hashtbl. Why not for Set and Map as well? Why is this unsatisfactory? I actually use heaps of Hashtbl of polymorphic kind and am ready to switch some over to an functor instance with key type int -- most of my tables use int keys and I hope to gain some performance and reasoning ability. The duplicate interface has let me experiment rapid prototyping style, then lock down the typing a bit, leaving the raw function names and semantics the same. I think that's nice -- one reason I use Hashtbl even when Set or Map would be better. -- John Skaller, mailto:skaller@users.sf.net voice: 061-2-9660-0850, snail: PO BOX 401 Glebe NSW 2037 Australia Checkout the Felix programming language http://felix.sf.net ------------------- 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