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 MAA05590; Wed, 11 Jul 2001 12:13:48 +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 MAA05587 for ; Wed, 11 Jul 2001 12:13:47 +0200 (MET DST) Received: from fichte.ai.univie.ac.at (fichte.ai.univie.ac.at [131.130.174.156]) by concorde.inria.fr (8.11.1/8.10.0) with ESMTP id f6BADj915200; Wed, 11 Jul 2001 12:13:45 +0200 (MET DST) Received: (from markus@localhost) by fichte.ai.univie.ac.at (8.9.3/8.9.3/Debian 8.9.3-21) id MAA28455; Wed, 11 Jul 2001 12:13:44 +0200 Date: Wed, 11 Jul 2001 12:13:44 +0200 From: Markus Mottl To: Francois Pottier Cc: caml-list@inria.fr Subject: Re: [Caml-list] Dynamic types, casts, and rights amplification Message-ID: <20010711121344.A24765@fichte.ai.univie.ac.at> References: <20010703214914J.mrs35@cam.ac.uk> <20010711095236.A3033@pauillac.inria.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010711095236.A3033@pauillac.inria.fr>; from Francois.Pottier@inria.fr on Wed, Jul 11, 2001 at 09:52:36 +0200 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk On Wed, 11 Jul 2001, Francois Pottier wrote: > The first one generates exceptions dynamically and uses them as > tags. The fact that they are exceptions is irrelevant; what matters > is the ability to generate new tags at runtime. Unfortunately, this > piece of code isn't accepted by O'Caml, because it doesn't recognize > the type variable 'a in the exception declaration as bound by the > preceding type annotation. I also mentioned this limitation only a few days ago ("polymorphic" exceptions - they are not really polymorphic, of course, but make use of type variables bound elsewhere). Unfortunately, I didn't get any response so far whether there are inherent difficulties in implementing an extension. It wouldn't require any syntax change at all, won't break old code, but clearly gives more expressiveness to the developer. Any comments? Regards, Markus Mottl -- Markus Mottl markus@oefai.at Austrian Research Institute for Artificial Intelligence http://www.oefai.at/~markus ------------------- Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr