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 KAA30561; Thu, 2 May 2002 10:33:44 +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 KAA30557 for ; Thu, 2 May 2002 10:33:43 +0200 (MET DST) Received: from fichte.ai.univie.ac.at (fichte.ai.univie.ac.at [131.130.174.156]) by concorde.inria.fr (8.11.1/8.11.1) with ESMTP id g428XgD09849 for ; Thu, 2 May 2002 10:33:42 +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 KAA16289; Thu, 2 May 2002 10:33:35 +0200 Date: Thu, 2 May 2002 10:33:35 +0200 From: Markus Mottl To: John Prevost Cc: OCaml Mailing list Subject: Re: [Caml-list] Breaking out of iterative loops Message-ID: <20020502083335.GB16030@fichte.ai.univie.ac.at> Mail-Followup-To: John Prevost , OCaml Mailing list References: <20020430202706.GA6791@vincent> <200204302331.32905.johan.baltie@wanadoo.fr> <3CD08EE3.9010202@ozemail.com.au> <863cxbmgww.fsf@laurelin.dementia.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <863cxbmgww.fsf@laurelin.dementia.org> User-Agent: Mutt/1.3.26i Organization: Austrian Research Institute for Artificial Intelligence Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk On Wed, 01 May 2002, John Prevost wrote: > The drawback to allowing: > > let rec ones = 1 :: ones > > and such expressions is that when looking at the definition of, for > example, 'a list and length, one would expect it to be guaranteed that > length terminates. Since you can't prevent recursive use of > constructors, well, you can no longer guarantee that. I second this. Does anybody here really benefit from such cyclic structures? I haven't found a single practical case where this was useful, but would assume that some future program transformation tools that use proofs by induction would have an easier life if this were disallowed... Regards, Markus Mottl -- Markus Mottl markus@oefai.at Austrian Research Institute for Artificial Intelligence http://www.oefai.at/~markus ------------------- 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