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 LAA31646; Thu, 2 May 2002 11:14:23 +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 LAA31642 for ; Thu, 2 May 2002 11:14:23 +0200 (MET DST) Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35]) by concorde.inria.fr (8.11.1/8.11.1) with ESMTP id g429EMD12118 for ; Thu, 2 May 2002 11:14:22 +0200 (MET DST) Received: (from fpottier@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id LAA31638 for caml-list@inria.fr; Thu, 2 May 2002 11:14:22 +0200 (MET DST) Date: Thu, 2 May 2002 11:14:22 +0200 From: Francois Pottier To: caml-list@inria.fr Subject: Re: [Caml-list] Breaking out of iterative loops Message-ID: <20020502111422.A31527@pauillac.inria.fr> Reply-To: Francois.Pottier@inria.fr References: <20020430202706.GA6791@vincent> <200204302331.32905.johan.baltie@wanadoo.fr> <3CD08EE3.9010202@ozemail.com.au> <863cxbmgww.fsf@laurelin.dementia.org> <20020502083335.GB16030@fichte.ai.univie.ac.at> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Mailer: Mutt 1.0i In-Reply-To: <20020502083335.GB16030@fichte.ai.univie.ac.at>; from markus@oefai.at on Thu, May 02, 2002 at 10:33:35AM +0200 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk On Thu, May 02, 2002 at 10:33:35AM +0200, Markus Mottl wrote: > > I second this. Does anybody here really benefit from such cyclic > structures? Yes, they can be useful, at least when they are mutable. Sometimes a pointer to a known node (i.e. a cyclic pointer) can be used instead of None. This can save the use of an option type, for instance. Anyway, in the presence of mutable fields, you can't prevent cyclic structures from appearing, so there is no point in disallowing their explicit definition. The situation is different in the case of immutable structures. I don't know of any situation where immutable, cyclic structures are useful. -- François Pottier Francois.Pottier@inria.fr http://pauillac.inria.fr/~fpottier/ ------------------- 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