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 DAA26604; Sat, 1 May 2004 03:59:21 +0200 (MET DST) X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id DAA28581 for ; Sat, 1 May 2004 03:59:20 +0200 (MET DST) Received: from smtp1.adl2.internode.on.net (smtp1.adl2.internode.on.net [203.16.214.181]) by nez-perce.inria.fr (8.12.10/8.12.10) with ESMTP id i411xGEV024828 for ; Sat, 1 May 2004 03:59:18 +0200 Received: from [192.168.1.200] (ppp116-155.lns1.syd2.internode.on.net [150.101.116.155]) by smtp1.adl2.internode.on.net (8.12.9/8.12.9) with ESMTP id i411xBZq050917 for ; Sat, 1 May 2004 11:29:12 +0930 (CST) Subject: [Caml-list] List.rev From: skaller Reply-To: skaller@users.sourceforge.net To: caml-list In-Reply-To: <4092A448.6080909@1969.ws> References: <20040430175429.GB11118@online.fr> <4092A448.6080909@1969.ws> Content-Type: text/plain Message-Id: <1083376750.2581.183.camel@pelican.wigram> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-4) Date: 01 May 2004 11:59:10 +1000 Content-Transfer-Encoding: 7bit X-Miltered: at nez-perce with ID 40930474.001 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Loop: caml-list@inria.fr X-Spam: no; 0.00; sourceforge:01 2004:99 9660:01 glebe:01 rec:01 nsw:01 snail:02 complexity:02 match:02 checkout:02 2037:03 wrote:03 wrote:03 recursive:03 btw:03 Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk On Sat, 2004-05-01 at 05:08, Karl Zilles wrote: > Rahul Siddharthan wrote: > List.rev is not tail recursive, so you wouldn't want to use this > function on industrial size lists. But it should be. Why isn't it??? let rev lst = let r = ref [] in let rec aux lst = match lst with | [] -> !r | h::t -> r:= h :: !r; aux t in aux lst BTW: documentation that says a function is 'tail recursive' is misguided. That's an implementation detail of no possible use to a user of the function. The user may benefit from knowing the complexity of the function in terms of speed and auxilliary storage required. -- 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