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 LAA29616; Thu, 15 Aug 2002 11:18:55 +0200 (MET DST)
X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f
Received: (from weis@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id LAA29778 for caml-list@pauillac.inria.fr; Thu, 15 Aug 2002 11:18:54 +0200 (MET DST)
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 RAA27166 for <caml-list@pauillac.inria.fr>; Tue, 13 Aug 2002 17:12:02 +0200 (MET DST)
Received: from mail.tepkom.ru (mail.tepkom.ru [195.9.10.14])
	by nez-perce.inria.fr (8.11.1/8.11.1) with ESMTP id g7DFC0b10417
	for <caml-list@inria.fr>; Tue, 13 Aug 2002 17:12:00 +0200 (MET DST)
Received: from youngkouzdra (max.tepkom.ru [195.19.226.43])
	by mail.tepkom.ru (8.11.6/8.11.6) with SMTP id g7DFBfF01453;
	Tue, 13 Aug 2002 19:11:41 +0400 (MSD)
	(envelope-from msk@post.tepkom.ru)
Message-ID: <012001c242db$ba4c9f90$2be213c3@youngkouzdra>
From: "Anton Moscal" <msk@mail.tepkom.ru>
To: "Oleg" <oleg_inconnu@myrealbox.com>
Cc: <caml-list@inria.fr>
References: <Pine.A32.3.95.1020813125617.63202A-100000@ibm1.cicrp.jussieu.fr> <200208131430.KAA23206@hickory.cc.columbia.edu>
Subject: Re: [Caml-list] Doubly-linked list
Date: Tue, 13 Aug 2002 19:11:40 +0400
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
FL-Build: Fidolook Express 2001 UIExt. BuildID: 3BC00FAD (7/10/2001 12:17:49).
Sender: owner-caml-list@pauillac.inria.fr
Precedence: bulk

Hello, Oleg!
You wrote to "Diego Olivier Fernandez Pons"
<Diego-Olivier.FERNANDEZ-PONS@cicrp.jussieu.fr> on Tue, 13 Aug 2002
10:30:59 -0400:

 O> Will it include imperative doubly-linked list or are all data types
 O> going to
 O> be purely functional? It's hard for me to think of an efficient
 O> purely  functional doubly-linked list.

For example:

type 'a dll = 'a list (* before *) * 'a * 'a list (* next *)

let ins_after elem (bef, cur, aft) = (cur::bef, elem, aft)
let next = function (bef, cur, (cur'::aft)) -> Some ((cur::bef), cur', aft)
| _ -> None
let prev = function ((cur'::bef), cur, aft) -> Some (bef, cur', (cur::aft))
| _ -> None
...

Anton Moscal.
-------------------
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