From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=AWL autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail1-relais-roc.national.inria.fr (mail1-relais-roc.national.inria.fr [192.134.164.82]) by yquem.inria.fr (Postfix) with ESMTP id 2566FBBC1 for ; Thu, 6 Mar 2008 08:41:18 +0100 (CET) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAANouz0eBrw8En2dsb2JhbACQeQEBAQEBBgoJCBiaHA X-IronPort-AV: E=Sophos;i="4.25,454,1199660400"; d="scan'208";a="9020858" Received: from ext.lri.fr ([129.175.15.4]) by mail1-smtp-roc.national.inria.fr with ESMTP; 06 Mar 2008 08:41:17 +0100 Received: from localhost (localhost [127.0.0.1]) by ext.lri.fr (Postfix) with ESMTP id 03D20A4687; Thu, 6 Mar 2008 08:41:18 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at lri.fr Received: from ext.lri.fr ([127.0.0.1]) by localhost (ext.lri.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AQApHxk287dn; Thu, 6 Mar 2008 08:41:17 +0100 (CET) Received: from [129.175.4.117] (lri4-117 [129.175.4.117]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ext.lri.fr (Postfix) with ESMTP id DF9C6A466C; Thu, 6 Mar 2008 08:41:17 +0100 (CET) Message-ID: <47CFA134.50800@lri.fr> Date: Thu, 06 Mar 2008 08:45:56 +0100 From: =?UTF-8?B?SmVhbi1DaHJpc3RvcGhlIEZpbGxpw6J0cmU=?= User-Agent: Thunderbird 1.5.0.14pre (X11/20071023) MIME-Version: 1.0 To: Jon Harrop Cc: caml-list@yquem.inria.fr Subject: Re: [Caml-list] Canonical Set/Map datastructure? References: <47CECF23.1020508@exalead.com> <47CED80A.1010504@frisch.fr> <200803052003.46517.jon@ffconsultancy.com> In-Reply-To: <200803052003.46517.jon@ffconsultancy.com> X-Enigmail-Version: 0.94.2.0 OpenPGP: url=http://www.lri.fr/~filliatr/mykey.asc Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam: no; 0.00; filliatre:01 lri:01 frisch:01 hash-consing:01 structurally:01 lri:01 filliatr:01 publis:01 hash-consing:01 equality:01 equality:01 wrote:01 wrote:01 caml-list:01 strings:01 Jon Harrop wrote: > On Wednesday 05 March 2008 17:27:38 Alain Frisch wrote: >> Patricia trees work fine when the set elements can easily be represented >> as strings of bits. >> ... >> structural equality = physical equality = set equality > > This is very interesting. What are the disadvantages? I'm guessing: slow value > creation for small values and heavy memory consumption. Regarding memory consumpion, it is true that hash-consing tables are using memory, but sharing structurally equal values may also save some space; see for instance the benchmarks on page 4 of http://www.lri.fr/~filliatr/ftp/publis/hash-consing2.ps -- Jean-Christophe