From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: remove-duplicates performances Date: Fri, 20 May 2011 15:01:07 -0300 Message-ID: References: <877h9lv5tl.fsf@gmail.com> <878vu1qwde.fsf@fencepost.gnu.org> <87pqndcqfr.fsf@gmail.com> <871uztqpb7.fsf@fencepost.gnu.org> <87k4dlcm82.fsf@gmail.com> <87tycpp8nt.fsf@fencepost.gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1305914481 27878 80.91.229.12 (20 May 2011 18:01:21 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 20 May 2011 18:01:21 +0000 (UTC) Cc: emacs-devel@gnu.org To: David Kastrup Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri May 20 20:01:17 2011 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QNU0i-00066J-LF for ged-emacs-devel@m.gmane.org; Fri, 20 May 2011 20:01:16 +0200 Original-Received: from localhost ([::1]:41507 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNU0h-0006zB-VP for ged-emacs-devel@m.gmane.org; Fri, 20 May 2011 14:01:15 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:37831) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNU0e-0006yz-D1 for emacs-devel@gnu.org; Fri, 20 May 2011 14:01:13 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QNU0d-0006JU-EI for emacs-devel@gnu.org; Fri, 20 May 2011 14:01:12 -0400 Original-Received: from fencepost.gnu.org ([140.186.70.10]:58391) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNU0d-0006JQ-BU for emacs-devel@gnu.org; Fri, 20 May 2011 14:01:11 -0400 Original-Received: from 213-159-126-200.fibertel.com.ar ([200.126.159.213]:42941 helo=ceviche.home) by fencepost.gnu.org with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1QNU0c-0005eq-SE; Fri, 20 May 2011 14:01:11 -0400 Original-Received: by ceviche.home (Postfix, from userid 20848) id 77D076610B; Fri, 20 May 2011 15:01:07 -0300 (ART) In-Reply-To: <87tycpp8nt.fsf@fencepost.gnu.org> (David Kastrup's message of "Fri, 20 May 2011 19:46:14 +0200") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 140.186.70.10 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:139562 Archived-At: >> Yes, i understand that, what i mean is you have to write a predicate >> each time, which could be inconvenient, instead of using :test 'equal. > With all due respect, you are proposing a hashtable as an alternate > mechanism. A hashtable requires a hash function and an equality test. We do have a built-in hash function that corresponds to the `equal' equality test, as well as one for the `eq' equality test. Total ordering predicates consistent with `eq' or `equal' OTOH are not currently provided, so the use of `sort' requires extra work. Stefan