From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Thierry Volpiatto Newsgroups: gmane.emacs.devel Subject: Re: What to do for faster `remove-duplicates'? Date: Wed, 06 May 2015 20:48:02 +0200 Message-ID: <87a8xhee59.fsf@gmail.com> References: <87383atb2p.fsf@gmail.com> <873839ltoa.fsf@gmail.com> <87bnhxeh4j.fsf@gmail.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1430938120 32710 80.91.229.3 (6 May 2015 18:48:40 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 6 May 2015 18:48:40 +0000 (UTC) Cc: emacs-devel To: bruce.connor.am@gmail.com Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed May 06 20:48:35 2015 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Yq4N0-0002Uj-QV for ged-emacs-devel@m.gmane.org; Wed, 06 May 2015 20:48:34 +0200 Original-Received: from localhost ([::1]:46755 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yq4N0-00033Q-Cr for ged-emacs-devel@m.gmane.org; Wed, 06 May 2015 14:48:34 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:41069) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yq4Mf-0002ww-A2 for emacs-devel@gnu.org; Wed, 06 May 2015 14:48:22 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yq4Mc-0003u5-5F for emacs-devel@gnu.org; Wed, 06 May 2015 14:48:13 -0400 Original-Received: from mail-wi0-x22a.google.com ([2a00:1450:400c:c05::22a]:36947) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yq4Mb-0003sZ-Ui for emacs-devel@gnu.org; Wed, 06 May 2015 14:48:10 -0400 Original-Received: by widdi4 with SMTP id di4so33278076wid.0 for ; Wed, 06 May 2015 11:48:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=references:from:to:cc:subject:in-reply-to:date:message-id :mime-version:content-type; bh=iUEg4Ug49m0EWaVCpNMP/uddt7rpebaxotruhMqH+K4=; b=tdu53mNZTSdCBZNX0mjlWvGbQkIn0PZPBHPysYEBJgaihZwlrYnOFkNDAFox2KTk2+ tEan03Ln0GAwx/tfq64AUQH1R7Xx8TK+9Fx5KL6sJIyvD1GqRg0D+DoOQJcUT3Oc7Jb6 YylcOSxzZk/ryou8pzq6fi9KwdUh+8VWHe1Fv/BHVJONxytY/9k/5jTle9U2tmZ5ITPk 9zU1Taa0b9n0ydHyB4VCDir4G8txoKHnsHmjxs6LSctYxCurKek2Q8Qo+6VP/XSTEqHR dFMz3kCqvTNlVxLSMkudHbKf7l/XrrgE7U1J9VjVbvZXOBEPw8hrHwvDhD5uDTI0+QsN +kXQ== X-Received: by 10.180.105.233 with SMTP id gp9mr16682697wib.83.1430938088499; Wed, 06 May 2015 11:48:08 -0700 (PDT) Original-Received: from dell-14z ([37.160.22.27]) by mx.google.com with ESMTPSA id y7sm4001651wjw.16.2015.05.06.11.48.06 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 06 May 2015 11:48:07 -0700 (PDT) In-reply-to: X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a00:1450:400c:c05::22a 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:186297 Archived-At: Artur Malabarba writes: >>> Looks good, please install. >> >> Not so good as now it is no more destructive for a seq > 100. > > Just pushed the following: > > modified lisp/subr.el > @@ -424,12 +424,12 @@ one is kept." > (unless (gethash elt hash) > (puthash elt elt hash) > (push elt res))) > - (nreverse res)) > + (setcdr list (cdr (nreverse res)))) > (let ((tail list)) > (while tail > (setcdr tail (delete (car tail) (cdr tail))) > - (setq tail (cdr tail)))) > - list)) > + (setq tail (cdr tail))))) > + list) Also I am not sure pushing to a list (res) and returning this list at end is faster than returning the maphash. At first it looks faster but the time spent consing+gc'ing seems longer than just returning the maphash. But I may be wrong, just a thought. -- Thierry Get my Gnupg key: gpg --keyserver pgp.mit.edu --recv-keys 59F29997