From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: pjb@informatimago.com (Pascal J. Bourguignon) Newsgroups: gmane.emacs.help Subject: Re: Vector and List Performance Date: Tue, 09 Jun 2009 14:51:22 +0200 Organization: Anevia SAS Message-ID: <7cd49d6051.fsf@pbourguignon.anevia.com> References: <7c63f5n48y.fsf@pbourguignon.informatimago.com> <4b62dc88-b861-4f9c-82d6-e175b2247c45@w40g2000yqd.googlegroups.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1244554932 26144 80.91.229.12 (9 Jun 2009 13:42:12 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 9 Jun 2009 13:42:12 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Jun 09 15:42:06 2009 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1ME1aX-0006kv-Q4 for geh-help-gnu-emacs@m.gmane.org; Tue, 09 Jun 2009 15:42:06 +0200 Original-Received: from localhost ([127.0.0.1]:47889 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ME1aT-0003Tr-Au for geh-help-gnu-emacs@m.gmane.org; Tue, 09 Jun 2009 09:42:01 -0400 Original-Path: news.stanford.edu!headwall.stanford.edu!news.glorb.com!news2.glorb.com!de-l.enfer-du-nord.net!usenet-fr.net!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!cleanfeed4-a.proxad.net!nnrp19-1.free.fr!not-for-mail Original-Newsgroups: gnu.emacs.help Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwAQMAAABtzGvEAAAABlBMVEUAAAD///+l2Z/dAAAA oElEQVR4nK3OsRHCMAwF0O8YQufUNIQRGIAja9CxSA55AxZgFO4coMgYrEDDQZWPIlNAjwq9 033pbOBPtbXuB6PKNBn5gZkhGa86Z4x2wE67O+06WxGD/HCOGR0deY3f9Ijwwt7rNGNf6Oac l/GuZTF1wFGKiYYHKSFAkjIo1b6sCYS1sVmFhhhahKQssRjRT90ITWUk6vvK3RsPGs+M1RuR mV+hO/VvFAAAAABJRU5ErkJggg== X-Accept-Language: fr, es, en X-Disabled: X-No-Archive: no User-Agent: Gnus/5.101 (Gnus v5.10.10) Emacs/22.2 (gnu/linux) Cancel-Lock: sha1:NzJmODA1ZDYxZTE2NTQ5MDk1MmU5YzcyZGJjMTdkMDYzMjE3MjM2ZQ== Original-Lines: 30 Original-NNTP-Posting-Date: 09 Jun 2009 14:51:22 MEST Original-NNTP-Posting-Host: 88.170.236.224 Original-X-Trace: 1244551882 news-2.free.fr 23744 88.170.236.224:42807 Original-X-Complaints-To: abuse@proxad.net Original-Xref: news.stanford.edu gnu.emacs.help:169857 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:65088 Archived-At: Nordlöw writes: > Aahh, we needed a macro instead: > > (defmacro bench (&rest forms) > "Convenience wrapper for benchmark-run-compiled." > `(let ((n 10)) > (/ (nth 0 (benchmark-run n ,@forms)) n))) > > This gives a reasonable difference in performance. > > By the way, does elisp lists have extra pointers to the middle of the > list (a skip-list)? No, because it wouldn't be efficient to have to maintain them. (let* ((c (list 7 8 9)) (b (list* 4 5 6 c)) (a (list* 1 2 3 b))) (push -1 (cddr c)) (push -2 (cddr c)) ; you may have to update a big number of skip-lists! (list a b c)) --> ((1 2 3 . #1=(4 5 6 . #2=(7 8 -2 -1 9))) #1# #2#) (deftype list () '(or null (cons t list))) ; nothing more. -- __Pascal Bourguignon__