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: Adding many elements to a list Date: Tue, 22 Sep 2009 13:53:57 +0200 Organization: Anevia SAS Message-ID: <7cws3rp54a.fsf@pbourguignon.lefevre.anevia.com> References: <979e809f-0b95-46bf-afa4-1a25cda5bae0@j9g2000vbp.googlegroups.com> <7chbv0fjuj.fsf@informatimago.com> <87vdjgxrga.fsf@lola.goethe.zz> <7ceiq4s405.fsf@pbourguignon.lefevre.informatimago.com> <87my4sxpzv.fsf@lola.goethe.zz> <7cab0ss2ud.fsf@pbourguignon.lefevre.informatimago.com> <87ws3rtq2b.fsf@lola.goethe.zz> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1253623370 19707 80.91.229.12 (22 Sep 2009 12:42:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 22 Sep 2009 12:42:50 +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 Sep 22 14:42:43 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 1Mq4he-0000Ye-1Z for geh-help-gnu-emacs@m.gmane.org; Tue, 22 Sep 2009 14:42:42 +0200 Original-Received: from localhost ([127.0.0.1]:52114 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mq4hd-0002Bv-Cs for geh-help-gnu-emacs@m.gmane.org; Tue, 22 Sep 2009 08:42:41 -0400 Original-Path: news.stanford.edu!usenet.stanford.edu!postnews.google.com!news4.google.com!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!cleanfeed1-a.proxad.net!nnrp6-1.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: sha1:0oiM/fwDzKhbz2ftX1ufvB0AvIQ= Original-Lines: 72 Original-NNTP-Posting-Date: 22 Sep 2009 13:53:57 MEST Original-NNTP-Posting-Host: 88.170.236.224 Original-X-Trace: 1253620437 news-1.free.fr 11316 88.170.236.224:43308 Original-X-Complaints-To: abuse@proxad.net Original-Xref: news.stanford.edu gnu.emacs.help:173253 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:68377 Archived-At: David Kastrup writes: > pjb@anevia.com (Pascal J. Bourguignon) writes: > >> David Kastrup writes: >> >>> pjb@anevia.com (Pascal J. Bourguignon) writes: >>> >>>> David Kastrup writes: >>>> >>>>> pjb@informatimago.com (Pascal J. Bourguignon) writes: >>>>> >>>>>> So better use (require 'cl) (push new-item list) >>>>>> or (cons new-item list) >>>>>> or (append (list new-items...) list) >>>>> >>>>> (require 'cl) is quite unnecessary for all of the mentioned >>>>> alternatives. >>>> >>>> Not on emacs version < 23. >>> >>> Nonsense. push&pop were officially announced in Emacs 21.1. I may be >>> mistaken, but I think they have been there even earlier. >>> >>> And the other options certainly were there from the earliest versions of >>> GNU Emacs. >> >> C-h f push RET >> push is a Lisp macro in `cl.el'. >> (push x place) >> >> Insert x at the head of the list stored in place. >> Analogous to (setf place (cons x place)), though more careful about >> evaluating each argument only once and in the right order. place may >> be a symbol, or any generalized variable allowed by `setf'. >> >> [back] >> >> M-x emacs-version RET >> GNU Emacs 22.2.1 (x86_64-unknown-linux-gnu, X toolkit) of 2008-08-21 on simias > > Try emacs -Q. Just because you choose to load some library overloading > the default operators does not mean that other people should do the same > when Emacs will provide those operators by default, with better > performance. Ah! :-) The cl package wouldn't be provided if the default had any performance at all... (defvar *a* (cons nil nil)) (push 1 (car *a*)) Debugger entered--Lisp error: (wrong-type-argument symbolp (car *a*)) (setq (car *a*) (cons 1 (car *a*))) (push 1 (car *a*)) eval((push 1 (car *a*))) eval-last-sexp-1((4)) eval-last-sexp((4)) call-interactively(eval-last-sexp) (require 'cl) (push 1 (car *a*)) --> (1) *a* --> ((1)) -- __Pascal Bourguignon__