From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: cl-dolist, dolist, cl-return, Date: Tue, 07 Jul 2015 23:09:18 -0400 Message-ID: References: <87fv4za4jo.fsf@nl106-137-147.student.uu.se> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1436324984 30093 80.91.229.3 (8 Jul 2015 03:09:44 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 8 Jul 2015 03:09:44 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Jul 08 05:09:43 2015 Return-path: Envelope-to: geh-help-gnu-emacs@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 1ZCfjx-0001t5-Nk for geh-help-gnu-emacs@m.gmane.org; Wed, 08 Jul 2015 05:09:41 +0200 Original-Received: from localhost ([::1]:33063 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCfjw-0007fq-Oo for geh-help-gnu-emacs@m.gmane.org; Tue, 07 Jul 2015 23:09:40 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52574) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCfjm-0007fk-IH for help-gnu-emacs@gnu.org; Tue, 07 Jul 2015 23:09:31 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZCfjj-0007R9-AL for help-gnu-emacs@gnu.org; Tue, 07 Jul 2015 23:09:30 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:43359) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCfjj-0007Qy-3H for help-gnu-emacs@gnu.org; Tue, 07 Jul 2015 23:09:27 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZCfjg-0001jE-Im for help-gnu-emacs@gnu.org; Wed, 08 Jul 2015 05:09:24 +0200 Original-Received: from 157-52-6-103.cpe.teksavvy.com ([157-52-6-103.cpe.teksavvy.com]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 08 Jul 2015 05:09:24 +0200 Original-Received: from monnier by 157-52-6-103.cpe.teksavvy.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 08 Jul 2015 05:09:24 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 11 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 157-52-6-103.cpe.teksavvy.com User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:tw2MZx+vHZ9oh7/YPFQiAQ7Igdc= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:105510 Archived-At: > Just once. Besides inefficiency, evaluating it every time would lead to > wrong results. Right, the question often makes sense for loop boundary computations, but for this specific case, if you think enough about it, it makes no sense to re-evaluate it: you'd have to use an index into the list, and at each iteration, increment the index, recompute the list, and do an (nth ), which would overall be *really* inefficient. Stefan