From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Samuel Wales Newsgroups: gmane.emacs.help Subject: cycling commands do not go backward Date: Sat, 31 Jan 2009 19:51:24 -0700 Message-ID: <20524da70901311851n5a911228vc5ee78c70797a4c5@mail.gmail.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1233456721 22535 80.91.229.12 (1 Feb 2009 02:52:01 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 1 Feb 2009 02:52:01 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Feb 01 03:53:14 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 1LTSSJ-0000cz-Mq for geh-help-gnu-emacs@m.gmane.org; Sun, 01 Feb 2009 03:53:07 +0100 Original-Received: from localhost ([127.0.0.1]:53377 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LTSR0-00009X-Tn for geh-help-gnu-emacs@m.gmane.org; Sat, 31 Jan 2009 21:51:46 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LTSQh-00009A-9X for help-gnu-emacs@gnu.org; Sat, 31 Jan 2009 21:51:27 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LTSQf-00008x-Ra for help-gnu-emacs@gnu.org; Sat, 31 Jan 2009 21:51:27 -0500 Original-Received: from [199.232.76.173] (port=34622 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LTSQf-00008u-MW for help-gnu-emacs@gnu.org; Sat, 31 Jan 2009 21:51:25 -0500 Original-Received: from nf-out-0910.google.com ([64.233.182.184]:13919) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LTSQf-0001WN-8o for help-gnu-emacs@gnu.org; Sat, 31 Jan 2009 21:51:25 -0500 Original-Received: by nf-out-0910.google.com with SMTP id c7so210592nfi.26 for ; Sat, 31 Jan 2009 18:51:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:date:message-id:subject :from:to:content-type:content-transfer-encoding; bh=djH0Cn+XEvZdflsUvdUabOa1lwkNcMsrHjxTGpEVF4c=; b=GZJSLA8kSZfNNJjt38T+QZkABFsJjHhGax/lJ+aYvb1pasiota1qeEEeYJOPtBsqm7 0aH3+U09HeUdy/pimRkgXQzm4skr7hmlgzjaRDt9UHbtKtBOtN290uL/mZ0MvYziKgDM AvO4U3+qSN1Vmbkqs57WxGYlQyHB19nzKSYhw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type :content-transfer-encoding; b=oHWoQ7UxAnyt/iI6/Ulgs022YOWvDB9ClOz/FHfD9jA4Py+JbINIiDz8ZkUgv7uElg sNaG5b3ABCBiopzqDRM1PgBsaZXvje9yKPGBnggZC+HtEMFUxKkr2iA1EbNBohitsm6M BUDaZ8eCOzjy4aynA8xTSLqE2dHg62OOcBaaU= Original-Received: by 10.210.22.16 with SMTP id 16mr3211403ebv.66.1233456684585; Sat, 31 Jan 2009 18:51:24 -0800 (PST) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 2) 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:61816 Archived-At: A philosophical note. Many commands in emacs cycle or rotate or go forward in a list. Examples include the mark ring, the global mark ring, undo, hippie-expand, dabbrev-expand, and other completion mechanisms. Yet most of those commands do not cycle backward. That is, if you overshoot, you have to do a lot more cycling to get around to the previous completion (or whatever). In the case of undo, it is more complicated than a ring, but the problem is the same. You can undo, but if you overshoot, you are often better off giving up. (If you think that the existing mechanisms are sufficient, take a look at the previous discussions of this on this list and on wikis to find out whey that is not correct.) I suspect that this is because it is slightly easier to code it one way. But for the user it would be great to be able to go both ways. Consider the right arrow. It has a complementary left arrow. Perhaps, as a user interface design goal, the same idea can be applied to cycling and rotating commands, and to undo. -- For personal gain, myalgic encephalomyelitis denialists are knowingly causing massive suffering and 25-years-early death by grossly corrupting science. http://www.meactionuk.org.uk/What_Is_ME_What_Is_CFS.htm