From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: undo an undo Date: Wed, 26 May 2004 18:26:38 GMT Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Message-ID: References: NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1085596855 622 80.91.224.253 (26 May 2004 18:40:55 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Wed, 26 May 2004 18:40:55 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed May 26 20:40:28 2004 Return-path: Original-Received: from monty-python.gnu.org ([199.232.76.173]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1BT3KF-0000Fo-00 for ; Wed, 26 May 2004 20:40:27 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1BT3D8-00035N-81 for geh-help-gnu-emacs@m.gmane.org; Wed, 26 May 2004 14:33:06 -0400 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!logbridge.uoregon.edu!snoopy.risq.qc.ca!charlie.risq.qc.ca!53ab2750!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 10 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3.50 Original-NNTP-Posting-Host: 132.204.24.84 Original-X-Complaints-To: abuse@umontreal.ca Original-X-Trace: charlie.risq.qc.ca 1085595998 132.204.24.84 (Wed, 26 May 2004 14:26:38 EDT) Original-NNTP-Posting-Date: Wed, 26 May 2004 14:26:38 EDT Original-Xref: shelby.stanford.edu gnu.emacs.help:123482 Original-To: help-gnu-emacs@gnu.org X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.4 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 Xref: main.gmane.org gmane.emacs.help:18775 X-Report-Spam: http://spam.gmane.org/gmane.emacs.help:18775 > It might be better to point out that the undo history is not a stack; Indeed, it's more like a tree, in the sense that when you undo something you go back towards the root and future changes will be recorded as a new branch. But since the undo itself is a change, it is also recorded in the tree at the tip of the current branch. So you really get a big ugly directed acyclic graph. Stefan