From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: rsharman@pobox.com Newsgroups: gmane.emacs.devel Subject: Re: highlight-changes-mode Date: Wed, 6 Dec 2006 18:39:42 -0500 Message-ID: <17783.21694.919909.627629@cube.homenetwork> References: <17721.60660.980363.609046@kahikatea.snap.net.nz> <17725.23383.490888.442550@cube.homenetwork> <17770.17915.319182.723314@cube.homenetwork> <17770.35080.725821.391914@kahikatea.snap.net.nz> <17782.25188.121126.54191@cube.homenetwork> NNTP-Posting-Host: dough.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: sea.gmane.org 1165463935 15497 80.91.229.10 (7 Dec 2006 03:58:55 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 7 Dec 2006 03:58:55 +0000 (UTC) Cc: nickrob@snap.net.nz, emacs-devel@gnu.org, rsharman@pobox.com Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Dec 07 04:58:52 2006 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by dough.gmane.org with esmtp (Exim 4.50) id 1GsAPI-0004eE-NH for ged-emacs-devel@m.gmane.org; Thu, 07 Dec 2006 04:58:49 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GsAPI-0006Fa-8t for ged-emacs-devel@m.gmane.org; Wed, 06 Dec 2006 22:58:48 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Gs6OZ-0003dD-JO for emacs-devel@gnu.org; Wed, 06 Dec 2006 18:41:47 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Gs6OX-0003bP-Ri for emacs-devel@gnu.org; Wed, 06 Dec 2006 18:41:47 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Gs6OX-0003b7-Cp for emacs-devel@gnu.org; Wed, 06 Dec 2006 18:41:45 -0500 Original-Received: from [209.217.78.136] (helo=mx5-1.spamtrap.magma.ca) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1Gs6OV-0001eJ-I7; Wed, 06 Dec 2006 18:41:43 -0500 Original-Received: from mail1.magma.ca (mail1.internal.magma.ca [10.0.10.11]) by mx5-1.spamtrap.magma.ca (8.13.1/8.13.1) with ESMTP id kB6Nfcxg002795; Wed, 6 Dec 2006 18:41:39 -0500 Original-Received: from cube.homenetwork (ottawa-hs-209-217-110-164.d-ip.magma.ca [209.217.110.164]) by mail1.magma.ca (Magma's Mail Server) with ESMTP id kB6NfcKh003723; Wed, 6 Dec 2006 18:41:39 -0500 Original-Received: by cube.homenetwork (Postfix, from userid 1000) id 17E3593CA9; Wed, 6 Dec 2006 18:39:43 -0500 (EST) Original-To: rms@gnu.org In-Reply-To: X-Mailer: VM 7.19 under Emacs 21.4.1 X-magma-MailScanner-Information: Magma Mailscanner Service X-magma-MailScanner: Clean X-Mailman-Approved-At: Wed, 06 Dec 2006 22:58:36 -0500 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:63388 Archived-At: Richard Stallman writes: > I added a new keyword :only-new EXPR which allows restricting > a change of mode to new only new buffers if EXPR is non-nil. > (So the default behaviour, without this keyword, is unchanged.) > > If we want that functionality, this is a clean way of providing it. I > think the real question is which way we want global minor modes to > work. Do we want the global mode command to affect only buffers > created subsequently? Do we want it to affect all existing buffers? > Only existing buffers in which the user has not specified any > setting for the mode? > > Is there a good reason why global-highlight-changes should > not be like Global Font Lock mode, and affect all buffers > where it is applicable? That wouldn't be a problem when the global mode is turned _on_; the problem occurs when the global mode is turned _off_. The current implementation allows the situation where a user no longer wants it turned on by default, but has an existing buffer that has some changes already highlighted. If disabling the global mode automatically disables highlight changes modes in that buffer, then the highlighting of the changes disappears; we have lost information. I don't remember if that _was_ the reason why it was done that way; that's the only reason I can think of for keeping that behaviour. One could argue against this, however, by noting that there are now [in the new version] two commands to markup the changes; one works by comparing against a file, the other against a buffer. So in some cases - probably most - this "lost" information could be recovered.