From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Text Properties And Buffer Modification Date: Thu, 06 Dec 2018 08:04:07 +0200 Message-ID: <83woon6vjc.fsf@gnu.org> References: <83y3948ov2.fsf@gnu.org> <87wooofnqf.fsf@fastmail.fm> <83o9a08jfq.fsf@gnu.org> <834lbr95nq.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1544077414 24683 195.159.176.226 (6 Dec 2018 06:23:34 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 6 Dec 2018 06:23:34 +0000 (UTC) Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Dec 06 07:23:30 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gUn4L-0006Jm-8J for ged-emacs-devel@m.gmane.org; Thu, 06 Dec 2018 07:23:29 +0100 Original-Received: from localhost ([::1]:39043 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gUn6R-0002Ep-KS for ged-emacs-devel@m.gmane.org; Thu, 06 Dec 2018 01:25:39 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:40482) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gUn1v-0003r4-Gw for emacs-devel@gnu.org; Thu, 06 Dec 2018 01:21:04 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gUmld-00062k-CK for emacs-devel@gnu.org; Thu, 06 Dec 2018 01:04:14 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:44032) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gUmlc-00061L-Vh; Thu, 06 Dec 2018 01:04:09 -0500 Original-Received: from [176.228.60.248] (port=3274 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1gUmlc-0007o1-Ih; Thu, 06 Dec 2018 01:04:08 -0500 In-reply-to: (message from Stefan Monnier on Wed, 05 Dec 2018 15:54:08 -0500) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:231667 Archived-At: > From: Stefan Monnier > Cc: emacs-devel@gnu.org > Date: Wed, 05 Dec 2018 15:54:08 -0500 > > >> > Don't forget that the modified status is important for more than > >> > just saving to a file: it is important for redisplaying the > >> > buffer, for example. > >> Really? > > Is that a rhetorical question? > > Not at all. I know that set-buffer-modified-p has historically been > linked to force-mode-line-update, but other than that I had no idea that > the ticks would affect redisplay in any significant way (beside the > obvious stars in the mode-line, obviously). > > I'm still not clear why either. See my response to Martin. Some redisplay optimizations need to know the reason why a buffer should be redisplayed, so they look at the buffer's modification tick count (and on a similar count for overlays). Maybe that's not "significant" for you, but IMO redisplay optimizations are very important, and disabling them could sometimes mean severe degradation in responsiveness.