From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Unbalanced change hooks (part 2) [Documentation fix still remaining] Date: Mon, 29 Aug 2016 20:25:06 -0400 Message-ID: References: <20160810161821.GB3413@acm.fritz.box> <83wpjofttf.fsf@gnu.org> <20160810185735.GD3413@acm.fritz.box> <20160811112951.GA2154@acm.fritz.box> <7e1478b6-cf00-fcbf-8c24-43bdaa57e2b6@dancol.org> <415d1cca-f32c-624e-a4be-9aadcf8a0f17@dancol.org> <83inujbpek.fsf@gnu.org> <83eg57bl8f.fsf@gnu.org> <5ee6ff4a-2d58-82f1-8e83-479c62f0b729@dancol.org> <837fazbjb4.fsf@gnu.org> <75100b15-d49f-5a1a-d73b-24db77c891bf@dancol.org> <831t17bged.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1472516558 31463 195.159.176.226 (30 Aug 2016 00:22:38 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 30 Aug 2016 00:22:38 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) Cc: Daniel Colascione , emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Aug 30 02:22:32 2016 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 1beWor-0006sV-Sz for ged-emacs-devel@m.gmane.org; Tue, 30 Aug 2016 02:22:26 +0200 Original-Received: from localhost ([::1]:46281 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1beWop-0005Mj-Io for ged-emacs-devel@m.gmane.org; Mon, 29 Aug 2016 20:22:23 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:38632) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1beWoh-0005Me-Sd for emacs-devel@gnu.org; Mon, 29 Aug 2016 20:22:18 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1beWod-0001lO-Kk for emacs-devel@gnu.org; Mon, 29 Aug 2016 20:22:14 -0400 Original-Received: from chene.dit.umontreal.ca ([132.204.246.20]:60242) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1beWod-0001lK-FD; Mon, 29 Aug 2016 20:22:11 -0400 Original-Received: from ceviche.home (lechon.iro.umontreal.ca [132.204.27.242]) by chene.dit.umontreal.ca (8.14.7/8.14.1) with ESMTP id u7U0MhcO016439; Mon, 29 Aug 2016 20:22:44 -0400 Original-Received: by ceviche.home (Postfix, from userid 20848) id CF17D66274; Mon, 29 Aug 2016 20:25:06 -0400 (EDT) In-Reply-To: <831t17bged.fsf@gnu.org> (Eli Zaretskii's message of "Mon, 29 Aug 2016 21:04:42 +0300") X-NAI-Spam-Flag: NO X-NAI-Spam-Threshold: 5 X-NAI-Spam-Score: 0 X-NAI-Spam-Rules: 1 Rules triggered RV5781=0 X-NAI-Spam-Version: 2.3.0.9418 : core <5781> : inlines <5153> : streams <1692173> : uri <2277654> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 132.204.246.20 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:206907 Archived-At: > So, while I agreed that #1 should probably be fixed, and even > suggested how to do that in the least risky way, actually doing that > is not a priority, IMO, not until we have a very grave problem caused > by it. FWIW, I think it's important to fix the insert-file-contents case. It breaks syntax-ppss, for example, although for various reasons of how syntax-ppss is implemented and used, this happens to rarely show up. [ So, yes, it's not top priority, but it should still be fixed. ] >> #1 breaks the entire b-c-f model --- "hey, I'm about to modify the >> buffer, so throw away caches" ---- and can lead to anything with a >> cache flush in b-c-f (like syntax-ppss) not properly discarding >> out-of-date buffer information. > That single case of #1 is revert-buffer, which conceptually throws > away the entire buffer and replaces it with what's on disk. That it > actually keeps portions of the buffer is an optimization, but the > concept still stands. So I don't see how it breaks the entire model, > at least not in practice. The optimization is beside the point: not calling b-c-f in some corner case breaks the entire model because a user such as syntax-ppss relies on b-c-f to know when to flush its cache, so if you don't call it when the buffer is modified, the cache ends up stale. Stefan