From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#9571: 24.0.50; user option to turn off bidi, please Date: Fri, 23 Sep 2011 21:24:03 +0300 Message-ID: <83k48zqfr0.fsf@gnu.org> References: <87obybg01n.fsf@gmail.com> <834o03sgsu.fsf@gnu.org> <87d3erfrb5.fsf@gmail.com> <878vpffm4z.fsf@gmail.com> <83r537qp1n.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: dough.gmane.org 1316802228 17156 80.91.229.12 (23 Sep 2011 18:23:48 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 23 Sep 2011 18:23:48 +0000 (UTC) Cc: 9571@debbugs.gnu.org, lekktu@gmail.com, stepnem@gmail.com To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Fri Sep 23 20:23:42 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1R7APW-0003HJ-0V for geb-bug-gnu-emacs@m.gmane.org; Fri, 23 Sep 2011 20:23:42 +0200 Original-Received: from localhost ([::1]:40599 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R7APV-0002q8-9h for geb-bug-gnu-emacs@m.gmane.org; Fri, 23 Sep 2011 14:23:41 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:54387) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R7APR-0002o0-3n for bug-gnu-emacs@gnu.org; Fri, 23 Sep 2011 14:23:39 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R7APP-0003dL-GU for bug-gnu-emacs@gnu.org; Fri, 23 Sep 2011 14:23:37 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:45856) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R7APP-0003dG-BA for bug-gnu-emacs@gnu.org; Fri, 23 Sep 2011 14:23:35 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1R7APq-0003QS-PY for bug-gnu-emacs@gnu.org; Fri, 23 Sep 2011 14:24:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 23 Sep 2011 18:24:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 9571 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: wontfix Original-Received: via spool by 9571-submit@debbugs.gnu.org id=B9571.131680222413131 (code B ref 9571); Fri, 23 Sep 2011 18:24:02 +0000 Original-Received: (at 9571) by debbugs.gnu.org; 23 Sep 2011 18:23:44 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1R7APX-0003Pi-S3 for submit@debbugs.gnu.org; Fri, 23 Sep 2011 14:23:44 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1R7APR-0003PH-3C for 9571@debbugs.gnu.org; Fri, 23 Sep 2011 14:23:39 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0LRZ00F00MXBBD00@a-mtaout22.012.net.il> for 9571@debbugs.gnu.org; Fri, 23 Sep 2011 21:22:57 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([84.228.8.215]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0LRZ00FVFN28BA80@a-mtaout22.012.net.il>; Fri, 23 Sep 2011 21:22:57 +0300 (IDT) In-reply-to: X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Fri, 23 Sep 2011 14:24:02 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 1) X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:51731 Archived-At: > From: Stefan Monnier > Cc: =A9t=ECp=E1n N=ECmec , > 9571@debbugs.gnu.org, lekktu@gmail.com > Date: Fri, 23 Sep 2011 13:46:35 -0400 >=20 > cursor positioning [is] the tricky part of your changes, and IIUC > the only part that can't just be turned off by bidi-display-reorder= ing By and large, yes. But cursor positioning is very central to user experience. And there are other, less major pieces of the display engine that were modified without keeping the old code conditioned on bidi-display-reordering. I never considered it a goal to keep the ol= d display code intact, so I cannot guarantee I did, and I know for a fact that some places other than cursor positioning have unconditiona= l changes. > The other source of problem has been performance, and AFAICT it's a= lways > been linked to bidi-paragraph-direction That is one potentially expensive part of the design. There's another: searching for portions of text covered by "replacing" displa= y properties (because those text parts are reordered for display as a single unit). Both issues are kept at bay by limiting the amount of text we search before giving up. That said, the above two performance are explicitly present in the design. There are others that are unintended (a.k.a. "bugs"). Lately, more often than not, I find that slowdown is due to those unintended factors, not to the above 2 inherently expensive design traits. Bug reports with details of the use case are necessary to find these and weed them out.