From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Perry E. Metzger" Newsgroups: gmane.emacs.devel Subject: Re: Speed of keyboard macro execution? Date: Thu, 10 Dec 2015 13:10:37 -0500 Message-ID: <20151210131037.7ab4ae05@jabberwock.cb.piermont.com> References: <20151209163954.0cefcc7f@jabberwock.cb.piermont.com> <87si3bcltu.fsf@isaac.fritz.box> <20151209180343.5a67c0e7@jabberwock.cb.piermont.com> <83r3iu9rvp.fsf@gnu.org> <20151210120051.6be8201f@jabberwock.cb.piermont.com> <87k2omciy2.fsf@isaac.fritz.box> <20151210123312.39c417c9@jabberwock.cb.piermont.com> <83lh929omw.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1449771990 16985 80.91.229.3 (10 Dec 2015 18:26:30 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 10 Dec 2015 18:26:30 +0000 (UTC) Cc: deng@randomsample.de, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Dec 10 19:26:27 2015 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1a75v8-0004ml-Ry for ged-emacs-devel@m.gmane.org; Thu, 10 Dec 2015 19:26:27 +0100 Original-Received: from localhost ([::1]:43774 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a75v7-0001MP-M7 for ged-emacs-devel@m.gmane.org; Thu, 10 Dec 2015 13:26:25 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53857) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a75fx-0002m8-Ky for emacs-devel@gnu.org; Thu, 10 Dec 2015 13:10:46 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a75fw-0007Gi-Oi for emacs-devel@gnu.org; Thu, 10 Dec 2015 13:10:45 -0500 Original-Received: from hacklheber.piermont.com ([166.84.7.14]:53075) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a75fq-0007FC-9T; Thu, 10 Dec 2015 13:10:38 -0500 Original-Received: from snark.cb.piermont.com (localhost [127.0.0.1]) by hacklheber.piermont.com (Postfix) with ESMTP id B74EB2B7; Thu, 10 Dec 2015 13:10:37 -0500 (EST) Original-Received: from jabberwock.cb.piermont.com (jabberwock.cb.piermont.com [10.160.2.107]) by snark.cb.piermont.com (Postfix) with ESMTP id 9EC412DE13C; Thu, 10 Dec 2015 13:10:37 -0500 (EST) In-Reply-To: <83lh929omw.fsf@gnu.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 166.84.7.14 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:196037 Archived-At: On Thu, 10 Dec 2015 19:53:11 +0200 Eli Zaretskii wrote: > This I can explain. "Redisplay" comes into play not only for > actually redrawing the screen, it also comes into play when, e.g., > a command moves cursor down, as in C-n. With (the default) > line-move-visual mode, Emacs no longer has an easy way of knowing > what character is directly below the current one, what with all the > variable-pitch fonts and long lines broken between several screen > lines. The only way of finding out where is "one visual line down" > is to _simulate_ redisplay. IOW, Emacs runs code that does exactly > what redisplay does, but without displaying anything; it just > accumulates pixel coordinates until it finds itself one visual line > down. Oh, my. Now I understand. Especially once you have issues like (as just one example) complicated Unicode rendering involved, this could get arbitrarily messy. I suppose there are only two obvious ways to handle that: 1) radically speed up the redisplay code. 2) memoize the output of the redisplay code. Have I missed an obvious approach or are those the choices? Perry -- Perry E. Metzger perry@piermont.com