From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andy Moreton Newsgroups: gmane.emacs.devel Subject: Re: `C-b' is backward-char, `left' is left-char - why? Date: Thu, 02 Jun 2011 22:42:05 +0100 Message-ID: <82d3ivewr6.fsf@gmail.com> References: <6F4054004B154CFB8E2753172D316C13@us.oracle.com> <4DE4F8D0.7010800@lanl.gov> <82y61l16bg.fsf@gmail.com> <83boygf7ta.fsf@gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1307050966 18383 80.91.229.12 (2 Jun 2011 21:42:46 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 2 Jun 2011 21:42:46 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Jun 02 23:42:42 2011 Return-path: Envelope-to: ged-emacs-devel@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 1QSFf7-000572-Kl for ged-emacs-devel@m.gmane.org; Thu, 02 Jun 2011 23:42:41 +0200 Original-Received: from localhost ([::1]:47773 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QSFf6-0001Um-QA for ged-emacs-devel@m.gmane.org; Thu, 02 Jun 2011 17:42:40 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:37353) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QSFes-0001UW-T7 for emacs-devel@gnu.org; Thu, 02 Jun 2011 17:42:27 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QSFer-00030j-Ns for emacs-devel@gnu.org; Thu, 02 Jun 2011 17:42:26 -0400 Original-Received: from lo.gmane.org ([80.91.229.12]:43162) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QSFer-00030f-Hj for emacs-devel@gnu.org; Thu, 02 Jun 2011 17:42:25 -0400 Original-Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1QSFeq-0004zQ-0x for emacs-devel@gnu.org; Thu, 02 Jun 2011 23:42:24 +0200 Original-Received: from 82-69-64-228.dsl.in-addr.zen.co.uk ([82.69.64.228]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 02 Jun 2011 23:42:24 +0200 Original-Received: from andrewjmoreton by 82-69-64-228.dsl.in-addr.zen.co.uk with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 02 Jun 2011 23:42:24 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 27 Original-X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: 82-69-64-228.dsl.in-addr.zen.co.uk User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (windows-nt) Cancel-Lock: sha1:nrWicQeoM9JIyY2Gw88Ip+1ZQk8= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 80.91.229.12 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:140103 Archived-At: On Thu 02 Jun 2011, Eli Zaretskii wrote: > Well, maybe if you look at the body of right-char, you will see the > light: > > (if (eq (current-bidi-paragraph-direction) 'left-to-right) > (forward-char n) > (backward-char n))) > > That's all there is to it: it does either forward-char or > backward-char, depending on the base direction of the current > paragraph. And we've already established that forward-char and > backward-char can move to the left or to the right according to the > text across which they move. > > The paragraph direction determines how the paragraph is displayed: in > a left-to-right paragraph, lines begin at the left margin of the > window, while in the right-to-left paragraph they begin at the right > margin. What happens if N is large enough to cross into another paragraph with a different value for current-bidi-paragraph-direction - is the resulting motion surprising for users ? Thanks for continuing my remedial education in the ways of bidi text :-) AndyM