From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: martin rudalics Newsgroups: gmane.emacs.devel Subject: Re: Mixed L2R and R2L paragraphs and horizontal scroll Date: Mon, 01 Feb 2010 09:34:41 +0100 Message-ID: <4B669221.9050507@gmx.at> References: <83tyu3iu6b.fsf@gnu.org> <4B645FF4.30205@gmx.at> <83ockbil1v.fsf@gnu.org> <4B646AD3.1010102@gmx.at> <83mxzviio5.fsf@gnu.org> <4B647AE5.5090001@gmx.at> <83ljffif09.fsf@gnu.org> <4B648C6E.8080905@gmx.at> <83eil7i84h.fsf@gnu.org> <4B654F24.5020603@gmx.at> <83aavui23z.fsf@gnu.org> <4B65E199.6070100@gmx.at> <878wbeaqlq.fsf@catnip.gol.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1265013830 15680 80.91.229.12 (1 Feb 2010 08:43:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 1 Feb 2010 08:43:50 +0000 (UTC) Cc: Eli Zaretskii , emacs-devel@gnu.org To: Miles Bader Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Feb 01 09:43:44 2010 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Nbrsk-00066J-UE for ged-emacs-devel@m.gmane.org; Mon, 01 Feb 2010 09:43:43 +0100 Original-Received: from localhost ([127.0.0.1]:46600 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Nbrsk-0006yP-AB for ged-emacs-devel@m.gmane.org; Mon, 01 Feb 2010 03:43:42 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Nbrk8-0001kD-6w for emacs-devel@gnu.org; Mon, 01 Feb 2010 03:34:48 -0500 Original-Received: from [199.232.76.173] (port=59854 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Nbrk6-0001jl-8E for emacs-devel@gnu.org; Mon, 01 Feb 2010 03:34:46 -0500 Original-Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1Nbrk4-0003gM-Q7 for emacs-devel@gnu.org; Mon, 01 Feb 2010 03:34:46 -0500 Original-Received: from mail.gmx.net ([213.165.64.20]:39079) by monty-python.gnu.org with smtp (Exim 4.60) (envelope-from ) id 1Nbrk4-0003fx-0q for emacs-devel@gnu.org; Mon, 01 Feb 2010 03:34:44 -0500 Original-Received: (qmail invoked by alias); 01 Feb 2010 08:34:42 -0000 Original-Received: from 62-47-38-158.adsl.highway.telekom.at (EHLO [62.47.38.158]) [62.47.38.158] by mail.gmx.net (mp049) with SMTP; 01 Feb 2010 09:34:42 +0100 X-Authenticated: #14592706 X-Provags-ID: V01U2FsdGVkX190aOk36XF0pNr+Mzh1x2mu6aed0oV+sumemdnqn5 6GBqtB0zie9t2o User-Agent: Thunderbird 2.0.0.21 (Windows/20090302) In-Reply-To: <878wbeaqlq.fsf@catnip.gol.com> X-Y-GMX-Trusted: 0 X-FuHaFi: 0.71999999999999997 X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:120770 Archived-At: >> Technically columns are numbered by counting characters following the >> last newline in the buffer text. > > Eh? Clearly they're not, because things like tabs expand into multiple > columns... Columns are a display concept, not a buffer concept. Expanding tabs does not depend on displaying the surrounding text but looks into the variable `tab-width' which is buffer-local and not related in any sense to display. Also, you can call a function like `move-to-column' without ever displaying the associated buffer. Or, for example, put an overlay with some string as a before-string property into a buffer and display that buffer so the overlay is shown. The characters of the overlay are displayed but the columns they occupy on screen are not counted. But you're right in that for non-displayable characters or characters displayed as octals, columns do not count from the last newline either. And the column numbers supplied by some compilers together with warnings or error messages are mostly pretty useless for finding the corresponding position in the source. So I think we should be able to meet somewhere in the middle ;-) Anyway - the point I wanted to make was that the number of a column does not depend on the size of the window displaying the character at that column or whether text in that window has been scrolled horizontally. martin