From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: How to test if the current line contains only white-spache? Date: Wed, 25 Nov 2015 21:36:33 +0100 Message-ID: <87h9k9zui6.fsf@mbork.pl> References: <87r3js7e8l.fsf@linux-qg7d.fritz.box> <87r3jeb2g8.fsf@ulb.ac.be> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1448483819 16684 80.91.229.3 (25 Nov 2015 20:36:59 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 25 Nov 2015 20:36:59 +0000 (UTC) Cc: Rolf Ade , help-gnu-emacs@gnu.org To: Nicolas Richard Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Nov 25 21:36:50 2015 Return-path: Envelope-to: geh-help-gnu-emacs@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 1a1go6-000187-5S for geh-help-gnu-emacs@m.gmane.org; Wed, 25 Nov 2015 21:36:50 +0100 Original-Received: from localhost ([::1]:47592 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1go7-00027Q-Ti for geh-help-gnu-emacs@m.gmane.org; Wed, 25 Nov 2015 15:36:51 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:51706) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1gnx-00027L-GC for help-gnu-emacs@gnu.org; Wed, 25 Nov 2015 15:36:42 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a1gnt-0003XB-FY for help-gnu-emacs@gnu.org; Wed, 25 Nov 2015 15:36:41 -0500 Original-Received: from mail.mojserwer.eu ([2a01:5e00:2:52::8]:38368) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1gnt-0003Wa-8j for help-gnu-emacs@gnu.org; Wed, 25 Nov 2015 15:36:37 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id BC5798F2003; Wed, 25 Nov 2015 21:36:36 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KZc-aHJigi4M; Wed, 25 Nov 2015 21:36:34 +0100 (CET) Original-Received: from localhost (unknown [109.232.24.28]) by mail.mojserwer.eu (Postfix) with ESMTPSA id 3404F8F2002; Wed, 25 Nov 2015 21:36:34 +0100 (CET) User-agent: mu4e 0.9.13; emacs 25.0.50.1 In-reply-to: <87r3jeb2g8.fsf@ulb.ac.be> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a01:5e00:2:52::8 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:108221 Archived-At: On 2015-11-25, at 15:04, Nicolas Richard wrote: > Rolf Ade writes: >> For some random minor elisp code I need to know, if the current line >> contains only white-space characters[1]. >> >> I came up with this somewhat convoluted code: >> >> (beginning-of-line) >> (skip-chars-forward " \t") >> (let ((text-start (current-column))) >> (end-of-line) >> (if (= text-start (current-column)) >> t >> nil) > > FWIW I would do : > (save-excursion > (beginning-of-line) > (skip-chars-forward " \t") > (eolp)) > > but IANAL(isper). Nice! And quite possibly faster, since no regex is involved. OTOH, I'm not sure whether this (or any other solution, for that matter) would work with visual lines (or what it actually /should/ do). Regards, -- Marcin Borkowski http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski Faculty of Mathematics and Computer Science Adam Mickiewicz University