From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: W. Greenhouse Newsgroups: gmane.emacs.help Subject: Re: How to make (format "%S" ...) print nothing? Date: Sat, 12 Jul 2014 14:30:45 +0000 Message-ID: <87ion2y7hm.fsf@motoko.kusanagi> References: <87sim6luw2.fsf@gmail.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1405175519 22871 80.91.229.3 (12 Jul 2014 14:31:59 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 12 Jul 2014 14:31:59 +0000 (UTC) To: help-gnu-emacs-mXXj517/zsQ@public.gmane.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org-mXXj517/zsQ@public.gmane.org Sat Jul 12 16:31:52 2014 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 1X5yLA-00088r-CR for geh-help-gnu-emacs@m.gmane.org; Sat, 12 Jul 2014 16:31:52 +0200 Original-Received: from localhost ([::1]:49254 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X5yLA-0001fd-0y for geh-help-gnu-emacs@m.gmane.org; Sat, 12 Jul 2014 10:31:52 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X5yKo-0001cT-65 for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Sat, 12 Jul 2014 10:31:37 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X5yKg-0001Sk-Mi for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Sat, 12 Jul 2014 10:31:30 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:56429) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X5yKg-0001SI-Fn for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Sat, 12 Jul 2014 10:31:22 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1X5yKb-0007WZ-Fn for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Sat, 12 Jul 2014 16:31:17 +0200 Original-Received: from destiny.enn.lu ([94.242.246.23]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 12 Jul 2014 16:31:17 +0200 Original-Received: from wgreenhouse by destiny.enn.lu with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 12 Jul 2014 16:31:17 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 10 Original-X-Complaints-To: usenet-dbVV3NMTNubNLxjTenLetw@public.gmane.org X-Gmane-NNTP-Posting-Host: destiny.enn.lu X-Archive: encrypt User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Cancel-Lock: sha1:4aGJbkJiKM1hE7yGv4V0pPF87RA= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs-mXXj517/zsQ@public.gmane.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-mXXj517/zsQ@public.gmane.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org-mXXj517/zsQ@public.gmane.org Xref: news.gmane.org gmane.emacs.help:98657 Archived-At: Thorsten Jolitz writes: > Is there any way to use (format "%S"...) and have it print nothing > when given an empty string, an empty list or nil (or something else)? No. The printed representation of the empty string is "", and the printed representation of the list () or nil is nil, so (format "%S" ...) will of course print something in these cases. Since you know what that something is going to be, perhaps you could use split-string or a similar text-mangling function to remove it.