From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: =?ISO-8859-1?Q?Jos=E9_A=2E_Romero_L=2E?= Newsgroups: gmane.emacs.help Subject: Re: How to put this in a macro Date: Sat, 17 Apr 2010 03:30:04 -0700 (PDT) Organization: http://groups.google.com Message-ID: References: <87pr1zw164.fsf@linux-lqcw.site> <87d3xywpm6.fsf@linux-lqcw.site> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1273008788 17716 80.91.229.12 (4 May 2010 21:33:08 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 4 May 2010 21:33:08 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue May 04 23:33:07 2010 connect(): No such file or directory Return-path: Envelope-to: geh-help-gnu-emacs@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 1O9Pjm-0008Gn-Vi for geh-help-gnu-emacs@m.gmane.org; Tue, 04 May 2010 23:33:07 +0200 Original-Received: from localhost ([127.0.0.1]:46967 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O9Pjm-00063h-9e for geh-help-gnu-emacs@m.gmane.org; Tue, 04 May 2010 17:33:06 -0400 Original-Path: usenet.stanford.edu!postnews.google.com!u34g2000yqu.googlegroups.com!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 41 Original-NNTP-Posting-Host: 89.78.68.41 Original-X-Trace: posting.google.com 1271500204 15461 127.0.0.1 (17 Apr 2010 10:30:04 GMT) Original-X-Complaints-To: groups-abuse@google.com Original-NNTP-Posting-Date: Sat, 17 Apr 2010 10:30:04 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: u34g2000yqu.googlegroups.com; posting-host=89.78.68.41; posting-account=mkEKGAoAAACAV2vhv5r9WHXWqsdL_niD User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3,gzip(gfe) Original-Xref: usenet.stanford.edu gnu.emacs.help:177744 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:73190 Archived-At: On 17 Kwi, 08:38, Cecil Westerhof wrote: > Barry Margolin writes: > > (defmacro canonicalize-start-end (start-var end-var) > > =A0 `(if (equal ,start-var ,end-var) > > =A0 =A0 =A0 =A0(setq ,start-var (point-min) > > =A0 =A0 =A0 =A0 =A0 =A0 =A0,end-var (point-max)) > > =A0 =A0 =A0(setq ,start-var (or ,start-var (point-min)) > > =A0 =A0 =A0 =A0 =A0 =A0,end-var (or ,end-var (point-max)))) > > This gives an error: > =A0 =A0 Debugger entered--Lisp error: (void-variable start-var) > =A0 =A0 =A0 (list (quote equal) start-var end-var) (...) Makes sense. In general writing things like `(setq ,foo bar) is (if possible at all) asking for trouble -- what would happen when foo is nil, or 5? Maybe you could do something like this: (defmacro cw/set-bounds (start-sym end-sym) `(if (equal (symbol-value ,start-sym) (symbol-value ,end-sym)) (progn (set ,start-sym (point-min)) (set ,end-sym (point-max))) (progn (set ,start-sym (or start (point-min))) (set ,end-sym (or end (point-max)))))) and use it as: (cw/set-bounds 'start 'end) i.e. passing the symbols of the variables you want to set. Cheers, -- Jos=E9 A. Romero L. escherdragon at gmail "We who cut mere stones must always be envisioning cathedrals." (Quarry worker's creed)