From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.help Subject: Re: Is it possible for a macro to expand to nothing? Date: Fri, 27 Nov 2009 13:15:07 +0000 (UTC) Organization: muc.de e.V. Message-ID: References: <87vdh1ccra.fsf@galatea.local> <87my2dc8d7.fsf@galatea.local> <873a44dcf2.fsf@galatea.local> <87pr78b6n9.fsf@galatea.local> <87ljhwb2dx.fsf@galatea.local> NNTP-Posting-Host: lo.gmane.org X-Trace: ger.gmane.org 1259330620 31327 80.91.229.12 (27 Nov 2009 14:03:40 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 27 Nov 2009 14:03:40 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Nov 27 15:03:33 2009 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 4.50) id 1NE1Q1-0008MG-VI for geh-help-gnu-emacs@m.gmane.org; Fri, 27 Nov 2009 15:03:30 +0100 Original-Received: from localhost ([127.0.0.1]:56305 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NE1Q1-0002ZP-60 for geh-help-gnu-emacs@m.gmane.org; Fri, 27 Nov 2009 09:03:29 -0500 Original-Path: news.stanford.edu!usenet.stanford.edu!news.tele.dk!news.tele.dk!small.news.tele.dk!newsfeed00.sul.t-online.de!t-online.de!inka.de!rz.uni-karlsruhe.de!news.belwue.de!news.tu-darmstadt.de!news.muc.de!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 32 Original-NNTP-Posting-Host: marvin.muc.de Original-X-Trace: colin2.muc.de 1259327707 43153 2001:608:1000::2 (27 Nov 2009 13:15:07 GMT) Original-X-Complaints-To: news-admin@muc.de Original-NNTP-Posting-Date: Fri, 27 Nov 2009 13:15:07 +0000 (UTC) User-Agent: tin/1.6.2-20030910 ("Pabbay") (UNIX) (FreeBSD/4.11-RELEASE (i386)) Original-Xref: news.stanford.edu gnu.emacs.help:175110 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:70183 Archived-At: Kevin Rodgers wrote: > Alan Mackenzie wrote: >> Your notion of the correct use of macros seems to be a religious idea >> rather than one fully thought through. You justify it with circular >> reasoning. Whilst using a macro to generate an evalable form may be >> the most usual thing, there is no reason not to use it to produce >> other list structure. > Except that such macros can only be executed in a particular context > i.e. they depend on something that cannot be expressed via their > argument list. Yes, many lisp structures can only be "executed" in particular contexts, `,@' for example, yet nobody slags them off for that. > At best that is poor style, and at worst it is poor engineering. That is so supercilious - you haven't even given an example of this phenomenom, discussing why it is poor style or poor engineering. There's just this vague insinuation that you know better. I will give an example, namely `c-lang-defconst' from cc-defs.el. Are you going to assert that it is poor style, or even poor engineering, simply because it generates an internal data structure rather than an excutable form? If so, then it's up to you to say how it could have been done better, preferably submitting a patch. -- Alan Mackenzie (Nuremberg, Germany).