From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: never use `eval' (was: Re: How to mapcar or across a list?) Date: Thu, 16 Jul 2015 01:57:43 +0200 Message-ID: <87bnfd2cug.fsf@nl106-137-147.student.uu.se> References: <87io9lmb4z.fsf@mbork.pl> <87oajdkqc7.fsf@kuiper.lan.informatimago.com> <87vbdlt4g3.fsf_-_@nl106-137-147.student.uu.se> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1437004779 11869 80.91.229.3 (15 Jul 2015 23:59:39 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 15 Jul 2015 23:59:39 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Jul 16 01:59:30 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 1ZFWaH-0000pQ-RC for geh-help-gnu-emacs@m.gmane.org; Thu, 16 Jul 2015 01:59:29 +0200 Original-Received: from localhost ([::1]:37855 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFWaH-0005tq-AA for geh-help-gnu-emacs@m.gmane.org; Wed, 15 Jul 2015 19:59:29 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:56279) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFWa5-0005tj-W5 for help-gnu-emacs@gnu.org; Wed, 15 Jul 2015 19:59:19 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZFWa1-0003zG-V7 for help-gnu-emacs@gnu.org; Wed, 15 Jul 2015 19:59:17 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:44185) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFWa1-0003zA-OB for help-gnu-emacs@gnu.org; Wed, 15 Jul 2015 19:59:13 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZFWZz-0000iW-RE for help-gnu-emacs@gnu.org; Thu, 16 Jul 2015 01:59:11 +0200 Original-Received: from nl106-137-156.student.uu.se ([130.243.137.156]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 16 Jul 2015 01:59:11 +0200 Original-Received: from embe8573 by nl106-137-156.student.uu.se with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 16 Jul 2015 01:59:11 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Original-Lines: 33 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: nl106-137-156.student.uu.se Mail-Copies-To: never User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) Cancel-Lock: sha1:X/FkNE1jmxKrE2Wb3Fza07vhcu0= 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@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:105751 Archived-At: John Mastro writes: > I would use something like this: > > (defmacro ... Macros never liked me, and that is mutual. Are they really preferrable to `eval'? > For this (and others like it) ... which are? Do you mean the eval + backquote combo? > it looks like you could instead simply use e.g. > (apply #'create-book nil title data) This is what it looks like: (eval `(create-book nil ,title ,@data)) With `apply', won't the last "data" be a list, i.e. (a b ... n) instead of a b ... n ? -- underground experts united http://user.it.uu.se/~embe8573