From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Drew Adams Newsgroups: gmane.emacs.help Subject: RE: How the backquote and the comma really work? Date: Thu, 25 Jun 2015 11:10:51 -0700 (PDT) Message-ID: <1e190a42-19c5-4755-b263-4334c402619a@default> References: <87vbebg1fs.fsf@mbork.pl> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1435255887 11842 80.91.229.3 (25 Jun 2015 18:11:27 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 25 Jun 2015 18:11:27 +0000 (UTC) To: Marcin Borkowski , Help Gnu Emacs mailing list Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Jun 25 20:11:15 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 1Z8BcG-0008Id-Io for geh-help-gnu-emacs@m.gmane.org; Thu, 25 Jun 2015 20:11:12 +0200 Original-Received: from localhost ([::1]:56961 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8BcF-0000kC-Ob for geh-help-gnu-emacs@m.gmane.org; Thu, 25 Jun 2015 14:11:11 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52242) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8Bc3-0000js-Iw for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 14:11:00 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z8Bby-0003Jc-Op for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 14:10:59 -0400 Original-Received: from aserp1040.oracle.com ([141.146.126.69]:49537) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8Bby-0003JQ-JI for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 14:10:54 -0400 Original-Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id t5PIAqMH031218 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 25 Jun 2015 18:10:53 GMT Original-Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0022.oracle.com (8.13.8/8.13.8) with ESMTP id t5PIAp9r004176 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Thu, 25 Jun 2015 18:10:52 GMT Original-Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0121.oracle.com (8.13.8/8.13.8) with ESMTP id t5PIApBB009675; Thu, 25 Jun 2015 18:10:51 GMT In-Reply-To: <87vbebg1fs.fsf@mbork.pl> X-Priority: 3 X-Mailer: Oracle Beehive Extensions for Outlook 2.0.1.9 (901082) [OL 12.0.6691.5000 (x86)] X-Source-IP: userv0022.oracle.com [156.151.31.74] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 141.146.126.69 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:105164 Archived-At: > So, I assume that when Emacs Lisp interpreter encounters a > backquote, it looks at the expression after it. If it is anything > but a list, it just works like the usual quote, and the backquoted > expression evaluates to what was backquoted. Not really. A comma (& additional backquotes & additional commas...) still tells the backquote preceding it to evaluate whatever sexp the comma precedes. So `,foo evaluates variable foo, and `',foo evaluates foo and quotes the result. (setq foo 'bar) ; =3D> bar (setq toto `,foo) ; =3D> bar (setq titi `',foo) ; =3D> 'bar (setq titi `',foo) is equivalent to (setq titi (list 'quote foo)) Michael H's advice about following the macroexpansion is good.=20