From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.help Subject: Re: How the backquote and the comma really work? Date: Thu, 25 Jun 2015 20:40:20 +0200 Message-ID: <877fqrbpij.fsf@web.de> References: <87vbebg1fs.fsf@mbork.pl> <1e190a42-19c5-4755-b263-4334c402619a@default> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1435257690 10945 80.91.229.3 (25 Jun 2015 18:41:30 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 25 Jun 2015 18:41:30 +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 Jun 25 20:41:16 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 1Z8C5M-00007o-58 for geh-help-gnu-emacs@m.gmane.org; Thu, 25 Jun 2015 20:41:16 +0200 Original-Received: from localhost ([::1]:57029 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8C5G-0007pX-Kh for geh-help-gnu-emacs@m.gmane.org; Thu, 25 Jun 2015 14:41:10 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:59982) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8C4t-0007pP-3P for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 14:40:47 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z8C4q-0000pZ-6n for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 14:40:47 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:45032) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8C4q-0000oO-08 for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 14:40:44 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Z8C4m-00088i-Ip for help-gnu-emacs@gnu.org; Thu, 25 Jun 2015 20:40:40 +0200 Original-Received: from ip-90-186-253-113.web.vodafone.de ([90.186.253.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 25 Jun 2015 20:40:40 +0200 Original-Received: from michael_heerdegen by ip-90-186-253-113.web.vodafone.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 25 Jun 2015 20:40:40 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 22 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: ip-90-186-253-113.web.vodafone.de User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:Mew+xKmAvk5scw95u5ihhVf0gqo= 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:105170 Archived-At: Drew Adams writes: > So `,foo evaluates variable foo, and `',foo evaluates foo and quotes > the result. Yes, that's an aspect that was missing in the mental model: backquote works recursively, i.e. unquoting at deeper list levels is handled as well. > (setq titi `',foo) ; => 'bar Whereby we don't want to conceal that the "'" is also a reader macro: 'thing -> (quote thing). Here is the expression the reader generates for "`',foo": (read "`',foo") ==> (\` (quote (\, foo))) (be sure to eval with print-quoted nil, the default). Michael.