From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Olaf Rogalsky Newsgroups: gmane.emacs.help Subject: Re: understanding backquote Date: Wed, 03 Jun 2015 01:00:30 +0200 Message-ID: <87k2vllnqp.fsf@aol.de> References: <87vbf65jem.fsf@free.fr> <87oakx513l.fsf@kuiper.lan.informatimago.com> 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 1433286065 20753 80.91.229.3 (2 Jun 2015 23:01:05 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 2 Jun 2015 23:01:05 +0000 (UTC) Cc: help-gnu-emacs@gnu.org To: "Pascal J. Bourguignon" Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Jun 03 01:00:56 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 1YzvB0-0003NM-FX for geh-help-gnu-emacs@m.gmane.org; Wed, 03 Jun 2015 01:00:54 +0200 Original-Received: from localhost ([::1]:32950 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzvAz-0006JQ-CN for geh-help-gnu-emacs@m.gmane.org; Tue, 02 Jun 2015 19:00:53 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:41557) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzvAk-0006JH-D1 for help-gnu-emacs@gnu.org; Tue, 02 Jun 2015 19:00:39 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YzvAg-00063Y-KI for help-gnu-emacs@gnu.org; Tue, 02 Jun 2015 19:00:38 -0400 Original-Received: from omr-m05.mx.aol.com ([64.12.143.79]:51495) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzvAg-00063E-GP for help-gnu-emacs@gnu.org; Tue, 02 Jun 2015 19:00:34 -0400 Original-Received: from mtaout-mce02.mx.aol.com (mtaout-mce02.mx.aol.com [172.29.27.206]) by omr-m05.mx.aol.com (Outbound Mail Relay) with ESMTP id 830DB70542175; Tue, 2 Jun 2015 19:00:33 -0400 (EDT) Original-Received: from blaubaer (p5DD06311.dip0.t-ipconnect.de [93.208.99.17]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mtaout-mce02.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id DAAD53800008D; Tue, 2 Jun 2015 19:00:32 -0400 (EDT) In-reply-to: <87oakx513l.fsf@kuiper.lan.informatimago.com> x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20140625; t=1433286033; bh=q5mgmLg99gXhyc22ck1yua5Ue5ppfqK004tRFvpywy0=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=mfwVqDBzUKBsDtCuIYcT4G4F2HI1WwCcgYEYaEABeSJjb2wj9M+Zcz3xVutB43Dch V2cOGwm2q3R3hSAS2LTrWTEcnGk3/ZbqUeZL8O0uqLZNfPMc4TluHbrzkiDrOiwFA/ XJr4iW3XEQd84sx9IXUKUHK9js0ZnHOO+i0Mzr2c= x-aol-sid: 3039ac1d1bce556e35906bde X-AOL-IP: 93.208.99.17 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 64.12.143.79 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:104723 Archived-At: >> I have problems in understanding the semantics of backquote. Consider ... > (info "(elisp) Backquote") Yes, I read that, but the manual does not make it entirly clear, at which time comma expressions are evaluated: at read or at compile-time: 9.4 Backquote ... The special marker =E2=80=98,=E2=80=99 inside of the argument to backqu= ote indicates a value that isn=E2=80=99t constant. The Emacs Lisp evaluator evaluates t= he argument of =E2=80=98,=E2=80=99, and puts the value in the list structu= re: ... > Now, the fact that you obtain a simple constant function is unrelated > to the backquote, but comes from the fact that you have a good and smar= t > compiler, that notices that the expression is a constant expression, an= d > therefore it is reduced at compilation time: Thanks for the confirmation, I already suspected this. Olaf