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, 3 Jun 2015 03:57:38 -0400 Message-ID: <14db86cf8dd-7b95-1235a@webprd-m64.mail.aol.com> References: <87vbf65jem.fsf@free.fr> <87k2vl4sm0.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: 7bit X-Trace: ger.gmane.org 1433318309 8635 80.91.229.3 (3 Jun 2015 07:58:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 3 Jun 2015 07:58:29 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Jun 03 09:58:20 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 1Z03Z5-0003GY-9e for geh-help-gnu-emacs@m.gmane.org; Wed, 03 Jun 2015 09:58:19 +0200 Original-Received: from localhost ([::1]:33909 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z03Yz-0007y7-Fn for geh-help-gnu-emacs@m.gmane.org; Wed, 03 Jun 2015 03:58:13 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:56273) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z03YV-0007XS-MZ for help-gnu-emacs@gnu.org; Wed, 03 Jun 2015 03:57:47 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z03YS-000591-HQ for help-gnu-emacs@gnu.org; Wed, 03 Jun 2015 03:57:43 -0400 Original-Received: from omr-m5.mx.aol.com ([64.12.232.237]:46119) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z03YS-00058o-At for help-gnu-emacs@gnu.org; Wed, 03 Jun 2015 03:57:40 -0400 Original-Received: from mtaomg-mad01.mx.aol.com (mtaomg-mad01.mx.aol.com [172.26.221.207]) by omr-m5.mx.aol.com (Outbound Mail Relay) with ESMTP id 39D8E38000085 for ; Wed, 3 Jun 2015 03:57:39 -0400 (EDT) Original-Received: from core-mfa09f.mail.aol.com (core-mfa09.mail.aol.com [172.27.61.9]) by mtaomg-mad01.mx.aol.com (OMAG/Core Interface) with ESMTP id F37FE38000081 for ; Wed, 3 Jun 2015 03:57:38 -0400 (EDT) Original-Received: from 195.33.171.8 by webprd-m64.mail.aol.com (10.74.55.14) with HTTP (WebMailUI); Wed, 03 Jun 2015 03:57:38 -0400 In-Reply-To: X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [195.33.171.8] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20140625; t=1433318259; bh=pAYFBnDd1qgVNYbVy+DDweMswUrRC6nPJLKpPT9eAlo=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=HLkGC42820m9FbcvTWGRiHtrS1XjsB+3ZSvS8L46igaIm0XQ0A2+m8WN2zXDPx1yx T6PK7GtOreEvTcJlttBvC3Fa9mqXj3ijlX90iuXOEiAAugkZ4oao5I8jmFI0qGdVX2 xoaUzAW6w5TVvItXEgMg6s9aP52rxAX5c0YtJzmw= x-aol-sid: 3039ac1addcf556eb3725735 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 64.12.232.237 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:104730 Archived-At: > If you want to compute it at compile-time, use `eval-when-compile'. E.g. Another possibility would be, to use a temporary variable with lexical scope (let ((tmp (* (+ 1 2) (+ 3 4)))) (defun test () tmp)) or even a global variable: (setq tmp (* (+ 1 2) (+ 3 4))) (defun test () tmp)) This is not exactly the same as having a read-time evaluation of the expression, since it adds a variable dereferencing at run-time to the code. But it gets pretty close. Olaf