From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Richard Stallman <rms@gnu.org> Newsgroups: gmane.emacs.bugs Subject: bug#66756: 30.0.50; [PATCH] Improve discussion of 'let' in Elisp Introduction manual Date: Sun, 05 Nov 2023 21:29:30 -0500 Message-ID: <E1qzpMo-0002Ai-Ao@fencepost.gnu.org> References: <a9812c1d-71e4-5f3f-83a4-a2923e649f3a@gmail.com> Reply-To: rms@gnu.org Content-Type: text/plain; charset=Utf-8 Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="36109"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 66756@debbugs.gnu.org To: Jim Porter <jporterbugs@gmail.com> Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Nov 06 03:30:40 2023 Return-path: <bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org> Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from <bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org>) id 1qzpNv-0009DW-Sf for geb-bug-gnu-emacs@m.gmane-mx.org; 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Mon, 06 Nov 2023 02:31:02 +0000 Original-Received: (at 66756) by debbugs.gnu.org; 6 Nov 2023 02:30:15 +0000 Original-Received: from localhost ([127.0.0.1]:38470 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces@debbugs.gnu.org>) id 1qzpNW-0006FT-SB for submit@debbugs.gnu.org; Sun, 05 Nov 2023 21:30:15 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:43846) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <rms@gnu.org>) id 1qzpNV-0006F8-8V for 66756@debbugs.gnu.org; Sun, 05 Nov 2023 21:30:13 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <rms@gnu.org>) id 1qzpMo-0007lS-Si; Sun, 05 Nov 2023 21:29:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=Date:References:Subject:In-Reply-To:To:From: mime-version; bh=QGmjkkHOijNZoYFM3F16Qowkk2bO45U0D797pXddglY=; b=qwdwDsJwfNCg 7bRgnfCSbZb0oApuoQ9IVTb6wnEUQrIJUn5/fbNhIAC/IroQHne3L4nIKegCnu0ttFT9o/T4APM/U iPtS2FjKQirhbTcOrg9AEUd9an1aZ1KVn0KcRZ/ZCfmbmXrs4fZMjqCyusdO4DMtmvoE57dZSj5Ub RNHJ2ynzuOypxvdNmxPSFBrzb/65b16q5tptV/YFrvzTpdTHijJl4k57x14LnzZBUf1BW2TC7/+2B 1x+3s3Iy/wVFH4Y7TewK2c46N2sILNWAHrv8eFc06LG2/SGXMQM8E6fAt67BZfX30CcCjno7pEgfx cZdk70YjF3xi/pKTXfw7nw==; Original-Received: from rms by fencepost.gnu.org with local (Exim 4.90_1) (envelope-from <rms@gnu.org>) id 1qzpMo-0002Ai-Ao; Sun, 05 Nov 2023 21:29:30 -0500 In-Reply-To: <a9812c1d-71e4-5f3f-83a4-a2923e649f3a@gmail.com> (message from Jim Porter on Wed, 25 Oct 2023 22:54:25 -0700) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs.gnu.org> List-Unsubscribe: <https://lists.gnu.org/mailman/options/bug-gnu-emacs>, <mailto:bug-gnu-emacs-request@gnu.org?subject=unsubscribe> List-Archive: <https://lists.gnu.org/archive/html/bug-gnu-emacs> List-Post: <mailto:bug-gnu-emacs@gnu.org> List-Help: <mailto:bug-gnu-emacs-request@gnu.org?subject=help> List-Subscribe: <https://lists.gnu.org/mailman/listinfo/bug-gnu-emacs>, <mailto:bug-gnu-emacs-request@gnu.org?subject=subscribe> Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:273852 Archived-At: <http://permalink.gmane.org/gmane.emacs.bugs/273852> [[[ To any NSA and FBI agents reading my email: please consider ]]] [[[ whether defending the US Constitution against all enemies, ]]] [[[ foreign or domestic, requires you to follow Snowden's example. ]]] > +The @code{let} special form provides a way to confine your variables > +to a particular section of your code (in computer science jargon, a > +``scope''). @code{let} creates a name for a @dfn{local variable} that > +overshadows any use of the same name outside the @code{let} expression > +(we call this ``binding'' the variable). This prevents any accidental > +usage of these variables outside of the @code{let} expression. This is one of several reasons to use `let'. Others are * To compute a value once and use it more than once. * To create a loop index variable. * For special variables, to bind them si as to control the behavior of other code. Should all of them be mentioned in this node? I am not sure; that is a pedagogical question. But this node shouldn't assert that one reason is the only reason. -- Dr Richard Stallman (https://stallman.org) Chief GNUisance of the GNU Project (https://gnu.org) Founder, Free Software Foundation (https://fsf.org) Internet Hall-of-Famer (https://internethalloffame.org)