From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Understanding the "let" construct and the setting of variables Date: Fri, 18 Dec 2020 21:48:53 +0100 Message-ID: <87sg82yh56.fsf@zoho.eu> References: <87zh2d1byp.fsf@fastmail.fm> <87o8is26nu.fsf@fastmail.fm> <87a6uc244a.fsf@fastmail.fm> Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="38795"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:UDCorFRCvCB07R/2cWKC0juZnls= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Dec 18 21:50:40 2020 Return-path: Envelope-to: geh-help-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 ) id 1kqMi0-0009wF-Db for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 18 Dec 2020 21:50:40 +0100 Original-Received: from localhost ([::1]:46234 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kqMhz-0006vs-FV for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 18 Dec 2020 15:50:39 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:54658) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kqMhQ-0006ta-RJ for help-gnu-emacs@gnu.org; Fri, 18 Dec 2020 15:50:04 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:43516) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kqMhP-0001Tu-BD for help-gnu-emacs@gnu.org; Fri, 18 Dec 2020 15:50:04 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1kqMhN-0009FF-Nw for help-gnu-emacs@gnu.org; Fri, 18 Dec 2020 21:50:01 +0100 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:126530 Archived-At: Joost Kremers wrote: > Not sure I understand the question. With `setq`, two things > can happen: either there is already a binding for the > variable, in which case `setq` updates the binding (assigns > a new value to the existing variable), or there is no such > binding (i.e., the variable doesn't exist), and in that case > the variable is created. That's right, so use `setq' to create and manipulate global variables; inside functions, use `let/let*'. -- underground experts united http://user.it.uu.se/~embe8573 https://dataswamp.org/~incal