From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.help Subject: Re: Lexical vs. dynamic: small examples? Date: Sat, 14 Aug 2021 20:23:35 +0000 Message-ID: <4a9bddb9ec23089cd1f6@heytings.org> References: <4a9bddb9ec57299b3b0c@heytings.org> <87mtpj3hpj.fsf@zoho.eu> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40109"; mail-complaints-to="usenet@ciao.gmane.io" Cc: help-gnu-emacs@gnu.org To: Emanuel Berg Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sat Aug 14 22:24:06 2021 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 1mF0CM-000A9l-66 for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 14 Aug 2021 22:24:06 +0200 Original-Received: from localhost ([::1]:36404 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mF0CK-0006oj-8z for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 14 Aug 2021 16:24:04 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34064) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mF0Bu-0006ls-Sa for help-gnu-emacs@gnu.org; Sat, 14 Aug 2021 16:23:39 -0400 Original-Received: from heytings.org ([95.142.160.155]:51800) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mF0Bt-0007ke-A4 for help-gnu-emacs@gnu.org; Sat, 14 Aug 2021 16:23:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20210101; t=1628972615; bh=ZqdoEfkdAioLltN7Cy2wDxHZ0lg5p9s6Cul17MPA+14=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=mpYIW530MV9/qhvW4d4RSKIICPyKCiTbKMikKgZ0dluWoiEqaEmsIhj1bxwKhyxZA toK8nPkgNd2JBnKaBr9zM90SE4+/Grs5DBtvZvNZH1moWCqApqJLDD6jNKIKxltH9f ly/P4jHcXEkFd4BwPDdjR8EPEoNfgfa5ThbOEOC+ZlIMIkpjA1ARYxmu8g7gCwnEkI 6V0xVGEj+qPAdx6YlTi68FQ70wdB81JTfmvzAnNBS6f0Jf0r7IfbaACZ1gJYjZcz21 hjYIZfs1Knq4iv7+sUI1q2fTQC7u+w+0QePA6z7psNfmYnr2hSeLNiXF0mMNLigubU OjYVISf6/KiAg== In-Reply-To: <87mtpj3hpj.fsf@zoho.eu> Received-SPF: pass client-ip=95.142.160.155; envelope-from=gregory@heytings.org; helo=heytings.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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:132544 Archived-At: >> (defvar saved-buffer-read-only) >> (defun delete-whitespace-at-eol () >> (interactive) >> (setq saved-buffer-read-only buffer-read-only) >> (setq buffer-read-only nil) >> (save-excursion (replace-regexp " *$" "" nil (point-min) (point-max))) >> (setq buffer-read-only saved-buffer-read-only)) > > OK, but you don't need to store the old value in a global variable... > Of course you do, you need to restore the original value, which could be either t or nil. But indeed TIMTOWTDI: for this specific example, another way to do it would be to introduce a conditional. In general however variables can hold more than two values, so for didactic purposes the above is much clearer.