From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: Why looking-at-p works? Date: Tue, 06 Mar 2018 09:49:59 +0100 Organization: Aioe.org NNTP Server Message-ID: <86r2oxsi4o.fsf@zoho.com> References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1520326119 22040 195.159.176.226 (6 Mar 2018 08:48:39 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 6 Mar 2018 08:48:39 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Mar 06 09:48:34 2018 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1et8Go-0003yr-WE for geh-help-gnu-emacs@m.gmane.org; Tue, 06 Mar 2018 09:48:27 +0100 Original-Received: from localhost ([::1]:54206 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1et8Iq-0002N7-2O for geh-help-gnu-emacs@m.gmane.org; Tue, 06 Mar 2018 03:50:32 -0500 Original-Path: usenet.stanford.edu!goblin2!goblin.stu.neva.ru!aioe.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 21 Original-NNTP-Posting-Host: UHWYWQF2IuZrSKObhXEbig.user.gioia.aioe.org Original-X-Complaints-To: abuse@aioe.org X-Notice: Filtered by postfilter v. 0.8.3 Mail-Copies-To: never Cancel-Lock: sha1:NetT3n87NmHVaK8gyds2gHOwhCM= Original-Xref: usenet.stanford.edu gnu.emacs.help:221998 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.help:116113 Archived-At: Marcin Borkowski wrote: > (defsubst looking-at-p (regexp) "\ Same as > `looking-at' except this function does not > change the match data." (let > ((inhibit-changing-match-data t)) (looking-at > regexp))) > > What happens is that if I make looking-at in > the above code fail (e.g., by saying > (looking-at-p 123)), > inhibit-changing-match-data remains nil, even > though there is no unwind-protect here. > Why does it work like this? Do you need dynamic scope for `let' to work like that? -- underground experts united http://user.it.uu.se/~embe8573