From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Explanation Request for the Function set-transient-map in subr.el Date: Sun, 28 Nov 2021 16:07:31 -0500 Message-ID: References: Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="37501"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:UwxuxIEyFcBMQcZQ+goGccp4cHE= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun Nov 28 22:08:10 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 1mrRP8-0009ZD-LX for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 28 Nov 2021 22:08:10 +0100 Original-Received: from localhost ([::1]:60684 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mrRP7-0001uK-EP for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 28 Nov 2021 16:08:09 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:38212) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mrROn-0001uC-Hc for help-gnu-emacs@gnu.org; Sun, 28 Nov 2021 16:07:49 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:55740) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mrROd-0006Yn-Lp for help-gnu-emacs@gnu.org; Sun, 28 Nov 2021 16:07:49 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1mrROa-0008rC-8y for help-gnu-emacs@gnu.org; Sun, 28 Nov 2021 22:07:36 +0100 X-Injected-Via-Gmane: http://gmane.org/ 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: 2.1.29 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:134713 Archived-At: > But then, isn't that second expression redundant? Lookup key is already looking > in our transient map, if it succeeds mc will be non-nil and equal this-command, > if it does not, 'and' will return nil anyway? It's somewhat redundant but tries to protect from cases where some other keymap was used instead (presumably a keymap with higher precedence). Stefan