From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: How to avoid compiler warning `unused lexical variable' for `dolist' or `dotimes'? Date: Sat, 09 Jan 2021 18:14:49 -0500 Message-ID: References: <868s92ntez.fsf@x201.butler.org> <86zh1hn21c.fsf@x201.butler.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2336"; 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:jsWS5xflSQEGN/aMWePCxLbQjU4= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun Jan 10 00:15:21 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 1kyNS5-0000Vs-2g for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 10 Jan 2021 00:15:21 +0100 Original-Received: from localhost ([::1]:60204 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kyNS4-00078v-54 for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 09 Jan 2021 18:15:20 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:37644) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kyNRh-00077L-DE for help-gnu-emacs@gnu.org; Sat, 09 Jan 2021 18:14:57 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:49480) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kyNRf-0005Dz-Si for help-gnu-emacs@gnu.org; Sat, 09 Jan 2021 18:14:57 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1kyNRe-000AUP-1q for help-gnu-emacs@gnu.org; Sun, 10 Jan 2021 00:14:54 +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: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, 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:127156 Archived-At: >> This distinction becomes relevant if BODY modifies VAR or captures it >> in a closure. > Maybe I am being thick, but I cannot think of how there would be a > different behaviour. Try: (let (funs) (dotimes (i 5) (push (lambda () i) funs)) (mapcar #'funcall funs)) IIUC the version you advocate would return (5 5 5 5 5) whereas the current version returns (4 3 2 1 0) Other differences occur if you do (let (vals) (dotimes (i 10) (push (setq i (1+ i)) vals)) vals) -- Stefan