From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jean Louis Newsgroups: gmane.emacs.help Subject: Re: How to avoid compiler warning `unused lexical variable' for `dolist' or `dotimes'? Date: Fri, 8 Jan 2021 05:08:26 +0300 Message-ID: References: <87mtxknsei.fsf@zoho.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="5334"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.0 (3d08634) (2020-11-07) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Jan 08 03:24:16 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 1kxhRn-0001FI-V7 for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 08 Jan 2021 03:24:15 +0100 Original-Received: from localhost ([::1]:45854 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kxhRn-00066Z-1x for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 07 Jan 2021 21:24:15 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:57500) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kxhR3-00066B-TG for help-gnu-emacs@gnu.org; Thu, 07 Jan 2021 21:23:29 -0500 Original-Received: from stw1.rcdrun.com ([217.170.207.13]:54435) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kxhR1-0003oy-MU for help-gnu-emacs@gnu.org; Thu, 07 Jan 2021 21:23:29 -0500 Original-Received: from localhost ([::ffff:41.210.145.49]) (AUTH: PLAIN securesender, TLS: TLS1.2,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 00000000002955DE.000000005FF7C21C.000046FF; Thu, 07 Jan 2021 19:23:24 -0700 Mail-Followup-To: help-gnu-emacs@gnu.org Content-Disposition: inline In-Reply-To: <87mtxknsei.fsf@zoho.eu> Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, 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:127073 Archived-At: * Emanuel Berg via Users list for the GNU Emacs text editor [2021-01-08 04:21]: > Jean Louis wrote: > > >> Same as for any other place where you might declare > >> a variable that you don't actually use: make sure the var's > >> name starts with an underscore. This tells the compiler > >> that you're aware of the fact the var is not used (but > >> still want this variable there for some reason; e.g. > >> in dotimes and dolist you don't have the choice not to put > >> a variable there). > >> > >> Traditionally for `dotimes`, I'd then use `_` as the > >> variable name unless I really want to give a hint to the > >> reader about what kind of things I'm counting like (dotimes > >> (_column-nb ...) ...). > > > > That also sounds like workaround around the real problem. > > In `dotimes' I do use the VAR counted. It is not same as > > (let ((_ (execute some program without)))) > > But is this really a workaround in your case? Because you _do_ > use it! > > (dolist (_ignored-var '(a b c)) > (message "%s" _ignored-var) ) > > geh.el:257:1: Warning: variable ‘_ignored-var’ not left unused > > See? Sometimes the byte-compiler gets it right! Then it is not a real solution as proposed earlier. If used, byte compiler will warn. Is it? I did not test it, it seem like you did.