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: Example use of macro to minimize and generalize the code Date: Tue, 1 Jun 2021 20:24:31 +0300 Message-ID: References: <87y2buscef.fsf@web.de> <87k0nes9s0.fsf@web.de> <878s3us8le.fsf@web.de> <87fsy1y97e.fsf@web.de> 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="22026"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.0.7+183 (3d24855) (2021-05-28) Cc: Michael Heerdegen , help-gnu-emacs To: Yuri Khan Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jun 01 19:28:04 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 1lo8BQ-0005T5-6s for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 01 Jun 2021 19:28:04 +0200 Original-Received: from localhost ([::1]:39490 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lo8BP-0006Zh-0r for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 01 Jun 2021 13:28:03 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:33248) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lo8B5-0006ZM-AN for help-gnu-emacs@gnu.org; Tue, 01 Jun 2021 13:27:43 -0400 Original-Received: from stw1.rcdrun.com ([217.170.207.13]:52831) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lo8B3-0001fP-IA for help-gnu-emacs@gnu.org; Tue, 01 Jun 2021 13:27:43 -0400 Original-Received: from localhost ([::ffff:197.157.0.35]) (AUTH: PLAIN admin, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 00000000000ADF01.0000000060B66E0A.0000750A; Tue, 01 Jun 2021 10:27:38 -0700 Mail-Followup-To: Yuri Khan , Michael Heerdegen , help-gnu-emacs Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_SORBS_WEB=1.5, SPF_HELO_PASS=-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:130464 Archived-At: * Yuri Khan [2021-06-01 20:12]: > On Tue, 1 Jun 2021 at 23:38, Jean Louis wrote: > > > > > (defmacro when-tabulated-id (table &rest body) > > > > (declare (indent 2) (debug t)) > > > > ;;(ignore id) > > > > `(if id > > > > Why don't you consider to make the id a real argument? > > > > I wish I could fully understand but I don't, and I consider your > > advises important. > > > > How would I make the ID a real argument? > > I believe Michael is hinting at this: > > (defmacro when-tabulated-id (id table &rest body) > `(if ,id > … > > which means “at macro expansion time, substitute the value of the > argument to the macro”, rather than your original > > (defmacro when-tabulated-id (id table &rest body) > `(if id > … > > which means “at evaluation time, substitute the value of the symbol > 'id”. I have removed `id' argument and now I have: (macroexpand '(when-tabulated-id "people" (ignore))) ⇒ (if id (progn (ignore)) (if (or (eq "people" 'any) (string-equal "people" rcd-current-table)) (let ((id (tabulated-list-get-id))) (if id (progn (ignore)) (message "Did not get ID"))) (message "This function is for table `%s' only" "people"))) If I would use ,d it would expand into number or nil, it seem it would end up same. Now I don't have compiler warnings, and functions work fine. Let me know if I am making errors in this. -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns Sign an open letter in support of Richard M. Stallman https://stallmansupport.org/