From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Heime Newsgroups: gmane.emacs.help Subject: Re: Defaulting optional numeric and string arguments Date: Thu, 12 Sep 2024 20:00:00 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="21601"; mail-complaints-to="usenet@ciao.gmane.io" Cc: help-gnu-emacs@gnu.org To: Stefan Monnier Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Sep 12 22:01:06 2024 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 1soq02-0005Q0-4Y for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 12 Sep 2024 22:01:06 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sopzB-0005tj-Ha; Thu, 12 Sep 2024 16:00:13 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sopz9-0005sa-9y for help-gnu-emacs@gnu.org; Thu, 12 Sep 2024 16:00:11 -0400 Original-Received: from mail-43167.protonmail.ch ([185.70.43.167]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sopz6-0002T5-Iz for help-gnu-emacs@gnu.org; Thu, 12 Sep 2024 16:00:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1726171206; x=1726430406; bh=gDuOuU9U5l+HEnYQDwB1cbp590CI1Qhpi3aYM8GmO6I=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=V5QWsoSNVTUyV7XkxAsRuSGlhlHUbxprFT1bhSqvyGSVFZXjIegFe8bawhGb42JRm nPbu9pp+/i02W1UQnOmwh2HQ8X62BK6dopcP53jDQXHv1jFAdU/EKjXXflt285K2f9 HVmmqNuxJMSlxySyYPsjLYz+ikDzaoSKvuXlgOwr009rWxV4JyEQMq87+fTd02MoO4 OuXak45mfnme54AVQtKJEGR+8DWdlHeUeEgDGQ9VO9vc7H48JgJsGO7CYsa8xUIIxJ cvJ/Ffl0GwDsexed0E+GJm53JN5YWOchnZwp2I0MSQ2OP41xYZlYdJxFujmptWgGIA 50+XRt8zaNIRw== In-Reply-To: Feedback-ID: 57735886:user:proton X-Pm-Message-ID: 24556f05785d994fc19547eb158294d2d4b1de96 Received-SPF: pass client-ip=185.70.43.167; envelope-from=heimeborgia@protonmail.com; helo=mail-43167.protonmail.ch X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: 2.1.29 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-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:147975 Archived-At: On Friday, September 13th, 2024 at 7:17 AM, Stefan Monnier via Users list f= or the GNU Emacs text editor wrote: > > I have an optional numeric argument n passed to a function. > >=20 > > Am having difficulty setting a default for it to cater for both the > > interactive and non-interactive cases. > >=20 > > Is the below how to do it ? > >=20 > > (setq n (if (or (not n) (not numberp n)) 0 n)) >=20 >=20 > Traditionally the default numeric value for an absent prefix arg is > 1 rather than 0. So if you can arrange to use 1 as default, it'll > integrate better into the overall Emacs experience. >=20 > Also you can simply the above to >=20 > (unless (numberp n) (setq n 0)) >=20 > > I also have an optional string bfrn, to which I am using > > (setq bfrn (if (or (not bfrn) (string=3D bfrn "")) "Context" bfrn)) >=20 >=20 > I'd recommend to ignore the "" case (i.e. change your callers and/or the > interactive spec so they don't accidentally send the empty string > (e.g. use `read-string` rather than `read-from-minibuffer`)) and > just use: >=20 > (unless bfrn (setq bfrn "Context")) =20 If user does not pass anything to read-string, would the value not be nothi= ng. I would like a value to be used as it should store a buffer name. =20 > - Stefan