From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Drew Adams Newsgroups: gmane.emacs.help Subject: RE: Suppress user-prompting when calling commands in programs Date: Fri, 13 Jun 2014 20:36:47 -0700 (PDT) Message-ID: References: <87r42skjd8.fsf@gmail.com> <877g4k7ux4.fsf@geodiff-mac3.ulb.ac.be> <878up0kfcv.fsf@gmail.com> <5b284aa3-068d-461d-a95b-52cd97ba292a@default> <874mzokvwr.fsf@ericabrahamsen.net> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1402717049 967 80.91.229.3 (14 Jun 2014 03:37:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 14 Jun 2014 03:37:29 +0000 (UTC) To: Eric Abrahamsen , help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Jun 14 05:37:21 2014 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WvemP-0001h7-5s for geh-help-gnu-emacs@m.gmane.org; Sat, 14 Jun 2014 05:37:21 +0200 Original-Received: from localhost ([::1]:34063 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WvemO-0001QY-Pm for geh-help-gnu-emacs@m.gmane.org; Fri, 13 Jun 2014 23:37:20 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:45814) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wvem6-0001Of-8j for help-gnu-emacs@gnu.org; Fri, 13 Jun 2014 23:37:11 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wvelx-0004Y8-HK for help-gnu-emacs@gnu.org; Fri, 13 Jun 2014 23:37:02 -0400 Original-Received: from userp1040.oracle.com ([156.151.31.81]:38193) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wvelx-0004Xr-A2 for help-gnu-emacs@gnu.org; Fri, 13 Jun 2014 23:36:53 -0400 Original-Received: from acsinet21.oracle.com (acsinet21.oracle.com [141.146.126.237]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s5E3aoej020517 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Sat, 14 Jun 2014 03:36:51 GMT Original-Received: from userz7022.oracle.com (userz7022.oracle.com [156.151.31.86]) by acsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s5E3amTS029399 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 14 Jun 2014 03:36:49 GMT Original-Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userz7022.oracle.com (8.14.5+Sun/8.14.4) with ESMTP id s5E3alZF021518; Sat, 14 Jun 2014 03:36:48 GMT In-Reply-To: <874mzokvwr.fsf@ericabrahamsen.net> X-Priority: 3 X-Mailer: Oracle Beehive Extensions for Outlook 2.0.1.8 (707110) [OL 12.0.6691.5000 (x86)] X-Source-IP: acsinet21.oracle.com [141.146.126.237] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 156.151.31.81 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:98234 Archived-At: > > What's wrong with them pushing the read into the interactive spec? > > > > (defun foo (&optional arg bar) > > (interactive (list current-prefix-arg > > (org-icompleting-read ...)))) > > ...) >=20 > A quick side-question: Everyone here is using &optional for the prefix > arg name. I used &optional because that is what was used in the original `foo'. Presumably there is existing code that uses `foo' and expects that signature, e.g., tries to evaluate `(foo)'. > I have several functions lying around that use the "P" > interactive spec but don't specify arg as &optional, and seem to work > fine. My understanding is that, if there is no prefix arg, arg will > simply be nil, as it should be. Correct. > Apart from style/code clarity, are there other reasons for specifying > &optional? See above. Use &optional if you want to be able to call the function without passing that argument.