From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: Accessing arg with (interactive "P") Date: Wed, 06 Jul 2022 03:16:17 +0200 Message-ID: <871quzkplq.fsf@dataswamp.org> References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="3040"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:smvBkTHyetny0M1goSTqinHP1NA= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jul 06 03:17:08 2022 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 1o8tf9-0000Vs-MM for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 06 Jul 2022 03:17:07 +0200 Original-Received: from localhost ([::1]:42228 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o8tf7-0004Uc-JX for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 05 Jul 2022 21:17:05 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50628) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o8teb-0004UF-UL for help-gnu-emacs@gnu.org; Tue, 05 Jul 2022 21:16:33 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:51098) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o8teV-0007yu-Dx for help-gnu-emacs@gnu.org; Tue, 05 Jul 2022 21:16:33 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1o8teS-000AB3-EL for help-gnu-emacs@gnu.org; Wed, 06 Jul 2022 03:16:24 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never 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: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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" Xref: news.gmane.io gmane.emacs.help:138327 Archived-At: carlmarcos--- via Users list for the GNU Emacs text editor wrote: > I have the following elisp function, using > `current-prefix-arg` to decide subsequent processing. You can do that but better is to use the argument directly just as you normally would, (defun poke (&optional n) (interactive "P") (if n (message "n is set") (message "n is nil") )) Try M-x poke RET and C-u M-x poke RET. Note that this also works from Lisp which ignores the interactive spec. Try eval these (poke) (poke 1) With (poke) you see that optional arguments defaults to nil. If you intends to use the arg, and nil doesn't make sense, you must explicitely set it to some default that does, say 0 which is common: (or n (setq n 0)) But in our example nil is fine so no need to do that. > Having made the command examine it directly, the usual > method for accessing it is with (interactive "P"). > The problem is that I do not know how to examine the prefix > arg through the interactive clause. Try evaluating the interactive form, for example (interactive "P") ; evals to (nil) so the list element(s) is/are assigned to the formal parameters, they become the arguments to the function. Eval this: (interactive "sString: \nnNumber: ") It will assign the data you input to the formal parameters of a function that looks like this for example (defun xy-problem (str num) ... ) -- underground experts united https://dataswamp.org/~incal