From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: carlmarcos--- via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Making a function than can only be used interactively Date: Fri, 8 Jul 2022 14:06:37 +0200 (CEST) Message-ID: References: <875yk8ehp8.fsf@dataswamp.org> <87bku0ce1f.fsf@dataswamp.org> Reply-To: carlmarcos@tutanota.com 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="35781"; mail-complaints-to="usenet@ciao.gmane.io" Cc: help-gnu-emacs To: Yuri Khan Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Jul 08 14:07:28 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 1o9mlb-0009AZ-7s for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 08 Jul 2022 14:07:27 +0200 Original-Received: from localhost ([::1]:40518 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o9mla-0008Qm-Bs for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 08 Jul 2022 08:07:26 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:44164) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o9mkt-0008OX-Im for help-gnu-emacs@gnu.org; Fri, 08 Jul 2022 08:06:45 -0400 Original-Received: from w1.tutanota.de ([81.3.6.162]:42472) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o9mkq-0006pC-Rj for help-gnu-emacs@gnu.org; Fri, 08 Jul 2022 08:06:43 -0400 Original-Received: from w3.tutanota.de (unknown [192.168.1.164]) by w1.tutanota.de (Postfix) with ESMTP id 2AC5EFBF94D; Fri, 8 Jul 2022 12:06:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1657281997; s=s1; d=tutanota.com; h=From:From:To:To:Subject:Subject:Content-Description:Content-ID:Content-Type:Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:In-Reply-To:In-Reply-To:MIME-Version:MIME-Version:Message-ID:Message-ID:Reply-To:References:References:Sender; bh=sZPcax4RB8Z6kwxchu5YQ4RoMi590XDbagujXkIFerA=; b=EDq9WhLl4JhpzUPgYXsHUqsJqi4K6L3sBJd7j6ko8am13p5V92esojgpx/JDzrzb dtduZYIfAmmbXzMlxBdzZSs5yhxKiinzcRpahI5t0KlkPD691Ro2yyHKrclm/sl9Sua BbJujwi452t4afRC4Nx6Xs6cBBhZzqfuJtYa/Ix9qrfKM3sAwx9V9pikcASz9ulqx9I OCVBPrE+9mXEGv+ennJN+Vov+6PlK5k752f/oqmfsqdcTZPq5RKOXBeLRgmFsD2YvvU FE7GobhIhmTC9OOgj3MrjNaACCwZBFT+9jIbtHRASM6kRX3C6po13b1t+qsVA77TVCz 6Ck5pyTKWQ== In-Reply-To: Received-SPF: pass client-ip=81.3.6.162; envelope-from=carlmarcos@tutanota.com; helo=w1.tutanota.de 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, HTML_MESSAGE=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-Content-Filtered-By: Mailman/MimeDel 2.1.29 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:138376 Archived-At: Jul 8, 2022, 06:55 by yuri.v.khan@gmail.com: > On Fri, 8 Jul 2022 at 13:31, Emanuel Berg wrote: > >> > It does not matter for interactive use. [...] =E2=80=98&optional=E2=80= =99 >> > comes into play if you use this function non-interactively, >> > from Lisp >> >> No, it matters. One example how it matters is that optional >> arguments defaults to nil. >> > > You=E2=80=99re right, with an interactive specification that evaluates to= a > list it matters, because the list you return may or may not have as > many arguments as the function takes. > > My point was that in the specific case of a three-argument function > and a three-item string-valued interactive specification, &optional > does not matter for interactive use. > > >> Check out this file and in particular example 4 which doesn't >> make sense to me? >> >> ;; DWIM example 1, from Lisp ignore region if set >> ;; example 2, use the region if available from Lisp as well >> >> (defun test-dwim (&optional beg end) >> (interactive (when (use-region-p) >> (list (region-beginning) (region-end)) )) >> > > Here you have two cases. If the region is active, you produce a > two-element list, otherwise, a 0-element list. The function signature > allows 0..2 arguments, so it works in either case. > >> ;; example 3, one call to `use-region-p' is enough >> >> (defun test-dwim-3 (re &optional beg end) >> (interactive `(,(read-regexp "re: ") >> ,@(when (use-region-p) >> (list (region-beginning) (region-end)) ))) >> > > Mostly same, except you build a list of 3 or 1 elements, and the > function accepts 1..3 arguments. > >> ;; example 4, let's do that with the `interactive' spec >> ;; string. but without `use-region-p' it doesn't reset after >> ;; I clear the region, or that's what I thought happened >> ;; anyway :) so this doesn't work as intended, which >> ;; `test-dwim-3' does, supposedly the worse one. >> >> (defun test-dwim-4 (re &optional beg end) >> (interactive "sre: \nr") >> > > Here you use a string interactive spec which always produces 3 > elements. In non-interactive use, it will work if called as > (test-dwim-4 "^foo$"), (test-dwim-4 "^foo$" 42), or (test-dwim-4 > "^foo$" 42 69). > > As to your =E2=80=9Cclearing=E2=80=9D the region, Emacs always maintains = the point and > mark positions, and the =E2=80=98r=E2=80=99 interactive spec code ignores= the region > activation flag and always passes the point and mark. (This could be > considered a bug, but I see no good alternative behavior, except maybe > passing two nils if the region is not active.) > There seems to exist total confusion on how to use the interactive clause a= nd how=20 when to use mandatory or optional arguments, and how to handle them.=C2=A0= =20