From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.bugs Subject: bug#49809: [PATCH] Add macro 'pcase-setq' Date: Wed, 11 Aug 2021 23:57:29 +0200 Message-ID: <87czqjod9y.fsf@gnus.org> References: <07ad5892-3343-4c35-00e3-9753bca5f67b@protonmail.com> <87eeb6dmvo.fsf@web.de> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="34548"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: okamsn@protonmail.com, 49809@debbugs.gnu.org, monnier@iro.umontreal.ca To: Michael Heerdegen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Aug 11 23:58:20 2021 Return-path: Envelope-to: geb-bug-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 1mDwEt-0008ip-RD for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 11 Aug 2021 23:58:19 +0200 Original-Received: from localhost ([::1]:59952 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mDwEs-0000t4-Kn for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 11 Aug 2021 17:58:18 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53466) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mDwEc-0000qf-8Z for bug-gnu-emacs@gnu.org; Wed, 11 Aug 2021 17:58:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:53517) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mDwEc-00088V-1A for bug-gnu-emacs@gnu.org; Wed, 11 Aug 2021 17:58:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1mDwEb-0002Xw-Ot for bug-gnu-emacs@gnu.org; Wed, 11 Aug 2021 17:58:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Lars Ingebrigtsen Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 11 Aug 2021 21:58:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 49809 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 49809-submit@debbugs.gnu.org id=B49809.16287190679753 (code B ref 49809); Wed, 11 Aug 2021 21:58:01 +0000 Original-Received: (at 49809) by debbugs.gnu.org; 11 Aug 2021 21:57:47 +0000 Original-Received: from localhost ([127.0.0.1]:36827 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mDwEM-0002XF-PI for submit@debbugs.gnu.org; Wed, 11 Aug 2021 17:57:47 -0400 Original-Received: from quimby.gnus.org ([95.216.78.240]:34368) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mDwEL-0002X0-2U for 49809@debbugs.gnu.org; Wed, 11 Aug 2021 17:57:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnus.org; s=20200322; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=pbwdaT8pHo4+HWcgo6iBl0GUKJ4nva/+Ccr2hC1IOJ0=; b=qTVzfIBn/6RTGz163eIYMpfqRC a9TYr55oHHcapWCF+RhV9640YbHYUkCtdjXLTW0K22hsMwAdt39VpeCN2KQ6hH0QAwtA+VMNhe44f msBQtp4oFzFZUEXnqvCou8EWfVe63dhrOJxz9sUD0IhSi1aPEnOC1L5jMbZQXLWC+8Vs=; Original-Received: from [84.212.220.105] (helo=elva) by quimby.gnus.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mDwE8-00050n-3x; Wed, 11 Aug 2021 23:57:36 +0200 In-Reply-To: <87eeb6dmvo.fsf@web.de> (Michael Heerdegen's message of "Sat, 07 Aug 2021 04:11:55 +0200") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:211636 Archived-At: Michael Heerdegen writes: >> +(defmacro pcase-setq (pat val &rest args) >> + "Assign values to variables by destructuring with `pcase'. >> + >> +\(fn PATTERN VALUE PATTERN VALUE ...)" It seems like there was general agreement to adding this, so I've now applied Earl's patch, with the following addition to the doc string: > Can we maybe enhance the docstring a bit? I think we should at least > cover these points: > > - The PATTERNs are normal `pcase' patterns, the VALUES are expressions. > > - Evaluation happens sequentially as in `setq' (not in parallel) > > - When a PATTERN doesn't match it's VALUE, the pair is silently skipped > (completely, no partial assignments are performed, AFAIU) > > Maybe adding a simple example would not be too bad as well? Stefan Monnier writes: > The result is the same whether `pcase-setq` assigns nil or doesn't touch > the vars, so this test is not very effective. I'd rather do: > > (should (equal (list nil nil) > (let ((a 'unset) > (b 'unset)) > (pcase-setq `(,a ,b) nil) > (list a b)))) I've also added this to the tests, but what it actually returns instead... > But Michael points out that it seems your code won't perform the > assignment if the pattern doesn't match, which I find to be an > odd behavior. > > I'd expect a behavior like that of `pcase-let`, instead. ... because I have no opinion here, really -- behaving like `pcase-let' would be good, but on the other hand, the current behaviour also kinda sorta makes sense. So feel free to adjust the behaviour (or not). -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no