From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Replace trivial pcase occurrences in the Emacs sources Date: Wed, 31 Oct 2018 16:06:38 -0400 Message-ID: References: <83tvlcsnee.fsf@gnu.org> <20181029134722.GC4195@ACM> <87lg6gifnb.fsf@web.de> <87muqwxs7m.fsf@ericabrahamsen.net> <83h8h3jlyd.fsf@gnu.org> <8b897e43-679b-d38c-e185-0efe19c09342@yandex.ru> <83y3aei08p.fsf@gnu.org> <83o9bahz6i.fsf@gnu.org> <877ehyx7xg.fsf@web.de> <83d0rpj4y0.fsf@gnu.org> <871s85yjx9.fsf@web.de> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1541016385 3095 195.159.176.226 (31 Oct 2018 20:06:25 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 31 Oct 2018 20:06:25 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Oct 31 21:06:21 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gHwkp-0000dP-UU for ged-emacs-devel@m.gmane.org; Wed, 31 Oct 2018 21:06:16 +0100 Original-Received: from localhost ([::1]:33294 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHwmw-0001oN-BM for ged-emacs-devel@m.gmane.org; Wed, 31 Oct 2018 16:08:26 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:58175) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHwlz-0001mg-4l for emacs-devel@gnu.org; Wed, 31 Oct 2018 16:07:27 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gHwlu-0006DX-JA for emacs-devel@gnu.org; Wed, 31 Oct 2018 16:07:27 -0400 Original-Received: from [195.159.176.226] (port=48718 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gHwls-0006AZ-H1 for emacs-devel@gnu.org; Wed, 31 Oct 2018 16:07:22 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1gHwji-0007go-Mp for emacs-devel@gnu.org; Wed, 31 Oct 2018 21:05:06 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 12 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:qykxqD096S+5inVFs9TZwnky8sE= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:230912 Archived-At: > (pcase '(1 2 3) > ((let a 3) a)) > ==> 3 > > Is the used pattern destructuring? It binds a variable. I think it's not worth trying to define precisely which patterns are "destructuring" and which aren't. We can just show two clear examples, like a 'emacs pattern and a `(,a . ,b) pattern to contrast the two. Stefan