From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: phillip.lord@newcastle.ac.uk (Phillip Lord) Newsgroups: gmane.emacs.devel Subject: Re: A protest against pcase, pcase-let, pcase-let* Date: Wed, 01 Apr 2015 10:59:36 +0100 Message-ID: <87d23ob247.fsf@newcastle.ac.uk> References: <20150331180029.GF2871@acm.fritz.box> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1427882429 10300 80.91.229.3 (1 Apr 2015 10:00:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 1 Apr 2015 10:00:29 +0000 (UTC) Cc: emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Apr 01 12:00:20 2015 Return-path: Envelope-to: ged-emacs-devel@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 1YdFRY-0004IW-H1 for ged-emacs-devel@m.gmane.org; Wed, 01 Apr 2015 12:00:16 +0200 Original-Received: from localhost ([::1]:48981 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YdFRX-0002xH-MR for ged-emacs-devel@m.gmane.org; Wed, 01 Apr 2015 06:00:15 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:55741) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YdFR7-0002w7-60 for emacs-devel@gnu.org; Wed, 01 Apr 2015 05:59:52 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YdFQz-0007eD-Uj for emacs-devel@gnu.org; Wed, 01 Apr 2015 05:59:49 -0400 Original-Received: from cheviot22.ncl.ac.uk ([128.240.234.22]:39121) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YdFQz-0007aW-Ng for emacs-devel@gnu.org; Wed, 01 Apr 2015 05:59:41 -0400 Original-Received: from smtpauth-vm.ncl.ac.uk ([10.8.233.129] helo=smtpauth.ncl.ac.uk) by cheviot22.ncl.ac.uk with esmtp (Exim 4.63) (envelope-from ) id 1YdFQu-0007l7-F2; Wed, 01 Apr 2015 10:59:36 +0100 Original-Received: from jangai.ncl.ac.uk ([10.66.67.223] helo=localhost) by smtpauth.ncl.ac.uk with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.63) (envelope-from ) id 1YdFQu-0004Mq-GZ; Wed, 01 Apr 2015 10:59:36 +0100 In-Reply-To: <20150331180029.GF2871@acm.fritz.box> (Alan Mackenzie's message of "Tue, 31 Mar 2015 18:00:29 +0000") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 128.240.234.22 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:184698 Archived-At: Alan Mackenzie writes: > Can we please have a moratorium on the use of pcase, etc.? Their use is > gradually proliferating through Emacs, yet they are not documented. > > OK, maybe pcase itself has a page in the elisp manual, but this page is > very difficult to understand, certainly for me. I have attempted quite > a lot of times to make sense of it, and failed. > > There are two possibilities here: (i) the page is difficult because > pcase is itself difficult. In this case we should stop using pcase and > systematically remove it from Emacs source. (ii) The page is difficult > because it is not well written. In this case it should be improved. > Personally, I think (ii) is more likely to be true than (i). The documentation is, I think, written from the perspective of someone who knows what this sort of pattern-matching does already. The elisp manual is, of course, a manual rather than a tutorial and the pcase documentation is particularly not an easy read. The emacs-wiki has tons of examples, which is much easier to understand I think! http://www.emacswiki.org/emacs/PatternMatching