From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.devel Subject: Re: pcase-dolist Date: Thu, 09 Jul 2015 22:27:34 +0200 Message-ID: <87a8v53wll.fsf@web.de> References: <87wpyaet7r.fsf@web.de> <87y4iqh7x0.fsf@web.de> <87oajmld49.fsf@gnu.org> <87oajlyif9.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1436473684 9989 80.91.229.3 (9 Jul 2015 20:28:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 9 Jul 2015 20:28:04 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Jul 09 22:27:55 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 1ZDIQE-0002pe-MJ for ged-emacs-devel@m.gmane.org; Thu, 09 Jul 2015 22:27:54 +0200 Original-Received: from localhost ([::1]:41746 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZDIQD-00067w-Qx for ged-emacs-devel@m.gmane.org; Thu, 09 Jul 2015 16:27:53 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:55915) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZDIQA-00067n-A5 for emacs-devel@gnu.org; Thu, 09 Jul 2015 16:27:51 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZDIQ5-0006F4-BL for emacs-devel@gnu.org; Thu, 09 Jul 2015 16:27:50 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:36051) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZDIQ5-0006Eq-49 for emacs-devel@gnu.org; Thu, 09 Jul 2015 16:27:45 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZDIQ2-0002iB-Se for emacs-devel@gnu.org; Thu, 09 Jul 2015 22:27:42 +0200 Original-Received: from ip-2-202-71-232.web.vodafone.de ([2.202.71.232]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 09 Jul 2015 22:27:42 +0200 Original-Received: from michael_heerdegen by ip-2-202-71-232.web.vodafone.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 09 Jul 2015 22:27:42 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 15 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: ip-2-202-71-232.web.vodafone.de User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:wzvoAwxA061B3i1NoGea1SlfARY= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 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:187794 Archived-At: Stefan Monnier writes: > But that does not match the usual uses of "tuples represented as > lists", where it's customary to use (A B) when the remaining fields > are all nil (since (car nil) returns nil and (nth 5 '(1 2)) also > returns nil rather than signaling an error) and where it's also > customary to ignore any additional element. Good argument. OTOH, if you _want_ to distinguish e.g. a two from a three element list, you will have to use something like `(,a ,b . ,r) and test whether r is nil. Mmh. Anyway, pcase and pcase-let should at least behave the same at the end I think... Michael.