From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: bojohan+news@dd.chalmers.se (Johan =?utf-8?Q?Bockg=C3=A5rd?=) Newsgroups: gmane.emacs.devel Subject: Re: Subtle bugs in interval code. Date: Fri, 23 Mar 2007 15:59:39 +0100 Message-ID: References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: sea.gmane.org 1174663049 17113 80.91.229.12 (23 Mar 2007 15:17:29 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Fri, 23 Mar 2007 15:17:29 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Mar 23 16:17:22 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1HUlVj-00033f-7U for ged-emacs-devel@m.gmane.org; Fri, 23 Mar 2007 16:16:59 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HUlXd-0001m7-LZ for ged-emacs-devel@m.gmane.org; Fri, 23 Mar 2007 10:18:57 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1HUlXZ-0001lc-Gs for emacs-devel@gnu.org; Fri, 23 Mar 2007 11:18:53 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1HUlXY-0001lJ-LV for emacs-devel@gnu.org; Fri, 23 Mar 2007 11:18:52 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HUlXY-0001lG-EI for emacs-devel@gnu.org; Fri, 23 Mar 2007 10:18:52 -0500 Original-Received: from main.gmane.org ([80.91.229.2] helo=ciao.gmane.org) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1HUlVc-0004An-VV for emacs-devel@gnu.org; Fri, 23 Mar 2007 11:16:53 -0400 Original-Received: from list by ciao.gmane.org with local (Exim 4.43) id 1HUlQb-0000hl-N1 for emacs-devel@gnu.org; Fri, 23 Mar 2007 16:11:41 +0100 Original-Received: from gamma02.me.chalmers.se ([129.16.50.72]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 23 Mar 2007 16:11:41 +0100 Original-Received: from bojohan+news by gamma02.me.chalmers.se with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 23 Mar 2007 16:11:41 +0100 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: emacs-devel@gnu.org Original-Lines: 18 Original-X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: gamma02.me.chalmers.se Mail-Copies-To: never User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.93 (gnu/linux) Cancel-Lock: sha1:KmX/M1I76CCjHo9ARiwwHKq9pNA= X-detected-kernel: Linux 2.6, seldom 2.4 (older, 4) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:68402 Archived-At: storm@cua.dk (Kim F. Storm) writes: > Note that we cannot just use plist-get instead of memq, as we then > cannot differentiate between "property is on list with nil value" > and "property is not on list". plist-member is a built-in function in `src/fns.c'. (plist-member plist prop) Return non-nil if plist has the property prop. plist is a property list, which is a list of the form (PROP1 VALUE1 PROP2 VALUE2 ...). prop is a symbol. Unlike `plist-get', this allows you to distinguish between a missing property and a property with the value nil. The value is actually the tail of plist whose car is prop. -- Johan Bockgård