From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.help Subject: Re: Elisp: What does ''nil mean? Date: 16 May 2003 13:57:06 +0200 Organization: Organization?!? Sender: help-gnu-emacs-bounces+gnu-help-gnu-emacs=m.gmane.org@gnu.org Message-ID: References: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1053095592 16866 80.91.224.249 (16 May 2003 14:33:12 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Fri, 16 May 2003 14:33:12 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+gnu-help-gnu-emacs=m.gmane.org@gnu.org Fri May 16 16:33:11 2003 Return-path: Original-Received: from monty-python.gnu.org ([199.232.76.173]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 19GgFl-0004Jd-00 for ; Fri, 16 May 2003 16:32:09 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 19GgDz-0006hM-02 for gnu-help-gnu-emacs@m.gmane.org; Fri, 16 May 2003 10:30:19 -0400 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed00.sul.t-online.de!newsmm00.sul.t-online.com!t-online.de!news.t-online.com!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 32 Original-X-Trace: news.t-online.com 1053086226 05 32104 Gc8+EoNXSGAZDj 030516 11:57:06 Original-X-Complaints-To: abuse@t-online.com X-ID: bEK4ZaZbweXGGfMzhAW7H9huztJ2Qjdhxy67ZJB0yiH2XXiEXbFU6l X-Face: 2FEFf>]>q>2iw=B6,xrUubRI>pR&Ml9=ao@P@i)L:\urd*t9M~y1^:+Y]'C0~{mAl`oQuAl \!3KEIp?*w`|bL5qr,H)LFO6Q=qx~iH4DN;i"; /yuIsqbLLCh/!U#X[S~(5eZ41to5f%E@'ELIi$t^ Vc\LWP@J5p^rst0+('>Er0=^1{]M9!p?&:\z]|;&=NP3AhB!B_bi^]Pfkw User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3.50 Original-Xref: shelby.stanford.edu gnu.emacs.help:113311 Original-To: help-gnu-emacs@gnu.org X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: help-gnu-emacs-bounces+gnu-help-gnu-emacs=m.gmane.org@gnu.org Xref: main.gmane.org gmane.emacs.help:9807 X-Report-Spam: http://spam.gmane.org/gmane.emacs.help:9807 Thomas Gehrlein writes: > David Kastrup writes: > > > Thomas Gehrlein writes: > > > > > The following line is from easy-menu-create-menu: > > > > > > ((eq keyword :active) (setq enable (or arg ''nil))) > > > > > > It is part of a (cond ...). > > > > > > What does "''nil" mean? > > > > The same as '(quote nil), an unevaluated list with the two members > > quote and nil. > > Is this the same as (quote (quote nil))? It is, like (quote nil), the result of evaluating (quote (quote nil)). > Why would you quote nil and not evaluate it? To make it different from nil, while evaluating to it eventually. > And if you evaluate it: Isn't nil the same as (quote nil)? Evaluating nil gives the same result as evaluating (quote nil), since nil is a self-quoting form. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum