From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Drew Adams" Newsgroups: gmane.emacs.help Subject: RE: What is the :eval form ? Date: Sat, 9 Jun 2012 07:08:07 -0700 Message-ID: <288D2D5C510A45E1ACA1B8F5F6E42F16@us.oracle.com> References: <87d35965s1.fsf@thinkpad.tsdh.de> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1339250914 17699 80.91.229.3 (9 Jun 2012 14:08:34 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 9 Jun 2012 14:08:34 +0000 (UTC) To: Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Jun 09 16:08:34 2012 Return-path: Envelope-to: geh-help-gnu-emacs@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 1SdML4-00018c-FL for geh-help-gnu-emacs@m.gmane.org; Sat, 09 Jun 2012 16:08:26 +0200 Original-Received: from localhost ([::1]:45669 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SdML4-0001Ay-7c for geh-help-gnu-emacs@m.gmane.org; Sat, 09 Jun 2012 10:08:26 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:35017) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SdMKz-0001At-MD for help-gnu-emacs@gnu.org; Sat, 09 Jun 2012 10:08:22 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SdMKx-0002vL-Rz for help-gnu-emacs@gnu.org; Sat, 09 Jun 2012 10:08:21 -0400 Original-Received: from rcsinet15.oracle.com ([148.87.113.117]:45246) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SdMKx-0002vF-Kx for help-gnu-emacs@gnu.org; Sat, 09 Jun 2012 10:08:19 -0400 Original-Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by rcsinet15.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id q59E8Fd7028940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sat, 9 Jun 2012 14:08:16 GMT Original-Received: from acsmt356.oracle.com (acsmt356.oracle.com [141.146.40.156]) by ucsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id q59E8FON003937 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 9 Jun 2012 14:08:15 GMT Original-Received: from abhmt116.oracle.com (abhmt116.oracle.com [141.146.116.68]) by acsmt356.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id q59E8EwG025212 for ; Sat, 9 Jun 2012 09:08:15 -0500 Original-Received: from dradamslap1 (/10.159.219.243) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sat, 09 Jun 2012 07:08:14 -0700 X-Mailer: Microsoft Office Outlook 11 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Thread-Index: Ac1GC267SYCnbFjCSc+FP8bN5jFW7AAPGTsg X-Source-IP: ucsinet22.oracle.com [156.151.31.94] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 1) X-Received-From: 148.87.113.117 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:85177 Archived-At: > > A symbol whose name starts with a colon (`:') is > > called a "keyword symbol". These symbols automatically > > act as constants, when evaluated. Debugger entered--Lisp error: (setting-constant :foo) (setq :foo 42) > Is that also true in a function call? Is what true? A keyword symbol is just a symbol (a) whose name starts with `:' and (b) that evaluates to itself. > e.g (notifications-notify :title "Wazzup!?" :message message)) > title and message are not keywords here. They are keyword symbols. When they are evaluated (during function application), the values returned are those same symbols. > Or is the keyword "symbol" here? Yes, the key word here is "symbol". Whether or not a keyword symbol serves as a keyword in some context depends on the context. It means what you want it to mean. Like everything in Lisp, you can use a keyword symbol as anything you like. But it always has properties (a) and (b).