From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Pascal J. Bourguignon" Newsgroups: gmane.emacs.help Subject: Re: How to use a symbol and its value to create alist? Date: Tue, 11 Aug 2015 16:39:45 +0200 Organization: Informatimago Message-ID: <87pp2tga8e.fsf@kuiper.lan.informatimago.com> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1439304024 17229 80.91.229.3 (11 Aug 2015 14:40:24 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 11 Aug 2015 14:40:24 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Aug 11 16:40:19 2015 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 1ZPAiw-0005Go-Te for geh-help-gnu-emacs@m.gmane.org; Tue, 11 Aug 2015 16:40:19 +0200 Original-Received: from localhost ([::1]:34759 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZPAiw-0003I5-6G for geh-help-gnu-emacs@m.gmane.org; Tue, 11 Aug 2015 10:40:18 -0400 Original-Path: usenet.stanford.edu!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 37 Original-X-Trace: individual.net J/ZqBuetXS7fqU7vjINHSguXCgWafA3SGeKTjM2whJ2c39G7V0 Cancel-Lock: sha1:MTk2MjZiMjk3NTYwNzNjODRkODY0NzA1NjFhZjk2ZjJlZWE1NmU0YQ== sha1:j2WE+QykNv9eJs6Xp+e4mRuuDkw= Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwAQMAAABtzGvEAAAABlBMVEUAAAD///+l2Z/dAAAA oElEQVR4nK3OsRHCMAwF0O8YQufUNIQRGIAja9CxSA55AxZgFO4coMgYrEDDQZWPIlNAjwq9 033pbOBPtbXuB6PKNBn5gZkhGa86Z4x2wE67O+06WxGD/HCOGR0deY3f9Ijwwt7rNGNf6Oac l/GuZTF1wFGKiYYHKSFAkjIo1b6sCYS1sVmFhhhahKQssRjRT90ITWUk6vvK3RsPGs+M1RuR mV+hO/VvFAAAAABJRU5ErkJggg== X-Accept-Language: fr, es, en User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Original-Xref: usenet.stanford.edu gnu.emacs.help:214183 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:106467 Archived-At: Navy Cheng writes: > For example: > > (setq a 1) > (setq b 2) > (setq c 3) > > How can I a alist, like: How can you WHAT a alist? > ((a . 1) (b . 2) (c .3)) > > The value of a, b and c may change, so don't do this like > (setq tree ((a . 1) (b . 2) (c .3))) This is not a valid form, because (a . 1) is not a function name, therefore it's not possible to apply it. If you want to BUILD an a-list, you can use acons: (let ((a 1) (b 2) (c 3)) (let ((tree (acons 'a a (acons 'b b (acons 'c c '()))))) tree)) --> ((a . 1) (b . 2) (c . 3)) -- __Pascal Bourguignon__ http://www.informatimago.com/ “The factory of the future will have only two employees, a man and a dog. The man will be there to feed the dog. The dog will be there to keep the man from touching the equipment.” -- Carl Bass CEO Autodesk