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: member Date: Thu, 03 Sep 2015 07:19:23 +0200 Organization: Informatimago Message-ID: <874mjccc6c.fsf@kuiper.lan.informatimago.com> References: <55E5C99B.3020608@yandex.ru> 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 1441257638 3403 80.91.229.3 (3 Sep 2015 05:20:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 3 Sep 2015 05:20:38 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Sep 03 07:20:34 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 1ZXMwr-0001J3-U8 for geh-help-gnu-emacs@m.gmane.org; Thu, 03 Sep 2015 07:20:34 +0200 Original-Received: from localhost ([::1]:44717 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZXMws-00073X-25 for geh-help-gnu-emacs@m.gmane.org; Thu, 03 Sep 2015 01:20:34 -0400 Original-Path: usenet.stanford.edu!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 26 Original-X-Trace: individual.net 2NNRFZme0KMh/I3ux8n64wyyrSIecpjddTbQUvj8/An07G3aUo Cancel-Lock: sha1:YWU2NzU4YzY3MzkyZmIxMGZhYzYwNGQ1ZjBiYTcwYzU5Njk2MDQ5OA== sha1:+OW0bsYh4E/7DUTsoUfHf1DMzd0= 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:214720 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:107003 Archived-At: Emanuel Berg writes: > Barry Margolin writes: > >> It's no more misleading than MEMBER, which >> intuitively seems like it would just return >> a boolean, but actually returns the tail of the list >> where the element was found. > > I guess one can do something like this. But probably > it will only lead to even more confusion. > > (defun memberp (e l) > (when (member e l) t) ) > > (memberp 1 '(1 2 3 4)) ; t > (memberp 0 '(1 2 3 4)) ; nil If you just want a more concise result, you can use position or find instead of member. As predicates, they're equivalent. -- __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