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: Why is booleanp defined this way? Date: Sat, 18 Apr 2015 02:43:27 +0200 Organization: Informatimago Message-ID: <87k2xamfkg.fsf@kuiper.lan.informatimago.com> References: <87lhhqnxip.fsf@debian.uxu> 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 1429318533 31797 80.91.229.3 (18 Apr 2015 00:55:33 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 18 Apr 2015 00:55:33 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Apr 18 02:55:30 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 1YjH2f-0004Lc-GC for geh-help-gnu-emacs@m.gmane.org; Sat, 18 Apr 2015 02:55:29 +0200 Original-Received: from localhost ([::1]:44117 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YjH2e-0004HS-GU for geh-help-gnu-emacs@m.gmane.org; Fri, 17 Apr 2015 20:55:28 -0400 Original-Path: usenet.stanford.edu!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 18 Original-X-Trace: individual.net tla6VxDmS0CS7jVIQeQjtAik6DWNmnXrVcUzfN3RE3bJqPWKRB Cancel-Lock: sha1:NzQ5ZWU0M2EzYWI0MmU1Y2IwNDY2NmYyMmJlMGZmYjBmYWJlYTI3Yw== sha1:qRM2h1g/j25Mc2XyPc3GYE0ihBE= 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:211508 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:103790 Archived-At: Emanuel Berg writes: > Barry Margolin writes: > >> (booleanp nil) => (nil t) >> (booleanp t) => (t) >> (booleanp something-else) => nil And even if that was true, that would still be a valid implementation, since both (nil t) and (t) are generalized booleans that are true! But it is probably better that (booleanp (booleanp object)) be true too. -- __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