From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Rusi Newsgroups: gmane.emacs.help Subject: Re: Why is booleanp defined this way? Date: Fri, 17 Apr 2015 19:33:28 -0700 (PDT) Message-ID: <138bf565-898d-4b5a-8bea-eecd223c652b@googlegroups.com> References: <87twwemaxx.fsf@debian.uxu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: ger.gmane.org 1429324525 17980 80.91.229.3 (18 Apr 2015 02:35:25 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 18 Apr 2015 02:35:25 +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 04:35:18 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 1YjIbF-0003mm-Hb for geh-help-gnu-emacs@m.gmane.org; Sat, 18 Apr 2015 04:35:17 +0200 Original-Received: from localhost ([::1]:44304 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YjIbE-0006A7-RX for geh-help-gnu-emacs@m.gmane.org; Fri, 17 Apr 2015 22:35:16 -0400 X-Received: by 10.52.142.78 with SMTP id ru14mr7834448vdb.2.1429324408955; Fri, 17 Apr 2015 19:33:28 -0700 (PDT) X-Received: by 10.50.65.38 with SMTP id u6mr26820igs.1.1429324408892; Fri, 17 Apr 2015 19:33:28 -0700 (PDT) Original-Path: usenet.stanford.edu!z60no2372626qgd.0!news-out.google.com!db6ni18639igc.0!nntp.google.com!m20no4258636iga.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Original-Newsgroups: gnu.emacs.help In-Reply-To: <87twwemaxx.fsf@debian.uxu> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=117.195.50.46; posting-account=mBpa7woAAAAGLEWUUKpmbxm-Quu5D8ui Original-NNTP-Posting-Host: 117.195.50.46 User-Agent: G2/1.0 Injection-Date: Sat, 18 Apr 2015 02:33:28 +0000 Original-Xref: usenet.stanford.edu gnu.emacs.help:211513 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:103795 Archived-At: On Saturday, April 18, 2015 at 7:48:56 AM UTC+5:30, Emanuel Berg wrote: > Rusi writes: > > > Elisp does not have a proper boolean type; unlike > > say symbols with symbolp, strings with stringp, > > numberp -- some union of numeric types etc. > > However programmers need boolean in their ontology > > even if (and even more if) the language does not > > support it. > > I never used `booleanp' and I never experienced that > the boolean built-in type was missing from my > "ontology". If you how to write (and grok) an 'if' you have boolean in your ontology. That you dont know that you know is ok; most programmers dont get that their 'thinking language' is a superset of their programming language. eg When we were students we learnt flowcharts (or flawcharts) Most today's kids think thats irrelevant but then they think UML is relevant. The Dijkstra school would tout logic The FP school will tout lambda calculus (or dependent types) Even the box-and-arrow diagrams of classic data structures books goes beyond the language the book claims to be using