From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: Why is booleanp defined this way? Date: Sat, 18 Apr 2015 04:23:22 +0200 Organization: Aioe.org NNTP Server Message-ID: <87twwemaxx.fsf@debian.uxu> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1429323626 5679 80.91.229.3 (18 Apr 2015 02:20:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 18 Apr 2015 02:20:26 +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 04:20:25 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 1YjIMp-0001FW-UC for geh-help-gnu-emacs@m.gmane.org; Sat, 18 Apr 2015 04:20:24 +0200 Original-Received: from localhost ([::1]:44271 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YjIMo-00022k-LT for geh-help-gnu-emacs@m.gmane.org; Fri, 17 Apr 2015 22:20:22 -0400 Original-Path: usenet.stanford.edu!news.kjsl.com!feeder.erje.net!1.eu.feeder.erje.net!news.roellig-ltd.de!open-news-network.org!news.muarf.org!news.ecp.fr!aioe.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 34 Original-NNTP-Posting-Host: feB02bRejf23rfBm51Mt7Q.user.speranza.aioe.org Original-X-Complaints-To: abuse@aioe.org User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) X-Notice: Filtered by postfilter v. 0.8.2 Cancel-Lock: sha1:GbnCDM0Jzdh0F/nysRZHyaHiZ5c= Mail-Copies-To: never Original-Xref: usenet.stanford.edu gnu.emacs.help:211512 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:103794 Archived-At: 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". I think one asset with Lisp compared to for example C is that you don't have to bother with types. The predicates aren't types in the sense stating the types in declarations and function definition argument lists etc. as in C. That's just tedious and it makes you focus on details of technology rather than solving your problem. (But I like C as well.) Rather the predicates add the flexibility to be able to do different thing depending on the nature of the data. One can see many applications... Compare this to the generic classes of C++ where it would instantly turn into a jungle, not to mention the C pointers. But no one said you should do "Lisp" in C. If you did "C" in Lisp, even Lisp wouldn't be good. -- underground experts united http://user.it.uu.se/~embe8573