From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: Why is booleanp defined this way? Date: Sat, 18 Apr 2015 01:03:23 -0400 Organization: A noiseless patient Spider Message-ID: References: <87bnimm6wy.fsf@kuiper.lan.informatimago.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1429333527 10496 80.91.229.3 (18 Apr 2015 05:05:27 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 18 Apr 2015 05:05:27 +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 07:05:27 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 1YjKwX-0002hQ-Hy for geh-help-gnu-emacs@m.gmane.org; Sat, 18 Apr 2015 07:05:25 +0200 Original-Received: from localhost ([::1]:44520 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YjKwW-0004Yc-P2 for geh-help-gnu-emacs@m.gmane.org; Sat, 18 Apr 2015 01:05:24 -0400 Original-Path: usenet.stanford.edu!news.kjsl.com!feeder.erje.net!1.eu.feeder.erje.net!news.albasani.net!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 16 Injection-Info: mx02.eternal-september.org; posting-host="8c9f62942bed0b1c29017c5c7eaf7d33"; logging-data="11106"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18CBzjyFP78+iex4soyin0i" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:mqWHrgwCHR6AsubtWIdCayP35F4= sha1:KOWf3ei5Y0UvgKVxmyxn6rstq4c= Original-Xref: usenet.stanford.edu gnu.emacs.help:211524 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:103805 Archived-At: >> 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. > Well, if you go this way, elisp doesn't have proper types at all!!! I think he was alluding to the difference between the types that `typeof' might recognize and those that are more like unions of other types. > deftype, typep, subtypep are all defined in cl.el and as such, "frowned > upon" by the PTB. cl-deftype, cl-typep, ... are alive and well and not frowned upon. Stefan