From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: How to mapcar or across a list? Date: Wed, 15 Jul 2015 22:14:20 +0200 Message-ID: <87io9lmb4z.fsf@mbork.pl> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1436991299 2547 80.91.229.3 (15 Jul 2015 20:14:59 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 15 Jul 2015 20:14:59 +0000 (UTC) To: Help Gnu Emacs mailing list Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Jul 15 22:14:54 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 1ZFT4v-0001rl-5u for geh-help-gnu-emacs@m.gmane.org; Wed, 15 Jul 2015 22:14:53 +0200 Original-Received: from localhost ([::1]:37306 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFT4u-0001dw-Lq for geh-help-gnu-emacs@m.gmane.org; Wed, 15 Jul 2015 16:14:52 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53261) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFT4i-0001dr-0H for help-gnu-emacs@gnu.org; Wed, 15 Jul 2015 16:14:41 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZFT4d-0006mO-TO for help-gnu-emacs@gnu.org; Wed, 15 Jul 2015 16:14:39 -0400 Original-Received: from mail.mojserwer.eu ([2a01:5e00:2:52::8]:49871) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFT4d-0006kl-Lq for help-gnu-emacs@gnu.org; Wed, 15 Jul 2015 16:14:35 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 61643512011 for ; Wed, 15 Jul 2015 22:14:32 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TnUFXCCPYYHz for ; Wed, 15 Jul 2015 22:14:25 +0200 (CEST) Original-Received: from localhost (unknown [109.232.24.146]) by mail.mojserwer.eu (Postfix) with ESMTPSA id 89A7C4F607B for ; Wed, 15 Jul 2015 22:14:25 +0200 (CEST) X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a01:5e00:2:52::8 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:105733 Archived-At: Hi there, so here's my problem: I have a list of Boolean values, and I want to `mapcar' an `or' across it (IOW, I want to test whether at least one of them is true). Of course, (apply #'or my-list) does not work. Of course, I can (cl-reduce (lambda (x y) (or x y)) my-list) -- but is there a better method? BTW, my-list doesn't really exist: it is a result of `mapcar'ing a function taking some value and yielding a Boolean value, so bonus points if the method does not process the whole list. (Note: I just noticed that my-list is in fact sorted so that all true values (if any) will occur at the beginning anyway, so I can just test the first one. This means that my problem is purely academic, though still interesting, I guess.) Best, -- Marcin Borkowski http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski Faculty of Mathematics and Computer Science Adam Mickiewicz University