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: member returns list (was: Re: To `boundp' or not to `boundp'?) Date: Wed, 02 Sep 2015 03:17:12 +0200 Message-ID: <87r3mhr55z.fsf@debian.uxu> References: <55E5C99B.3020608@yandex.ru> <87lhcpu2wb.fsf_-_@debian.uxu> <3c9412c3-3fff-446c-9e55-e8169b6a913d@default> <87zj15r7gs.fsf@debian.uxu> <75212b6a-133a-401a-8051-3931a7a40958@default> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1441156179 5235 80.91.229.3 (2 Sep 2015 01:09:39 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 2 Sep 2015 01:09:39 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Sep 02 03:09:29 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 1ZWwYL-0004z7-5i for geh-help-gnu-emacs@m.gmane.org; Wed, 02 Sep 2015 03:09:29 +0200 Original-Received: from localhost ([::1]:60018 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWwYL-0007bt-1u for geh-help-gnu-emacs@m.gmane.org; Tue, 01 Sep 2015 21:09:29 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35285) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWwYA-0007bC-JD for help-gnu-emacs@gnu.org; Tue, 01 Sep 2015 21:09:19 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZWwY5-0001LC-H5 for help-gnu-emacs@gnu.org; Tue, 01 Sep 2015 21:09:16 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:49087) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWwY5-0001L4-AU for help-gnu-emacs@gnu.org; Tue, 01 Sep 2015 21:09:13 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZWwY2-0004mw-T3 for help-gnu-emacs@gnu.org; Wed, 02 Sep 2015 03:09:10 +0200 Original-Received: from nl106-137-244.student.uu.se ([130.243.137.244]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 02 Sep 2015 03:09:10 +0200 Original-Received: from embe8573 by nl106-137-244.student.uu.se with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 02 Sep 2015 03:09:10 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Original-Lines: 24 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: nl106-137-244.student.uu.se Mail-Copies-To: never User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) Cancel-Lock: sha1:4s34BmHnIXatRUKUOHq//m/eCRU= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 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:106976 Archived-At: Drew Adams writes: > I don't understand the question. It always functions > the same way. Whether code uses it only to test > membership or to access the first tail that > corresponds is up to that code. But `member' behaves > ("functions") the same. It looks like this: (member ELT LIST) When is it beneficial to, instead of just getting a `t' on a hit, to get a list that consists of ELT and everything eastward of ELT, in LIST? The `car' example I provided may look cool (?) but it isn't anything that cannot be done with "memberp", because obviously the car is known, otherwise one wouldn't be able to search for it. -- underground experts united http://user.it.uu.se/~embe8573