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: if vs. when vs. and: style question Date: Mon, 23 Mar 2015 23:12:04 -0700 (PDT) Message-ID: <8d531e99-7260-4263-ac99-09c6871e2708@googlegroups.com> References: <87sicvwckx.fsf@wmi.amu.edu.pl> <87wq27yvqg.fsf@debian.uxu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1427177726 3175 80.91.229.3 (24 Mar 2015 06:15:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 24 Mar 2015 06:15:26 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Mar 24 07:15:26 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 1YaI7X-0006Z7-Fj for geh-help-gnu-emacs@m.gmane.org; Tue, 24 Mar 2015 07:15:23 +0100 Original-Received: from localhost ([::1]:59240 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YaI7W-0005K6-JY for geh-help-gnu-emacs@m.gmane.org; Tue, 24 Mar 2015 02:15:22 -0400 X-Received: by 10.50.85.115 with SMTP id g19mr23258492igz.0.1427177525188; Mon, 23 Mar 2015 23:12:05 -0700 (PDT) X-Received: by 10.50.178.180 with SMTP id cz20mr222687igc.14.1427177525125; Mon, 23 Mar 2015 23:12:05 -0700 (PDT) Original-Path: usenet.stanford.edu!news.glorb.com!border1.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!z20no2676322igj.0!news-out.google.com!db6ni61566igc.0!nntp.google.com!z20no4032786igj.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Original-Newsgroups: gnu.emacs.help In-Reply-To: <87wq27yvqg.fsf@debian.uxu> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=59.94.115.252; posting-account=mBpa7woAAAAGLEWUUKpmbxm-Quu5D8ui Original-NNTP-Posting-Host: 59.94.115.252 User-Agent: G2/1.0 Injection-Date: Tue, 24 Mar 2015 06:12:05 +0000 Original-Lines: 23 Original-Xref: usenet.stanford.edu gnu.emacs.help:211001 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:103282 Archived-At: On Tuesday, March 24, 2015 at 7:54:43 AM UTC+5:30, Emanuel Berg wrote: > "Pascal J. Bourguignon" writes: >=20 > > In general, WHEN is better than IF. > > > > Also, (unless (e1) (e2)) is better than (if (not (e1)) > > (e2)). > > > > Notably, WHEN and UNLESS have an implicit progn: >=20 > "In general", you say. Is there any other advantage > save for not having to do the explicit `progn' and/or > `not'? In general weaker is better http://www.w3.org/2001/tag/doc/leastPower.html (when a b) =E2=89=A1 (if a b) However (if a b c) =E2=89=A1 (when ??) Other example: destructuring-bind is strictly weaker than if/cond and so better when usabl= e