From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Barry Margolin Newsgroups: gmane.emacs.help Subject: Re: `append' vs. `nconc' Date: Thu, 31 Dec 2015 21:53:17 -0500 Organization: A noiseless patient Spider Message-ID: References: <568164D8.6050700@ojkastl.de> <87io3iyr7t.fsf@debian.uxu> <87si2kezg1.fsf@mithlond.arda> <87a8osrlj4.fsf_-_@debian.uxu> <87lh8bgafa.fsf@mithlond.arda> <87r3i3ch63.fsf@kuiper.lan.informatimago.com> <87si2jqee2.fsf@debian.uxu> <20151231093045.GB19900@tuxteam.de> NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1451616920 28317 80.91.229.3 (1 Jan 2016 02:55:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 1 Jan 2016 02:55:20 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Jan 01 03:55:19 2016 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 1aEps5-000603-FP for geh-help-gnu-emacs@m.gmane.org; Fri, 01 Jan 2016 03:55:17 +0100 Original-Received: from localhost ([::1]:57265 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aEps4-0007p8-ER for geh-help-gnu-emacs@m.gmane.org; Thu, 31 Dec 2015 21:55:16 -0500 Original-Path: usenet.stanford.edu!news.kjsl.com!feeder.erje.net!2.eu.feeder.erje.net!feeder2.usenet.farm!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!barmar.motzarella.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 33 Injection-Info: barmar.motzarella.org; posting-host="78fb7125a45724f15e21604c94a7d968"; logging-data="19249"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/fa0cqJnlAAjzyFtOkxAPl" User-Agent: MT-NewsWatcher/3.5.3b3 (Intel Mac OS X) Cancel-Lock: sha1:ZWCvAXI3RJQO2C6emVpYDdIoxUY= Original-Xref: usenet.stanford.edu gnu.emacs.help:216271 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:108561 Archived-At: In article , Emanuel Berg wrote: > writes: > > > - it's very obvious It's a local value you are > > keeping in your little scope. (One might argue that > > then, it's an idiomatic way to emphasize this fact > > to the (human) reader...) > > The thing here is, when it is very obvious and > everything is small and easy to handle, what is the > actual gain in time and space not using `append'? > > Answer: > > -> 0 > > But OK, as a matter of principle it can be a cool > thing to know/do. NCONC was created at least 40 years ago, when computers were slow and had very little memory (a modern cellphone is has the power of a roomful of 70's-era mainframes). And garbage collection was also very slow (generational GC hadn't been developed yet). So optimizations like NCONC could be very useful back then. These days, the benefit is probably very little. -- Barry Margolin, barmar@alum.mit.edu Arlington, MA *** PLEASE post questions in newsgroups, not directly to me ***