From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Appending lists Date: Thu, 17 Jun 2021 01:13:03 +0200 Message-ID: <871r91tncw.fsf@zoho.eu> References: <87o8c8l32h.fsf@posteo.net> <87zgvs2bup.fsf@zoho.eu> <87y2bby1kr.fsf@zoho.eu> <20210615091834.GB24886@tuxteam.de> <87im2ewr3k.fsf@zoho.eu> <20210616072819.GB17919@tuxteam.de> <20210616115404.GD30658@tuxteam.de> Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="33984"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:+L/PhzOaOt5dLNl7e6rShZfLVUw= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Jun 17 01:15:51 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ltelD-0008de-Hl for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 17 Jun 2021 01:15:51 +0200 Original-Received: from localhost ([::1]:46264 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltelC-0006qB-3R for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 16 Jun 2021 19:15:50 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:46484) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltekV-0006q2-7E for help-gnu-emacs@gnu.org; Wed, 16 Jun 2021 19:15:07 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:34950) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltekS-0006LJ-Cu for help-gnu-emacs@gnu.org; Wed, 16 Jun 2021 19:15:06 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1ltekP-0007Zs-PM for help-gnu-emacs@gnu.org; Thu, 17 Jun 2021 01:15:01 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:130935 Archived-At: Jean Louis wrote: >> What changed was the cdr of some cons cell downstream. >> The variable doesn't see it. > > You speak of some hidden flows? He speaks of how a list is implemented as a data structure. > How is that useful for programer in Emacs Lisp? Well, in this case, you yourself gave an example with potentially unexpected results from using `nconc'. So to not have that, it is good to be aware of. More broadly, because Lisp is all focused around the universal data structure, i.e. the list, is it helpful to know your way around them! And speaking even more generally, if you are into technology and use it every day, the more you know and understand, the higher you can take your own game... > Did variable's value change or not? No, the value is a reference to a cons cell and that reference didn't change. -- underground experts united https://dataswamp.org/~incal