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 01:19:57 +0200 Message-ID: <87wnqts8gy.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> <87im2eufop.fsf@posteo.net> 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="18500"; 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:vjJnLQoBoEi3e6DvUnOELpreLAs= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Jun 17 01:20:56 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 1lteq8-0004ci-3D for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 17 Jun 2021 01:20:56 +0200 Original-Received: from localhost ([::1]:52310 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lteq6-0002bu-La for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 16 Jun 2021 19:20:54 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47794) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltepO-0002Zy-Ex for help-gnu-emacs@gnu.org; Wed, 16 Jun 2021 19:20:10 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:53986) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltepM-0000Xf-SA for help-gnu-emacs@gnu.org; Wed, 16 Jun 2021 19:20:10 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1ltepK-0003gP-Vd for help-gnu-emacs@gnu.org; Thu, 17 Jun 2021 01:20:06 +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:130936 Archived-At: Jean Louis wrote: > (let* ((list-1 '(a b c)) > (list-2 (nconc list-1 '(1 2 3)))) > (eq list-1 list-2)) ;; => t > > eq - Return t if the two args are the same Lisp object. > > And we talked how variable's value does not change... values > or Lisp objects? Again, the value, a reference to a cons cell, doesn't change. Here I think what's demonstrated is that list-1 and list-2 are the same, i.e. they both hold references to the same cons cell. It seems `nconc' returns a reference to the first cons sell of the new list, which is the first of list-1 as well; and the new list was created by changing the cdr of list-1's last element so that instead of holding nil (denoting the end of the list) it holds a reference to the first cons cell of "list-2"... -- underground experts united https://dataswamp.org/~incal