From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.devel Subject: Re: Using empty_string as the only "" string Date: Wed, 25 Apr 2007 00:29:17 +0200 Message-ID: <857is1csoy.fsf@lola.goethe.zz> References: <462E310C.20400@yandex.ru> <85k5w1cu64.fsf@lola.goethe.zz> <462E7FB5.7090905@gmail.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1177453775 27563 80.91.229.12 (24 Apr 2007 22:29:35 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 24 Apr 2007 22:29:35 +0000 (UTC) Cc: Andreas Schwab , Dmitry Antipov , emacs-devel@gnu.org, Juanma Barranquero To: "Lennart Borgman \(gmail\)" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Apr 25 00:29:34 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1HgTVr-0002rc-RT for ged-emacs-devel@m.gmane.org; Wed, 25 Apr 2007 00:29:32 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HgTbQ-0003dz-26 for ged-emacs-devel@m.gmane.org; Tue, 24 Apr 2007 18:35:16 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1HgTbM-0003dq-PZ for emacs-devel@gnu.org; Tue, 24 Apr 2007 18:35:12 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1HgTbK-0003dd-Lh for emacs-devel@gnu.org; Tue, 24 Apr 2007 18:35:11 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HgTbK-0003da-GD for emacs-devel@gnu.org; Tue, 24 Apr 2007 18:35:10 -0400 Original-Received: from mail-in-11.arcor-online.net ([151.189.21.51]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1HgTVl-0003JP-Gs for emacs-devel@gnu.org; Tue, 24 Apr 2007 18:29:25 -0400 Original-Received: from mail-in-04-z2.arcor-online.net (mail-in-04-z2.arcor-online.net [151.189.8.16]) by mail-in-11.arcor-online.net (Postfix) with ESMTP id D0B8E1259A; Wed, 25 Apr 2007 00:29:23 +0200 (CEST) Original-Received: from mail-in-02.arcor-online.net (mail-in-02.arcor-online.net [151.189.21.42]) by mail-in-04-z2.arcor-online.net (Postfix) with ESMTP id C4DE0ABAEC; Wed, 25 Apr 2007 00:29:23 +0200 (CEST) Original-Received: from lola.goethe.zz (dslb-084-061-058-028.pools.arcor-ip.net [84.61.58.28]) by mail-in-02.arcor-online.net (Postfix) with ESMTP id ACEBC36E864; Wed, 25 Apr 2007 00:29:23 +0200 (CEST) Original-Received: by lola.goethe.zz (Postfix, from userid 1002) id 4CFA31CE2C4C; Wed, 25 Apr 2007 00:29:19 +0200 (CEST) In-Reply-To: <462E7FB5.7090905@gmail.com> (Lennart Borgman's message of "Wed\, 25 Apr 2007 00\:07\:49 +0200") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.98 (gnu/linux) X-detected-kernel: Linux 2.4-2.6 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:70006 Archived-At: "Lennart Borgman (gmail)" writes: > David Kastrup wrote: > >> '(a) is (cons 'a nil), '(b) is (cons 'b nil), >> so indeed the cdr of both lists is the identically same value. Lists >> are _identically_ grounded. > > And strings? Aren't grounded at all. (concat "a" "b") does not make "b" part of the result. So (concat "a" "") and (concat "b" "") would not share the same "" even if one replaced both of them by the same object. Every created string is a separate object not containing any other string as a part. The same is not true for lists. You can, for example, modify a sublist and in the process change the list containing it. This does not happen for substrings. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum