From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.help Subject: Re: Calling a function with undefined symbol Date: Fri, 04 Nov 2022 13:16:33 +0100 Message-ID: <87tu3egbj2.fsf@web.de> References: <87wn8dzh6o.fsf@web.de> <877d0d8g3e.fsf@web.de> <87zgd9ot4p.fsf@dataswamp.org> <87r0yk9tw6.fsf@web.de> <87o7toi68e.fsf@dataswamp.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="33059"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:7JcgvIeuSIAC6iIOC+aZpu4JBCs= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Nov 04 13:17:50 2022 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 1oqvdu-0008OR-Hz for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 04 Nov 2022 13:17:50 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oqvdH-0006U5-Pf; Fri, 04 Nov 2022 08:17:11 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oqvd6-0006Pz-WF for help-gnu-emacs@gnu.org; Fri, 04 Nov 2022 08:17:06 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oqvcq-0006Nz-Ih for help-gnu-emacs@gnu.org; Fri, 04 Nov 2022 08:17:00 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1oqvcm-0006pJ-Tj for help-gnu-emacs@gnu.org; Fri, 04 Nov 2022 13:16:40 +0100 X-Injected-Via-Gmane: http://gmane.org/ 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: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.001, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_PASS=-0.001, T_SPF_HELO_TEMPERROR=0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: "help-gnu-emacs" Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:140647 Archived-At: Emanuel Berg writes: > >> Yes, but why do you need the "strange value" for that? Let's call the strange `'''''''''...` values "quote-quine" for now so that it's easier to talk about them (better than saying "the strange value" all the time). I said value_s_ here because there is no unique quote-quine in the `eq' sense. > > I chose it because you get an `equal' value when you quote > > the value (to suggest a wrong track to an answer), and > > You do? > > (setq print-circle t) > > (setq x #1=(quote #1#)) > > (eq 'x x) ; nil > (equal 'x x) ; nil > > ? I don't see any place in your code where a quote-quine is quoted. You correctly assign a quote-quine to a variable. But then you only quote the symbol, not the value, and compare the quote-quine with the symbol you had bound it to. IOW: It's a trap! So how could a correct `equal'ity test of a quote-quine and that quote-quine quoted be achieved? This is exercise number 3. > So the length is 2, but the depth is infinite. IOW: It's a trap! Yes, this is the correct solution. Congratulations! Michael.