From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: Calling a function with undefined symbol Date: Thu, 03 Nov 2022 13:15:45 +0100 Message-ID: <87o7toi68e.fsf@dataswamp.org> References: <87wn8dzh6o.fsf@web.de> <877d0d8g3e.fsf@web.de> <87zgd9ot4p.fsf@dataswamp.org> <87r0yk9tw6.fsf@web.de> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19321"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:abiovDEZCvSxkN4YyhiETUn0wRs= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Nov 04 12:27:14 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 1oquqv-0004nr-Ms for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 04 Nov 2022 12:27:13 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oquqh-0005kI-LD; Fri, 04 Nov 2022 07:26:59 -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 1oqZ8Y-0002TE-Qs for help-gnu-emacs@gnu.org; Thu, 03 Nov 2022 08:15:58 -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 1oqZ8W-0004ex-94 for help-gnu-emacs@gnu.org; Thu, 03 Nov 2022 08:15:58 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1oqZ8T-0001f7-Bu for help-gnu-emacs@gnu.org; Thu, 03 Nov 2022 13:15:53 +0100 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: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Fri, 04 Nov 2022 07:26:50 -0400 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:140636 Archived-At: Michael Heerdegen wrote: >> Yes, but why do you need the "strange value" for that? > > 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 ? > Ok - so here is part two of the exercise to check whether > you have understood quoting. Is the `length' of this strange > value `''''''...` > > (a) 0 or > (b) 1 or > (c) 2 or > (d) infinite/undefined ? The length is 2 (it's a list) because `quote' does not evaluate anything, not even itself, however this pattern is repeated at the second element so there it is either cyclic or indefinite, (quote (quote (quote ... ))) So the length is 2, but the depth is infinite. IOW: It's a trap! -- underground experts united https://dataswamp.org/~incal