From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eric Abrahamsen Newsgroups: gmane.emacs.help Subject: Re: Closures - do you understand them well? Date: Fri, 09 Dec 2022 08:50:33 -0800 Message-ID: <87zgbwjzc6.fsf@ericabrahamsen.net> References: <87lenh7vrn.fsf@web.de> <87lenh7k9m.fsf@ericabrahamsen.net> <875yelpqh9.fsf@web.de> <87v8mlo4ud.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="4963"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:IADlNegGEUuA3b+N3+f9LyLJQnk= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Dec 09 17:51:19 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 1p3gai-0000wa-Pa for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 09 Dec 2022 17:51:16 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p3gaB-00052C-9a; Fri, 09 Dec 2022 11:50:43 -0500 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 1p3gaA-000524-9I for help-gnu-emacs@gnu.org; Fri, 09 Dec 2022 11:50:42 -0500 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 1p3ga8-0008GE-Hm for help-gnu-emacs@gnu.org; Fri, 09 Dec 2022 11:50:42 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1p3ga6-0000CY-JX for help-gnu-emacs@gnu.org; Fri, 09 Dec 2022 17:50:38 +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, 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-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: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:141514 Archived-At: Michael Heerdegen writes: > Michael Heerdegen writes: > >> The exercise originates from a mistake I made myself a while ago. >> Sometimes your brain establishes shortcuts that lead to wrong >> assumptions. It's human to fall into such traps. > > But I see that exercises that are just traps can be demotivating. > > I'm not sure how to write more motivating exercises, however, how would > they look like? Maybe like, you think it returns 3 but instead it > returns...the perfect Christmas present you were looking for? > > #+begin_src emacs-lisp > (if (you-think-this-is-non-nil-but-isnt) > 3 > "You should buy XYZ.") > #+end_src > > Have to think about it... It's true I don't enjoy "exercises" in general -- a nice Christmas present would be a motivation. I would love to know closures well enough to put them into use without having to spend extra time thinking and testing. But the fact is I *do* need to spend extra time on it, and I rarely hit upon a problem that's begging to be resolved with a closure, so...