From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: Function value changes after running function? Date: Fri, 05 Feb 2021 10:48:27 -0500 Message-ID: References: <87tuqr431d.fsf@zoho.eu> <17c2df48-8e9a-4c57-dfbf-b058d2836395@protonmail.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="11145"; 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: sha1:79UJeDMvRhyuHm1Jxox+cicrp9w= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Feb 05 16:50:46 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 1l83Ne-0002oc-BP for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 05 Feb 2021 16:50:46 +0100 Original-Received: from localhost ([::1]:34324 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l83Nd-000180-DX for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 05 Feb 2021 10:50:45 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58120) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l83La-0008Ac-9c for help-gnu-emacs@gnu.org; Fri, 05 Feb 2021 10:48:38 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:45548) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l83LY-0004oB-JF for help-gnu-emacs@gnu.org; Fri, 05 Feb 2021 10:48:38 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1l83LV-0000Ju-3I for help-gnu-emacs@gnu.org; Fri, 05 Feb 2021 16:48:33 +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: 2.1.23 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:127620 Archived-At: > No, I wrote a macro like `cl-loop` here: > > https://github.com/okamsn/loopy > > I received a bug report that said that the above function would raise an > error after running a second time here: In the current situation, the problem is: (setq loopy--main-body (nreverse loopy--main-body) loopy--with-vars (nreverse loopy--with-vars)) which reverses the "with vars" received as arguments. If you replace `nreverse` with `reverse` here, this particular problem should disappear. This said, this `nreverse` reverses the order of the bindings in (with ....) which maybe isn't what you intended (I suspect that the `nreverse` here is meant to reverse the bindings added to `loopy--with-vars` via `push`). So maybe a better solution is to replace (setq loopy--with-vars (cdr arg))) with (setq loopy--with-vars (reverse (cdr arg)))) so that the subsequent `nreverse` puts them back in the original order. Stefan