From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Tomas Hlavaty Newsgroups: gmane.emacs.devel Subject: Re: Opaque objects and Emacs documentation Date: Tue, 21 Jul 2020 22:49:33 +0200 Message-ID: <87blk8386a.fsf@logand.com> References: <20200712184908.13140.5739@vcs0.savannah.gnu.org> <20200712184909.BBC61209B1@vcs0.savannah.gnu.org> <7bf4d6ef-c0ec-43dc-ad5d-f6e81422ad90@yandex.ru> <83zh84m5ws.fsf@gnu.org> <3dd1c224-69b2-40af-5b2e-43a310253632@yandex.ru> <83tuybmtxs.fsf@gnu.org> <859f594b-1343-6d26-e1ac-7157c44eb56c@yandex.ru> <83a6zyk4tt.fsf@gnu.org> <6edffb7d-7708-534f-93ad-bf9180f5e0ed@yandex.ru> <835zamjsvk.fsf@gnu.org> <831rlajock.fsf@gnu.org> <1fcdc463-b3ab-2d32-31d7-904783ae0d81@yandex.ru> <83y2nii6sk.fsf@gnu.org> <750ecd90-0f89-5040-f737-2d8c1b8f01c9@yandex.ru> <83tuy3h87j.fsf@gnu.org> <412b0e60-7ccb-ee72-b361-566710156365@yandex.ru> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="30316"; mail-complaints-to="usenet@ciao.gmane.io" To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Jul 21 22:50:37 2020 Return-path: Envelope-to: ged-emacs-devel@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 1jxzDg-0007gm-IG for ged-emacs-devel@m.gmane-mx.org; Tue, 21 Jul 2020 22:50:36 +0200 Original-Received: from localhost ([::1]:58420 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jxzDf-0000kF-IR for ged-emacs-devel@m.gmane-mx.org; Tue, 21 Jul 2020 16:50:35 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:46044) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jxzCw-0000GI-3j for emacs-devel@gnu.org; Tue, 21 Jul 2020 16:49:50 -0400 Original-Received: from logand.com ([37.48.87.44]:55810) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jxzCu-0001r6-5b for emacs-devel@gnu.org; Tue, 21 Jul 2020 16:49:49 -0400 Original-Received: by logand.com (Postfix, from userid 1001) id 2496319F3BA; Tue, 21 Jul 2020 22:49:36 +0200 (CEST) X-Mailer: emacs 26.3 (via feedmail 11-beta-1 I) In-Reply-To: <412b0e60-7ccb-ee72-b361-566710156365@yandex.ru> Received-SPF: pass client-ip=37.48.87.44; envelope-from=tom@logand.com; helo=logand.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/21 16:49:36 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:253143 Archived-At: On Tue 21 Jul 2020 at 22:00, Dmitry Gutov wrote: > On 19.07.2020 17:48, Eli Zaretskii wrote: >> . a predicate to test whether an arbitrary Lisp value is an object >> of that type > > A predicate would look like: > > (defun project-instance-p (pr) > (condition-case nil > (progn > (project-roots pr) > t) > (error > nil))) that's ugly it's better not to use errors for control flow what happens if project-roots raises error on legitimate project instance?