From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Pip Cet Newsgroups: gmane.emacs.bugs Subject: bug#36407: 27.0.50; `plist-get', `equal' etc. and circular "lists" Date: Fri, 28 Jun 2019 08:05:10 +0000 Message-ID: References: <730806fc-5899-9bd0-81fd-42900406e874@cs.ucla.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="246106"; mail-complaints-to="usenet@blaine.gmane.org" Cc: 36407-done@debbugs.gnu.org To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Fri Jun 28 10:06:24 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hgltn-0011sh-0N for geb-bug-gnu-emacs@m.gmane.org; Fri, 28 Jun 2019 10:06:23 +0200 Original-Received: from localhost ([::1]:57500 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hgltk-0005vD-SG for geb-bug-gnu-emacs@m.gmane.org; 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Fri, 28 Jun 2019 08:06:01 +0000 Original-Received: (at 36407-done) by debbugs.gnu.org; 28 Jun 2019 08:05:54 +0000 Original-Received: from localhost ([127.0.0.1]:40323 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hgltJ-0005Zc-Th for submit@debbugs.gnu.org; Fri, 28 Jun 2019 04:05:54 -0400 Original-Received: from mail-ot1-f42.google.com ([209.85.210.42]:46533) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hgltI-0005ZQ-K5 for 36407-done@debbugs.gnu.org; Fri, 28 Jun 2019 04:05:53 -0400 Original-Received: by mail-ot1-f42.google.com with SMTP id z23so5089925ote.13 for <36407-done@debbugs.gnu.org>; Fri, 28 Jun 2019 01:05:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/nHHWlkG5KaJ/6JvIT7g/jLon3mQO+o53Hlu6jJaNB0=; b=av5/kEMtyuSubGi106srhwQ/pgdWGwy17bo7KVc1cMuVNo/ZwZKAgvUlnvlW4OXMAC fN/J675yMboMIDIEVU2zOhYMdqo8M4mm8k8XRjtDvnUvr8A940eRvLOoWwRKyjmf3y8+ OZ2QXA7dZi5W6j/0I6ct91reCszOl3CWFA6OptNsbLeiQzMSX/vEqD4gFkajThyck43s poQbBMGzPlHQYMtq7hYudx01zrMn+WCpK16EAxu/W/SvuBF85ZmqjJCKEVrV+7ko7SJL u223lMrpF+6qEzPsd+S+h5XeccFxrzwgPo/rysEwcbQi/hej6of23ytxEE1e4QWie/Ha safw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/nHHWlkG5KaJ/6JvIT7g/jLon3mQO+o53Hlu6jJaNB0=; b=Fd7qpAp6AUQi8+ZHvHzqKHwxIdy3lX5M3bdmskn6NXc6ZybHLmfPorfsKShtZrlKpv mIz3XvmBNTzd+KDR8rq+VqbHNKg587LNyY8D/MlC4Gfns9DqsMzmwsgGPJ2sxA5dMVf8 8tvfqbPqvbY++/BQLVdJM4KDg7KoKywZzi0GVEJ01hXjM8iUDQjCAVTMX+pyvOiayRjO Q5fq+xOT0nPhiKJKrv1DseRN6RhwysRt19U0B5jsNMVdkZ24KGVevB7fhAhwAO3S++vb t6qtPeMKO6yecKLdl3eMFvXMRb9HLYRhfwWG4TN0dvOOC9IK9S13M2cldvJAB5Krbr0C YeAA== X-Gm-Message-State: APjAAAWeHl7uJrib9BQjrHCJp6lcXr3rOp9h78CkA4cVYni/yJohzfJg VMpTFdz01rp7pRSEQ22UO59ASBxIQdt9hotwRu0= X-Google-Smtp-Source: APXvYqyLG6me/b5uEIbt3wVY7RuwXnZpQ6DIV6ta17xLoo21bNenQCyw6svKJ7QPl45VHmykmkztx0GwNUvmYKfji+0= X-Received: by 2002:a9d:7352:: with SMTP id l18mr7256862otk.292.1561709146726; Fri, 28 Jun 2019 01:05:46 -0700 (PDT) In-Reply-To: <730806fc-5899-9bd0-81fd-42900406e874@cs.ucla.edu> X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:161694 Archived-At: On Thu, Jun 27, 2019 at 10:52 PM Paul Eggert wrote: > aren't needed. I installed that patch; thanks. Thanks! > > shouldn't `equal' be symmetric? > > Yes, on its domain. But circular lists are outside its domain, and the > documentation doesn't promise any particular behavior on them. It's OK > if (equal a b) signals an error and (equal b a) does not. It's even OK > if (equal a b) signals an error and a later call (equal a b) with > exactly the same (unchanged) arguments does not (because the stack > happens to have more room the second time). We still have symmetry in > the sense that (eq (equal a b) (equal b a)) always either returns t or > signals an error; it never returns nil. Thanks for your explanation, that makes perfect sense. I was confused, in part, by the hash table code in internal_equal, which appears to be designed to handle circular structures with some generality. On further thought, maybe that code is written for DAGs which contain diamond-shaped subgraphs. However, those don't appear to be working very well... > I installed the attached doc patch to try to make this a bit clearer. Thanks again! I'm closing this bug.