From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.devel Subject: Re: Comparing hash table objects Date: Sat, 11 Jun 2022 13:52:25 +0800 Message-ID: <878rq3d9wm.fsf@localhost> References: <871qvz4kdw.fsf@localhost> <87leu7tsyc.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4534"; mail-complaints-to="usenet@ciao.gmane.io" Cc: schwab@suse.de, emacs-devel@gnu.org To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jun 11 07:55:42 2022 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 1nzu62-00012B-9s for ged-emacs-devel@m.gmane-mx.org; Sat, 11 Jun 2022 07:55:42 +0200 Original-Received: from localhost ([::1]:36876 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nzu61-0005TH-0V for ged-emacs-devel@m.gmane-mx.org; Sat, 11 Jun 2022 01:55:41 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:41490) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nzu2I-0003fj-NY for emacs-devel@gnu.org; Sat, 11 Jun 2022 01:51:50 -0400 Original-Received: from mail-pl1-x62b.google.com ([2607:f8b0:4864:20::62b]:40527) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nzu2G-0000zi-TD; Sat, 11 Jun 2022 01:51:50 -0400 Original-Received: by mail-pl1-x62b.google.com with SMTP id i1so922881plg.7; Fri, 10 Jun 2022 22:51:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=7va5KgNYWMuYMRUR8ePkBdvhB2Z53r42nEgOoNt/Ab4=; b=bh0OQFYv4s7bCvm1NHdaJPM0grjKhc3t/vUI2Qfu4QWvNwyrQLrbkFeuMgNU4VUWc3 U4sMBEsse0UIsoOYPvbOgHGIM1u3pFvJ+d+H8/6BFdAshKg+MMvcqlEtPTB/H0LAGOPG ra2eTxqy/ZVWjBPjGjGxsSa8D0rYQtfWRlXGtDmV/8sxawckAJP+lo2wTTGxBi9YPZ43 dNAq6LP73RaEgCPekXMI3gdlzBKBYS3l3JPhuD3zVc43rzUUzywtqQEEPvEti+J4qc64 vHFLqvta5KB7Pcxkdw+YNDrhYwpMKt7avAykdX3bQbdascAMsctSEM9/Hatj9QaT2aOJ 7YAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=7va5KgNYWMuYMRUR8ePkBdvhB2Z53r42nEgOoNt/Ab4=; b=K0HK1dQEyGHxKP9STP+tvL1sKHtHK5V3Xe0WtCEOoCkpfV3LMb+/IpSQKtEYLd3Xxp Zv165/q0ZwS54tSmBX1NTykh2W/X26zud/T7Q88uRbhslLgJhEMcSLfb/OkQ6X7amk23 XTs6q7+Jly7gnecAJ+MxhoZEWtg6vdSiC40yWM5AM2V+T53aqt+KbERGqBod+ZNPgsaq b4N2RGoe7phSjukxMiQq+4Uy6R3UXI17B90YLyq2SumW8lqTFN16PlCA9gpvkbTyqu2c BLSRy3yh4SsQvWsM1G7yltqHwMjuVUzWktEYQXwUVXW7AnKISc6Flf9sqRrSxW8qvcth thpg== X-Gm-Message-State: AOAM531pjXduAsQBtDFWu13SK0xF1J+Ovovrhb/owko1nfZ1QLdyFWwO SzyHmfdFJ0wd2eZhfd4hXhyc8JlT2SZwSxVm X-Google-Smtp-Source: ABdhPJwiingcDbMqrCfqBII7+eHH47Lwsr0aDQkNgsdoYwr16bZU/72hN4yYhI91KS9HwqjRl0aZiw== X-Received: by 2002:a17:902:eb90:b0:163:e4c1:b2fc with SMTP id q16-20020a170902eb9000b00163e4c1b2fcmr46930479plg.159.1654926706472; Fri, 10 Jun 2022 22:51:46 -0700 (PDT) Original-Received: from localhost ([64.32.23.62]) by smtp.gmail.com with ESMTPSA id e26-20020a63371a000000b003fadc415bfdsm709115pga.8.2022.06.10.22.51.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jun 2022 22:51:45 -0700 (PDT) In-Reply-To: Received-SPF: pass client-ip=2607:f8b0:4864:20::62b; envelope-from=yantar92@gmail.com; helo=mail-pl1-x62b.google.com 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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:291018 Archived-At: Richard Stallman writes: > It clearly can be useful to compare hash tables for equivalence > of contents. I see two ways to offer that facility: > > * As a new function. That would be upward-compatible. I have seen various variants of such function in third-party packages and just in internet search results. For example, ht-equal? from https://github.com/Wilfred/ht.el/blob/master/ht.el: (defun ht-equal? (table1 table2) "Return t if TABLE1 and TABLE2 have the same keys and values. Does not compare equality predicates." (declare (side-effect-free t)) (let ((keys1 (ht-keys table1)) (keys2 (ht-keys table2)) (sentinel (make-symbol "ht-sentinel"))) (and (equal (length keys1) (length keys2)) (--all? (equal (ht-get table1 it) (ht-get table2 it sentinel)) keys1)))) However, it will not help with the problem of comparing objects containing hash tables. Unless those obejcts also define special comparison function (which is inconvenient). > * By making `equal' compare them that way. That would fit the spirit > of `equal', but could break some existing uses of `equal'. I'd say that using `equal' on hash tables with the actual intention of comparing tables by `eq' is calling for a trouble. At least, it is misleading. Best, Ihor