From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on starla X-Spam-Level: X-Spam-Status: No, score=0.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_BL_SPAMCOP_NET,SPF_HELO_PASS, SPF_PASS autolearn=no autolearn_force=no version=3.4.6 Received: from nue.mailmanlists.eu (nue.mailmanlists.eu [94.130.110.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id A9B351F4CC for ; Mon, 6 Jan 2025 13:32:23 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (1024-bit key; unprotected) header.d=ml.ruby-lang.org header.i=@ml.ruby-lang.org header.a=rsa-sha256 header.s=mail header.b=Wj6RklhQ; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ruby-lang.org header.i=@ruby-lang.org header.a=rsa-sha256 header.s=s1 header.b=OfHJxdyU; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1736170341; bh=JhNnX0Bf07p2GJyzOAy4JHkxIvCz86/18S4cYS4RN0E=; h=Date:References:To:Reply-To:Subject:List-Id:List-Archive: List-Help:List-Owner:List-Post:List-Subscribe:List-Unsubscribe: From:Cc:From; b=Wj6RklhQ+CQO/EI7wOuvyKmYiwqnQgUQ6KMLyEWXAXbu14vQSSNwo7JuCzboMewlR 8aJOVnrBP63JSp4/PV2Lkaoq9S7BW2xEZNCp/3s28sJNvYGBEgeeBQndQxbqjnbPmn lpo9sSHbj7JjSmXQY5PfHo8OQ/heh/kMrdgovCQc= Received: from nue.mailmanlists.eu (localhost [IPv6:::1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 317BD4661E for ; Mon, 6 Jan 2025 13:32:21 +0000 (UTC) Authentication-Results: nue.mailmanlists.eu; dkim=pass (2048-bit key; unprotected) header.d=ruby-lang.org header.i=@ruby-lang.org header.a=rsa-sha256 header.s=s1 header.b=OfHJxdyU; dkim-atps=neutral Received: from s.wrqvwxzv.outbound-mail.sendgrid.net (s.wrqvwxzv.outbound-mail.sendgrid.net [149.72.154.232]) by nue.mailmanlists.eu (Postfix) with ESMTPS id A078D465FC for ; Mon, 6 Jan 2025 13:32:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ruby-lang.org; h=from:references:subject:mime-version:content-type: content-transfer-encoding:list-id:to:cc:content-type:from:subject:to; s=s1; bh=s/G3pVw4PPrmMC77IW5bgwparGJNEQwwxrqzFj3kMo8=; b=OfHJxdyUzhHXgeOkW5PhqIlfkXPw0vQEwe1F31lSGR20kuwOc0aohxBAip+0OKqkv+Pi 95hjdZvwJf/H3T02kJWdTWM8ioAcyn34w9Fuz1QMYuddkNh92PKoh9e5tGctrjwASu24my CArFjvNfIWTdrkXNcr6mTsZud6KDE/GXcJa7xqG+h2EpxK3EAwAf1VDybmrrODvAWhXwFS 38OA2SHtc68SGGTqSPCNi0HKyKhT/ZnrG/GdbR+isSPQ8w2fR/kENWbCpI6byb8+4q4Va7 DHf991vvR7JY/OdyCs6b41YbrQmEYrUNb8Gb4DfmIJ6ZYNLGoV2oBrdJVQPLD2Nw== Received: by recvd-5f54b5d587-w4jt6 with SMTP id recvd-5f54b5d587-w4jt6-1-677BDB5F-1 2025-01-06 13:32:15.026983541 +0000 UTC m=+4550886.609434161 Received: from herokuapp.com (unknown) by geopod-ismtpd-34 (SG) with ESMTP id A8N7ziyuRUCwf9UJFpBGMA for ; Mon, 06 Jan 2025 13:32:14.963 +0000 (UTC) Date: Mon, 06 Jan 2025 13:32:15 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 21000 X-Redmine-Issue-Author: Dan0042 X-Redmine-Issue-Priority: Normal X-Redmine-Sender: Dan0042 X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-Redmine-MailingListIntegration-Message-Ids: 97177 X-SG-EID: =?us-ascii?Q?u001=2EHy4LB1bizMxDg=2Fk6r7dYDS9qUDe3jZN8DIPm4OS+F86l7XdLFEAVX=2F2lh?= =?us-ascii?Q?z0Jj=2Ft7J6DgKnq5Qaf6Ba4+egck=2FoKuUHMa9Cn6?= =?us-ascii?Q?7D+EQ8vUJVtgbcWv6VWCxB3x8d21LUkIV9YL6kD?= =?us-ascii?Q?YPHBZTvTCUvudNFkVJ4WHjtnK05vPBrcluKWWol?= =?us-ascii?Q?iJJSzfyjjkUlcvR3PCsqMeMQgYTqS1j5+Ayze1m?= =?us-ascii?Q?FUWd=2FtiiXZgRjBOZCBg6LHkBRXuOeE=2FLXbRa9+r?= =?us-ascii?Q?VdN62r6KNbtk4D3+AEsV9U7REg=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: CBQX5XLENFO4GECCA6ZTT3HQALBIBTCQ X-Message-ID-Hash: CBQX5XLENFO4GECCA6ZTT3HQALBIBTCQ X-MailFrom: bounces+313651-b711-ruby-core=ml.ruby-lang.org@em5188.ruby-lang.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.9 Precedence: list Reply-To: Ruby developers Subject: [ruby-core:120501] [Ruby master Feature#21000] A way to avoid loading constant required by a type check List-Id: Ruby developers Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: "Dan0042 (Daniel DeLorme) via ruby-core" Cc: "Dan0042 (Daniel DeLorme)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Issue #21000 has been updated by Dan0042 (Daniel DeLorme). Eregon (Benoit Daloze) wrote in #note-2: > So `defined?(Foo::Bar)` will actually try to load `Foo`. It would be a good idea to fix that right? ---------------------------------------- Feature #21000: A way to avoid loading constant required by a type check https://bugs.ruby-lang.org/issues/21000#change-111294 * Author: Dan0042 (Daniel DeLorme) * Status: Open ---------------------------------------- There is this pattern I encounter sometimes: ```ruby if defined?(NameSpace::ClassName) and obj.is_a?(NameSpace::ClassName) ``` Searching in gems, the pattern is fairly common: https://pastebin.com/VGfjRWNu I would like a way to avoid the repetition of `NameSpace::ClassName` above. I can think of a number of ways to approach the issue, each with different tradeoffs... ### Pattern match ignores uninitialized constant Pattern match like `obj in XYZ` could return false if XYZ is not defined. The danger here is that a typo could go undetected and just silently ignore the error even when the constants is expected to be defined. ### Pattern match has special syntax to ignore uninitialized constant Pattern match such as `obj in XYZ?` (or some other syntax) could return false if XYZ is not defined. The downside is that we're adding yet more new syntax. But it could be `obj in defined?(XYZ)` and then it doesn't really feel like new syntax. ### Do not autoload constants required by pattern match If we have `autoload :XYZ, "xyz"` then `obj in XYZ` could skip the autoload and return false. There is a possibility that `XYZ` might be defined as a regexp or other matcher that return true, but in general autoload is only used for classes/modules. And if the class/module is not yet loaded, obviously an object of that type cannot exist so we can avoid loading it. But this would only work for autoloaded constants, so can't be used to check a library that might not be loaded, ex: `obj in ActiveRecord::Base` ### defined?(mod) returns mod if it's a class/module If XYZ is a module, `defined?(XYZ)` could return XYZ instead of returning "constant". So it can be used in expressions like ```ruby case obj when nil when defined?(XYZ) if obj and defined?(XYZ) === obj if defined?(Gem::Specification)&.respond_to?(:each) ``` Very versatile, with the downside that it's a small backward incompatibiliy. -- https://bugs.ruby-lang.org/ ______________________________________________ ruby-core mailing list -- ruby-core@ml.ruby-lang.org To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/