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) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id EDF591F4CC for ; Wed, 8 Jan 2025 09:55:12 +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=vtd4UQ/4; 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=r5lFF4No; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1736330110; bh=1fxF0sDFJTI1iolkJyYuDmtoTZdtCtbdbSFF6IzH8eQ=; 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=vtd4UQ/4FmneR3XJNBO5UH5KQb85YC2sBzfRbAl2tzA12dE2/5qq7cBZHIZFfWCVV z5Xm8BHvgqz+D9FUr8cgdGhkf9KTn1eA88jSzGS4ndTA8nnkpnhIH5HhIhxgmfRtIR A9/cAaEVrF8gfPZ1IaZbZBKRJGw3KGOKNp/g/FN4= Received: from nue.mailmanlists.eu (localhost [IPv6:::1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 42AAC466F7 for ; Wed, 8 Jan 2025 09:55:10 +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=r5lFF4No; dkim-atps=neutral Received: from s.wrqvtzvf.outbound-mail.sendgrid.net (s.wrqvtzvf.outbound-mail.sendgrid.net [149.72.126.143]) by nue.mailmanlists.eu (Postfix) with ESMTPS id F21A946687 for ; Wed, 8 Jan 2025 09:55:04 +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=ucpZSPfzhGMFKN7ldHl1Ptpb0r9Hs5R3n4FXrGCsVnk=; b=r5lFF4NoxMNk2M1OsC1D4o8Ay50LXxDnCCgk8SbZZLhZqAeZBsLDfvsQv8/5zjTwKMO9 us5pfz1S0OA33sFi2bQlyM99oIyVlGMi7UFTQl25GU2z6wB/ynSggxnn8x2oRoOHOwxZUA OjE44tWH+oKVxqH/yVlEO9ex7sstorogxkEwCJpxAwhcVcI07NjEbxVf7u9jDxwo65FiAg fC/L4upMfuJhuMEyyt5auu9xbeLdhlsCs46JT36Od0UB4Lsz0uLszd0lKxWKBQBOJHMbUX OicZKHLl6BuMs0jKeupsX45BjK0RTqHBgs6UF8Jl2o+wZSZvlnZiq03st47PL88A== Received: by recvd-5f54b5d587-cddpk with SMTP id recvd-5f54b5d587-cddpk-1-677E4B77-2E 2025-01-08 09:55:03.455512156 +0000 UTC m=+4710730.956792586 Received: from herokuapp.com (unknown) by geopod-ismtpd-35 (SG) with ESMTP id dTM4Ez7IQpmzI9D97Ypgcg for ; Wed, 08 Jan 2025 09:55:03.398 +0000 (UTC) Date: Wed, 08 Jan 2025 09:55:03 +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: Eregon 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: 97230 X-SG-EID: =?us-ascii?Q?u001=2EByjZWvxTCjdoV8K03xEuhE7KqN4thWULFLM7+oH78KY30oYB3qFthsDpL?= =?us-ascii?Q?4w4cbYa3ttBh8bAHPOnE=2FkzPba67JNu7Lnrked2?= =?us-ascii?Q?O7K9VQ=2FJax2DrqmPrXjVe9NRxKODWfAFoIbm636?= =?us-ascii?Q?X=2FePCLNVXtvbmBfykrQ4ZtvPOi=2FQJizCWrlGFBB?= =?us-ascii?Q?EdlYgUqjsCyeodukVZClDEOk193R90Xnm=2F9LaO+?= =?us-ascii?Q?CG2BuzTfbsu427jSkw+DRwEXH6PApaN8khOxvkp?= =?us-ascii?Q?+9el99+hHbe3WbC+YWvtMFT2+g=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: LSFKWEN4BBL5GTAP7622JL6JNUTIEC7G X-Message-ID-Hash: LSFKWEN4BBL5GTAP7622JL6JNUTIEC7G 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:120554] [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: "Eregon (Benoit Daloze) via ruby-core" Cc: "Eregon (Benoit Daloze)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Issue #21000 has been updated by Eregon (Benoit Daloze). IMO the pattern is not frequent enough to justify adding new syntax for this or breaking compatibility. In https://pastebin.com/VGfjRWNu many cases are actually not classes, e.g. `defined?(::JSON::JSON_LOADED) and ::JSON::JSON_LOADED`, `defined?(RUBY_ENGINE) and RUBY_ENGINE == 'jruby'`, etc. Maybe a new method or kwarg to `const_get` which has some special behavior regarding autoload (to not trigger them)? ---------------------------------------- Feature #21000: A way to avoid loading constant required by a type check https://bugs.ruby-lang.org/issues/21000#change-111365 * 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) ``` ```ruby if obj and defined?(XYZ) === obj ``` ```ruby 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/