From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-2.8 required=3.0 tests=AWL,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS shortcircuit=no autolearn=no autolearn_force=no version=3.4.2 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id 594251F4C0 for ; Tue, 15 Oct 2019 07:23:41 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 67FA1120978; Tue, 15 Oct 2019 16:23:32 +0900 (JST) Received: from o1678948x4.outbound-mail.sendgrid.net (o1678948x4.outbound-mail.sendgrid.net [167.89.48.4]) by neon.ruby-lang.org (Postfix) with ESMTPS id 6A1E8120975 for ; Tue, 15 Oct 2019 16:23:30 +0900 (JST) Received: by filter0083p3mdw1.sendgrid.net with SMTP id filter0083p3mdw1-21442-5DA573F5-32 2019-10-15 07:23:33.699757382 +0000 UTC m=+312195.114604023 Received: from herokuapp.com (unknown [52.91.31.13]) by ismtpd0048p1mdw1.sendgrid.net (SG) with ESMTP id DFAtAWqhTLq2DCKTVfpZIw for ; Tue, 15 Oct 2019 07:23:33.481 +0000 (UTC) Date: Tue, 15 Oct 2019 07:23:33 +0000 (UTC) From: eregontp@gmail.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 70916 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 16157 X-Redmine-Issue-Author: Dan0042 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-SG-EID: =?us-ascii?Q?KippOI8ZHtTweq7XfQzW93937kJ4QNWwSBuHnaMEcr12BJS=2Fa4PRf=2FfUeGlzvL?= =?us-ascii?Q?AOFfzqDuKfJYwrehLr82C6GH4gdnGCax9YoqX80?= =?us-ascii?Q?E7HCaFGJjh9hxKqwmpS7K4SuEKW6BV65njteMQ0?= =?us-ascii?Q?pZjrDrF4+1fD629yuQWrtMmY465VZVwQzpxPm8L?= =?us-ascii?Q?w4JIiYkErlnoGC3leKMdVs5QtgHT16d6gjg=3D=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 95328 Subject: [ruby-core:95328] [Ruby master Misc#16157] What is the correct and *portable* way to do generic delegation? X-BeenThere: ruby-core@ruby-lang.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: Ruby developers List-Id: Ruby developers List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #16157 has been updated by Eregon (Benoit Daloze). At the end of my comment in https://bugs.ruby-lang.org/issues/16188#note-5 I discussed why I believe `ruby2_keywords` is a non-trivial cost on performance, and so should be IMHO only in Ruby 2.7. I also propose there an explicit way to mark call sites converting the Hash flagged by `ruby2_keywords` to keywords again with `send_keyword_hash`. That I think would make it easier to understand by being less magic and limit the performance cost to only where it's needed. ---------------------------------------- Misc #16157: What is the correct and *portable* way to do generic delegation? https://bugs.ruby-lang.org/issues/16157#change-82037 * Author: Dan0042 (Daniel DeLorme) * Status: Open * Priority: Normal * Assignee: ---------------------------------------- With the keyword argument changes in 2.7 we must now specify keyword arguments explicitly when doing generic delegation. But this change is not compatible with 2.6, where it adds an empty hash to the argument list of methods that do not need/accept keyword arguments. To illustrate the problem: ```ruby class ProxyWithoutKW < BasicObject def initialize(target) @target = target end def method_missing(*a, &b) @target.send(*a, &b) end end class ProxyWithKW < BasicObject def initialize(target) @target = target end def method_missing(*a, **o, &b) @target.send(*a, **o, &b) end end class Test def args(*a) a end def arg(a) a end def opts(**o) o end end # 2.6 2.7 3.0 ProxyWithoutKW.new(Test.new).args(42) # [42] [42] [42] ok ProxyWithoutKW.new(Test.new).arg(42) # 42 42 42 ok ProxyWithoutKW.new(Test.new).opts(k: 42) # {:k=>42} {:k=>42} +warn [{:k=>42}] incompatible with >= 2.7 ProxyWithKW.new(Test.new).args(42) # [42, {}] [42] [42] incompatible with <= 2.6 ProxyWithKW.new(Test.new).arg(42) # error 42 42 incompatible with <= 2.6 ProxyWithKW.new(Test.new).opts(k: 42) # {:k=>42} {:k=>42} +warn {:k=>42} must ignore warning? cannot use pass_positional_hash in 2.6 ``` I don't know how to solve this, so I'm asking for the **official** correct way to write portable delegation code. And by **portable** I mean code that can be used in gems that target ruby 2.6 and above. -- https://bugs.ruby-lang.org/