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-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY shortcircuit=no autolearn=ham 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 3B54F1F66E for ; Wed, 26 Aug 2020 19:18:17 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 230EF120A40; Thu, 27 Aug 2020 04:17:37 +0900 (JST) Received: from xtrwkhkc.outbound-mail.sendgrid.net (xtrwkhkc.outbound-mail.sendgrid.net [167.89.16.28]) by neon.ruby-lang.org (Postfix) with ESMTPS id 93FE9120A3C for ; Thu, 27 Aug 2020 04:17:34 +0900 (JST) Received: by filterdrecv-p3iad2-68944c5fcc-4hwmz with SMTP id filterdrecv-p3iad2-68944c5fcc-4hwmz-19-5F46B566-2C 2020-08-26 19:17:58.382735784 +0000 UTC m=+5432.716971049 Received: from herokuapp.com (unknown) by ismtpd0118p1mdw1.sendgrid.net (SG) with ESMTP id cnVpK7rmSBy8E29vQ_D3KA for ; Wed, 26 Aug 2020 19:17:58.236 +0000 (UTC) Date: Wed, 26 Aug 2020 19:17:58 +0000 (UTC) From: daniel@dan42.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 75546 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Bug X-Redmine-Issue-Id: 17030 X-Redmine-Issue-Author: marcandre 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-SG-EID: =?us-ascii?Q?8sy4RigFvRTdBfCVJrT9zb2J88PC92TMQwdNgaWYaq4gnWHYu4rKDNaNEFnTdN?= =?us-ascii?Q?4sAAlJ8sLGqcrR5CvEAFvs8W+r4ESbRz9nFA3ej?= =?us-ascii?Q?RKwdtuvnZWX8qpjIA6Wy20trXUts22nysSNQ7bP?= =?us-ascii?Q?IShTIoaQvjfjg9sebFBgGI0Umhw2IOxD5hyBAmp?= =?us-ascii?Q?+s+fI1ahTQeKr1Cf6CGsHwK0IRuxglOeOxqBdQi?= =?us-ascii?Q?pqfUlwze3H1GH01cQ=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 99713 Subject: [ruby-core:99713] [Ruby master Bug#17030] Enumerable#grep{_v} should be optimized for Regexp 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 #17030 has been updated by Dan0042 (Daniel DeLorme). > Couldn't static analysis of the code determine in most cases if match data need be generated or not? scivola20 had a good idea, but this is even better. We can automatically get the best performance without having to manually optimize each case. But static analysis has other limits besides `const_get(:Regexp).last_match` ```ruby def foo(v) /x/ =~ 'x' # needs_last_match? depends on whether 'v' is regexp case method when v $1 end end ``` So a simpler approach would be to check if the match operation's scope (in this case the method body) contains any of the regexp-related pseudo-globals. ---------------------------------------- Bug #17030: Enumerable#grep{_v} should be optimized for Regexp https://bugs.ruby-lang.org/issues/17030#change-87203 * Author: marcandre (Marc-Andre Lafortune) * Status: Open * Priority: Normal * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- Currently: ```ruby array.select { |e| e.match?(REGEXP) } # about 3x faster and 6x more memory efficient than array.grep(REGEXP) ``` This is because `grep` calls `Regexp#===` which creates useless `MatchData` -- https://bugs.ruby-lang.org/