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=-3.7 required=3.0 tests=AWL,BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,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 1BCDF1F4B4 for ; Wed, 21 Oct 2020 10:07:16 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 8F005120AC7; Wed, 21 Oct 2020 19:06:36 +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 8BAA2120AC1 for ; Wed, 21 Oct 2020 19:06:34 +0900 (JST) Received: by filterdrecv-p3las1-68f969d758-mwx2t with SMTP id filterdrecv-p3las1-68f969d758-mwx2t-19-5F90084E-7 2020-10-21 10:07:10.189810837 +0000 UTC m=+33692.723976999 Received: from herokuapp.com (unknown) by geopod-ismtpd-3-2 (SG) with ESMTP id qFpwhovDRiS5bY5zy_LmQQ for ; Wed, 21 Oct 2020 10:07:10.020 +0000 (UTC) Date: Wed, 21 Oct 2020 10:07:10 +0000 (UTC) From: grzegorz.jakubiak@outlook.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 76341 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 17277 X-Redmine-Issue-Author: greggzst X-Redmine-Sender: greggzst 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?VGo1Yotd4zCzfg3lZZGknPzkEWcl6BbwQWWlBuZDX4Y7dCWTFW5Sa13VeKSq+h?= =?us-ascii?Q?C9IktGVTK4o=2FVDmemTw++i0NeKsPmneUPbqFWMR?= =?us-ascii?Q?APlWLruyDYvUIcQlSvZy7iDbQB0oVgDr0mQsQ6Q?= =?us-ascii?Q?rdGsrchI3vvxxDXOQ5TWvpTR5dwXwuFg1ggR9Z+?= =?us-ascii?Q?+QBPCumweEI84DZPDqv2ZeDYkpHX2NfLdOQEW6m?= =?us-ascii?Q?D0iUnJ6WTOzy9wHr0=3D?= To: ruby-core@ruby-lang.org X-Entity-ID: b/2+PoftWZ6GuOu3b0IycA== X-ML-Name: ruby-core X-Mail-Count: 100471 Subject: [ruby-core:100471] [Ruby master Feature#17277] Make Enumerator#with_index yield row and col indices for Matrix 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 #17277 has been reported by greggzst (Grzegorz Jakubiak). ---------------------------------------- Feature #17277: Make Enumerator#with_index yield row and col indices for Matrix https://bugs.ruby-lang.org/issues/17277 * Author: greggzst (Grzegorz Jakubiak) * Status: Open * Priority: Normal ---------------------------------------- Currently this code seems to be counting index based on the internal array of arrays and it's not correct for the matrix which should return row and col indices ``` Matrix[[0,2,3,4], [6,7,8,9], [1,4,5,8]].each.with_index { |e, index| print "#{index} " } ; puts 0 1 2 3 4 5 6 7 8 9 10 11 => nil ``` I'm aware of the fact that you could do following and you get the correct results: ``` Matrix[[0,2,3,4], [6,7,8,9], [1,4,5,8]].each_with_index { |e, row, col| print "[#{row}, #{col}] " } ; puts [0, 0] [0, 1] [0, 2] [0, 3] [1, 0] [1, 1] [1, 2] [1, 3] [2, 0] [2, 1] [2, 2] [2, 3] => nil ``` You can even chain `each_with_index` with other enumerators and access indices within them e.g. ``` Matrix[[0,2,3,4], [6,7,8,9], [1,4,5,8]].each_with_index.filter_map { |e, row, col| [row, col] if e % 4 == 0} => [[0, 0], [0, 3], [1, 2], [2, 1], [2, 3]] ``` However, I feel we should override `with_index` for Matrix so it returns row and col indices. -- https://bugs.ruby-lang.org/