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 BBA2D1F4BD for ; Tue, 8 Oct 2019 21:35:44 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 1C716120A37; Wed, 9 Oct 2019 06:35:35 +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 E09EB120997 for ; Wed, 9 Oct 2019 06:35:32 +0900 (JST) Received: by filter0046p3iad2.sendgrid.net with SMTP id filter0046p3iad2-16127-5D9D0124-5E 2019-10-08 21:35:32.826733901 +0000 UTC m=+440146.257364190 Received: from herokuapp.com (unknown [54.157.57.165]) by ismtpd0013p1iad2.sendgrid.net (SG) with ESMTP id NcaRdBWvSL-IDyhLDUCdLg for ; Tue, 08 Oct 2019 21:35:32.769 +0000 (UTC) Date: Tue, 08 Oct 2019 21:35:32 +0000 (UTC) From: eregontp@gmail.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 70870 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 15323 X-Redmine-Issue-Author: alfonsojimenez 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?KippOI8ZHtTweq7XfQzW93937kJ4QNWwSBuHnaMEcr02B2jdBTqq8xx8Co2uY6?= =?us-ascii?Q?gMWgxHWBFRf0Zv8dAaYPlno25sirNtnUe46Stfw?= =?us-ascii?Q?jFAjjIv=2FfQVL1i4hbzV9FuWj8bQPVzW9PFByae9?= =?us-ascii?Q?DVY38IBQ9Lsmsg1DkyJf8twh8uiokfkqNeUKLfY?= =?us-ascii?Q?pdmlSYaKAItdqZJ+Fh+78=2FQXB0byzkX0+FA=3D=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 95283 Subject: [ruby-core:95283] [Ruby master Feature#15323] [PATCH] Proposal: Add Enumerable#filter_map 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="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #15323 has been updated by Eregon (Benoit Daloze). jonathanhefner (Jonathan Hefner) wrote: > Eregon (Benoit Daloze) wrote: > I would expect to get a value for every valid record, no matter what `fie= ld` is. What if `record.send(field)` returns `nil`? Then the only way is: ```ruby records.filter { |record| record.valid? }.map { |record| record.send(field)= } ``` So this kind of issue is intrinsically there for `filter_map`. `filter_map` is a footgun if `nil` can be returned. I see the point that `nil` is like "missing element, filter it out" versus = `false` being a regular value (and `true` too). I tend to agree with you now, I think just filtering out `nil` values would= be better than also removing `false`. ---------------------------------------- Feature #15323: [PATCH] Proposal: Add Enumerable#filter_map https://bugs.ruby-lang.org/issues/15323#change-81961 * Author: alfonsojimenez (Alfonso Jim=E9nez) * Status: Closed * Priority: Normal * Assignee: = * Target version: = ---------------------------------------- This is a proposal for a combined `filter` + `map` method (https://bugs.rub= y-lang.org/issues/5663). This method both filters and maps the elements of an enumerable in just one= iteration: ~~~ ruby (1..10).filter_map { |i| i * 2 if i.even? } #=3D> [4, 8, 12, 16, 20] ~~~ GitHub PR: https://github.com/ruby/ruby/pull/2017 = ---Files-------------------------------- 0001-Adding-Enumerable-filter_map.patch (4.61 KB) -- = https://bugs.ruby-lang.org/ Unsubscribe: