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=-4.1 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,SPF_PASS 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 EECB21F45F for ; Sat, 11 May 2019 07:13:09 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 17ADF120998; Sat, 11 May 2019 16:13:04 +0900 (JST) Received: from o1678916x28.outbound-mail.sendgrid.net (o1678916x28.outbound-mail.sendgrid.net [167.89.16.28]) by neon.ruby-lang.org (Postfix) with ESMTPS id 02D0B120998 for ; Sat, 11 May 2019 16:13:00 +0900 (JST) Received: by filter0066p3las1.sendgrid.net with SMTP id filter0066p3las1-27297-5CD675FD-4 2019-05-11 07:13:01.167370128 +0000 UTC m=+133716.027817097 Received: from herokuapp.com (unknown [3.93.58.81]) by ismtpd0063p1mdw1.sendgrid.net (SG) with ESMTP id e-2IDzebSXy5-fpGO-o-UQ for ; Sat, 11 May 2019 07:13:01.022 +0000 (UTC) Date: Sat, 11 May 2019 07:13:01 +0000 (UTC) From: nobu@ruby-lang.org Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 68103 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 15829 X-Redmine-Issue-Author: foonlyboy X-Redmine-Sender: nobu 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?q8Dly+pU2+3ektTtZVXgZtbJPXwqo7p86jCsvYTW4Bybk+K8Y8C+HbapK+js3D?= =?us-ascii?Q?jIiBzHMfjlRkrAEj5hzUZZOhQZVX7LndUycCkkP?= =?us-ascii?Q?NDgRz39bM4xsNLOsNwGmIFgKQvf1BlMq0WCfC=2F7?= =?us-ascii?Q?S+STLsvr85phBaqKUvDaqdQsiXAeL4ZUXEIWC+I?= =?us-ascii?Q?MCUkC7+fYjL7wDqmlFtQAI6yMNEasRR1QtA=3D=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 92620 Subject: [ruby-core:92620] [Ruby trunk Feature#15829] Object#then_if(condition){} 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 #15829 has been updated by nobu (Nobuyoshi Nakada). Description updated As it seems useful only when `condition` doesn't use the parameter `query`, it is questionable to me if it is generic enough to be a language feature. ---------------------------------------- Feature #15829: Object#then_if(condition){} https://bugs.ruby-lang.org/issues/15829#change-77979 * Author: foonlyboy (Eike Dierks) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- I'd like to propose some sugar to Object#then There should be `Object#then_if(condition, &block)` The block should only be applied when the condition is true, otherwise the object should be returned without applying the block. Rationale: I frequently use `Object#then` with Rails to extend queries like this: ```ruby foo.then {|query| if(condition) query.where(zip:zap) else query end } ``` by using the proposed `Object#then_if` the example could be simplified to: ```ruby foo.then_if(condition) {|query| query.where(zip:zap) } ``` I believe that this also applies to a lot of other use cases, i.e. only applying some transformation if some condition is true, but otherwise leaving the result untouched. -- https://bugs.ruby-lang.org/