From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: poffice@blade.nagaokaut.ac.jp Delivered-To: poffice@blade.nagaokaut.ac.jp Received: from kankan.nagaokaut.ac.jp (kankan.nagaokaut.ac.jp [133.44.2.24]) by blade.nagaokaut.ac.jp (Postfix) with ESMTP id 6615119C003C for ; Mon, 9 Nov 2015 23:44:13 +0900 (JST) Received: from voscc.nagaokaut.ac.jp (voscc.nagaokaut.ac.jp [133.44.1.100]) by kankan.nagaokaut.ac.jp (Postfix) with ESMTP id DA43FB5D896 for ; Tue, 10 Nov 2015 00:13:41 +0900 (JST) Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by voscc.nagaokaut.ac.jp (Postfix) with ESMTP id 6009518CC7EA for ; Tue, 10 Nov 2015 00:13:42 +0900 (JST) Received: from [221.186.184.76] (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 1501912049D; Tue, 10 Nov 2015 00:13:41 +0900 (JST) X-Original-To: ruby-core@ruby-lang.org Delivered-To: ruby-core@ruby-lang.org Received: from o2.heroku.sendgrid.net (o2.heroku.sendgrid.net [67.228.50.55]) by neon.ruby-lang.org (Postfix) with ESMTPS id B87B1120461 for ; Tue, 10 Nov 2015 00:13:37 +0900 (JST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sendgrid.me; h=from:to:references:subject:mime-version:content-type:content-transfer-encoding:list-id; s=smtpapi; bh=ZuCU1WHYl4wPAjvR9F9OBi91mSU=; b=yfAvJq79pdoNagNsY5 4Wcz303gE9cmragKVNSPBJWJQoyEwab0sMpwNxX79yXENKpfWGh5JLRm3oV9HIvW IQjWpJkAw/TGfNTDo+1GN27yHqfvq+6/TLPA8iiUPpDMMDu9eP5bRZlL6g5p9AQI ZDkpaPLSOSremGZrGQXBiTAgU= Received: by filter-506.sjc1.sendgrid.net with SMTP id filter-506.16637.5640B67825 2015-11-09 15:06:32.359526993 +0000 UTC Received: from herokuapp.com (ec2-54-145-97-147.compute-1.amazonaws.com [54.145.97.147]) by ismtpd0004p1iad1.sendgrid.net (SG) with ESMTP id B4e9-U7sTyei4V6mHpjY9g Mon, 09 Nov 2015 15:06:32.166 +0000 (UTC) Date: Mon, 09 Nov 2015 15:06:32 +0000 From: hi@olivierlacan.com To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Redmine-MailingListIntegration-Message-Ids: 46060 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 10984 X-Redmine-Issue-Author: olivierlacan X-Redmine-Issue-Assignee: akr X-Redmine-Sender: olivierlacan 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: ync6xU2WACa70kv/Ymy4QrNMhiuLXJG8OTL2vJD1yS6tGfydoIJnc2aKSqhYjxrZ4SPRELBtEP7Shl vT1IPdsgmFqParx7O2QYVnVKhVIgDIIeJQrZdWVle4snYxiviWKiNtKkjuTN6wBhMJlszvPDaPsqnb PjgRJcU2XonH+Uo= X-ML-Name: ruby-core X-Mail-Count: 71419 Subject: [ruby-core:71419] [Ruby trunk - Feature #10984] Hash#contain? to check whether hash contains other hash 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: , Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #10984 has been updated by Olivier Lacan. Yukihiro Matsumoto wrote: > Hash#contain? has slight ambiguity problem. I'd vote for adding `>=`, along with '<='. > > Matz. Thanks for considering this feature, Matz. :-) If I understand correctly, the following examples would be correct? ``` { a: 1, b: 2 } >= { b: 2 } => true { b: 2 } <= { a: 1, b: 2 } => true # also { b: 2 } >= { b: 2 } => true { a: 1 } >= { b: 2 } => false { b: 2 } <= { b: 2 } => true { b: 2 } <= { a: 1 } => false ``` I think the versatility of this alone would make it even more useful than the one direction method I suggested. ---------------------------------------- Feature #10984: Hash#contain? to check whether hash contains other hash https://bugs.ruby-lang.org/issues/10984#change-54788 * Author: Olivier Lacan * Status: Open * Priority: Normal * Assignee: Akira Tanaka ---------------------------------------- Comparing hashes seems like a common practice but there currently isn't a method to ask a hash instance whether it includes another hash instance. The most intuitive method to reach for would be `Hash#include?` but it is in fact an alias to `Hash#has_key?` What I'm looking for can be achieved with: ~~~ class Hash def contain?(other) self.merge(other) == self end end ~~~ Here's a simple demo of `#contain?` in use: ~~~ { a: true, b: false }.contain?({ a: true}) # => true { a: true, b: false }.contain?({ b: false}) # => true { a: true, b: false }.contain?({ a: false}) # => false { a: true, b: false }.contain?({ c: true}) # => false ~~~ One important note is that this method is *not checking for nested hash matches*. This may need to be addressed when the parameters include a nested hash perhaps. Thanks to Terence Lee's help, nobu created a patch for this feature last year. I've only modified the name of the method from [his original patch](https://gist.github.com/nobu/dfe8ba14a48fc949f2ed) and attached it to this issue. ---Files-------------------------------- Hash#contain_.patch (2.22 KB) -- https://bugs.ruby-lang.org/