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=-3.1 required=3.0 tests=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_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 CDD771F803 for ; Wed, 9 Jan 2019 07:19:58 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 00141121F40; Wed, 9 Jan 2019 16:19:56 +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 85576121F2D for ; Wed, 9 Jan 2019 16:19:54 +0900 (JST) Received: by filter0021p3iad2.sendgrid.net with SMTP id filter0021p3iad2-7192-5C35A097-23 2019-01-09 07:19:51.653897856 +0000 UTC m=+109979.484819152 Received: from herokuapp.com (ec2-54-82-77-37.compute-1.amazonaws.com [54.82.77.37]) by ismtpd0027p1iad2.sendgrid.net (SG) with ESMTP id nLzrFng2QheBMoRpQh3B4Q for ; Wed, 09 Jan 2019 07:19:51.629 +0000 (UTC) Date: Wed, 09 Jan 2019 07:19:52 +0000 (UTC) From: sawadatsuyoshi@gmail.com To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 66370 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 15518 X-Redmine-Issue-Author: sakuro X-Redmine-Sender: sawa 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/Ymy4QrNMhiuLXJG8OTL2vJD1yS7eYYtkGQqNOos8ghQ3nfIZVlpehch039lPXo zKSV3IfWSa3hXqgOUMyshVf3/ugm3+YaHDj2/azML11UOQW17HFad+6LuaHIKAGgvhRpoA6P+4MD4L tEYw3pAG7Dgy4QjOVtz90cP6eJTiu1iWUDnOH/x8Vr7Utxo2gMBvj5JvXw== X-ML-Name: ruby-core X-Mail-Count: 90940 Subject: [ruby-core:90940] [Ruby trunk Bug#15518] good old Infinite range notation behavior 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 #15518 has been updated by sawa (Tsuyoshi Sawada). With finite ranges, the class of the elements in the return value seems to reflect the class of the `step` parameter as shown below (although, I am not sure why the one with rational has `1` instead of `(1/1)`. A bug, perhaps?): ```ruby (1..10).step(1).first(5) # => [1, 2, 3, 4, 5] (1..10).step(1.0).first(5) # => [1.0, 2.0, 3.0, 4.0, 5.0] (1..10).step(1/1r).first(5) #=> [1, (2/1), (3/1), (4/1), (5/1)] ``` Given that, without explicit `step`, the returned numbers are integers, it should be understood that the default step for a range is the integer `1`: ```ruby (1..10).first(5) # => [1, 2, 3, 4, 5] ``` The above claim that the class of the number is determined by the `step` parameter (and nothing else, such as the end of range) is confirmed by the fact that a range ending with `Float::INFINITY` that has default step `1` returns integers. ```ruby (1..Float::INFINITY).first(5) #=> [1, 2, 3, 4, 5] ``` Given the argument above, I think `(1..Float::INFINITY).step(1).first(5)` should return integers as follows: ```ruby (1..Float::INFINITY).step(1).first(5) # => [1, 2, 3, 4, 5] ``` Thus, to me, neither Ruby 2.5.3 nor Ruby 2.6.0's behavior makes sense. ---------------------------------------- Bug #15518: good old Infinite range notation behavior https://bugs.ruby-lang.org/issues/15518#change-76140 * Author: sakuro (Sakuro OZAWA) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-darwin18] * Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN ---------------------------------------- Ruby 2.5.3's behavior ~~~ # without step, it produces integer sequence (1..Float::INFINITY).first(10) #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] # with step, it produces floats instead of integers (1..Float::INFINITY).step(1).first(10) #=> [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0] ~~~ Ruby 2.6.0's behavior ~~~ # endless range (1..).first(10) #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] # with step, all numbers are integer now (1..).step(1).first(10) #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] # old idiom with Float::INFINITY (1..Float::INFINITY).first(10) #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] (1..Float::INFINITY).step(1).first(10) #=> FloatDomainError (Infinity) ~~~ Which are intended change and which are not? -- https://bugs.ruby-lang.org/