From: sawadatsuyoshi@... Date: 2019-01-09T07:19:52+00:00 Subject: [ruby-core:90940] [Ruby trunk Bug#15518] good old Infinite range notation behavior 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/ Unsubscribe: