Bug #18994
closedRange#last(n) returns empty for single-element Integer Range
Description
Range#last(n)
with a single-element of Integer returns an empty Array. It should return a one-element Array.
Interestingly, when the element is a String, last(n)
returns a one-element Array, expectedly.
I have checked the behaviour with some selected past versions of Ruby. In up to Ruby-2.6.5, it worked correctly. In Ruby-2.7.0, it doesn't. Nor in Ruby-3, including the current version (Ruby-3.1.2).
The following demonstrates the behaviour (Ruby-3.1.2; same in Ruby-2.7.0). Only the first one does not work in the way it should.
(8..8).last(1) # => [] (!!) (should be: [8])
(8..8).to_a.last(1) # => [8]
(8..8).first(1) # => [8]
(?a..?a).last(1) #=> ["a"]
(?a..?a).to_a.last(1) #=> ["a"]
(?a..?a).first(1) #=> ["a"]
Updated by byroot (Jean Boussier) about 2 years ago
- Backport changed from 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN to 2.7: WONTFIX, 3.0: REQUIRED, 3.1: REQUIRED
Thanks, I have a patch for it: https://github.com/ruby/ruby/pull/6324
Updated by byroot (Jean Boussier) about 2 years ago
- Status changed from Open to Closed
Applied in changeset git|bbe5ec78463f8d6ef2e1a3571f17357a3d9ec8e4.
rb_int_range_last: properly handle non-exclusive range
[Bug #18994]
Updated by nagachika (Tomoyuki Chikanaga) about 2 years ago
- Backport changed from 2.7: WONTFIX, 3.0: REQUIRED, 3.1: REQUIRED to 2.7: WONTFIX, 3.0: REQUIRED, 3.1: DONE
ruby_3_1 941c888b041decb45034572d766120f9be34986e merged revision(s) bbe5ec78463f8d6ef2e1a3571f17357a3d9ec8e4.