Feature #20894: Allow `Range#last(n)` for beginless ranges with Integer end

• Status: Open
• Assignee: -
• Target version: -

[kyanagi (Kouhei Yanagita)]

Range#last(n) raises an exception on beginless ranges.

(..5).last(3) #=> can't iterate from NilClass (TypeError)

Since Ruby 3.3, Range#reverse_each for beginless ranges with an integer end has been allowed.

(..5).reverse_each { p _1 } #=> 5, 4, 3, 2, 1, ...

Therefore, shouldn't Range#last(n) for such ranges also be acceptable?

# before
(..5).last(3) #=> can't iterate from NilClass (TypeError)
# after
(..5).last(3) #=> [3, 4, 5]

If this is accepted, a similar change could be considered for Range#max(n) as well.

https://github.com/ruby/ruby/pull/12084

[kyanagi (Kouhei Yanagita)]

• Description updated (diff)