Feature #18515
Updated by kyanagi (Kouhei Yanagita) about 2 years ago
PR is https://github.com/ruby/ruby/pull/5489
Current `Range#reverse_each` uses `Enumerable#reverse_each` which is implemented with `#to_a`.
So we are virtually not able to use `reverse_each` for a very large or beginless range, even if few elements are iterated on actually.
```
(1..2**100).reverse_each { |x| p x; break if x.odd? }
(..5).reverse_each { |x| p x; break if x == 0 }
(1..2**32).reverse_each.lazy.select { |x| Prime.prime?(x) }.take(3).to_a
```
This patch, implements `Range#reverse_each` for Integer elements, enables these examples.
I think `#reverse_each` for an endless range should raise an exception.
This is a different issue, so I'll create another ticket later.
-> posted: https://bugs.ruby-lang.org/issues/18551