Ruby Issue Tracking System

02/14/2025

08:14 AM Ruby Bug #21138 (Closed): The modifier expression with "it" is parsed differently in parse.y and Prism, which is unexpected in both.

## Actual
### parse.y
In parse.y, the block parameter "it" behaves as if it is not assigned.
```ruby
# parse.y
loop.rb:1:in 'block in <main>': undefined method '<' for nil (NoMethodError)
1.then { it *= 10 while it < 1000 }... kinoppyd (Yasuhiro Kinoshita)

07:42 AM Ruby Bug #21137 (Closed): Compound assignment operator with "it" parsed differently between parse.y and prism

``` ruby
# parse.y OK: no error
# prism OK: no error
proc { it = 1 }
# parse.y OK: no error
# prism OK: no error
proc { it = it + 1 }
# parse.y OK: no error
# prism NG: syntax errors found (SyntaxError)
proc { it += 1 ... kinoppyd (Yasuhiro Kinoshita)

10/17/2019

06:24 AM Ruby Feature #13683: Add strict Enumerable#single

```
[1, 2].mono
[1, 2].solo
[1, 2].alone
``` kinoppyd (Yasuhiro Kinoshita)