[ANN] ruby_parser 3.18.1 Released

ruby_parser version 3.18.1 has been released!

* home: <GitHub - seattlerb/ruby_parser: ruby_parser is a ruby parser written in pure ruby. It outputs s-expressions which can be manipulated and converted back to ruby via the ruby2ruby gem.>
* bugs: <Issues · seattlerb/ruby_parser · GitHub>
* rdoc: <ruby_parser-3.18.0 Documentation>

ruby_parser (RP) is a ruby parser written in pure ruby (utilizing
racc--which does by default use a C extension). It outputs
s-expressions which can be manipulated and converted back to ruby via
the ruby2ruby gem.

As an example:

    def conditional1 arg1
      return 1 if arg1 == 0
      return 0
    end

becomes:

    s(:defn, :conditional1, s(:args, :arg1),
      s(:if,
        s(:call, s(:lvar, :arg1), :==, s(:lit, 0)),
        s(:return, s(:lit, 1)),
        nil),
      s(:return, s(:lit, 0)))

Tested against 801,039 files from the latest of all rubygems (as of 2013-05):

* 1.8 parser is at 99.9739% accuracy, 3.651 sigma
* 1.9 parser is at 99.9940% accuracy, 4.013 sigma
* 2.0 parser is at 99.9939% accuracy, 4.008 sigma
* 2.6 parser is at 99.9972% accuracy, 4.191 sigma

Changes:

### 3.18.1 / 2021-11-10

* 1 minor enhancement:

  * All parser tests are now explicitly testing line numbers at every level.

* 3 bug fixes:

  * Fixed endless method with noargs. (mitsuru)
  * Fixed line numbers on some yield forms.
  * Handle and clearly report if unifdef is missing.