MatchData#named_captures: a hash of names and matches of captures

named_captures.rb

require "active_support/core_ext/hash/transform_values"

class MatchData
  # Returns a hash containing the names and matches of captures or nil.
  # 
  # A key of the hash is a name of the named captures. A value of the hash is a
  # matched string or an array of corresponding matches.
  # 
  #   puts /(?<foo>.)(?<bar>.)(?<baz>.)(?<baz>.)/.match("hoge", &:named_captures).inspect
  #   # => {"foo"=>"h", "bar"=>"o", "baz"=>["g", "e"]}
  def named_captures
    regexp.named_captures.transform_values! do |indicies|
      if indicies.one?
        self[*indicies]
      else
        values_at(*indicies)
      end
    end
  end
end