kind=defined
names=matched?
visibility=public

--- matched?
前回のマッチが成功していたら true を、
失敗していたら false を返します。

      s = StringScanner.new('test string')
      s.matched?    # => false
      s.scan(/\w+/) # => "test"
      s.matched?    # => true
      s.scan(/\w+/) # => nil
      s.matched?    # => false
      s.scan(/\s+/) # => " "
      s.matched?    # => true

