def array
      buffer = ''

      while (bracket = accept :square_bracket)
        buffer += bracket
        accept_newline
        buffer += array_elements
        accept_newline
        buffer += accept :'[', :*
      end

      buffer == '' ? nil : buffer
    end
def array
      buffer = ''

      while (bracket = accept :square_bracket)
        buffer += bracket
        accept_newline
        buffer += array_elements
        accept_newline
        buffer += accept :'[', :*
      end

      buffer == '' ? nil : buffer
    end
Check if it's possible to parse a ruby array literal. First, try to see
 if the next sequence is a hash_open token: "[", and if it is, then a
 hash_close: "]" token is required next

 [array_elements]
 [access][access]