docs: def readstream(self, stream):
          """ Reads the specified stream and parses the token elements generated
              from tokenizing the input data.
  
              `stream`
                  ``File``-like object.
  
              Returns boolean.
              """
  
          self._reset()
  
          try:
              # tokenize input stream
              self._lexer = SettingLexer()
              self._lexer.readstream(stream)
  
              # parse tokens into AST
              self._parse()
              return True
  
          except IOError:
              self._reset()
              return False