def _process_newline(self, char):
        """ Process a newline character.
            """

        state = self._state

        # inside string, just append char to token
        if state == self.ST_STRING:
            self._token_chars.append(char)
        else:
            # otherwise, add new token
            self._new_token()

        self._line_no += 1  # update line counter

        # finished with comment
        if state == self.ST_COMMENT:
            self._state = self.ST_TOKEN
Process a newline character.