'Return a tuple (name, line, col) representing the location of
the last token read using the read() method. |name| is the
name that was provided to the Scanner constructor; |line|
is the line number in the stream (1-based); |col| is the
position within the line of the first character of the token
(0-based).'

def position(self):

    return (self.name, self.start_line, self.start_col)
