Define name for this expression, makes debugging and exception messages clearer.

        Example::

            Word(nums).parseString("ABC")  # -> Exception: Expected W:(0123...) (at char 0), (line:1, col:1)
            Word(nums).setName("integer").parseString("ABC")  # -> Exception: Expected integer (at char 0), (line:1, col:1)

def setName( self, name ):
        """
        Define name for this expression, makes debugging and exception messages clearer.

        Example::

            Word(nums).parseString("ABC")  # -> Exception: Expected W:(0123...) (at char 0), (line:1, col:1)
            Word(nums).setName("integer").parseString("ABC")  # -> Exception: Expected integer (at char 0), (line:1, col:1)
        """
        self.name = name
        self.errmsg = "Expected " + self.name
        if hasattr(self,"exception"):
            self.exception.msg = self.errmsg
        return self