def addstate ( ps )
      raise TypeError, ps.class.to_s + ': Incorrectly types for \'<<\' method of <Parser>.' unless
	ps.instance_of? State
      @states << ps
    end
def addstate ( ps )
      raise TypeError, ps.class.to_s + ': Incorrectly types for \'<<\' method of <Parser>.' unless
	ps.instance_of? State
      @states << ps
    end
call-seq:
  s = Parser::State.new('idle')
  p = Parser::Machine.new
  p << s

 Add any parser-state to current parser.