new_op_asgn (RubyParser)

    # File lib/ruby_parser_extras.rb, line 568
      def new_op_asgn val
        lhs, asgn_op, arg = val[0], val[1].to_sym, val[2]
        name = lhs.value
        arg = remove_begin(arg)
        result = case asgn_op # REFACTOR
                 when "||""||" then
                   lhs << arg
                   s(:op_asgn_or, self.gettable(name), lhs)
                 when "&&""&&" then
                   lhs << arg
                   s(:op_asgn_and, self.gettable(name), lhs)
                 else
                   # TODO: why [2] ?
                   lhs[2] = new_call(self.gettable(name), asgn_op,
                                     s(:arglist, arg))
                   lhs
                 end
        result.line = lhs.line
        result
      end