# File lib/parser/builders/default.rb, line 317
    def pair_list_18(list)
      if list.size % 2 != 0
        diagnostic :error, :odd_hash, nil, list.last.loc.expression
      else
        list.
          each_slice(2).map do |key, value|
            n(:pair, [ key, value ],
              binary_op_map(key, nil, value))
          end
      end
    end