code: function daisy_chain(head, tail) {
        var result = head;
        for (var i = 0; i < tail.length; i++) {
          result = new node({
            type: "binary",
            operator: tail[i][1],
            left: result,
            right: tail[i][3]
          });
        }
        return result;
      }
docs: Helper function to daisy chain together a series of binary operations.