gistfile1.txt

function generate_math_operator(op) {
  return function(args) {
    var res = args[0], i, tmp;
    for (i=1; i<args.length; i++) {
      tmp = predicates.is_object(op) ? ast_to_js(op) : op;
      res += " " + tmp + " " + args[i];
    }
    return res;
  };
}

var add = generate_math_operator("+");
var sub = generate_math_operator("-");
var mul = generate_math_operator("*");
var div = generate_math_operator("/");