http://lnkd.in/dqTPRcx

js fun challenge

function sum(args){ 
    return Array.prototype.reduce.call(args, function(a, b){ return a + b }, 0)
}

function add(){
    var total = sum(arguments),
        self = function(){ total += sum(arguments); return self }
    return (self.valueOf = function(){ return total }, self)
}
 
console.log(add(1, 2, 3, 4));
console.log(add(5)(6)(7)(8));
console.log(add(1, 3)(5, 7));
console.log(add(2, 4, 6)(8));
console.log(add(1)(2, 1, 2));