Understanding Curry

gistfile1.txt

var add = function(a, b, c) {
    return a + b + c;
};

Function.prototype.method = function(name, func) {
	this.prototype[name] = func;
	return this;
};
Function.method('curry', function() {
    //keep the value of curry inside a closure
    var slice = Array.prototype.slice,
        args = slice.apply(arguments), 
        that = this;

    console.log("arguments in curry is - " + arguments);
    console.log("args in curry is - " + args);

    return function() {
    //at that point the arguments is the arguments of the function (here add)
    	var finalarg = args.concat(slice.apply(arguments));
		console.log("arguments in func is - " + arguments);
    	console.log("finalarg in func is - " + finalarg);
      	return that.apply(null, finalarg);
    };
});

var add1 = add.curry(1,5);

console.log(add1(5));