Support for both curried and uncurried application in functional JavaScript

currying.js

function curry(f) {
    return function(x) {
        var g = f.bind(this, x);
        if(g.length == 0) return g();
        if(arguments.length > 1) return curry(g).apply(this, [].slice.call(arguments, 1));
        return curry(g);
    };
}

var sum = curry(function(x, y) {
    return x + y;
});

var incr = sum(1);
console.log(incr(2));

console.log(sum(1)(2));
console.log(sum(1, 2));

var tuple4 = curry(function(a, b, c, d) {
    return [a, b, c, d];
});

console.log(tuple4(1)(2, 3, 4));
console.log(tuple4(1, 2)(3, 4));
console.log(tuple4(1, 2)(3)(4));
console.log(tuple4(1, 2, 3)(4));