Currying

How to implement an add funtion?

function add(x, y) {
    return x+y;
}
add(1, 3)===4//true

How to implement add(1)(3) === 4?

function add(x) {
	return function(y) {
		return x+y;
	}
}

How to implement add3(2) === 5?

function currying(fn, ...args1) {
    return function(...args2) {
        fn(...args1, ...args1);
    }
}

var increment = currying(add, 1);
increment(5)===6//true

How to implement infinite arguments?

function trueCurrying(fn, ...args1) {
    if(args1.length>=fn.length) return fn(...args1);
    return function(...args2) {
        return trueCurrying(fn, ...args1, ...args2);
    }
}

function triAdd(x, y, z) = {
    return x+y+z;
}

var curryAdd = trueCurrying(triAdd);
curryAdd(1,2,3)===6//true;
curryAdd(1,2)(3)===6//true;
curryAdd(1)(2)(3)===6//true;