function factorial(n) {
 if (n === 1) return 1
 return n * factorial(n - 1)
}

function factorial(n, total = 1) {
if (n === 1) return total
return factorial(n - 1, n * total)
}

factorial(5)

function Fibonacci (n) {
 if ( n <= 1 ) {return 1};

 return Fibonacci(n - 1) + Fibonacci(n - 2);
}

Fibonacci(10) // 89
Fibonacci(100) // 堆栈溢出
Fibonacci(500) // 堆栈溢出

function Fibonacci2 (n , ac1 = 1 , ac2 = 1) {
 if( n <= 1 ) {return ac2};

 return Fibonacci2 (n - 1, ac2, ac1 + ac2);
}

Fibonacci2(100) // 573147844013817200000
Fibonacci2(1000) // 7.0330367711422765e+208
Fibonacci2(10000) // Infinity

function currying(fn, n) {
return function(m) {
return fn.call(this, m, n)
}
}