柯里化-多参数合成一个参数

function currying(fn, n) {  return function (m) {    return fn.call(this, m, n);  };}function tailFactorial(n, total) {  if (n === 1) return total;  return tailFactorial(n - 1, n * total);}const factorial = currying(tailFactorial, 1);factorial(5) // 120