函數式編程概念:柯里化(currying)

//函數式編程概念:柯里化(currying):將多參數的函數轉爲單參數的形式
           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)
           console.log(factorial(5));//120