How do I make a function involving futures tail recursive?

Question

In my Scala app, I have a function that calls a function which returns a result of type Future[T]. I need to pass the mapped result in my recursive function call. I want t

Answer 1

Make factorialAcc return an Int and only wrap it in a future in the factorial function.

def factorial(n: Int): Future[Int] = {

    @tailrec
    def factorialAcc(acc: Int, n: Int): Int = {
      if (n <= 1) {
        acc
      } else {
        factorialAcc(n*acc,n-1)
      }
    }

    future {
      factorialAcc(1, n)
    }
}

should probably work.