Tail Recursive Fibonacci

fibTailRec.scala

def fib(n: Int): Int = {
  @tailrec
  def recFib(a: Int, b: Int, i: Int): Int = i match {
    case 0 => a
    case _ => recFib(b, a + b, i - 1)
  }
  recFib(0, 1, n)
}