Random Stuff in Scala

RandomFun.scala

def swap (x : Int; y : Int) = {
   var a = x; var b =y;
   a= a -b; b= b+a; a= b -a;
}


def fibonacci(n : Int) = recursiveFib(n, 1, 0)

def recursiveFib ( n : Int, next : Int, result : Int) : Int = {
               n match {
                  case 0 => result
                  case _ => recursiveFib( n-1, next + result, next)
                }
}

def streamFibonacci (n : Int) = nextFib(1,1).take(n).last

def nextFib(x: Int, y: Int): Stream[Int] = {
    x #:: nextFib(y, x+y)
  }
  
//#############Prime numbers and print the first 1000 ###########################
def isPrime = (2 until (math.sqrt(n).floor.toInt + 1)) forall (n % _ != 0)

(1 until 1000) filter(isPrime) foreach println