quicksort.scala

#!/bin/sh
exec scala "$0" "$@"
!#

def quicksort(l: List[Int]): List[Int] = {
    l match {
        case Nil         => Nil
        case List(a, _*) => quicksort(l.tail.filter(_ < a)) ::: a :: quicksort(l.tail.filter(_ >= a))
    }
}

println(quicksort(List(10, 6, 9, 3, 5, 11, 20, 2)).mkString(" "))