gistfile1.txt

def loopOver(xs: List[Int]) = {
  val vs = xs.toStream
  
  def loop(rem:Int):Stream[Stream[Int]] = rem match {
    case 0 => for(v <- vs) yield Stream(v)
    case n => for(head <- vs; tails <- loop(n-1)) yield head #:: tails
  }
  for(i <- Stream.from(0); items <- loop(i)) yield items
}