Selection sort in scala. Purely functional implementation with iterative behavior and using persistent collections.

gistfile1.scala

  def selectionSort[T <% Ordered[T]](seq: Seq[T]): Seq[T] = {
    def pickMax(seq: Seq[T]): (T, Seq[T]) = 
      seq.tail.foldRight((seq.head, Seq.empty[T])) {
        case (next, (max, passed)) =>
          if (next > max) 
            (next, max +: passed) 
          else 
            (max, next +: passed)
      }

    Iterator.iterate((Seq.empty[T], seq)) { case (sorted, seq) =>
      val (max, rest) = pickMax(seq)
      (max +: sorted, rest)
    } dropWhile { case (_, seq) => !seq.isEmpty } next() _1
  }