// Lex found this (object Stream.cons is new, but currently does not work due to)
// library has now
// Stream { ... object cons { ... apply,unapply ... }}

object StreamFoo extends TestCase("unapply for Streams") with Assert {

  def sum(stream: Stream[int]): int =
    stream match {
      case Stream.empty => 0
      case Stream.cons(hd, tl) => hd + sum(tl)
    }
  val str: Stream[int] = Stream.fromIterator(List(1,2,3).elements)
  assertEquals(sum(str), 6)
  
}