object Tails {
  // Finds all 'tails' of a list
  def tails[A](xs: List[A]): List[List[A]] = xs match {
    case Nil => Nil :: Nil
    // The as-pattern is denoted here using @
    // <identifier> @ <expression> reads 'identifier as expression'
    // so this case match reads 'xxs as _ :: xs'
    case (xxs @ _ :: xs) => xxs :: tails(xs)
  }
 
  def main(args: Array[String]) = {
    // List(List(1, 2, 3, 4, 5), List(2, 3, 4, 5), List(3, 4, 5), List(4, 5), List(5), List())
    println(tails(List(1, 2, 3, 4, 5)))
  }
}