T.scala

object L {
  def main(args: Array[String]): Unit = {
    val oneToTenList = (1 to 10).toList
    val oneList = List(1)

    assert("none" == checker(11)(oneToTenList))
    assert("end of 10" == checker(10)(oneToTenList))
    assert("contains 9" == checker(9)(oneToTenList))
    assert("start with 1" == checker(1)(oneToTenList))

    assert("none" == checker(0)(oneList))
    assert("start or end of 1" == checker(1)(oneList))

    assert("none" == checker(1)(Nil))
  }

  def checker(item: Int): List[Int] => String = {
    case Nil => "none"
    case h :: Nil if h equals item => s"start or end of $item"
    case h :: _ if h equals item  => s"start with $item"
    case _ :: rest => contain(item)(rest)
  }

  def contain(item: Int): List[Int] => String = {
    case Nil => "none"
    case h :: Nil if h.equals(item) => s"end of $item"
    case h :: rest => if (h.equals(item)) s"contains $item" else contain(item)(rest)
  }

}