scalaステップ24-抽出器とモードマッチング

/**
  *      (   )
  *      unapply    
  *           ,              (      )
  */
object :> {
  def unapply[A](list: List[A]) = {
    Some((list.init, list.last))//init            
  }
}

object Extractor_Advanced {
  def main(args: Array[String]): Unit = {
    //  :        ,last 9
    (1 to 9).toList match { case _ :> 9 => println("Hadoop") }
    (1 to 9).toList match { case _ :> 8 :> 9 => println("Spark")} //   
    (1 to 9).toList match { case :>(:>(_, 8), 9) => println("Flink")}
  }
}