def time[R](name: String)(block: => R): R = {
  val t0 = System.currentTimeMillis()
  val result = block
  val t1 = System.currentTimeMillis()
  println(s" $name time: " + (t1 - t0) + "ns")
  result
}

val Times = 1000000

case object dummy{
  val data = List.fill(10000)("aaa")
}

case object data {
  val dlist = List.fill(Times)(dummy)
}

val reverseTime = time("reverseTime") { 1 to 1000 foreach { _ =>
  data.dlist.reverse.head
  }
}
val lastTime = time("lastTime") { 1 to 1000 foreach { _ =>
    data.dlist.last
  }
}