parallel collectionを使う。 http://docs.scala-lang.org/ja/overviews/parallel-collections/overview.html scala> val l = List(1,2,3,4,5,6,7,8,9,10) l: List[Int] = List(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)scala> l.par.foreach(i => println(s"[${Threa…

scala.util.Randomを使う。 scala> scala.util.Random.shuffle(List(1,2,3,4,5)) res0: List[Int] = List(3, 5, 4, 2, 1)scala> scala.util.Random.shuffle(List(1,2,3,4,5)) res1: List[Int] = List(5, 4, 1, 2, 3)