Question

My code is as follows

  val hash = new HashMap[String, List[Any]]
  hash.put("test", List(1, true, 3))
  val result = hash.get("test")
  result match {
    case List(Int, Boolean, Int) => println("found")
    case _ => println("not found")
  }

I would expect “found” to be printed but “not found” is printed. I’m trying to match on any List that has three elements of type Int, Boolean, Int

Answer 1

You are checking for a list containing the companion objects Int and Boolean. These are not the same as the classes Int and Boolean.

Use a Typed Pattern instead.

val result: Option[List[Any]] = ...
result match {
  case Some(List(_: Int, _: Boolean, _: Int)) => println("found")
  case _                                      => println("not found")
}

Scala Reference, Section 8.1 describes the different patterns you can use.