Paranoia

Java.java

List<String> list = Arrays.asList("a", "b", "c", "d");
match(list)
    .when(nil()).then(() -> System.out.println("Empty List"))
    .when(headNil(eq("b"))).then(() -> System.out.println("Singleton List of 'b'"))
    .when(headNil(any())).then(head -> System.out.println("Singleton List of " + head))
    .when(headTail(any(), any())).then(
        (head, tail) -> System.out.println("head: " + head + " Remaining: " + tail))
    .doMatch();

Scala.scala

val list = List("a", "b", "c", "d")

list match {
  case Nil => println("Empty List")
  case List("b") => println("Singleton List of 'b'")
  case List(head) => println("Singleton List of " + head)
  case head :: tail => println("head: " + head + " Remaining: " + tail)
}