Motif

IntStream.range(0, 101).forEach(
    n -> System.out.println(
        match(Tuple2.of(n % 3, n % 5))
            .when(tuple2(eq(0), eq(0))).get(() -> "FizzBuzz")
            .when(tuple2(eq(0), any())).get(y -> "Fizz")
            .when(tuple2(any(), eq(0))).get(x -> "Buzz")
            .orElse(String.valueOf(n))
            .getMatch()
    )
);

Optional<Person> personOpt = getPerson();
match(personOpt)
    .when(some(any())).then(person -> doStuff(person))
    .when(none()).then(() -> System.out.println("Person not found"))
    .doMatch();

public long factorial(long i) {
  return match(i)
      .when(eq(0)).get(() -> 1l)
      .when(any()).get(x -> x * factorial(x - 1))
      .getMatch();
}

Optional<Tuple2<String, String>> opt = Optional.of(Tuple2.of("first", "second"));
match(opt)
    .when(some(tuple2(eq("third"), any()))).then(b -> doStuff(b))
    .when(some(tuple2(any(), eq("second")))).then(a -> doStuff(a))
    .when(none()).then(() -> System.out.println("Tuple not found"))
    .doMatch();

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();