Switch on several values

[Tagir Valeev]

On Wed, Sep 27, 2023 at 4:18 PM Brian Goetz <brian.goetz at oracle.com> wrote:
> As an example of a "the simple cases are very pretty", I give you a world-class FizzBuzz:
>
>     Function<Integer, String> fizzbuzz =
>         x -> switch (x % 3, x % 5) {
>                  case (0, 0) -> "FizzBuzz";
>                  case (0, _) -> "Fizz";
>                  case (_, 0) -> "Buzz";
>                  default -> Integer.toString(x);
>              };

This is basically a syntactic sugar for an unnamed tuple. I think,
Java is not going to the unnamed tuples direction, as we have named
ones (records). So it should be enough. We just need constant
patterns:

record Rems(int by3, int by5) {}
Function<Integer, String> fizzbuzz =
         x -> switch (new Rems(x % 3, x % 5)) {
                  case Rems(0, 0) -> "FizzBuzz";
                  case Rems(0, _) -> "Fizz";
                  case Rems(_, 0) -> "Buzz";
                  default -> Integer.toString(x);
              };

In future, with custom matchers, we'll be able to do it even better.

With best regards,
Tagir Valeev.