FizzBuzz demonstrating JDK 21 LTS features

FizzBuzz

#!/usr/bin/env -S java --source 21 --enable-preview

/*
	FizzBuzz demonstrating JDK 21 LTS features
*/

import java.util.Map;
import java.util.Map.Entry;
import java.util.stream.IntStream;

class FizzBuzz {
    static final String FIZZ = "fizz";
    static final String BUZZ = "buzz";

    //  String template
    static final String FIZZBUZZ = STR."\{FIZZ}\{BUZZ}";

    static final int N = 3;
    static final int M = 5;

    static final int LIMIT = 64;

    static boolean divisibleBy(final int n, final int d) {
        return n % d == 0;
    }

    public static void main(final String args[]) {
        //  Switch expression
        final Integer limit = switch(args) {
            case String[] a when a.length > 0 -> Integer.parseInt(a[0]);
            default -> LIMIT;
        };

        IntStream.range(1, limit).forEach(n -> {
            final Map.Entry<Boolean, Boolean> pair = Map.entry(
                divisibleBy(n, N), 
                divisibleBy(n, M)
            );

            // Switch expression
            final String result = switch(pair) {
                case Map.Entry<Boolean, Boolean> e when e.getKey() && !e.getValue() -> FIZZ;
                case Map.Entry<Boolean, Boolean> e when !e.getKey() && e.getValue() -> BUZZ;
                case Map.Entry<Boolean, Boolean> e when e.getKey() && e.getValue() -> FIZZBUZZ;
                default -> String.valueOf(n);
            };

            System.out.println(result);
        });
    }
}

// vi:syntax=java