Write Java that's clean, fast and built to last.

// Modern Java: records, sealed types, pattern matching
sealed interface Shape permits Circle, Square {}
record Circle(double r) implements Shape {}
record Square(double side) implements Shape {}

double area(Shape s) {
  return switch (s) {
    case Circle(var r)    -> Math.PI * r * r;
    case Square(var side) -> side * side;
  };
}

void main() {
  try (var ex = Executors.newVirtualThreadPerTaskExecutor()) {
    ex.submit(() -> IO.println("Hello from Shaun ☕"));
  }
}