Simple Kipper program to check if a number is prime

is-prime.kip

def isPrime(n: num) -> bool {
  if (n <= 1) {
    return false; // Never a prime
  } else if (n == 2 || n == 3) {
    return true; // Base primes
  } else if (n % 2 == 0 || n % 3 == 0) {
    return false; // Easy base prime checks
	}

  for (var i: num = 5; i * i <= n; i += 6) {
    if (n % i == 0 || n % (i + 2) == 0) {
      return false;
    }
  }
  return true;
}

var numToCheck: num = 7; // is prime
print(f"{numToCheck} - isPrime: {isPrime(numToCheck)}");

numToCheck = 9; // is not prime
print(f"{numToCheck} - isPrime: {isPrime(numToCheck)}");

numToCheck = 97; // is prime
print(f"{numToCheck} - isPrime: {isPrime(numToCheck)}");