src/toys/godel/js/godel-worker.js


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const isPrime = (n) => {
  if (n < 2) {
    return false;
  }
  if (n === 2) {
    return true;
  }
  if (n % 2 === 0) {
    return false;
  }
  const limit = Math.floor(Math.sqrt(n));
  for (let i = 3; i <= limit; i += 2) {
    if (n % i === 0) {
      return false;
    }
  }
  return true;
};

const primes = [2];
const primeAt = (index) => {
  while (primes.length < index) {
    let candidate = primes[primes.length - 1] + 1;
    while (!isPrime(candidate)) {
      candidate += 1;
    }
    primes.push(candidate);
  }
  return primes[index - 1];
};

const computeGodelNumber = (sequence) => {
  return sequence.reduce((acc, exponent, idx) => {
    const prime = BigInt(primeAt(idx + 1));
    return acc * prime ** BigInt(exponent);
  }, BigInt(1)) - BigInt(1);
};

self.addEventListener("message", (event) => {
  const result = computeGodelNumber(event.data);
  self.postMessage(result.toString());
});