Factor

1 files changed, 42 insertions, 0 deletions

diff --git a/html/toys/godel/js/godel-worker.js b/html/toys/godel/js/godel-worker.js
new file mode 100644
index 0000000..1ba9da4
--- /dev/null
+++ b/html/toys/godel/js/godel-worker.js
@@ -0,0 +1,42 @@
+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());
+});