Primes.ts

/**
 * Prime number generator
 */
const Primes = function*(upto: number = Infinity) {
  const primesList: number[] = [];
  for (let current = 2; current < upto; current++) {
    const hasPrimeFactor = Boolean(primesList.find(prime => current % prime === 0));
    if (hasPrimeFactor) {
      continue;
    } else {
      primesList.push(current);
      yield current;
    }
  }
};

// Example: log the first 1000000 primes
for (const prime of Primes(1000000)) {
  console.log(prime);
}