Sieve of Eratosthenes

sieveAll.js

// all primes

const sieve = function * () {
    const C = {}
    let q = 2
    while (true) {
        if (C [q]) {
            C [q] .forEach (n => C [n + q] = [... (C [n + q] || []), n]  )
            delete C[q]
        } else {
            C [q * q] = [q]
            yield q
        }
        q += 1
    }
};

sieveBetween.js

// primes between `lo` (inclusive) and `hi` (inclusive)

const sieve = function * (lo, hi) {
    const C = {}
    let q = 2
    while (q <= hi) {
        if (C [q]) {
            C [q] .forEach (n => C [n + q] = [... (C [n + q] || []), n]  )
            delete C[q]
        } else {
            C [q * q] = [q]
            if (q >= lo) {
              yield q
            }
        }
        q += 1
    }
};

sieveUpTo.js

// primes up to `hi` (inclusive)

const sieve = function * (hi) {
    const C = {}
    let q = 2
    while (q <= hi) {
        if (C [q]) {
            C [q] .forEach (n => C [n + q] = [... (C [n + q] || []), n]  )
            delete C[q]
        } else {
            C [q * q] = [q]
            yield q
        }
        q += 1
    }
};