sieveOddPrimesTo.ts

function sieveOddPrimesTo(bufferLimit: number) {
    const lmti = (bufferLimit - 3) >> 1;
    const sz = (lmti >> 3) + 1;
    const cmpSts = new Uint8Array(sz);
    for (let i = 0; ; ++i) {
        const p = i + i + 3;
        const sqri = (i << 1) * (i + 3) + 3;
        if (sqri > lmti) {
            break;
        }
        if ((cmpSts[i >> 3] & ((1 >>> 0) << (i & 7))) == 0 >>> 0) {
            for (let c = sqri; c <= lmti; c += p) {
                cmpSts[c >> 3] |= (1 >>> 0) << (c & 7);
            }
        }
    }
    let bi = -1;
    return function () {
        if (bi < 0) {
            ++bi;
        }
        while (bi <= lmti && (cmpSts[bi >> 3] & ((1 >>> 0) << (bi & 7))) != 0 >>> 0) {
            ++bi;
        }
        if (bi > lmti) {
            // this can only happen when the number of pre-generated primes
            // matches the number of requested primes exactly.
            return null;
        }
        return (bi++ << 1) + 3;
    };
}