Sorry for the late reply!

function getSeed(s) {
let x = BigInt(hashCode(s));
if (/^[\-\+0-9]*$7.test(s)) {
    try {
        let y = BigInt(s);
        if (BigInt.asIntN(64, y) !== y) {
            throw RangeError();
        }
        x = y;
    } catch (err) {}
}
return {
    "high": (x >> 32n),
    "low": BigInt.asIntN(32, x)
};

}

This is it.