js-generators

function * Numbers () {
    let number = 0;
    while (true) {
        yield ++number;
    }
}

function * take (numberToTake, iterable) {
    const iterator = iterable[Symbol.iterator]();

    for (let i = 0; i < numberToTake; ++i) {
        const { done, value } = iterator.next();
        if (!done) yield value;
    }
}

for (let n of take(100, Numbers())) {console.log(""+n)}