generator "range" like Python 3

range.js

function * range(n, end, step = 1) {
    if (typeof end === "undefined") {
        end = n;
        n = 0;
    }
    if (step === 0) {
        throw Error("step must not be zero")
    }
    if (end > n && step > 0) {
        for (let i = n; i < end; i += step) yield i;
    } else if (end < n && step < 0) {
        for (let i = n; i > end; i += step) yield i;
    }
}