gistfile1.txt

// Not-very-compliant polyfill for setTimeout, based on Promise.

// When this array becomes non-empty, call scheduleWork.
let timeouts = [];

// Fake clock used to order timeouts.
let now = 0;

// Least positive integer not yet used as a timer id.
let next_id = 1;

// Add an active timer record to timeouts.
function enqueue(id, t, cb) {
    if (typeof cb !== 'function') {
	let code = "" + cb;
	cb = () => eval(code);
    }
    t += now;
    timeouts.push({id, t, cb});
    timeouts.sort((a, b) => a.t - b.t);
    if (timeouts.length === 1) {
	scheduleWork();
    }
}

// Register a microtask to make sure timers are actually processed. There
// should be at most one of these microtasks pending at a time.
function scheduleWork() {
    // Number of times to let the microtask queue spin before running a
    // timeout. The idea is to let all Promises resolve between consecutive
    // timer callbacks. Of course, this is a hack; whatever number is used
    // here, an async function can simply await that many times plus one to
    // observe that timeouts are being handled as microtasks, not events.
    let delay = 10;

    function handleTimeouts() {
	if (--delay > 0) {
            Promise.resolve().then(handleTimeouts);
            return;
	}
	if (timeouts.length > 0) {
            let {t, cb} = timeouts.shift();
            if (now < t) {
		now = t;
            }
            if (timeouts.length > 0) {
		scheduleWork();  // There's more to do after this.
            }
            cb();
	}
    }
    Promise.resolve().then(handleTimeouts);
}

this.fakeSetInterval = function (cb, t, ...args) {
    let id = next_id++;
    let func = () => {
	enqueue(id, t, func);
	cb(...args);
    };
    enqueue(id, t, func);
    return id;
};


var intensity = 1;
var Color3 = function(r) {
  this.r = r;
};
Color3.prototype.scale = function(t) {
  this.r = this.r * t;
};
var groundColor = new Color3(0);

fakeSetInterval(function() {
  groundColor.scale(intensity);
}, 0);