Timers (`forever`!)

Goals:

forever sets up a recurring timer that by default executes a callback 30 times per second. Set the timer to fire more or less frequently by specifying the optional first argument.
forever returns a unique id for each timer
Remove a timer from within its callback by calling stop(). Outside of its own callback, remove a timer by passing its ID as the argument to stop.

forever is a Pencil Code function that facilitates executing a callback repeatedly at fixed intervals. It is an alternative to setting up a timing event using the built-in JavaScript function setInterval.
Remove a timer created with forever using the stop method. From within a timer's callback, stop() (with no arguments) references that timer. Outside of the callback, stop() removes all timers. stop(x) removes a timer with an ID referenced by x.

When working with forever loops, it is often advantageous to work with frame-based animation. Call speed Infinity at the beginning of your script, and no longer worry about animation queues! The tradeoff is that you have to code the animation logic yourself.

Save each of the following in a folder called Forever.

PermaPerfectFit: place calls to sizexy inside the callback to forever, and use these values to constantly display a circle that always fits inside the window perfectly (i.e., centered at the origin with diameter equal to the smaller of the page width or height).
ConfettiCount: use forever to perpetually draw dots on the screen in random positions. Use a label to display the number of dots, updating it using techniques described in Label Recycling!
Code a new RandomTurtles program that uses frame-based animation and timers so that it repeats indefinitely. As an added challenge, avoid explicit use of for loops; rather, use hatch to create your sprites and the each method to iterate over that collection.
Code a program that displays two different AnalogClocks, displayed side-by-side. They should both have second hands that move in discrete units (i.e., ticking away once per second). For the first clock, set the time initially with a call to Date, then update it using a timer that fires once per second. For the second clock, use a timer that fires more frequently, and re-set the clock each time based on a new call to Date. (Why is the second version the better approach?)