Well, there is we have in the whatwg spec step that says following thing:
Let taskQueue be one of the event loop's task queues, chosen in an implementation-defined manner, with the constraint that the chosen task queue must contain at least one runnable task. If there is no such task queue, then jump to the microtasks step below.
If whatwg doesn't define concrete order of queues, I'd like to know by what criteria implementors run? How do they evaluate importantness of queues? And in the end I'd like to see example that shows order these queues, if it possible.
