Use ao_interval(ms=1000) to create an ao_fence generator from a setInterval timer.
Use ao_timeout(ms=1000) to create an ao_fence generator from successive setTimeout timers.
Use ao_debounce(ms=300, gen_in) to create an ao_fence generator from input gen_in debounced with setTimeout.
async * ao_times(gen_in) asynchronously iterates over gen_in and yields time elapsed.