Temporal

Temporal extends Concurrent with the ability to suspend a fiber by sleeping for a specified duration.

firstThing >> Temporal[F].sleep(5.seconds) >> secondThing

Of course this could be achieved by Sync[F].delay(Thread.sleep(duration)) but this is a very bad idea as it will block a thread from the compute pool (see the thread model docs for more details on why this is bad). Instead, Temporal[F]#sleep is assigned its own typeclass and is a primitive of the implementation that semantically blocks the execution of the calling fiber by de-scheduling it. Internally a scheduler is used to wait for the specified duration before rescheduling the fiber.

The ability to sleep for a specified duration enables us to define powerful time-dependent derived combinators like timeoutTo:

val data = fetchFromRemoteService.timeoutTo(2.seconds, cachedValue)