TryableDeferred

Obtains the current value of the Deferred, or None if it hasn't completed.

If this Deferred is empty, sets the current value to a, and notifies any and all readers currently blocked on a get.

Note that the returned action may complete after the reference has been successfully set: use F.start(r.complete) if you want asynchronous behaviour.

If this Deferred has already been completed, the returned action immediately fails with an IllegalStateException. In the uncommon scenario where this behavior is problematic, you can handle failure explicitly using attempt or any other ApplicativeError/MonadError combinator on the returned action.

Satisfies: Deferred[F, A].flatMap(r => r.complete(a) *> r.get) == a.pure[F]

Obtains the value of the Deferred, or waits until it has been completed. The returned value may be canceled.

Modify the context F using transformation f.