How to implement state machine for Async operations?

[makeevvd]

Either gives us an option to process Error state and Success state, but for frontend rendering I need also a pending state of asynchronous functions. What is the best way (monad) to implement a state machine, which will give us Error, Pending and Success state, so I can fold 3 values, depending on whether my computation is in the progress, resolved or rejected.

[samhh]

RemoteData

[0x706b]

Or Datum (includes a Reloading state)