Chapter 8: Diving Deeper into Futures
In the second chapter I walked you through some code that used futures, but I didn't spend much time on them. I'd like to develop the idea a bit further here and show you how they can be used effectively to interact with actors and to sequence operations (or, computations, speaking more formally).
Clarifying our definition
Earlier I defined futures very generally, but let's be a bit more specific. A future represents the value of some expression or computation that may not have yet completed or which is not yet known. This mechanism was first proposed as a model for obtaining the result of parallel evaluation of expressions in a programming language.
As you saw earlier, futures are useful when you need to ...