Learning about futures

Last but not least, we can find goodies in the PPL, which are futures. A future can be defined as a value that we already know we'll need in the future. The key point is getting (calculating, building, retrieving, and so on) a value that is expensive in terms of computation resources (CPU, time, network, and so on), and that we don't want to affect the main/UI thread with this burden. 

The following code shows the implementation of a future:

var
  LFuture: IFuture<Integer>;
begin
  LFuture := TTask.Future<Integer>(
    function : Integer
    begin
      Sleep(5000); // Do something...
      Result := 42;
    end
  );

  ShowMessage(LFuture.Value.ToString);
end;

The previous code example shows how a future is defined. Basically, we provide a builder function that is capable of returning our value and we wrap this function in a task.

The future implementation relies on another modern language feature—generics. We are trying...