Demonstration of dataflow.

Are you interested in this? An implementation of dataflow, on top of your existing futures.

At the moment I've just done a demo. The documentation shows how it's derived, and then the implementation is also in the library. There isn't full documentation, specs, or any error handling yet, but if you're interested I will complete those to the same high standards as you've done for the other constructs.

Dataflow is more about parallelism than concurrency, I know, but I think it still fits.