<@U3D2DCKQT> Suspend function invocations are much...

# coroutines

[elizarov]

@pniederw Suspend function invocations are much more light-weight than futures. You pay the cost of state-machine when you have suspending invocations in non-tail positions of your code. But that is something you have to pay this cost in some form anyway. Now, if your function returns a future, you pay an extra cost of a future object on top of that.