Please don't actually do this. It completely violates all expectations of how both user-facing web servers and REST endpoints are supposed to behave.
The stateless nature of web programming is always frustrating, but attempts to use continuations to pretend a sequence of http requests can be treated as a single linear thread of execution simply don't work.
It is one thing to say that a protocol is designed to be stateless, it is quite another to say a particular programming technique is so. If anything, functional programming leads to programming style that concerns less with how a particular state leads to another, and more with what transitions we want to make.
One is retries on failure or timeout. The other is waiting for something to execute a certain number of times. The latter is something I've used only in tests, but it might have other uses I'm not thinking of. I've implemented both of these in the past with recursion, which is great, but scares some folks, esp when mixed with promises.
With regards to your first comment, I'm actually considering porting some of the logics to rxjs or other reactive extensions.
EDIT: After posting this I just found out the library isn't compatible with the latest node release (6.5.0; still works well with 6.4.0). Will work with nodejs to see how we can address the problem.
