> async red/blue functions That "problem" is completely overblown and comes up all the time anyway in other contexts. Other programming languages have a distinction between "pure" functions and impure ones, some environments have the notion of "save to call in a signal handler".
You can call an async proc from a sync proc and you can call a sync proc from an async proc. Yes, it might be "blocking", omg, so what, at least you are not worse off than with the strictly sequential programming model. The real problem here is the complexity of modelling concurrency in the `async` mindset where the event loop is hidden from you but not well enough so that concurrency bugs can easily creep into your code. This has nothing to do with "red/blue" functions.
