Asynchronous functions be like: We'll call you back.
Me: Promise?

in c# i can just leave an astral instance of myself standing inside, watching the function, waiting for it to continue, while my actual self hops one callstack level up and does whatever it wants/needs to do in the meantime.

no need for promises if the function will yield under my watchful stare, sooner or later.

p. s. how incredibly weird the word yield. i've tried three spellings and none of them looks right while any of them might be =D

Reactor Java be like:

Hold my Mono while I come.