When functions dissolve (2020) (rubber-duck-typing.com)

Nice clear description of tail call optimisation. The coroutine section seemed too brief to me. Is it accurate to say that a coroutine is just a subroutine with multiple entry points and possibly some state? I thought a coroutine needed at least enough state to resume where it left off, but resumption was not mentioned.

Enforcing modularity at a component level could be a thing ...