Yes, I agree, but it's not what the OP does, also, mostly often, co-routines gets conflated with cooperative threads/scheduling. For some color to your other p

Yes, I agree, but it's not what the OP does, also, mostly often, co-routines gets conflated with cooperative threads/scheduling. For some color to your other points: the previous version was actually using continuation passing style which worked and was very fast (faster than coroutines), but challenging to understand without a good background in FP and FP implementations.