continuation try 1

[pereman2]

This is a draft of how an architecture of callbacks would look like instead of a state machine. I tried with next first because it's easier.

This approach seems to be hard to get right because rust forces so many borrowing rules that I just don't care about, you will notice how much I despise it in op_next, where I unsafely cast to pointers knowingly the lifetimes are okay and I just don't want to create more bullshit Rcs