Thanks for the encouragement!
I've been working some more on it since I had some more free cycles in the last few days and I think I've got to the limit of my capabilities. I think I've got it to a point where it needs more eyes because my experience level writing code in the python interpreter is pretty low, so I know that I have holes in there, especially around using INCREF/DECREF. I'm currently stuck on 3 things:
1. repr( pickle.loads( pickle.dumps(int | str) ) ) causes an infinite recursion that I can't figure out. I might end up re-specializing `repr()` again since it isn't defined in the PEP.
2. - `None | "forwardref"` and `None | None` - `"forwardref" | None` and `"forwardRefA" | "forwardRefB"` I've had a go at adding a `type.__ror__` as suggested by GvR, but I think I'm missing something.
3. type parameters - I'm not sure how to handle this: ``` MaybeT = None | "T" # creates shadow union T = TypeVar('T') maybe_int = MaybeT[int] # should this stay in shadow land, or go back to typing.py isinstance(1, maybe_int) isinstance(1, MaybeT[int]) ``` I have a couple options for this: - implement the type substitution in c; which can be done, but feels like overkill? - store the type parameters on the shadow object and vivify when needed (which will end up being in the isinstance call) - implement the __getitem__ as a call into the typing.py library and promote as it's requested. This is how I've currently implemented it.
I'm happy to keep going on this if/when needed,