Three Dollar Quill

I know there are some typos in the code from last post, but the bigger issue is that typing descriptors is... frustrating, and I ended up going with a solution that was just simple enough that Mypy couldn't totally biff it:

class Failing(Protocol):
    @classmethod
    def failure(cls) -> Self: ...


def coerce[T: Failing](
    cls: type[T], bundle: Bundle[Any]
) -> Constraints[Bundle[T]]:
    obj = bundle.data
    if isinstance(obj, cls):
        return Bundle(obj, bundle.metadata)
    yield from ()
    return bundle.extend(lambda _: cls.failure(), CoercionFailure())

With this, I have what I need to be confident updating the rest of the nodes. I think.

Anyway, it's late and I'm tired.

Good night.