Provide *pyi files

[ferrine]

As in numpy https://github.com/numpy/numpy/blob/297c66131f2a32ebb7dfb0aeb9d88d917a791430/numpy/lib/arraysetops.pyi#L110
There is a plenty of stuff that could be improved for mypy. Multiple signatures and return types, clever type hints and introspection. We don't do that so far

[ferrine]

@michaelosthege

[michaelosthege]

I think this should be covered by our py.typed file: e464e50

At least that's how I understood https://peps.python.org/pep-0561/#packaging-type-information

The presence of the py.typed file, and our existing inline type annotations should be all we need.

[michaelosthege]

Maybe the .pyi stubs support more than what we currently have? But maintaining them separate from the inline annotations sounds very cumbersome..

For the @overload example you linked, we can also fix this on the .py side by writing two functions (one having an @overload decorator).