Adding type stubs

[sbdchd]

In the course of using msgpack in a project I've written some basic type stubs for the parts of the API I'm using.
I don't think it would be too hard to fill out the type stubs for the rest of the API.

Would you accept a PR adding stub files to the package?
Not sure if you have a preference on adding the types to the code itself or keeping them as separate stub files.

related: https://www.python.org/dev/peps/pep-0561/

[methane]

Would you accept a PR adding stub files to the package?

I expect it will be very complex types and very low benefit for users, because msgpack can pack/unpack various types. I don't want to maintain it.

But if it is simple and very useful, I will consider it.

[methane]

See #404.

[sbdchd]

I ended up creating a separate type stub package: https://github.com/sbdchd/msgpack-types

If you aren't interested in have the types in the package itself, would you be okay with me adding them to the type shed?

https://github.com/python/typeshed/

[jfolz]

Well, I know for a fact that this is incorrect. Unpacking methods accept any object that implements the buffer protocol, so next to bytes there's also bytearray, array, memoryview, numpy.ndarray, etc. There is a long-standing issue to add the ability to describe things as "buffer-like". It's an open issue, because buffers are very variable (writeable or not, data types, contiguous or non-contiguous, strided) and you need to describe them pretty accurately so your type annotation is actually useful.

[rodrigogiraoserrao]

It's been almost 2 years but a comment on the linked issue says PEP 688 is here to save the day.
Was that the thing that we needed to unblock this?

[jfolz]

Well, for one a PEP needs to be accepted and implemented first to make a difference. As of now it's just a draft.

[rodrigogiraoserrao]

Ugh, sorry. Got so carried away by it that I didn't even check the PEP status.

[jfolz]

Good news is that PEP 688 has been accepted. Bad news is that it'll be available in Python 3.12 at the earliest. Any earlier version would need a backport.

[clokep]

Good news is that PEP 688 has been accepted. Bad news is that it'll be available in Python 3.12 at the earliest. Any earlier version would need a backport.

typing-extensions now supports Buffer in the latest release, this is a common way to backport new typing PEPs to projects.

[rexzhang]

Would you accept a PR adding stub files to the package?

I expect it will be very complex types and very low benefit for users, because msgpack can pack/unpack various types. I don't want to maintain it.

But if it is simple and very useful, I will consider it.

The return value of msgpack.packb is bytes, which can reduce many warnings if it is type-annotated.