xrudelis

It looks to me like the goals with typing.Protocol are for static type checking. Whereas this module is intended both for interfaces (much like ABCs) and implementation re-use (see Rust's "blanket implementations"). These Traits could definitely be used in type annotation, and maybe there's a way to use typing.Protocol with them to aid static type checking in Python. I haven't tried static type checking in Python yet, but it sounds promising!

I think these are all equally good. The Impl's name should never need to be referred to, so ultimately the choice should be based on what's easiest to read.

EDIT: actually, your examples wouldn't work as-is, since it would result in circular references (something Python isn't well-equipped to handle). Your target names would need to be strings instead of the actual class.

EDIT2: I have updated the code to allow for another syntax:

    class AnyImplNameIWant(MyTrait, metaclass=Impl, target="MyStruct"):
        ...

It would certainly be nicer if `MyStruct` didn't need to be a string of course. I really think these options are mostly down to taste, so I'll just have to trust that this alternative reads sufficiently more nicely.

That's right. The reason for this is that it's a lot of boilerplate if you were to require listing every relevant Impl block as a superclass of your struct. I also, as a bonus, like enforcing a consistent class naming style.

This is an idea I had while thinking about how flexible Python inheritance is. I decided to turn it into a weekend project, and now it is my first open-source package. I hope someone finds it useful!