Use typing-extensions only on Python < 3.8

[mgorny]

All necessary attributes are available in the built-in typing module
since Python 3.8. Use typing-extensions only for older versions
of Python, and avoid the unnecessary dep in 3.8+.

[Byron]

Thanks a lot!

Do you think that it would be possible to use git.compat.typing instead to avoid repeating the logic everywhere where typing is used? I don't know if re-exporting entire modules is possible.

[muggenhor]

I think you meant git.types instead of git.compat.typing? The latter doesn't exist...

[Byron]

I think this was a clumsy way of asking if there is a less redundant way of specifying the imports. In git.compat types are re-exported based on some logic, so code could rely on importing git.compat.typing alone without repeating any logic.

[muggenhor]

Ah, like this?

# git/compat.py:ifsys.version_info[:2] >= (3, 8):
importtypingelse:
importtyping_extensionsastyping# elsewhere:from .compatimporttyping

Unfortunately that has the annoying side effect of not being able to do from git.compat.typing import Literal because git.compat.typing wouldn't be a package/module.

[mgorny]

@Byron, something like this? Or do you mean entirely replacing from typing ... with from git.compat.typing ...?

[Byron]

Thank you very much for this contribution, this looks good to me, and I assume @muggenhor saw nothing that would prevent a merge either.

[mgorny]

Thanks! We're removing Python 3.7 support real soon from Gentoo, and so we're going to be one step closer to eliminating typing-extensions as well ;-).

[muggenhor]

Thank you very much for this contribution, this looks good to me, and I assume @muggenhor saw nothing that would prevent a merge either.

Nope, didn't see any obstacles. It looks good!