Add type hints / annotations to `array_namespace()`: `array_api_strict` as return type?

[34j]

Without type hints, it is very inconvenient because of spelling errors of array_api functions. As array_api_compat seems to be a superset of array_api_strict, I would like to propose to simply set the return type of array_namespace() to array_api_strict, although it might be confusing.

array-api-compat/array_api_compat/common/_helpers.py

Line 424 in c5ef3dc

def array_namespace(*xs, api_version=None, use_compat=None):

from typing import overload
import array_api_strict

array_api_compat_type = array_api_strict

@overload
def array_namespace(*xs, api_version=None, use_compat: None=None) -> array_api_compat_type:
	...

[asmeurer]

I think upstream work to make a protocol out of the array API namespace would be what we'd want here.

data-apis/array-api#685
data-apis/array-api#267

Setting the return type as array_api_strict seems wrong. array_api_strict isn't a type, it's a module, and it isn't even the module that's returned in most cases. The correct return type would be typing.ModuleType, which we can definitely add, although I don't think that alone would make it infer much.

[lucascolley]

let's close this one - we would of course like to annotate all of array-api-compat once the necessary tools are available in array-api-typing.