Support array api

[arogozhnikov]

Einops implements a basic set of operations based on array api:

from einops.array_api import rearrange, reduce, repeat, asnumpy, pack, unpack

cc: @shoyer @rgommers

[rgommers]

Thanks for implementing and sharing @arogozhnikov!

It looks like right now, this is one extra backend (right?). I guess/hope that in the future, when another known backend is fully compliant (e.g., numpy 2.0), it would be only extra code to support the array API standard, but it would simplify a few things.

[arogozhnikov]

It looks like right now, this is one extra backend (right?)

Correct, that's an additional backend with an exclusive API.

For other frameworks user would call einops.rearrange and similar

For array-api based calls user would use einops.array_api.rearrange and similar