add `is_*_namespace` helper functions

[lucascolley]

closes gh-156

[asmeurer]

Let's make these not depend on the name array_api_compat. Vendoring supports renaming the module. We should be able to just compare against __name__.

[lucascolley]

Let's make these not depend on the name array_api_compat. Vendoring supports renaming the module. We should be able to just compare against name.

How should we do that? Create an array and pass it to is_*_array or is there a cheaper way?

Using just xp.__name__ seems to have problems when there are both {custom name for array_api_compat}.numpy and jax.numpy, right?

[asmeurer]

I mean the global variable __name__ will contain the name of the current module.

[lucascolley]

sorry, I don't follow - what would one of the functions look like?

[asmeurer]

Something like

def _compat_module_name():
    assert __name__.endswith('.common._helpers')
    return __name__.removesuffix('.common._helpers')

[lucascolley]

thanks, done

[asmeurer]

Can we add some simple tests for this and also something in the vendoring test to make sure that works?

[lucascolley]

Okay. Are there existing tests for the is_*_array functions or should I add tests for those too?

[asmeurer]

Yes, those are tested in test_common.py

[asmeurer]

One more change and this can be merged: can you add these functions to the API docs?

[lucascolley]

can you add these functions to the API docs?

done (I think)!