ENH: Adding default_xp context manager for xp_assert functions

[prady0t]

No description provided.

[lucascolley]

thanks Pradyot! Could you update the SciPy branch to use this branch?

[prady0t]

Could you update the SciPy branch to use this branch?

Will have to merge this first right?

[lucascolley]

Could you update the SciPy branch to use this branch?

Will have to merge this first right?

Ah, no! I think the easiest way is to run gh pr checkout 747 from within the submodule.

[prady0t]

We till can't remove these parts from scipy for two reasons:

• We need a fallback to find XP if not given before converting scalar to array (something we do not do here)
• xp_assert_close_nulp exists and uses it too.

@lucascolley What do you think?

[lucascolley]

We need a fallback to find XP if not given before converting scalar to array (something we do not do here)

Could you explain this in more detail?

[prady0t]

Currently, we do not allow for scalar or Python lists as input, but Scipy uses them everywhere. For this reason, we have to convert them to their respective xp.asarray, but to do that, we need to know' xp' in advance. Hence, we use this block before _convert_scalar_to_array:

    if xp is None:
        try:
            xp = _default_xp_ctxvar.get()
        except LookupError:
            xp = array_namespace(desired)

Hence, we need this block before we convert to xp.asarray and send it to our xp assert functions.

[prady0t]

We can remove the default_xp context manager code from scipy and keep it here (and import from here), but we would still do this before converting the inputs to asarrays in scipy. On another thought, we can wrap this around a function and expose it.