REF: Share NumericArray/NumericDtype methods

[jbrockmendel]

• closes #xxxx (Replace xxxx with the Github issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

[mroeschke]

I'd be more partial to _dtype_checker, but won't die on that hill

[jbrockmendel]

sure. OK for follow-up?

[mroeschke]

Yup sounds good

[mroeschke]

Off-topic question: I am interested in exploring the feasibility of adding an Arrow-back NumericArray. It doesn't appear that I can just subclass this since NumericArray and it's subclass are heavily numpy based.

Any recommendations on where to start? Would I need to essentially create MaskedArrowArray and go from there?

[jbrockmendel]

Any recommendations on where to start? Would I need to essentially create MaskedArrowArray and go from there?

I've been thinking we should refactor as much of ArrowStringArray as possible out into a general arrow-backed EA. Not sure if that could be a fully-formed EA or if it would need to be a mixin. (also in the tests there's an ArrowExtensionArray but I think its half-baked)

FWIW my current thought with MaskedArray is to try to get as much of NumericArray and BooleanArray pushed down into MaskedArray as possible so it can just become a wrapper around an arbitrary non-masked array (including e.g. other EAs)

[mroeschke]

Thanks for the gameplan. LGTM.

[jreback]

luv it