Ability to override behavior at exactly one dimension above a record

[jpivarski]

There are two ways to overload an array that contains a named record:

ak._v2.behavior["*", "NameOfRecord"] = ClassForArray
ak._v2.behavior[".", "NameOfRecord"] = ClassForArray

The first of these overrides any kind of list that is surrounding the records, so that you can define vectorized operations.

The second only overrides one dimension above the records.

The second case was broken, never tested, and no one has ever asked me about it. In #1651, I dropped it for v2 with the idea that we can reintroduce it correctly if asked.

What do you think? Does anybody need the "." method?

@nsmith-, is this used in NanoEvents?

[nsmith-]

NanoEvents always uses awkward.mixin_class to define classes, and that uses only the "*" method:

awkward/src/awkward/behaviors/mixins.py

Line 46 in 15318e1

registry["*", behavior_name] = array