Support simple aggregations on list columns

[DavideCanton]

Problem description

Sorry if this is a duplicate, but I did not find anything related by searching in the issue tracker.

Is there any plan regarding supporting simple aggregations (like min or max) on list columns?

Something like a lexicographic order, such that:

• simple list are ordered by comparing value by value, stopping at the shortest one (for example [1,2] < [1,3], [1,2] < [1,2,3] and so on).
• nested list are ordered recursively (for example [[1,2],[1,3]] < [[1,3]], [[1,2]] < [[1,2],[1,3]] and so on`.

AFAIK, polars by now returns always null in these cases.

[stinodego]

This is something we'd like to support, but there are some quirks to work out with regards to (nested) null values.

This is not high priority for us right now.

[DavideCanton]

I see, at least now those operation error when executed on list columns, it's better than returning null 👍🏻