Hey all, Whilst working on some UDAFs, I noticed I essentially had to reimplement GroupByScalar to use scalars as HashMap keys inside accumulator struct state, as ScalarValue (correctly!) doesn't implement Eq/Hash.
A simple fix to ease this process would be to remove the crate-only access qualifier so that it can be reused in user code. Do we have any stability guidelines for public types that need considering before doing so? Otherwise, if there's general approval for this, can I just create an issue in JIRA myself to associate with the future PR, or is there a process to be followed? Arrow/general ASF newb here :) Cheers, Ruan
