TypedDataset.selectMany & co capped at arity 22

[OlivierBlanvillain]

Due to their used of shapeless.ops.hlist.Tupler, withColumn, selectMany, aggMany and groupByMany are limited to output tuples of size 22. There could be several ways around that, a simple option would be to add alternate implementations of these methods that take a type argument for the "targeted" case class (instead of using tuples). I would start by fixing withColumn which looks like the most urgent.

[iravid]

The bigger issue at hand is the usage of tuples rather than records, right?

[OlivierBlanvillain]

Indeed! But switching to a record representation would be much bigger of a change. We went back and forth between the two options and stick to this one because it's close to vanilla and tries to not expose types from shapeless._ to end users...

[iravid]

Ok. Perhaps we should revisit this question as I'd love to solve #188 :-)

[atamborrino]

From my work on #206, I have also wondered why we do not work with TypedDataset of records directly, as it will simplify a lot TypedTransformer/TypedEstimator code flow by removing the need to write each intermediate transformed case class.
I do also understand the idea to not expose shapeless to end-users. But I guess people interested in using frameless know anyway a little about type level programming.

[frosforever]

Not sure if this is the right issue (#188?) to chime in on this, but as I start using frameless in anger, I too would put a vote toward supporting record types and exposing shapeless to the end user.

[cchantep]

As inactive for ~4y, closing it for now.