# Pastebin PGucY4I0
type Partial a = HKD a Last

data User = User
  { name :: Text,
    age :: Int,
    adult :: Bool
  }
  deriving (Generic)

test :: [(String, Bool)]
test =
  labelsWhere' (isJust . getLast) $
    (mempty :: Partial User)
      & field @"name" .~ pure "name here"

labelsWhere' ::
  forall structure f.
  ( Label structure,
    ApplicativeB (HKD structure),
    TraversableB (HKD structure),
    AllB Show (HKD structure)
  ) =>
  (forall a. f a -> Bool) ->
  HKD structure f ->
  [(String, Bool)]
labelsWhere' p =
  getConst . btraverse go . bprod label
  where
    go :: Product (Const String) f a -> (Const [(String, Bool)]) (Maybe a)
    go (Pair (Const key) value) = Const [(key, p value) | p value]