fourmolu-0.0.6.0: data/examples/declaration/value/function/operator-comments-0.hs

foo =
  bar
  ++
    {- some comment -}
    case foo of
      a -> a

foo =
  bar
    ++ {- some comment -}
    case foo of
      a -> a

foo =
  bar
    ++ case foo of {- some comment -}
      a -> a