Singletons/T332.hs:(0,0)-(0,0): Splicing declarations
    promote
      [d| f :: Foo -> ()
          f MkFoo {} = ()
          
          data Foo = MkFoo |]
  ======>
    data Foo = MkFoo
    f :: Foo -> ()
    f MkFoo {} = ()
    type MkFooSym0 :: Foo
    type family MkFooSym0 :: Foo where
      MkFooSym0 = MkFoo
    type FSym0 :: (~>) Foo ()
    data FSym0 :: (~>) Foo ()
      where
        FSym0KindInference :: SameKind (Apply FSym0 arg) (FSym1 arg) =>
                              FSym0 a0123456789876543210
    type instance Apply FSym0 a0123456789876543210 = F a0123456789876543210
    instance SuppressUnusedWarnings FSym0 where
      suppressUnusedWarnings = snd ((,) FSym0KindInference ())
    type FSym1 :: Foo -> ()
    type family FSym1 (a0123456789876543210 :: Foo) :: () where
      FSym1 a0123456789876543210 = F a0123456789876543210
    type F :: Foo -> ()
    type family F (a :: Foo) :: () where
      F MkFoo = Tuple0Sym0
Singletons/T332.hs:(0,0)-(0,0): Splicing declarations
    singletons
      [d| b :: Bar -> ()
          b MkBar {} = ()
          
          data Bar = MkBar |]
  ======>
    data Bar = MkBar
    b :: Bar -> ()
    b MkBar {} = ()
    type MkBarSym0 :: Bar
    type family MkBarSym0 :: Bar where
      MkBarSym0 = MkBar
    type BSym0 :: (~>) Bar ()
    data BSym0 :: (~>) Bar ()
      where
        BSym0KindInference :: SameKind (Apply BSym0 arg) (BSym1 arg) =>
                              BSym0 a0123456789876543210
    type instance Apply BSym0 a0123456789876543210 = B a0123456789876543210
    instance SuppressUnusedWarnings BSym0 where
      suppressUnusedWarnings = snd ((,) BSym0KindInference ())
    type BSym1 :: Bar -> ()
    type family BSym1 (a0123456789876543210 :: Bar) :: () where
      BSym1 a0123456789876543210 = B a0123456789876543210
    type B :: Bar -> ()
    type family B (a :: Bar) :: () where
      B MkBar = Tuple0Sym0
    sB ::
      (forall (t :: Bar). Sing t -> Sing (Apply BSym0 t :: ()) :: Type)
    sB SMkBar = STuple0
    instance SingI (BSym0 :: (~>) Bar ()) where
      sing = singFun1 @BSym0 sB
    data SBar :: Bar -> Type where SMkBar :: SBar (MkBar :: Bar)
    type instance Sing @Bar = SBar
    instance SingKind Bar where
      type Demote Bar = Bar
      fromSing SMkBar = MkBar
      toSing MkBar = SomeSing SMkBar
    instance SingI MkBar where
      sing = SMkBar