Promote/CaseExpressions.hs:0:0: Splicing declarations
    promote
      [d| foo1 :: a -> Maybe a -> a
          foo1 d x
            = case x of {
                Just y -> y
                Nothing -> d }
          foo2 :: a -> Maybe a -> a
          foo2 d _
            = case (Just d) of {
                Just y -> y
                Nothing -> d }
          foo3 :: a -> b -> a
          foo3 a b = case (a, b) of { (p, _) -> p }
          foo4 :: forall a. a -> a
          foo4 x
            = case x of {
                y -> let
                       z :: a
                       z = y
                     in z }
          foo5 :: a -> a
          foo5 x = case x of { y -> (\ _ -> x) y } |]
  ======>
    Promote/CaseExpressions.hs:(0,0)-(0,0)
    foo1 :: forall a. a -> Maybe a -> a
    foo1 d x
      = case x of {
          Just y -> y
          Nothing -> d }
    foo2 :: forall a. a -> Maybe a -> a
    foo2 d _
      = case Just d of {
          Just y -> y
          Nothing -> d }
    foo3 :: forall a b. a -> b -> a
    foo3 a b = case (a, b) of { (p, _) -> p }
    foo4 :: forall a. a -> a
    foo4 x
      = case x of {
          y -> let
                 z :: a
                 z = y
               in z }
    foo5 :: forall a. a -> a
    foo5 x = case x of { y -> \ _ -> x y }
    type family Case_0123456789 (t :: k) (d :: d) (x :: x) :: r
    type instance Case_0123456789 (Just y) d x = y
    type instance Case_0123456789 Nothing d x = d
    type family Case_0123456789 (t :: k) (d :: d) :: r
    type instance Case_0123456789 (Just y) d = y
    type instance Case_0123456789 Nothing d = d
    type family Case_0123456789 (t :: k) (a :: a) (b :: b) :: r
    type instance Case_0123456789 '(p, z) a b = p
    type family Let_0123456789z (a :: x) (a :: y) :: a
    type instance Let_0123456789z x y = y
    data Let_0123456789zSym1 (l :: x) (l :: TyFun y a)
    data Let_0123456789zSym0 (k :: TyFun x (TyFun y a -> *))
    type instance Apply (Let_0123456789zSym1 a) a = Let_0123456789z a a
    type instance Apply Let_0123456789zSym0 a = Let_0123456789zSym1 a
    type family Case_0123456789 (t :: k) (x :: x) :: r
    type instance Case_0123456789 y x =
        Apply (Apply Let_0123456789zSym0 x) y
    type family Lambda_0123456789 (x :: x) (y :: y) (t :: k) :: r
    type instance Lambda_0123456789 x y z = x
    data Lambda_0123456789Sym2 (l :: x) (l :: y) (l :: TyFun k r)
    type instance Apply (Lambda_0123456789Sym2 a a) a =
        Lambda_0123456789 a a a
    type family Case_0123456789 (t :: k) (x :: x) :: r
    type instance Case_0123456789 y x =
        Apply (Lambda_0123456789Sym2 x y) y
    type family Foo1 (a :: a) (a :: Maybe a) :: a
    type instance Foo1 d x = Case_0123456789 x d x
    data Foo1Sym1 (l :: a) (l :: TyFun (Maybe a) a)
    data Foo1Sym0 (k :: TyFun a (TyFun (Maybe a) a -> *))
    type instance Apply (Foo1Sym1 a) a = Foo1 a a
    type instance Apply Foo1Sym0 a = Foo1Sym1 a
    type family Foo2 (a :: a) (a :: Maybe a) :: a
    type instance Foo2 d z = Case_0123456789 (Apply JustSym0 d) d
    data Foo2Sym1 (l :: a) (l :: TyFun (Maybe a) a)
    data Foo2Sym0 (k :: TyFun a (TyFun (Maybe a) a -> *))
    type instance Apply (Foo2Sym1 a) a = Foo2 a a
    type instance Apply Foo2Sym0 a = Foo2Sym1 a
    type family Foo3 (a :: a) (a :: b) :: a
    type instance Foo3 a b = Case_0123456789 '(a, b) a b
    data Foo3Sym1 (l :: a) (l :: TyFun b a)
    data Foo3Sym0 (k :: TyFun a (TyFun b a -> *))
    type instance Apply (Foo3Sym1 a) a = Foo3 a a
    type instance Apply Foo3Sym0 a = Foo3Sym1 a
    type family Foo4 (a :: a) :: a
    type instance Foo4 x = Case_0123456789 x x
    data Foo4Sym0 (k :: TyFun a a)
    type instance Apply Foo4Sym0 a = Foo4 a
    type family Foo5 (a :: a) :: a
    type instance Foo5 x = Case_0123456789 x x
    data Foo5Sym0 (k :: TyFun a a)
    type instance Apply Foo5Sym0 a = Foo5 a