Less manual Foldable instances

1 files changed, 4 insertions, 16 deletions

diff --git a/src/Data/Array/Nested/Internal.hs b/src/Data/Array/Nested/Internal.hs
index 4577967..18f458e 100644
--- a/src/Data/Array/Nested/Internal.hs
+++ b/src/Data/Array/Nested/Internal.hs
@@ -896,10 +896,7 @@ type role IxR nominal representational
 type IxR :: INat -> Type -> Type
 newtype IxR n i = IxR (ListR n i)
   deriving (Show, Eq, Ord)
-  deriving newtype (Functor)
-
-instance Foldable (IxR n) where
-  foldr f z (IxR l) = foldr f z l
+  deriving newtype (Functor, Foldable)
 
 pattern ZIR :: forall n i. () => n ~ Z => IxR n i
 pattern ZIR = IxR ZR
@@ -928,10 +925,7 @@ type role ShR nominal representational
 type ShR :: INat -> Type -> Type
 newtype ShR n i = ShR (ListR n i)
   deriving (Show, Eq, Ord)
-  deriving newtype (Functor)
-
-instance Foldable (ShR n) where
-  foldr f z (ShR l) = foldr f z l
+  deriving newtype (Functor, Foldable)
 
 pattern ZSR :: forall n i. () => n ~ Z => ShR n i
 pattern ZSR = ShR ZR
@@ -1115,10 +1109,7 @@ type role IxS nominal representational
 type IxS :: [Nat] -> Type -> Type
 newtype IxS sh i = IxS (ListS sh i)
   deriving (Show, Eq, Ord)
-  deriving newtype (Functor)
-
-instance Foldable (IxS sh) where
-  foldr f z (IxS l) = foldr f z l
+  deriving newtype (Functor, Foldable)
 
 pattern ZIS :: forall sh i. () => sh ~ '[] => IxS sh i
 pattern ZIS = IxS ZS
@@ -1144,10 +1135,7 @@ type role ShS nominal representational
 type ShS :: [Nat] -> Type -> Type
 newtype ShS sh i = ShS (ListS sh i)
   deriving (Show, Eq, Ord)
-  deriving newtype (Functor)
-
-instance Foldable (ShS sh) where
-  foldr f z (ShS l) = foldr f z l
+  deriving newtype (Functor, Foldable)
 
 pattern ZSS :: forall sh i. () => sh ~ '[] => ShS sh i
 pattern ZSS = ShS ZS