Prefer newtype deriving over Generic deriving for simplicity

1 files changed, 4 insertions, 17 deletions

diff --git a/src/Data/Array/Nested/Mixed/Shape.hs b/src/Data/Array/Nested/Mixed/Shape.hs
index 6b7708f..1071859 100644
--- a/src/Data/Array/Nested/Mixed/Shape.hs
+++ b/src/Data/Array/Nested/Mixed/Shape.hs
@@ -1,10 +1,10 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE ImportQualifiedPost #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE NoStarIsType #-}
@@ -39,7 +39,6 @@ import Data.Monoid (Sum(..))
 import Data.Proxy
 import Data.Type.Equality
 import GHC.Exts (Int(..), Int#, build, quotRemInt#, withDict)
-import GHC.Generics (Generic)
 import GHC.IsList (IsList)
 import GHC.IsList qualified as IsList
 import GHC.TypeLits
@@ -191,7 +190,7 @@ listxZipWith f (i ::% is) (j ::% js) = f i j ::% listxZipWith f is js
 type role IxX nominal representational
 type IxX :: [Maybe Nat] -> Type -> Type
 newtype IxX sh i = IxX (ListX sh (Const i))
-  deriving (Eq, Ord, Generic)
+  deriving (Eq, Ord, NFData)
 
 pattern ZIX :: forall sh i. () => sh ~ '[] => IxX sh i
 pattern ZIX = IxX ZX
@@ -231,8 +230,6 @@ instance Foldable (IxX sh) where
   null ZIX = False
   null _ = True
 
-instance NFData i => NFData (IxX sh i)
-
 ixxLength :: IxX sh i -> Int
 ixxLength (IxX l) = listxLength l
 
@@ -468,7 +465,7 @@ listhLast (x `ConsKnown` ZH) = SKnown x
 type role ShX nominal representational
 type ShX :: [Maybe Nat] -> Type -> Type
 newtype ShX sh i = ShX (ListH sh i)
-  deriving (Eq, Ord, Generic)
+  deriving (Eq, Ord, NFData)
 
 pattern ZSX :: forall sh i. () => sh ~ '[] => ShX sh i
 pattern ZSX = ShX ZH
@@ -496,11 +493,6 @@ instance Functor (ShX sh) where
   {-# INLINE fmap #-}
   fmap f (ShX l) = ShX (listhFmap (fromSMayNat (SUnknown . f) SKnown) l)
 
-instance NFData i => NFData (ShX sh i) where
-  rnf (ShX ZH) = ()
-  rnf (ShX (i `ConsUnknown` l)) = rnf i `seq` rnf (ShX l)
-  rnf (ShX (SNat `ConsKnown` l)) = rnf (ShX l)
-
 -- | This checks only whether the types are equal; unknown dimensions might
 -- still differ. This corresponds to 'testEquality', except on the penultimate
 -- type parameter.
@@ -658,7 +650,7 @@ shxCast' ssh sh = case shxCast ssh sh of
 -- | The part of a shape that is statically known. (A newtype over 'ListH'.)
 type StaticShX :: [Maybe Nat] -> Type
 newtype StaticShX sh = StaticShX (ListH sh ())
-  deriving (Eq, Ord)
+  deriving (Eq, Ord, NFData)
 
 pattern ZKX :: forall sh. () => sh ~ '[] => StaticShX sh
 pattern ZKX = StaticShX ZH
@@ -681,11 +673,6 @@ instance Show (StaticShX sh) where
   showsPrec _ (StaticShX l) = listhShow (fromSMayNat shows (shows . fromSNat)) l
 #endif
 
-instance NFData (StaticShX sh) where
-  rnf (StaticShX ZH) = ()
-  rnf (StaticShX (() `ConsUnknown` l)) = rnf (StaticShX l)
-  rnf (StaticShX (SNat `ConsKnown` l)) = rnf (StaticShX l)
-
 instance TestEquality StaticShX where
   testEquality (StaticShX l1) (StaticShX l2) = listhEqType l1 l2