move instance Eq1 NValueF to the parent

Author: Anton-Latukha

src/Nix/Value.hs

@@ -27,7 +27,8 @@ import           Control.Monad.Trans.Class      ( MonadTrans, lift )
 import qualified Data.Aeson                    as A
 import           Data.Functor.Classes           ( Show1
                                                 , liftShowsPrec
-                                                , showsUnaryWith )
+                                                , showsUnaryWith
+                                                , Eq1(liftEq) )
 import           Data.HashMap.Lazy              ( HashMap )
 import           Data.Text                      ( Text )
 import           Data.Typeable                  ( Typeable )
@@ -96,6 +97,14 @@ instance Show r => Show (NValueF p m r) where
     showsCon1 con a d =
       showParen (d > 10) $ showString (con ++ " ") . showsPrec 11 a
 
+instance Eq1 (NValueF p m) where
+  liftEq _  (NVConstantF x) (NVConstantF y) = x == y
+  liftEq _  (NVStrF      x) (NVStrF      y) = x == y
+  liftEq eq (NVListF     x) (NVListF     y) = liftEq eq x y
+  liftEq eq (NVSetF x _   ) (NVSetF y _   ) = liftEq eq x y
+  liftEq _  (NVPathF x    ) (NVPathF y    ) = x == y
+  liftEq _  _               _               = False
+
 lmapNValueF :: Functor m => (b -> a) -> NValueF a m r -> NValueF b m r
 lmapNValueF f = \case
   NVConstantF a  -> NVConstantF a

src/Nix/Value/Equal.hs

@@ -19,7 +19,6 @@
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE TypeOperators #-}
-{-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE ViewPatterns #-}
 
 
@@ -35,7 +34,6 @@ import           Control.Monad.Trans.Class
 import           Control.Monad.Trans.Except
 import           Data.Align
 import           Data.Eq.Deriving
-import           Data.Functor.Classes
 import           Data.Functor.Identity
 import qualified Data.HashMap.Lazy             as M
 import           Data.These
@@ -179,12 +177,4 @@ thunkEqM lt rt = force lt $ \lv -> force rt $ \rv ->
         (NVSet _ _    , NVSet _ _    ) -> unsafePtrEq
         _                              -> valueEqM lv rv
 
-instance Eq1 (NValueF p m) where
-  liftEq _  (NVConstantF x) (NVConstantF y) = x == y
-  liftEq _  (NVStrF      x) (NVStrF      y) = x == y
-  liftEq eq (NVListF     x) (NVListF     y) = liftEq eq x y
-  liftEq eq (NVSetF x _   ) (NVSetF y _   ) = liftEq eq x y
-  liftEq _  (NVPathF x    ) (NVPathF y    ) = x == y
-  liftEq _  _               _               = False
-
 $(deriveEq1 ''NValue')