Refactor ai

src/SameConstr.hs

@@ -0,0 +1,37 @@
+{-# LANGUAGE DefaultSignatures, TypeOperators, FlexibleContexts #-}
+{- | Pulled from
+https://stackoverflow.com/questions/10112733/haskell-simple-constructor-comparison-function
+ -}
+module SameConstr where
+
+import GHC.Generics
+import Data.Function (on)
+
+--class EqC a where
+--    eqConstr :: a -> a -> Bool
+--    default eqConstr :: (Generic a, GEqC (Rep a)) => a -> a -> Bool
+--    eqConstr = geqConstr `on` from
+
+eqConstr :: (Generic a, GEqC (Rep a)) => a -> a -> Bool
+eqConstr = geqConstr `on` from
+
+class GEqC f where
+  geqConstr :: f p -> f p -> Bool
+  {-# INLINE geqConstr #-}
+  geqConstr _ _ = True
+
+instance GEqC f => GEqC (M1 i c f) where
+  {-# INLINE geqConstr #-}
+  geqConstr (M1 x) (M1 y) = geqConstr x y
+
+instance GEqC (K1 i c)
+instance GEqC (f :*: g)
+instance GEqC U1
+instance GEqC V1
+
+instance (GEqC f, GEqC g) => GEqC (f :+: g) where
+  {-# INLINE geqConstr #-}
+  geqConstr (L1 x) (L1 y) = geqConstr x y
+  geqConstr (R1 x) (R1 y) = geqConstr x y
+  geqConstr _ _ = False
+