1 files changed, 31 insertions, 6 deletions
diff --git a/src/Data/Dependent/EnumMap/Strict/Internal.hs b/src/Data/Dependent/EnumMap/Strict/Internal.hs
index ae56051..d2fdcb6 100644
--- a/src/Data/Dependent/EnumMap/Strict/Internal.hs
+++ b/src/Data/Dependent/EnumMap/Strict/Internal.hs
@@ -329,21 +329,46 @@ differenceWithKey f (DEnumMap m1) (DEnumMap m2) = DEnumMap (IM.differenceWithKey
 
 -- ** Intersection
 
--- intersection
--- intersectionWith
--- intersectionWithKey
+intersection :: DEnumMap k1 v1 -> DEnumMap k2 v2 -> DEnumMap k1 v1
+intersection (DEnumMap m1) (DEnumMap m2) = DEnumMap (IM.intersection m1 m2)
+
+intersectionWith :: forall k v1 v2 v3. (Enum1 k, TestEquality k)
+                 => (forall a. v1 a -> v2 a -> v3 a) -> DEnumMap k v1 -> DEnumMap k v2 -> DEnumMap k v3
+intersectionWith f (DEnumMap m1) (DEnumMap m2) = DEnumMap (IM.intersectionWithKey f' m1 m2)
+  where
+    f' :: Int -> KV k v1 -> KV k v2 -> KV k v3
+    f' i (KV inf1 v1) (KV inf2 v2) =
+      typeCheck2 (Proxy @k) i inf1 inf2 $ KV inf1 $ f (coe1 v1) (coe1 v2)
+
+intersectionWithKey :: forall k v1 v2 v3. (Enum1 k, TestEquality k)
+                    => (forall a. k a -> v1 a -> v2 a -> v3 a) -> DEnumMap k v1 -> DEnumMap k v2 -> DEnumMap k v3
+intersectionWithKey f (DEnumMap m1) (DEnumMap m2) = DEnumMap (IM.intersectionWithKey f' m1 m2)
+  where
+    f' :: Int -> KV k v1 -> KV k v2 -> KV k v3
+    f' i (KV inf1 v1) (KV inf2 v2) = case toEnum1 i inf1 of
+      Some k1 -> typeCheck1 k1 i inf2 $ KV inf1 $ f k1 (coe1 v1) (coe1 v2)
 
 -- ** Disjoint
 
--- disjoint
+disjoint :: DEnumMap k v1 -> DEnumMap k v2 -> Bool
+disjoint (DEnumMap m1) (DEnumMap m2) = IM.disjoint m1 m2
 
 -- ** Compose
 
--- compose
+compose :: Enum1 k => DEnumMap k v -> DEnumMap k k -> DEnumMap k v
+compose (DEnumMap m1) (DEnumMap m2) = DEnumMap (IM.compose m1 (IM.map (\(KV _ v) -> fst $ fromEnum1 v) m2))
 
 -- ** Universal combining function
 
--- mergeWithKey
+mergeWithKey :: forall k v1 v2 v3. (Enum1 k, TestEquality k)
+             => (forall a. k a -> v1 a -> v2 a -> Maybe (v3 a)) -> (DEnumMap k v1 -> DEnumMap k v3) -> (DEnumMap k v2 -> DEnumMap k v3) -> DEnumMap k v1 -> DEnumMap k v2 -> DEnumMap k v3
+mergeWithKey f g1 g2 (DEnumMap m1) (DEnumMap m2) = DEnumMap (IM.mergeWithKey f' g1' g2' m1 m2)
+  where
+    f' :: Int -> KV k v1 -> KV k v2 -> Maybe (KV k v3)
+    f' i (KV inf1 v1) (KV inf2 v2) = case toEnum1 i inf1 of
+      Some k1 -> typeCheck1 k1 i inf2 . KV inf1 <$> f k1 (coe1 v1) (coe1 v2)
+    g1' m = let DEnumMap m' = g1 (DEnumMap m) in m'
+    g2' m = let DEnumMap m' = g2 (DEnumMap m) in m'
 
 -- * Traversal
 -- ** Map