Remove redundant constraints

quasar/src/Quasar/PreludeExtras.hs

@@ -65,7 +65,7 @@ leftToMaybe (Left x) = Just x
 leftToMaybe (Right _) = Nothing
 
 -- | Returns all duplicate elements in a list. The order of the produced list is unspecified.
-duplicates :: forall a. (Eq a, Hashable.Hashable a) => [a] -> [a]
+duplicates :: forall a. Hashable.Hashable a => [a] -> [a]
 duplicates = HS.toList . duplicates' HS.empty
   where
     duplicates' :: HS.HashSet a -> [a] -> HS.HashSet a
@@ -77,14 +77,14 @@ duplicates = HS.toList . duplicates' HS.empty
         otherDuplicates = duplicates' (HS.insert x set) xs
 
 -- | Lookup and delete a value from a HashMap in one operation
-lookupDelete :: forall k v. (Eq k, Hashable.Hashable k) => k -> HM.HashMap k v -> (Maybe v, HM.HashMap k v)
+lookupDelete :: forall k v. Hashable.Hashable k => k -> HM.HashMap k v -> (Maybe v, HM.HashMap k v)
 lookupDelete key m = swap $ State.runState fn Nothing
   where
     fn :: State.State (Maybe v) (HM.HashMap k v)
     fn = HM.alterF (\c -> State.put c >> return Nothing) key m
 
 -- | Lookup a value and insert the given value if it is not already a member of the HashMap.
-lookupInsert :: forall k v. (Eq k, Hashable.Hashable k) => k -> v -> HM.HashMap k v -> (v, HM.HashMap k v)
+lookupInsert :: forall k v. Hashable.Hashable k => k -> v -> HM.HashMap k v -> (v, HM.HashMap k v)
 lookupInsert key value hm = runExtra $ HM.alterF fn key hm
   where
     fn :: Maybe v -> Extra v (Maybe v)
@@ -92,7 +92,7 @@ lookupInsert key value hm = runExtra $ HM.alterF fn key hm
     fn (Just oldValue) = Extra (oldValue, Just oldValue)
 
 -- | Insert the given value if it is not already a member of the HashMap. Returns `True` if the element was inserted.
-checkInsert :: forall k v. (Eq k, Hashable.Hashable k) => k -> v -> HM.HashMap k v -> (Bool, HM.HashMap k v)
+checkInsert :: forall k v. Hashable.Hashable k => k -> v -> HM.HashMap k v -> (Bool, HM.HashMap k v)
 checkInsert key value hm = runExtra $ HM.alterF fn key hm
   where
     fn :: Maybe v -> Extra Bool (Maybe v)