Use higher order declaredName function in Declarations1 instance

src/Data/Abstract/Declarations.hs

@@ -13,7 +13,7 @@ class Declarations syntax where
 
 class Declarations1 syntax where
   -- | Lift a function mapping each element to its set of free variables through a containing structure, collecting the results into a single set.
-  liftDeclaredName :: Declarations a => (a -> [Name]) -> syntax a -> Maybe Name
+  liftDeclaredName :: (a -> [Name]) -> syntax a -> Maybe Name
   liftDeclaredName _ _ = Nothing
 
 instance Declarations t => Declarations (Subterm t a) where
@@ -21,7 +21,7 @@ instance Declarations t => Declarations (Subterm t a) where
 
 deriving instance (Declarations1 syntax, FreeVariables1 syntax) => Declarations (Term syntax ann)
 
-instance (Declarations recur, FreeVariables recur, Declarations1 syntax) => Declarations (TermF syntax ann recur) where
+instance (FreeVariables recur, Declarations1 syntax) => Declarations (TermF syntax ann recur) where
   declaredName = liftDeclaredName freeVariables . termFOut
 
 instance (Apply Declarations1 fs) => Declarations1 (Sum fs) where

src/Data/Syntax/Declaration.hs

@@ -34,7 +34,9 @@ instance Declarations a => Declarations (Function a) where
   declaredName Function{..} = declaredName functionName
 
 instance Declarations1 Function where
-  liftDeclaredName _ = declaredName
+  liftDeclaredName declaredName Function{..} = case declaredName functionName of
+                                                 [] -> Nothing
+                                                 (x:_) -> Just x
 
 data Method a = Method { methodContext :: ![a], methodReceiver :: !a, methodName :: !a, methodParameters :: ![a], methodBody :: !a }
   deriving (Eq, Ord, Show, Foldable, Traversable, Functor, Generic1, Hashable1, Mergeable, FreeVariables1, Declarations1, ToJSONFields1, Named1, Message1)