Pick out delcarations for ScopeResolution and through Context better

src/Data/Syntax.hs

@@ -289,7 +289,7 @@ instance Ord ErrorStack where
 
 
 data Context a = Context { contextTerms :: NonEmpty a, contextSubject :: a }
-  deriving (Declarations1, Eq, Foldable, FreeVariables1, Functor, Generic1, Message1, Named1, Ord, Show, ToJSONFields1, Traversable, NFData1)
+  deriving (Eq, Foldable, FreeVariables1, Functor, Generic1, Message1, Named1, Ord, Show, ToJSONFields1, Traversable, NFData1)
 
 instance Diffable Context where
   subalgorithmFor blur focus (Context n s) = Context <$> traverse blur n <*> focus s
@@ -307,3 +307,6 @@ instance Evaluatable Context where
 
 instance Tokenize Context where
   tokenize Context{..} = sequenceA_ (sepTrailing contextTerms) *> contextSubject
+
+instance Declarations1 Context where
+  liftDeclaredName declaredName = declaredName . contextSubject

src/Data/Syntax/Expression.hs

@@ -16,6 +16,7 @@ import qualified Data.Reprinting.Scope as Scope
 import           Diffing.Algorithm hiding (Delete)
 import           Reprinting.Tokenize
 import qualified Data.Reprinting.Token as Token
+import qualified Data.List.NonEmpty as NonEmpty
 
 -- | Typical prefix function application, like `f(x)` in many languages, or `f x` in Haskell.
 data Call a = Call { callContext :: ![a], callFunction :: !a, callParams :: ![a], callBlock :: !a }
@@ -503,7 +504,7 @@ instance Evaluatable InstanceOf
 
 -- | ScopeResolution (e.g. import a.b in Python or a::b in C++)
 newtype ScopeResolution a = ScopeResolution { scopes :: NonEmpty a }
-  deriving (Declarations1, Diffable, Eq, Foldable, FreeVariables1, Functor, Generic1, Ord, Show, ToJSONFields1, Traversable, Named1, Message1, NFData1)
+  deriving (Diffable, Eq, Foldable, FreeVariables1, Functor, Generic1, Ord, Show, ToJSONFields1, Traversable, Named1, Message1, NFData1)
 
 instance Hashable1 ScopeResolution where liftHashWithSalt = foldl
 instance Eq1 ScopeResolution where liftEq = genericLiftEq
@@ -514,6 +515,8 @@ instance Evaluatable ScopeResolution where
   eval eval (ScopeResolution xs) = Rval <$> foldl1 f (fmap (eval >=> address) xs)
     where f ns id = ns >>= flip evaluateInScopedEnv id
 
+instance Declarations1 ScopeResolution where
+  liftDeclaredName declaredName = declaredName . NonEmpty.last . scopes
 
 -- | A non-null expression such as Typescript or Swift's ! expression.
 newtype NonNullExpression a = NonNullExpression { nonNullExpression :: a }