1 files changed, 26 insertions, 4 deletions
diff --git a/src/Haskell/AST.hs b/src/Haskell/AST.hs
index 1e181e2..f8b5c72 100644
--- a/src/Haskell/AST.hs
+++ b/src/Haskell/AST.hs
@@ -105,7 +105,29 @@ instance Pretty Inst where
     pretty (Inst n t ds) = Node ("instance " ++ n ++ " " ++ pprintOneline t ++ " where") [Bracket "{" "}" ";" (map pretty ds)]
 
 
-mapInit :: (a -> a) -> [a] -> [a]
-mapInit _ [] = []
-mapInit _ [x] = [x]
-mapInit f (x:y:zs) = f x : mapInit f (y:zs)
+class AllRefs a where
+    allRefs :: a -> [Name]
+
+instance AllRefs AST where
+    allRefs (AST tops) = nub $ concatMap allRefs tops
+
+instance AllRefs Toplevel where
+    allRefs (TopDef def) = allRefs def
+    allRefs (TopDecl _) = []
+    allRefs (TopData _) = []
+    allRefs (TopClass _) = []
+    allRefs (TopInst inst) = allRefs inst
+
+instance AllRefs Def where
+    allRefs (Def _ e) = allRefs e
+
+instance AllRefs Expr where
+    allRefs (App e es) = nub $ concatMap allRefs (e : es)
+    allRefs (Ref n) = [n]
+    allRefs (Num _) = []
+    allRefs (Tup es) = nub $ concatMap allRefs es
+    allRefs (Lam ns e) = allRefs e \\ ns
+    allRefs (Case e pairs) = nub $ allRefs e ++ concatMap (allRefs . snd) pairs
+
+instance AllRefs Inst where
+    allRefs (Inst _ _ ds) = nub $ concatMap allRefs ds