[project @ 1997-12-04 11:02:12 by simonm]

[ghc-hetmet.git] / ghc / compiler / reader / RdrHsSyn.lhs

diff --git a/ghc/compiler/reader/RdrHsSyn.lhs b/ghc/compiler/reader/RdrHsSyn.lhs
index 0539152..22827fa 100644 (file)
--- a/ghc/compiler/reader/RdrHsSyn.lhs
+++ b/ghc/compiler/reader/RdrHsSyn.lhs
@@ -127,16 +127,16 @@ extractHsTyVars ty
 
        -- In (All a => a -> a) -> Int, there are no free tyvars
        -- We just assume that we quantify over all type variables mentioned in the context.
-    get (HsPreForAllTy ctxt ty)  acc = filter (`notElem` locals) (get ty [])
-                                      ++ acc
-                                    where
-                                      locals = foldr (get . snd) [] ctxt
+    get (HsPreForAllTy ctxt ty)  acc = 
+               foldr insert acc (filter (`notElem` locals) (get ty []))
+           where
+               locals = foldr (get . snd) [] ctxt
 
-    get (HsForAllTy tvs ctxt ty) acc = (filter (`notElem` locals) $
+    get (HsForAllTy tvs ctxt ty) acc = 
+               foldr insert acc (filter (`notElem` locals) $
                                        foldr (get . snd) (get ty []) ctxt)
-                                      ++ acc
-                                    where
-                                      locals = map getTyVarName tvs
+            where
+               locals = map getTyVarName tvs
 
     insert (Qual _ _ _)              acc = acc
     insert (Unqual (TCOcc _)) acc = acc