Restore tidying up of tyvars in :print

It wasn't a good idea to disable it

compiler/ghci/Debugger.hs

@@ -18,6 +18,7 @@ import RtClosureInspect
 import HscTypes
 import IdInfo
 --import Id
+import Name
 import Var hiding ( varName )
 import VarSet
 import VarEnv
@@ -61,9 +62,10 @@ pprintClosureCommand session bindThings force str = do
 
    -- Do the obtainTerm--bindSuspensions-computeSubstitution dance
    go :: Session -> Id -> IO (Maybe TvSubst)
-   go cms id = do
-     mb_term <- obtainTerm cms force id
-     maybe (return Nothing) `flip` mb_term $ \term -> do
+   go cms id = do 
+     mb_term <- obtainTerm cms force id 
+     maybe (return Nothing) `flip` mb_term $ \term_ -> do
+       term      <- tidyTermTyVars cms term_
        term'     <- if not bindThings then return term 
                      else bindSuspensions cms term                         
        showterm  <- printTerm cms term'
@@ -100,6 +102,17 @@ pprintClosureCommand session bindThings force str = do
           ictxt'   = ictxt { ic_type_env = type_env' }
       writeIORef ref (hsc_env {hsc_IC = ictxt'})
 
+   tidyTermTyVars :: Session -> Term -> IO Term
+   tidyTermTyVars (Session ref) t = do
+     hsc_env <- readIORef ref
+     let env_tvs      = ic_tyvars (hsc_IC hsc_env)
+         my_tvs       = termTyVars t
+         tvs          = env_tvs `minusVarSet` my_tvs
+         tyvarOccName = nameOccName . tyVarName 
+         tidyEnv      = (initTidyOccEnv (map tyvarOccName (varSetElems tvs))
+                        , env_tvs `intersectVarSet` my_tvs)
+     return$ mapTermType (snd . tidyOpenType tidyEnv) t
+
 -- | Give names, and bind in the interactive environment, to all the suspensions
 --   included (inductively) in a term
 bindSuspensions :: Session -> Term -> IO Term

compiler/ghci/RtClosureInspect.hs

@@ -22,6 +22,8 @@ module RtClosureInspect(
      isFullyEvaluated, 
      isPointed,
      isFullyEvaluatedTerm,
+     mapTermType,
+     termTyVars
 --     unsafeDeepSeq, 
  ) where 
 
@@ -284,6 +286,18 @@ idTermFoldM = TermFold {
               fSuspension = (((return.).).). Suspension
                        }
 
+mapTermType f = foldTerm idTermFold {
+          fTerm       = \ty dc hval tt -> Term (f ty) dc hval tt,
+          fSuspension = \ct mb_ty hval n ->
+                          Suspension ct (fmap f mb_ty) hval n }
+
+termTyVars = foldTerm TermFold {
+            fTerm       = \ty _ _ tt   -> 
+                          tyVarsOfType ty `plusVarEnv` concatVarEnv tt,
+            fSuspension = \_ mb_ty _ _ -> 
+                          maybe emptyVarEnv tyVarsOfType mb_ty,
+            fPrim       = \ _ _ -> emptyVarEnv }
+    where concatVarEnv = foldr plusVarEnv emptyVarEnv
 ----------------------------------
 -- Pretty printing of terms
 ----------------------------------
@@ -374,7 +388,7 @@ type TR a = TcM a
 
 runTR :: HscEnv -> TR Term -> IO Term
 runTR hsc_env c = do 
-  mb_term <- initTcPrintErrors hsc_env iNTERACTIVE (c >>= zonkTerm)
+  mb_term <- initTcPrintErrors hsc_env iNTERACTIVE c
   case mb_term of 
     Nothing -> panic "Can't unify"
     Just term -> return term
@@ -475,17 +489,14 @@ cvObtainTerm :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term
 cvObtainTerm hsc_env force mb_ty hval = runTR hsc_env $ do
    tv <- liftM mkTyVarTy (newVar argTypeKind)
    case mb_ty of
-     Nothing -> go tv tv hval
-     Just ty | isMonomorphic ty -> go ty ty hval
+     Nothing -> go tv tv hval >>= zonkTerm
+     Just ty | isMonomorphic ty -> go ty ty hval >>= zonkTerm
      Just ty -> do 
               (ty',rev_subst) <- instScheme (sigmaType ty)
               addConstraint tv ty'
-              term <- go tv tv hval
+              term <- go tv tv hval >>= zonkTerm
               --restore original Tyvars
-              return$ flip foldTerm term idTermFold {
-                fTerm = \ty dc hval tt -> Term (substTy rev_subst ty) dc hval tt,
-                fSuspension = \ct mb_ty hval n -> 
-                          Suspension ct (substTy rev_subst `fmap` mb_ty) hval n}
+              return$ mapTermType (substTy rev_subst) term
     where 
   go tv ty a = do 
     let monomorphic = not(isTyVarTy tv)   -- This is a convention. The ancestor tests for