X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FType.lhs;h=37f915be1dfca92944994916e3bc02fe5a1d3fae;hb=2eb04ca0f8d0ec72b417cddc60672c696b4a3daa;hp=147f54678b213394941f49d0e1cb7f14b4a24bb8;hpb=3548802de235eca280982270463db84910ee3748;p=ghc-hetmet.git

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index 147f546..37f915b 100644
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -54,8 +54,7 @@ module Type (
 	applyTy, applyTys, isForAllTy, dropForAlls,
 
 	-- Source types
-	predTypeRep, mkPredTy, mkPredTys,
-	tyConOrigHead, pprSourceTyCon,
+	predTypeRep, mkPredTy, mkPredTys, pprSourceTyCon, mkFamilyTyConApp,
 
 	-- Newtypes
 	splitRecNewType_maybe, newTyConInstRhs,
@@ -89,13 +88,14 @@ module Type (
 	mkTvSubst, mkOpenTvSubst, zipOpenTvSubst, zipTopTvSubst, mkTopTvSubst, notElemTvSubst,
 	getTvSubstEnv, setTvSubstEnv, getTvInScope, extendTvInScope,
  	extendTvSubst, extendTvSubstList, isInScope, composeTvSubst, zipTyEnv,
+        isEmptyTvSubst,
 
 	-- Performing substitution on types
 	substTy, substTys, substTyWith, substTheta, 
 	substPred, substTyVar, substTyVars, substTyVarBndr, deShadowTy, lookupTyVar,
 
 	-- Pretty-printing
-	pprType, pprParendType, pprTyThingCategory, pprForAll,
+	pprType, pprParendType, pprTypeApp, pprTyThingCategory, pprForAll,
 	pprPred, pprTheta, pprThetaArrow, pprClassPred, pprKind, pprParendKind
     ) where
 
@@ -603,19 +603,29 @@ predTypeRep (ClassP clas tys) = mkTyConApp (classTyCon clas) tys
 	-- look through that too if necessary
 predTypeRep (EqPred ty1 ty2) = pprPanic "predTypeRep" (ppr (EqPred ty1 ty2))
 
--- The original head is the tycon and its variables for a vanilla tycon and it
--- is the family tycon and its type indexes for a family instance.
-tyConOrigHead :: TyCon -> (TyCon, [Type])
-tyConOrigHead tycon = case tyConFamInst_maybe tycon of
-		        Nothing      -> (tycon, mkTyVarTys (tyConTyVars tycon))
-			Just famInst -> famInst
+mkFamilyTyConApp :: TyCon -> [Type] -> Type
+-- Given a family instance TyCon and its arg types, return the
+-- corresponding family type.  E.g.
+--	data family T a
+--	data instance T (Maybe b) = MkT b	-- Instance tycon :RTL
+-- Then 
+--	mkFamilyTyConApp :RTL Int  =  T (Maybe Int)
+mkFamilyTyConApp tc tys
+  | Just (fam_tc, fam_tys) <- tyConFamInst_maybe tc
+  , let fam_subst = zipTopTvSubst (tyConTyVars tc) tys
+  = mkTyConApp fam_tc (substTys fam_subst fam_tys)
+  | otherwise
+  = mkTyConApp tc tys
 
 -- Pretty prints a tycon, using the family instance in case of a
--- representation tycon.
-pprSourceTyCon tycon | Just (repTyCon, tys) <- tyConFamInst_maybe tycon =
-  ppr $ repTyCon `TyConApp` tys	       -- can't be FunTyCon
-                     | otherwise                                        =
-  ppr tycon
+-- representation tycon.  For example
+--  	e.g.  data T [a] = ...
+-- In that case we want to print `T [a]', where T is the family TyCon
+pprSourceTyCon tycon 
+  | Just (fam_tc, tys) <- tyConFamInst_maybe tycon
+  = ppr $ fam_tc `TyConApp` tys	       -- can't be FunTyCon
+  | otherwise
+  = ppr tycon
 \end{code}
 
 
@@ -641,9 +651,6 @@ splitRecNewType_maybe (TyConApp tc tys)
 			 Just (substTyWith tvs tys rep_ty)
 	
 splitRecNewType_maybe other = Nothing
-
-
-
 \end{code}
 
 
@@ -730,13 +737,17 @@ It doesn't change the uniques at all, just the print names.
 
 \begin{code}
 tidyTyVarBndr :: TidyEnv -> TyVar -> (TidyEnv, TyVar)
-tidyTyVarBndr (tidy_env, subst) tyvar
+tidyTyVarBndr env@(tidy_env, subst) tyvar
   = case tidyOccName tidy_env (getOccName name) of
-      (tidy', occ') -> 	((tidy', subst'), tyvar')
-		    where
-			subst' = extendVarEnv subst tyvar tyvar'
-			tyvar' = setTyVarName tyvar name'
-			name'  = tidyNameOcc name occ'
+      (tidy', occ') -> ((tidy', subst'), tyvar'')
+	where
+	  subst' = extendVarEnv subst tyvar tyvar''
+	  tyvar' = setTyVarName tyvar name'
+	  name'  = tidyNameOcc name occ'
+		-- Don't forget to tidy the kind for coercions!
+	  tyvar'' | isCoVar tyvar = setTyVarKind tyvar' kind'
+		  | otherwise	  = tyvar'
+	  kind'  = tidyType env (tyVarKind tyvar)
   where
     name = tyVarName tyvar
 
@@ -1213,7 +1224,7 @@ zipTopTvSubst :: [TyVar] -> [Type] -> TvSubst
 zipTopTvSubst tyvars tys 
 #ifdef DEBUG
   | length tyvars /= length tys
-  = pprTrace "zipOpenTvSubst" (ppr tyvars $$ ppr tys) emptyTvSubst
+  = pprTrace "zipTopTvSubst" (ppr tyvars $$ ppr tys) emptyTvSubst
   | otherwise
 #endif
   = TvSubst emptyInScopeSet (zipTyEnv tyvars tys)