Fixed two bugs concerning fanilies

[ghc-hetmet.git] / compiler / basicTypes / DataCon.lhs

diff --git a/compiler/basicTypes/DataCon.lhs b/compiler/basicTypes/DataCon.lhs
index f873977..3de9905 100644 (file)
--- a/compiler/basicTypes/DataCon.lhs
+++ b/compiler/basicTypes/DataCon.lhs
@@ -38,7 +38,8 @@ import Type           ( Type, ThetaType,
 import Coercion                ( isEqPred, mkEqPred )
 import TyCon           ( TyCon, FieldLabel, tyConDataCons, 
                          isProductTyCon, isTupleTyCon, isUnboxedTupleTyCon,
-                          isNewTyCon, isRecursiveTyCon )
+                          isNewTyCon, isClosedNewTyCon, isRecursiveTyCon,
+                          tyConFamInst_maybe )
 import Class           ( Class, classTyCon )
 import Name            ( Name, NamedThing(..), nameUnique, mkSysTvName, mkSystemName )
 import Var             ( TyVar, CoVar, Id, mkTyVar, tyVarKind, setVarUnique,
@@ -459,7 +460,8 @@ mkDataCon name declared_infix
                  dcStupidTheta = stupid_theta, dcTheta = theta,
                  dcOrigArgTys = orig_arg_tys, dcTyCon = tycon, 
                  dcRepArgTys = rep_arg_tys,
-                 dcStrictMarks = arg_stricts, dcRepStrictness = rep_arg_stricts,
+                 dcStrictMarks = arg_stricts, 
+                 dcRepStrictness = rep_arg_stricts,
                  dcFields = fields, dcTag = tag, dcRepType = ty,
                  dcIds = ids }
 
@@ -606,6 +608,8 @@ dataConUserType :: DataCon -> Type
 --     T :: forall a. a -> T [a]
 -- rather than
 --     T :: forall b. forall a. (a=[b]) => a -> T b
+-- NB: If the constructor is part of a data instance, the result type
+-- mentions the family tycon, not the internal one.
 dataConUserType  (MkData { dcUnivTyVars = univ_tvs, 
                           dcExTyVars = ex_tvs, dcEqSpec = eq_spec,
                           dcTheta = theta, dcOrigArgTys = arg_tys,
@@ -613,7 +617,9 @@ dataConUserType  (MkData { dcUnivTyVars = univ_tvs,
   = mkForAllTys ((univ_tvs `minusList` map fst eq_spec) ++ ex_tvs) $
     mkFunTys (mkPredTys theta) $
     mkFunTys arg_tys $
-    mkTyConApp tycon (map (substTyVar subst) univ_tvs)
+    case tyConFamInst_maybe tycon of
+      Nothing             -> mkTyConApp tycon (map (substTyVar subst) univ_tvs)
+      Just (ftc, insttys) -> mkTyConApp ftc insttys        -- data instance
   where
     subst = mkTopTvSubst eq_spec
 
@@ -722,9 +728,10 @@ splitProductType str ty
 deepSplitProductType_maybe ty
   = do { (res@(tycon, tycon_args, _, _)) <- splitProductType_maybe ty
        ; let {result 
-             | isNewTyCon tycon && not (isRecursiveTyCon tycon)
+             | isClosedNewTyCon tycon && not (isRecursiveTyCon tycon)
              = deepSplitProductType_maybe (newTyConInstRhs tycon tycon_args)
-             | isNewTyCon tycon = Nothing  -- cannot unbox through recursive newtypes
+             | isNewTyCon tycon = Nothing  -- cannot unbox through recursive
+                                          -- newtypes nor through families
              | otherwise = Just res}
        ; result
        }