diff options
| -rw-r--r-- | compiler/types/Type.lhs | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs index cd484f4f46..8c969226d8 100644 --- a/compiler/types/Type.lhs +++ b/compiler/types/Type.lhs @@ -281,10 +281,12 @@ repSplitAppTy_maybe :: Type -> Maybe (Type,Type) -- Does the AppTy split, but assumes that any view stuff is already done repSplitAppTy_maybe (FunTy ty1 ty2) = Just (TyConApp funTyCon [ty1], ty2) repSplitAppTy_maybe (AppTy ty1 ty2) = Just (ty1, ty2) -repSplitAppTy_maybe (TyConApp tc tys) = case snocView tys of - Just (tys', ty') -> Just (TyConApp tc tys', ty') - Nothing -> Nothing -repSplitAppTy_maybe other = Nothing +repSplitAppTy_maybe (TyConApp tc tys) + | not (isOpenSynTyCon tc) || length tys > tyConArity tc + = case snocView tys of -- never create unsaturated type family apps + Just (tys', ty') -> Just (TyConApp tc tys', ty') + Nothing -> Nothing +repSplitAppTy_maybe _other = Nothing ------------- splitAppTy :: Type -> (Type, Type) splitAppTy ty = case splitAppTy_maybe ty of @@ -297,7 +299,13 @@ splitAppTys ty = split ty ty [] where split orig_ty ty args | Just ty' <- coreView ty = split orig_ty ty' args split orig_ty (AppTy ty arg) args = split ty ty (arg:args) - split orig_ty (TyConApp tc tc_args) args = (TyConApp tc [], tc_args ++ args) + split orig_ty (TyConApp tc tc_args) args + = let -- keep type families saturated + n | isOpenSynTyCon tc = tyConArity tc + | otherwise = 0 + (tc_args1, tc_args2) = splitAt n tc_args + in + (TyConApp tc tc_args1, tc_args2 ++ args) split orig_ty (FunTy ty1 ty2) args = ASSERT( null args ) (TyConApp funTyCon [], [ty1,ty2]) split orig_ty ty args = (orig_ty, args) |