newTyConInstRhs,
-- (Type families)
- tyFamInsts,
+ tyFamInsts, predFamInsts,
-- (Source types)
mkPredTy, mkPredTys, mkFamilyTyConApp,
(mkForAllTys (drop n_args tvs) rho_ty)
| otherwise -- Too many type args
= ASSERT2( n_tvs > 0, doc $$ ppr orig_fun_ty ) -- Zero case gives infnite loop!
- applyTys (substTyWith tvs (take n_tvs arg_tys) rho_ty)
- (drop n_tvs arg_tys)
+ applyTysD doc (substTyWith tvs (take n_tvs arg_tys) rho_ty)
+ (drop n_tvs arg_tys)
where
(tvs, rho_ty) = splitForAllTys orig_fun_ty
n_tvs = length tvs
tyFamInsts (FunTy ty1 ty2) = tyFamInsts ty1 ++ tyFamInsts ty2
tyFamInsts (AppTy ty1 ty2) = tyFamInsts ty1 ++ tyFamInsts ty2
tyFamInsts (ForAllTy _ ty) = tyFamInsts ty
+tyFamInsts (PredTy pty) = predFamInsts pty
+
+-- | Finds type family instances occuring in a predicate type after expanding
+-- synonyms.
+predFamInsts :: PredType -> [(TyCon, [Type])]
+predFamInsts (ClassP _cla tys) = concat (map tyFamInsts tys)
+predFamInsts (IParam _ ty) = tyFamInsts ty
+predFamInsts (EqPred ty1 ty2) = tyFamInsts ty1 ++ tyFamInsts ty2
\end{code}