-\begin{code}
-isTauTy :: Type -> Bool
-isTauTy (TyVarTy v) = True
-isTauTy (TyConApp _ tys) = all isTauTy tys
-isTauTy (AppTy a b) = isTauTy a && isTauTy b
-isTauTy (FunTy a b) = isTauTy a && isTauTy b
-isTauTy (PredTy p) = isTauTy (predRepTy p)
-isTauTy (NoteTy _ ty) = isTauTy ty
-isTauTy (UsageTy _ ty) = isTauTy ty
-isTauTy other = False
-\end{code}
-
-\begin{code}
-mkRhoTy :: [PredType] -> Type -> Type
-mkRhoTy theta ty = UASSERT2( not (isUTy ty), pprType ty )
- foldr (\p r -> FunTy (mkUTyM (mkPredTy p)) (mkUTyM r)) ty theta
-
-splitRhoTy :: Type -> ([PredType], Type)
-splitRhoTy ty = split ty ty []
- where
- split orig_ty (FunTy arg res) ts = case splitPredTy_maybe arg of
- Just p -> split res res (p:ts)
- Nothing -> (reverse ts, orig_ty)
- split orig_ty (NoteTy _ ty) ts = split orig_ty ty ts
- split orig_ty (UsageTy _ ty) ts = split orig_ty ty ts
- split orig_ty ty ts = (reverse ts, orig_ty)
-\end{code}
-
-The type of a method for class C is always of the form:
- Forall a1..an. C a1..an => sig_ty
-where sig_ty is the type given by the method's signature, and thus in general
-is a ForallTy. At the point that splitMethodTy is called, it is expected
-that the outer Forall has already been stripped off. splitMethodTy then
-returns (C a1..an, sig_ty') where sig_ty' is sig_ty with any Notes or
-Usages stripped off.
-
-\begin{code}
-splitMethodTy :: Type -> (PredType, Type)
-splitMethodTy ty = split ty
- where
- split (FunTy arg res) = case splitPredTy_maybe arg of
- Just p -> (p, res)
- Nothing -> panic "splitMethodTy"
- split (NoteTy _ ty) = split ty
- split (UsageTy _ ty) = split ty
- split _ = panic "splitMethodTy"
-\end{code}
-
-
-isSigmaType returns true of any qualified type. It doesn't *necessarily* have
-any foralls. E.g.
- f :: (?x::Int) => Int -> Int
-
-\begin{code}
-mkSigmaTy tyvars theta tau = mkForAllTys tyvars (mkRhoTy theta tau)
-
-isSigmaTy :: Type -> Bool
-isSigmaTy (ForAllTy tyvar ty) = True
-isSigmaTy (FunTy a b) = isPredTy a
-isSigmaTy (NoteTy _ ty) = isSigmaTy ty
-isSigmaTy (UsageTy _ ty) = isSigmaTy ty
-isSigmaTy _ = False
-
-splitSigmaTy :: Type -> ([TyVar], [PredType], Type)
-splitSigmaTy ty =
- (tyvars, theta, tau)
- where
- (tyvars,rho) = splitForAllTys ty
- (theta,tau) = splitRhoTy rho
-\end{code}