\section[TcMonoType]{Typechecking user-specified @MonoTypes@}
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module TcHsType (
- tcHsSigType, tcHsDeriv,
+ tcHsSigType, tcHsDeriv,
+ tcHsInstHead, tcHsQuantifiedType,
UserTypeCtxt(..),
-- Kind checking
import SrcLoc
import UniqSupply
import Outputable
+
+import Control.Monad
\end{code}
do { kinded_ty <- kcTypeType hs_ty
; ty <- tcHsKindedType kinded_ty
; checkValidType ctxt ty
- ; returnM ty }
+ ; return ty }
+
+tcHsInstHead :: LHsType Name -> TcM ([TyVar], ThetaType, Type)
+-- Typecheck an instance head. We can't use
+-- tcHsSigType, because it's not a valid user type.
+tcHsInstHead hs_ty
+ = do { kinded_ty <- kcHsSigType hs_ty
+ ; poly_ty <- tcHsKindedType kinded_ty
+ ; return (tcSplitSigmaTy poly_ty) }
+
+tcHsQuantifiedType :: [LHsTyVarBndr Name] -> LHsType Name -> TcM ([TyVar], Type)
+-- Behave very like type-checking (HsForAllTy sig_tvs hs_ty),
+-- except that we want to keep the tvs separate
+tcHsQuantifiedType tv_names hs_ty
+ = kcHsTyVars tv_names $ \ tv_names' ->
+ do { kc_ty <- kcHsSigType hs_ty
+ ; tcTyVarBndrs tv_names' $ \ tvs ->
+ do { ty <- dsHsType kc_ty
+ ; return (tvs, ty) } }
-- Used for the deriving(...) items
tcHsDeriv :: LHsType Name -> TcM ([TyVar], Class, [Type])
tcHsKindedContext :: LHsContext Name -> TcM ThetaType
-- Used when we are expecting a ClassContext (i.e. no implicit params)
-- Does not do validity checking, like tcHsKindedType
-tcHsKindedContext hs_theta = addLocM (mappM dsHsLPred) hs_theta
+tcHsKindedContext hs_theta = addLocM (mapM dsHsLPred) hs_theta
\end{code}
--
-- The translated type has explicitly-kinded type-variable binders
-kc_hs_type (HsParTy ty)
- = kcHsType ty `thenM` \ (ty', kind) ->
- returnM (HsParTy ty', kind)
+kc_hs_type (HsParTy ty) = do
+ (ty', kind) <- kcHsType ty
+ return (HsParTy ty', kind)
-kc_hs_type (HsTyVar name)
- = kcTyVar name `thenM` \ kind ->
- returnM (HsTyVar name, kind)
+kc_hs_type (HsTyVar name) = do
+ kind <- kcTyVar name
+ return (HsTyVar name, kind)
-kc_hs_type (HsListTy ty)
- = kcLiftedType ty `thenM` \ ty' ->
- returnM (HsListTy ty', liftedTypeKind)
+kc_hs_type (HsListTy ty) = do
+ ty' <- kcLiftedType ty
+ return (HsListTy ty', liftedTypeKind)
-kc_hs_type (HsPArrTy ty)
- = kcLiftedType ty `thenM` \ ty' ->
- returnM (HsPArrTy ty', liftedTypeKind)
+kc_hs_type (HsPArrTy ty) = do
+ ty' <- kcLiftedType ty
+ return (HsPArrTy ty', liftedTypeKind)
kc_hs_type (HsNumTy n)
- = returnM (HsNumTy n, liftedTypeKind)
-
-kc_hs_type (HsKindSig ty k)
- = kcCheckHsType ty k `thenM` \ ty' ->
- returnM (HsKindSig ty' k, k)
-
-kc_hs_type (HsTupleTy Boxed tys)
- = mappM kcLiftedType tys `thenM` \ tys' ->
- returnM (HsTupleTy Boxed tys', liftedTypeKind)
-
-kc_hs_type (HsTupleTy Unboxed tys)
- = mappM kcTypeType tys `thenM` \ tys' ->
- returnM (HsTupleTy Unboxed tys', ubxTupleKind)
-
-kc_hs_type (HsFunTy ty1 ty2)
- = kcCheckHsType ty1 argTypeKind `thenM` \ ty1' ->
- kcTypeType ty2 `thenM` \ ty2' ->
- returnM (HsFunTy ty1' ty2', liftedTypeKind)
-
-kc_hs_type ty@(HsOpTy ty1 op ty2)
- = addLocM kcTyVar op `thenM` \ op_kind ->
- kcApps op_kind (ppr op) [ty1,ty2] `thenM` \ ([ty1',ty2'], res_kind) ->
- returnM (HsOpTy ty1' op ty2', res_kind)
-
-kc_hs_type ty@(HsAppTy ty1 ty2)
- = kcHsType fun_ty `thenM` \ (fun_ty', fun_kind) ->
- kcApps fun_kind (ppr fun_ty) arg_tys `thenM` \ ((arg_ty':arg_tys'), res_kind) ->
- returnM (foldl mk_app (HsAppTy fun_ty' arg_ty') arg_tys', res_kind)
+ = return (HsNumTy n, liftedTypeKind)
+
+kc_hs_type (HsKindSig ty k) = do
+ ty' <- kcCheckHsType ty k
+ return (HsKindSig ty' k, k)
+
+kc_hs_type (HsTupleTy Boxed tys) = do
+ tys' <- mapM kcLiftedType tys
+ return (HsTupleTy Boxed tys', liftedTypeKind)
+
+kc_hs_type (HsTupleTy Unboxed tys) = do
+ tys' <- mapM kcTypeType tys
+ return (HsTupleTy Unboxed tys', ubxTupleKind)
+
+kc_hs_type (HsFunTy ty1 ty2) = do
+ ty1' <- kcCheckHsType ty1 argTypeKind
+ ty2' <- kcTypeType ty2
+ return (HsFunTy ty1' ty2', liftedTypeKind)
+
+kc_hs_type ty@(HsOpTy ty1 op ty2) = do
+ op_kind <- addLocM kcTyVar op
+ ([ty1',ty2'], res_kind) <- kcApps op_kind (ppr op) [ty1,ty2]
+ return (HsOpTy ty1' op ty2', res_kind)
+
+kc_hs_type ty@(HsAppTy ty1 ty2) = do
+ (fun_ty', fun_kind) <- kcHsType fun_ty
+ ((arg_ty':arg_tys'), res_kind) <- kcApps fun_kind (ppr fun_ty) arg_tys
+ return (foldl mk_app (HsAppTy fun_ty' arg_ty') arg_tys', res_kind)
where
(fun_ty, arg_tys) = split ty1 [ty2]
split (L _ (HsAppTy f a)) as = split f (a:as)
split f as = (f,as)
mk_app fun arg = HsAppTy (noLoc fun) arg -- Add noLocs for inner nodes of
- -- the application; they are never used
-
-kc_hs_type (HsPredTy pred)
- = kcHsPred pred `thenM` \ pred' ->
- returnM (HsPredTy pred', liftedTypeKind)
+ -- the application; they are
+ -- never used
+
+kc_hs_type ty@(HsPredTy (HsEqualP _ _))
+ = wrongEqualityErr
+
+kc_hs_type (HsPredTy pred) = do
+ pred' <- kcHsPred pred
+ return (HsPredTy pred', liftedTypeKind)
kc_hs_type (HsForAllTy exp tv_names context ty)
- = kcHsTyVars tv_names $ \ tv_names' ->
+ = kcHsTyVars tv_names $ \ tv_names' ->
do { ctxt' <- kcHsContext context
; ty' <- kcLiftedType ty
-- The body of a forall is usually a type, but in principle
; return (HsForAllTy exp tv_names' ctxt' ty', liftedTypeKind) }
-kc_hs_type (HsBangTy b ty)
- = do { (ty', kind) <- kcHsType ty
- ; return (HsBangTy b ty', kind) }
+kc_hs_type (HsBangTy b ty) = do
+ (ty', kind) <- kcHsType ty
+ return (HsBangTy b ty', kind)
kc_hs_type ty@(HsSpliceTy _)
= failWithTc (ptext SLIT("Unexpected type splice:") <+> ppr ty)
-> SDoc -- Function
-> [LHsType Name] -- Arg types
-> TcM ([LHsType Name], TcKind) -- Kind-checked args
-kcApps fun_kind ppr_fun args
- = split_fk fun_kind (length args) `thenM` \ (arg_kinds, res_kind) ->
- zipWithM kc_arg args arg_kinds `thenM` \ args' ->
- returnM (args', res_kind)
+kcApps fun_kind ppr_fun args = do
+ (arg_kinds, res_kind) <- split_fk fun_kind (length args)
+ args' <- zipWithM kc_arg args arg_kinds
+ return (args', res_kind)
where
- split_fk fk 0 = returnM ([], fk)
- split_fk fk n = unifyFunKind fk `thenM` \ mb_fk ->
- case mb_fk of
- Nothing -> failWithTc too_many_args
- Just (ak,fk') -> split_fk fk' (n-1) `thenM` \ (aks, rk) ->
- returnM (ak:aks, rk)
+ split_fk fk 0 = return ([], fk)
+ split_fk fk n = do mb_fk <- unifyFunKind fk
+ case mb_fk of
+ Nothing -> failWithTc too_many_args
+ Just (ak,fk') -> do (aks, rk) <- split_fk fk' (n-1)
+ return (ak:aks, rk)
kc_arg arg arg_kind = kcCheckHsType arg arg_kind
---------------------------
kcHsContext :: LHsContext Name -> TcM (LHsContext Name)
-kcHsContext ctxt = wrapLocM (mappM kcHsLPred) ctxt
+kcHsContext ctxt = wrapLocM (mapM kcHsLPred) ctxt
kcHsLPred :: LHsPred Name -> TcM (LHsPred Name)
kcHsLPred = wrapLocM kcHsPred
kcHsPred :: HsPred Name -> TcM (HsPred Name)
-kcHsPred pred -- Checks that the result is of kind liftedType
- = kc_pred pred `thenM` \ (pred', kind) ->
- checkExpectedKind pred kind liftedTypeKind `thenM_`
- returnM pred'
+kcHsPred pred = do -- Checks that the result is of kind liftedType
+ (pred', kind) <- kc_pred pred
+ checkExpectedKind pred kind liftedTypeKind
+ return pred'
---------------------------
kc_pred :: HsPred Name -> TcM (HsPred Name, TcKind)
-- Does *not* check for a saturated
-- application (reason: used from TcDeriv)
kc_pred pred@(HsIParam name ty)
- = kcHsType ty `thenM` \ (ty', kind) ->
- returnM (HsIParam name ty', kind)
-
+ = do { (ty', kind) <- kcHsType ty
+ ; return (HsIParam name ty', kind)
+ }
kc_pred pred@(HsClassP cls tys)
- = kcClass cls `thenM` \ kind ->
- kcApps kind (ppr cls) tys `thenM` \ (tys', res_kind) ->
- returnM (HsClassP cls tys', res_kind)
+ = do { kind <- kcClass cls
+ ; (tys', res_kind) <- kcApps kind (ppr cls) tys
+ ; return (HsClassP cls tys', res_kind)
+ }
+kc_pred pred@(HsEqualP ty1 ty2)
+ = do { (ty1', kind1) <- kcHsType ty1
+-- ; checkExpectedKind ty1 kind1 liftedTypeKind
+ ; (ty2', kind2) <- kcHsType ty2
+-- ; checkExpectedKind ty2 kind2 liftedTypeKind
+ ; checkExpectedKind ty2 kind2 kind1
+ ; return (HsEqualP ty1' ty2', liftedTypeKind)
+ }
---------------------------
kcTyVar :: Name -> TcM TcKind
-kcTyVar name -- Could be a tyvar or a tycon
- = traceTc (text "lk1" <+> ppr name) `thenM_`
- tcLookup name `thenM` \ thing ->
- traceTc (text "lk2" <+> ppr name <+> ppr thing) `thenM_`
+kcTyVar name = do -- Could be a tyvar or a tycon
+ traceTc (text "lk1" <+> ppr name)
+ thing <- tcLookup name
+ traceTc (text "lk2" <+> ppr name <+> ppr thing)
case thing of
- ATyVar _ ty -> returnM (typeKind ty)
- AThing kind -> returnM kind
- AGlobal (ATyCon tc) -> returnM (tyConKind tc)
- other -> wrongThingErr "type" thing name
+ ATyVar _ ty -> return (typeKind ty)
+ AThing kind -> return kind
+ AGlobal (ATyCon tc) -> return (tyConKind tc)
+ other -> wrongThingErr "type" thing name
kcClass :: Name -> TcM TcKind
-kcClass cls -- Must be a class
- = tcLookup cls `thenM` \ thing ->
+kcClass cls = do -- Must be a class
+ thing <- tcLookup cls
case thing of
- AThing kind -> returnM kind
- AGlobal (AClass cls) -> returnM (tyConKind (classTyCon cls))
- other -> wrongThingErr "class" thing cls
+ AThing kind -> return kind
+ AGlobal (AClass cls) -> return (tyConKind (classTyCon cls))
+ other -> wrongThingErr "class" thing cls
\end{code}
ds_type (HsKindSig ty k)
= dsHsType ty -- Kind checking done already
-ds_type (HsListTy ty)
- = dsHsType ty `thenM` \ tau_ty ->
- checkWiredInTyCon listTyCon `thenM_`
- returnM (mkListTy tau_ty)
+ds_type (HsListTy ty) = do
+ tau_ty <- dsHsType ty
+ checkWiredInTyCon listTyCon
+ return (mkListTy tau_ty)
-ds_type (HsPArrTy ty)
- = dsHsType ty `thenM` \ tau_ty ->
- checkWiredInTyCon parrTyCon `thenM_`
- returnM (mkPArrTy tau_ty)
+ds_type (HsPArrTy ty) = do
+ tau_ty <- dsHsType ty
+ checkWiredInTyCon parrTyCon
+ return (mkPArrTy tau_ty)
-ds_type (HsTupleTy boxity tys)
- = dsHsTypes tys `thenM` \ tau_tys ->
- checkWiredInTyCon tycon `thenM_`
- returnM (mkTyConApp tycon tau_tys)
+ds_type (HsTupleTy boxity tys) = do
+ tau_tys <- dsHsTypes tys
+ checkWiredInTyCon tycon
+ return (mkTyConApp tycon tau_tys)
where
tycon = tupleTyCon boxity (length tys)
-ds_type (HsFunTy ty1 ty2)
- = dsHsType ty1 `thenM` \ tau_ty1 ->
- dsHsType ty2 `thenM` \ tau_ty2 ->
- returnM (mkFunTy tau_ty1 tau_ty2)
+ds_type (HsFunTy ty1 ty2) = do
+ tau_ty1 <- dsHsType ty1
+ tau_ty2 <- dsHsType ty2
+ return (mkFunTy tau_ty1 tau_ty2)
-ds_type (HsOpTy ty1 (L span op) ty2)
- = dsHsType ty1 `thenM` \ tau_ty1 ->
- dsHsType ty2 `thenM` \ tau_ty2 ->
+ds_type (HsOpTy ty1 (L span op) ty2) = do
+ tau_ty1 <- dsHsType ty1
+ tau_ty2 <- dsHsType ty2
setSrcSpan span (ds_var_app op [tau_ty1,tau_ty2])
ds_type (HsNumTy n)
- = ASSERT(n==1)
- tcLookupTyCon genUnitTyConName `thenM` \ tc ->
- returnM (mkTyConApp tc [])
+ = ASSERT(n==1) do
+ tc <- tcLookupTyCon genUnitTyConName
+ return (mkTyConApp tc [])
ds_type ty@(HsAppTy _ _)
= ds_app ty []
-ds_type (HsPredTy pred)
- = dsHsPred pred `thenM` \ pred' ->
- returnM (mkPredTy pred')
+ds_type (HsPredTy pred) = do
+ pred' <- dsHsPred pred
+ return (mkPredTy pred')
ds_type full_ty@(HsForAllTy exp tv_names ctxt ty)
- = tcTyVarBndrs tv_names $ \ tyvars ->
- mappM dsHsLPred (unLoc ctxt) `thenM` \ theta ->
- dsHsType ty `thenM` \ tau ->
- returnM (mkSigmaTy tyvars theta tau)
+ = tcTyVarBndrs tv_names $ \ tyvars -> do
+ theta <- mapM dsHsLPred (unLoc ctxt)
+ tau <- dsHsType ty
+ return (mkSigmaTy tyvars theta tau)
ds_type (HsSpliceTy {}) = panic "ds_type: HsSpliceTy"
-dsHsTypes arg_tys = mappM dsHsType arg_tys
+ds_type (HsDocTy ty _) -- Remove the doc comment
+ = dsHsType ty
+
+dsHsTypes arg_tys = mapM dsHsType arg_tys
\end{code}
Help functions for type applications
ds_app (HsAppTy ty1 ty2) tys
= ds_app (unLoc ty1) (ty2:tys)
-ds_app ty tys
- = dsHsTypes tys `thenM` \ arg_tys ->
+ds_app ty tys = do
+ arg_tys <- dsHsTypes tys
case ty of
HsTyVar fun -> ds_var_app fun arg_tys
- other -> ds_type ty `thenM` \ fun_ty ->
- returnM (mkAppTys fun_ty arg_tys)
+ other -> do fun_ty <- ds_type ty
+ return (mkAppTys fun_ty arg_tys)
ds_var_app :: Name -> [Type] -> TcM Type
-ds_var_app name arg_tys
- = tcLookup name `thenM` \ thing ->
+ds_var_app name arg_tys = do
+ thing <- tcLookup name
case thing of
- ATyVar _ ty -> returnM (mkAppTys ty arg_tys)
- AGlobal (ATyCon tc) -> returnM (mkTyConApp tc arg_tys)
+ ATyVar _ ty -> return (mkAppTys ty arg_tys)
+ AGlobal (ATyCon tc) -> return (mkTyConApp tc arg_tys)
other -> wrongThingErr "type" thing name
\end{code}
dsHsLPred pred = dsHsPred (unLoc pred)
dsHsPred pred@(HsClassP class_name tys)
- = dsHsTypes tys `thenM` \ arg_tys ->
- tcLookupClass class_name `thenM` \ clas ->
- returnM (ClassP clas arg_tys)
-
+ = do { arg_tys <- dsHsTypes tys
+ ; clas <- tcLookupClass class_name
+ ; return (ClassP clas arg_tys)
+ }
+dsHsPred pred@(HsEqualP ty1 ty2)
+ = do { arg_ty1 <- dsHsType ty1
+ ; arg_ty2 <- dsHsType ty2
+ ; return (EqPred arg_ty1 arg_ty2)
+ }
dsHsPred (HsIParam name ty)
- = dsHsType ty `thenM` \ arg_ty ->
- returnM (IParam name arg_ty)
+ = do { arg_ty <- dsHsType ty
+ ; return (IParam name arg_ty)
+ }
\end{code}
GADT constructor signatures
-> ([LHsTyVarBndr Name] -> TcM r) -- These binders are kind-annotated
-- They scope over the thing inside
-> TcM r
-kcHsTyVars tvs thing_inside
- = mappM (wrapLocM kcHsTyVar) tvs `thenM` \ bndrs ->
+kcHsTyVars tvs thing_inside = do
+ bndrs <- mapM (wrapLocM kcHsTyVar) tvs
tcExtendKindEnvTvs bndrs (thing_inside bndrs)
kcHsTyVar :: HsTyVarBndr Name -> TcM (HsTyVarBndr Name)
-- Return a *kind-annotated* binder, and a tyvar with a mutable kind in it
-kcHsTyVar (UserTyVar name) = newKindVar `thenM` \ kind ->
- returnM (KindedTyVar name kind)
-kcHsTyVar (KindedTyVar name kind) = returnM (KindedTyVar name kind)
+kcHsTyVar (UserTyVar name) = KindedTyVar name <$> newKindVar
+kcHsTyVar (KindedTyVar name kind) = return (KindedTyVar name kind)
------------------
tcTyVarBndrs :: [LHsTyVarBndr Name] -- Kind-annotated binders, which need kind-zonking
-> TcM r
-- Used when type-checking types/classes/type-decls
-- Brings into scope immutable TyVars, not mutable ones that require later zonking
-tcTyVarBndrs bndrs thing_inside
- = mapM (zonk . unLoc) bndrs `thenM` \ tyvars ->
+tcTyVarBndrs bndrs thing_inside = do
+ tyvars <- mapM (zonk . unLoc) bndrs
tcExtendTyVarEnv tyvars (thing_inside tyvars)
where
zonk (KindedTyVar name kind) = do { kind' <- zonkTcKindToKind kind
; return (mkTyVar name kind') }
- zonk (UserTyVar name) = pprTrace "Un-kinded tyvar" (ppr name) $
+ zonk (UserTyVar name) = WARN( True, ptext SLIT("Un-kinded tyvar") <+> ppr name )
return (mkTyVar name liftedTypeKind)
-----------------------------------
= do { checkTc (isLiftedTypeKind res_kind) (badKindSig kind)
; span <- getSrcSpanM
; us <- newUniqueSupply
- ; let loc = srcSpanStart span
- uniqs = uniqsFromSupply us
- ; return [ mk_tv loc uniq str kind
+ ; let uniqs = uniqsFromSupply us
+ ; return [ mk_tv span uniq str kind
| ((kind, str), uniq) <- arg_kinds `zip` names `zip` uniqs ] }
where
(arg_kinds, res_kind) = splitKindFunTys kind
| n <- nameSetToList (extractHsTyVars hs_ty),
not (in_scope n) ]
- -- Behave very like type-checking (HsForAllTy sig_tvs hs_ty),
- -- except that we want to keep the tvs separate
- ; (kinded_tvs, kinded_ty) <- kcHsTyVars sig_tvs $ \ kinded_tvs -> do
- { kinded_ty <- kcTypeType hs_ty
- ; return (kinded_tvs, kinded_ty) }
- ; tcTyVarBndrs kinded_tvs $ \ tyvars -> do
- { sig_ty <- dsHsType kinded_ty
+ ; (tyvars, sig_ty) <- tcHsQuantifiedType sig_tvs hs_ty
; checkValidType ctxt sig_ty
; return (tyvars, sig_ty)
- } }
+ }
tcPatSig :: UserTypeCtxt
-> LHsType Name
pp_sig (FunSigCtxt n) = pp_n_colon n
pp_sig (ConArgCtxt n) = pp_n_colon n
pp_sig (ForSigCtxt n) = pp_n_colon n
- pp_sig (RuleSigCtxt n) = pp_n_colon n
pp_sig other = ppr (unLoc hs_ty)
pp_n_colon n = ppr n <+> dcolon <+> ppr (unLoc hs_ty)
= hang (ptext SLIT("The scoped type variables") <+> quotes (ppr n) <+> ptext SLIT("and") <+> quotes (ppr n'))
2 (vcat [ptext SLIT("are bound to the same type (variable)"),
ptext SLIT("Distinct scoped type variables must be distinct")])
+
+wrongEqualityErr
+ = failWithTc (text "Equality predicate used as a type")
\end{code}
projects / ghc-hetmet.git / blobdiff