-
+%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\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
#include "HsVersions.h"
-import HsSyn ( HsType(..), LHsType, HsTyVarBndr(..), LHsTyVarBndr,
- LHsContext, HsPred(..), LHsPred )
-import RnHsSyn ( extractHsTyVars )
+import HsSyn
+import RnHsSyn
import TcRnMonad
-import TcEnv ( tcExtendTyVarEnv, tcExtendKindEnvTvs,
- tcLookup, tcLookupClass, tcLookupTyCon,
- TyThing(..), getInLocalScope, getScopedTyVarBinds,
- wrongThingErr
- )
-import TcMType ( newKindVar,
- zonkTcKindToKind,
- tcInstBoxyTyVar, readFilledBox,
- checkValidType
- )
-import TcUnify ( boxyUnify, unifyFunKind, checkExpectedKind )
-import TcIface ( checkWiredInTyCon )
-import TcType ( Type, PredType(..), ThetaType, BoxySigmaType,
- TcType, TcKind, isRigidTy,
- UserTypeCtxt(..), pprUserTypeCtxt,
- substTyWith, mkTyVarTys, tcEqType,
- tcIsTyVarTy, mkFunTy, mkSigmaTy, mkPredTy,
- mkTyConApp, mkAppTys, typeKind )
-import {- Kind parts of -} Type ( Kind, isLiftedTypeKind, liftedTypeKind, ubxTupleKind,
- openTypeKind, argTypeKind, splitKindFunTys )
-import Var ( TyVar, mkTyVar, tyVarName )
-import TyCon ( TyCon, tyConKind )
-import Class ( Class, classTyCon )
-import Name ( Name, mkInternalName )
-import OccName ( mkOccName, tvName )
+import TcEnv
+import TcMType
+import TcUnify
+import TcIface
+import TcType
+import {- Kind parts of -} Type
+import Var
+import TyCon
+import Class
+import Name
+import OccName
import NameSet
-import PrelNames ( genUnitTyConName )
-import TysWiredIn ( mkListTy, listTyCon, mkPArrTy, parrTyCon, tupleTyCon )
-import BasicTypes ( Boxity(..) )
-import SrcLoc ( Located(..), unLoc, noLoc, getLoc, srcSpanStart )
-import UniqSupply ( uniqsFromSupply )
+import PrelNames
+import TysWiredIn
+import BasicTypes
+import SrcLoc
+import UniqSupply
import Outputable
\end{code}
; checkValidType ctxt ty
; returnM 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])
tcHsDeriv = addLocM (tc_hs_deriv [])
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
-
+ -- the application; they are
+ -- never used
+
+kc_hs_type ty@(HsPredTy (HsEqualP _ _))
+ = wrongEqualityErr
+
kc_hs_type (HsPredTy pred)
= kcHsPred pred `thenM` \ pred' ->
returnM (HsPredTy pred', liftedTypeKind)
-- 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
+ ; returnM (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
+ ; returnM (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
+ ; returnM (HsEqualP ty1' ty2', liftedTypeKind)
+ }
---------------------------
kcTyVar :: Name -> TcM TcKind
ds_type (HsSpliceTy {}) = panic "ds_type: HsSpliceTy"
+ds_type (HsDocTy ty _) -- Remove the doc comment
+ = dsHsType ty
+
dsHsTypes arg_tys = mappM dsHsType arg_tys
\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
+ ; returnM (ClassP clas arg_tys)
+ }
+dsHsPred pred@(HsEqualP ty1 ty2)
+ = do { arg_ty1 <- dsHsType ty1
+ ; arg_ty2 <- dsHsType ty2
+ ; returnM (EqPred arg_ty1 arg_ty2)
+ }
dsHsPred (HsIParam name ty)
- = dsHsType ty `thenM` \ arg_ty ->
- returnM (IParam name arg_ty)
+ = do { arg_ty <- dsHsType ty
+ ; returnM (IParam name arg_ty)
+ }
\end{code}
GADT constructor signatures
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}