X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcMType.lhs;h=df9bd1134468c93d4e39a4b68df45b2e3d86d34c;hb=98688c6e8fd33f31c51218cf93cbf03fe3a5e73d;hp=cc45bf4a16e36af87e9d7c2cbc9a8dacebbf3aa5;hpb=79c93a8a30aaaa6bd940c0677d6f3c57eb727fa2;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcMType.lhs b/ghc/compiler/typecheck/TcMType.lhs index cc45bf4..df9bd11 100644 --- a/ghc/compiler/typecheck/TcMType.lhs +++ b/ghc/compiler/typecheck/TcMType.lhs @@ -14,7 +14,7 @@ module TcMType ( newTyVar, newSigTyVar, newTyVarTy, -- Kind -> TcM TcType newTyVarTys, -- Int -> Kind -> TcM [TcType] - newKindVar, newKindVars, newOpenTypeKind, + newKindVar, newKindVars, newBoxityVar, putTcTyVar, getTcTyVar, newMutTyVar, readMutTyVar, writeMutTyVar, @@ -25,17 +25,17 @@ module TcMType ( -------------------------------- -- Checking type validity Rank, UserTypeCtxt(..), checkValidType, pprUserTypeCtxt, - SourceTyCtxt(..), checkValidTheta, - checkValidTyCon, checkValidClass, + SourceTyCtxt(..), checkValidTheta, checkFreeness, checkValidInstHead, instTypeErr, checkAmbiguity, - arityErr, + arityErr, -------------------------------- -- Zonking zonkType, zonkTcTyVar, zonkTcTyVars, zonkTcTyVarsAndFV, zonkTcType, zonkTcTypes, zonkTcClassConstraints, zonkTcThetaType, - zonkTcPredType, zonkTcTyVarToTyVar, zonkKindEnv, + zonkTcPredType, zonkTcTyVarToTyVar, + zonkTcKindToKind ) where @@ -43,48 +43,41 @@ module TcMType ( -- friends: -import TypeRep ( Type(..), SourceType(..), TyNote(..), -- Friend; can see representation - Kind, ThetaType, typeCon +import TypeRep ( Type(..), PredType(..), TyNote(..), -- Friend; can see representation + Kind, ThetaType ) import TcType ( TcType, TcThetaType, TcTauType, TcPredType, TcTyVarSet, TcKind, TcTyVar, TyVarDetails(..), tcEqType, tcCmpPred, isClassPred, tcSplitPhiTy, tcSplitPredTy_maybe, tcSplitAppTy_maybe, tcSplitTyConApp_maybe, tcSplitForAllTys, - tcIsTyVarTy, tcSplitSigmaTy, mkTyConApp, + tcIsTyVarTy, tcSplitSigmaTy, isUnLiftedType, isIPPred, isTyVarTy, mkAppTy, mkTyVarTy, mkTyVarTys, tyVarsOfPred, getClassPredTys_maybe, - liftedTypeKind, openTypeKind, defaultKind, superKind, + liftedTypeKind, defaultKind, superKind, superBoxity, liftedBoxity, typeKind, tyVarsOfType, tyVarsOfTypes, eqKind, isTypeKind, - isFFIArgumentTy, isFFIImportResultTy ) import Subst ( Subst, mkTopTyVarSubst, substTy ) -import Class ( Class, DefMeth(..), classArity, className, classBigSig ) +import Class ( Class, classArity, className ) import TyCon ( TyCon, isSynTyCon, isUnboxedTupleTyCon, - tyConArity, tyConName, tyConTheta, - getSynTyConDefn, tyConDataCons ) -import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig, dataConFieldLabels ) -import FieldLabel ( fieldLabelName, fieldLabelType ) -import Var ( TyVar, idType, idName, tyVarKind, tyVarName, isTyVar, + tyConArity, tyConName ) +import Var ( TyVar, tyVarKind, tyVarName, isTyVar, mkTyVar, mkMutTyVar, isMutTyVar, mutTyVarRef ) -- others: -import Generics ( validGenericMethodType ) import TcRnMonad -- TcType, amongst others -import PrelNames ( hasKey ) -import ForeignCall ( Safety(..) ) import FunDeps ( grow ) -import PprType ( pprPred, pprSourceType, pprTheta, pprClassPred ) +import PprType ( pprPred, pprTheta, pprClassPred ) import Name ( Name, setNameUnique, mkSystemTvNameEncoded ) import VarSet import CmdLineOpts ( dopt, DynFlag(..) ) -import Util ( nOfThem, isSingleton, equalLength, notNull, lengthExceeds ) -import ListSetOps ( equivClasses, removeDups ) +import Util ( nOfThem, isSingleton, equalLength, notNull ) +import ListSetOps ( removeDups ) import Outputable \end{code} @@ -134,11 +127,11 @@ newKindVar newKindVars :: Int -> TcM [TcKind] newKindVars n = mappM (\ _ -> newKindVar) (nOfThem n ()) -newOpenTypeKind :: TcM TcKind -- Returns the kind (Type bx), where bx is fresh -newOpenTypeKind - = newUnique `thenM` \ uniq -> - newMutTyVar (mkSystemTvNameEncoded uniq FSLIT("bx")) superBoxity VanillaTv `thenM` \ kv -> - returnM (mkTyConApp typeCon [TyVarTy kv]) +newBoxityVar :: TcM TcKind -- Really TcBoxity + = newUnique `thenM` \ uniq -> + newMutTyVar (mkSystemTvNameEncoded uniq FSLIT("bx")) + superBoxity VanillaTv `thenM` \ kv -> + returnM (TyVarTy kv) \end{code} @@ -319,19 +312,17 @@ zonkTcPredType (IParam n t) are used at the end of type checking \begin{code} -zonkKindEnv :: [(Name, TcKind)] -> TcM [(Name, Kind)] -zonkKindEnv pairs - = mappM zonk_it pairs - where - zonk_it (name, tc_kind) = zonkType zonk_unbound_kind_var tc_kind `thenM` \ kind -> - returnM (name, kind) - +zonkTcKindToKind :: TcKind -> TcM Kind +zonkTcKindToKind tc_kind + = zonkType zonk_unbound_kind_var tc_kind + where -- When zonking a kind, we want to -- zonk a *kind* variable to (Type *) -- zonk a *boxity* variable to * - zonk_unbound_kind_var kv | tyVarKind kv `eqKind` superKind = putTcTyVar kv liftedTypeKind - | tyVarKind kv `eqKind` superBoxity = putTcTyVar kv liftedBoxity - | otherwise = pprPanic "zonkKindEnv" (ppr kv) + zonk_unbound_kind_var kv + | tyVarKind kv `eqKind` superKind = putTcTyVar kv liftedTypeKind + | tyVarKind kv `eqKind` superBoxity = putTcTyVar kv liftedBoxity + | otherwise = pprPanic "zonkKindEnv" (ppr kv) -- zonkTcTyVarToTyVar is applied to the *binding* occurrence -- of a type variable, at the *end* of type checking. It changes @@ -421,14 +412,17 @@ zonkType unbound_var_fn ty go (TyConApp tycon tys) = mappM go tys `thenM` \ tys' -> returnM (TyConApp tycon tys') + go (NewTcApp tycon tys) = mappM go tys `thenM` \ tys' -> + returnM (NewTcApp tycon tys') + go (NoteTy (SynNote ty1) ty2) = go ty1 `thenM` \ ty1' -> go ty2 `thenM` \ ty2' -> returnM (NoteTy (SynNote ty1') ty2') go (NoteTy (FTVNote _) ty2) = go ty2 -- Discard free-tyvar annotations - go (SourceTy p) = go_pred p `thenM` \ p' -> - returnM (SourceTy p') + go (PredTy p) = go_pred p `thenM` \ p' -> + returnM (PredTy p') go (FunTy arg res) = go arg `thenM` \ arg' -> go res `thenM` \ res' -> @@ -450,8 +444,6 @@ zonkType unbound_var_fn ty go_pred (ClassP c tys) = mappM go tys `thenM` \ tys' -> returnM (ClassP c tys') - go_pred (NType tc tys) = mappM go tys `thenM` \ tys' -> - returnM (NType tc tys') go_pred (IParam n ty) = go ty `thenM` \ ty' -> returnM (IParam n ty') @@ -521,6 +513,7 @@ data UserTypeCtxt -- f x :: t = .... | ForSigCtxt Name -- Foreign inport or export signature | RuleSigCtxt Name -- Signature on a forall'd variable in a RULE + | DefaultDeclCtxt -- Types in a default declaration -- Notes re TySynCtxt -- We allow type synonyms that aren't types; e.g. type List = [] @@ -542,19 +535,22 @@ pprUserTypeCtxt PatSigCtxt = ptext SLIT("a pattern type signature") pprUserTypeCtxt ResSigCtxt = ptext SLIT("a result type signature") pprUserTypeCtxt (ForSigCtxt n) = ptext SLIT("the foreign signature for") <+> quotes (ppr n) pprUserTypeCtxt (RuleSigCtxt n) = ptext SLIT("the type signature on") <+> quotes (ppr n) +pprUserTypeCtxt DefaultDeclCtxt = ptext SLIT("a `default' declaration") \end{code} \begin{code} checkValidType :: UserTypeCtxt -> Type -> TcM () -- Checks that the type is valid for the given context checkValidType ctxt ty - = doptM Opt_GlasgowExts `thenM` \ gla_exts -> + = traceTc (text "checkValidType" <+> ppr ty) `thenM_` + doptM Opt_GlasgowExts `thenM` \ gla_exts -> let rank | gla_exts = Arbitrary | otherwise = case ctxt of -- Haskell 98 GenPatCtxt -> Rank 0 PatSigCtxt -> Rank 0 + DefaultDeclCtxt-> Rank 0 ResSigCtxt -> Rank 0 TySynCtxt _ -> Rank 0 ExprSigCtxt -> Rank 1 @@ -582,31 +578,13 @@ checkValidType ctxt ty -- but for type synonyms we allow them even at -- top level in - addErrCtxt (checkTypeCtxt ctxt ty) $ - -- Check that the thing has kind Type, and is lifted if necessary checkTc kind_ok (kindErr actual_kind) `thenM_` -- Check the internal validity of the type itself - check_poly_type rank ubx_tup ty - - -checkTypeCtxt ctxt ty - = vcat [ptext SLIT("In the type:") <+> ppr_ty ty, - ptext SLIT("While checking") <+> pprUserTypeCtxt ctxt ] - - -- Hack alert. If there are no tyvars, (ppr sigma_ty) will print - -- something strange like {Eq k} -> k -> k, because there is no - -- ForAll at the top of the type. Since this is going to the user - -- we want it to look like a proper Haskell type even then; hence the hack - -- - -- This shows up in the complaint about - -- case C a where - -- op :: Eq a => a -> a -ppr_ty ty | null forall_tvs && notNull theta = pprTheta theta <+> ptext SLIT("=>") <+> ppr tau - | otherwise = ppr ty - where - (forall_tvs, theta, tau) = tcSplitSigmaTy ty + check_poly_type rank ubx_tup ty `thenM_` + + traceTc (text "checkValidType done" <+> ppr ty) \end{code} @@ -665,7 +643,7 @@ check_tau_type :: Rank -> UbxTupFlag -> Type -> TcM () -- No foralls otherwise check_tau_type rank ubx_tup ty@(ForAllTy _ _) = failWithTc (forAllTyErr ty) -check_tau_type rank ubx_tup (SourceTy sty) = getDOpts `thenM` \ dflags -> +check_tau_type rank ubx_tup (PredTy sty) = getDOpts `thenM` \ dflags -> check_source_ty dflags TypeCtxt sty check_tau_type rank ubx_tup (TyVarTy _) = returnM () check_tau_type rank ubx_tup ty@(FunTy arg_ty res_ty) @@ -701,6 +679,9 @@ check_tau_type rank ubx_tup (NoteTy (SynNote syn) ty) check_tau_type rank ubx_tup (NoteTy other_note ty) = check_tau_type rank ubx_tup ty +check_tau_type rank ubx_tup (NewTcApp tc tys) + = mappM_ check_arg_type tys + check_tau_type rank ubx_tup ty@(TyConApp tc tys) | isSynTyCon tc = -- NB: Type.mkSynTy builds a TyConApp (not a NoteTy) for an unsaturated @@ -734,9 +715,9 @@ check_tau_type rank ubx_tup ty@(TyConApp tc tys) ubx_tup_msg = ubxArgTyErr ty ---------------------------------------- -forAllTyErr ty = ptext SLIT("Illegal polymorphic type:") <+> ppr_ty ty -unliftedArgErr ty = ptext SLIT("Illegal unlifted type argument:") <+> ppr_ty ty -ubxArgTyErr ty = ptext SLIT("Illegal unboxed tuple type as function argument:") <+> ppr_ty ty +forAllTyErr ty = ptext SLIT("Illegal polymorphic type:") <+> ppr ty +unliftedArgErr ty = ptext SLIT("Illegal unlifted type argument:") <+> ppr ty +ubxArgTyErr ty = ptext SLIT("Illegal unboxed tuple type as function argument:") <+> ppr ty kindErr kind = ptext SLIT("Expecting an ordinary type, but found a type of kind") <+> ppr kind \end{code} @@ -789,7 +770,7 @@ check_valid_theta ctxt theta = getDOpts `thenM` \ dflags -> warnTc (notNull dups) (dupPredWarn dups) `thenM_` -- Actually, in instance decls and type signatures, - -- duplicate constraints are eliminated by TcMonoType.hoistForAllTys, + -- duplicate constraints are eliminated by TcHsType.hoistForAllTys, -- so this error can only fire for the context of a class or -- data type decl. mappM_ (check_source_ty dflags ctxt) theta @@ -799,8 +780,10 @@ check_valid_theta ctxt theta ------------------------- check_source_ty dflags ctxt pred@(ClassP cls tys) = -- Class predicates are valid in all contexts - mappM_ check_arg_type tys `thenM_` checkTc (arity == n_tys) arity_err `thenM_` + + -- Check the form of the argument types + mappM_ check_arg_type tys `thenM_` checkTc (check_class_pred_tys dflags ctxt tys) (predTyVarErr pred $$ how_to_allow) @@ -825,8 +808,6 @@ check_source_ty dflags SigmaCtxt (IParam _ ty) = check_arg_type ty -- constraint Foo [Int] might come out of e,and applying the -- instance decl would show up two uses of ?x. -check_source_ty dflags TypeCtxt (NType tc tys) = mappM_ check_arg_type tys - -- Catch-all check_source_ty dflags ctxt sty = failWithTc (badSourceTyErr sty) @@ -931,7 +912,7 @@ checkThetaCtxt ctxt theta = vcat [ptext SLIT("In the context:") <+> pprTheta theta, ptext SLIT("While checking") <+> pprSourceTyCtxt ctxt ] -badSourceTyErr sty = ptext SLIT("Illegal constraint") <+> pprSourceType sty +badSourceTyErr sty = ptext SLIT("Illegal constraint") <+> pprPred sty predTyVarErr pred = ptext SLIT("Non-type variables in constraint:") <+> pprPred pred dupPredWarn dups = ptext SLIT("Duplicate constraint(s):") <+> pprWithCommas pprPred (map head dups) @@ -947,133 +928,6 @@ arityErr kind name n m %************************************************************************ %* * -\subsection{Validity check for TyCons} -%* * -%************************************************************************ - -checkValidTyCon is called once the mutually-recursive knot has been -tied, so we can look at things freely. - -\begin{code} -checkValidTyCon :: TyCon -> TcM () -checkValidTyCon tc - | isSynTyCon tc = checkValidType (TySynCtxt name) syn_rhs - | otherwise - = -- Check the context on the data decl - checkValidTheta (DataTyCtxt name) (tyConTheta tc) `thenM_` - - -- Check arg types of data constructors - mappM_ checkValidDataCon data_cons `thenM_` - - -- Check that fields with the same name share a type - mappM_ check_fields groups - - where - name = tyConName tc - (_, syn_rhs) = getSynTyConDefn tc - data_cons = tyConDataCons tc - - fields = [field | con <- data_cons, field <- dataConFieldLabels con] - groups = equivClasses cmp_name fields - cmp_name field1 field2 = fieldLabelName field1 `compare` fieldLabelName field2 - - check_fields fields@(first_field_label : other_fields) - -- These fields all have the same name, but are from - -- different constructors in the data type - = -- Check that all the fields in the group have the same type - -- NB: this check assumes that all the constructors of a given - -- data type use the same type variables - checkTc (all (tcEqType field_ty) other_tys) (fieldTypeMisMatch field_name) - where - field_ty = fieldLabelType first_field_label - field_name = fieldLabelName first_field_label - other_tys = map fieldLabelType other_fields - -checkValidDataCon :: DataCon -> TcM () -checkValidDataCon con - = checkValidType ctxt (idType (dataConWrapId con)) `thenM_` - -- This checks the argument types and - -- ambiguity of the existential context (if any) - addErrCtxt (existentialCtxt con) - (checkFreeness ex_tvs ex_theta) - where - ctxt = ConArgCtxt (dataConName con) - (_, _, ex_tvs, ex_theta, _, _) = dataConSig con - - -fieldTypeMisMatch field_name - = sep [ptext SLIT("Different constructors give different types for field"), quotes (ppr field_name)] - -existentialCtxt con = ptext SLIT("When checking the existential context of constructor") - <+> quotes (ppr con) -\end{code} - - -checkValidClass is called once the mutually-recursive knot has been -tied, so we can look at things freely. - -\begin{code} -checkValidClass :: Class -> TcM () -checkValidClass cls - = -- CHECK ARITY 1 FOR HASKELL 1.4 - doptM Opt_GlasgowExts `thenM` \ gla_exts -> - - -- Check that the class is unary, unless GlaExs - checkTc (notNull tyvars) (nullaryClassErr cls) `thenM_` - checkTc (gla_exts || unary) (classArityErr cls) `thenM_` - - -- Check the super-classes - checkValidTheta (ClassSCCtxt (className cls)) theta `thenM_` - - -- Check the class operations - mappM_ check_op op_stuff `thenM_` - - -- Check that if the class has generic methods, then the - -- class has only one parameter. We can't do generic - -- multi-parameter type classes! - checkTc (unary || no_generics) (genericMultiParamErr cls) - - where - (tyvars, theta, _, op_stuff) = classBigSig cls - unary = isSingleton tyvars - no_generics = null [() | (_, GenDefMeth) <- op_stuff] - - check_op (sel_id, dm) - = checkValidTheta SigmaCtxt (tail theta) `thenM_` - -- The 'tail' removes the initial (C a) from the - -- class itself, leaving just the method type - - checkValidType (FunSigCtxt op_name) tau `thenM_` - - -- Check that for a generic method, the type of - -- the method is sufficiently simple - checkTc (dm /= GenDefMeth || validGenericMethodType op_ty) - (badGenericMethodType op_name op_ty) - where - op_name = idName sel_id - op_ty = idType sel_id - (_,theta,tau) = tcSplitSigmaTy op_ty - -nullaryClassErr cls - = ptext SLIT("No parameters for class") <+> quotes (ppr cls) - -classArityErr cls - = vcat [ptext SLIT("Too many parameters for class") <+> quotes (ppr cls), - parens (ptext SLIT("Use -fglasgow-exts to allow multi-parameter classes"))] - -genericMultiParamErr clas - = ptext SLIT("The multi-parameter class") <+> quotes (ppr clas) <+> - ptext SLIT("cannot have generic methods") - -badGenericMethodType op op_ty - = hang (ptext SLIT("Generic method type is too complex")) - 4 (vcat [ppr op <+> dcolon <+> ppr op_ty, - ptext SLIT("You can only use type variables, arrows, and tuples")]) -\end{code} - - -%************************************************************************ -%* * \subsection{Checking for a decent instance head type} %* * %************************************************************************