X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyDecls.lhs;h=450dad952c46465bb45262a215f73b95473a6614;hb=bebb2614af8819da9298fb537d2a777743b3fabb;hp=0e83986ca8bfc9f8e1a46304fe1963f976e0e407;hpb=2c8f04b5b883db74f449dfc8c224929fe28b027d;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyDecls.lhs b/ghc/compiler/typecheck/TcTyDecls.lhs index 0e83986..450dad9 100644 --- a/ghc/compiler/typecheck/TcTyDecls.lhs +++ b/ghc/compiler/typecheck/TcTyDecls.lhs @@ -1,195 +1,322 @@ % -% (c) The AQUA Project, Glasgow University, 1996 +% (c) The AQUA Project, Glasgow University, 1996-1998 % \section[TcTyDecls]{Typecheck type declarations} \begin{code} module TcTyDecls ( - tcTyDecl, + tcTyDecl, kcTyDecl, tcConDecl, - mkDataBinds + mkImplicitDataBinds, mkNewTyConRep ) where #include "HsVersions.h" import HsSyn ( MonoBinds(..), - TyDecl(..), ConDecl(..), ConDetails(..), BangType(..), - andMonoBinds - ) -import HsTypes ( getTyVarName ) -import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..) ) -import TcHsSyn ( mkHsTyLam, mkHsDictLam, tcIdType, - TcHsBinds, TcMonoBinds + TyClDecl(..), ConDecl(..), ConDetails(..), BangType(..), + andMonoBindList ) +import RnHsSyn ( RenamedTyClDecl, RenamedConDecl ) +import TcHsSyn ( TcMonoBinds, idsToMonoBinds ) import BasicTypes ( RecFlag(..), NewOrData(..) ) -import Inst ( newDicts, InstOrigin(..), Inst ) -import TcMonoType ( tcHsTypeKind, tcHsType, tcContext ) -import TcSimplify ( tcSimplifyCheckThetas ) -import TcType ( tcInstTyVars ) -import TcEnv ( TcIdOcc(..), tcInstId, - tcLookupTyCon, tcLookupTyVar, tcLookupClass, - newLocalId, newLocalIds, tcLookupClassByKey +import TcMonoType ( tcExtendTopTyVarScope, tcExtendTyVarScope, + tcHsTypeKind, kcHsType, tcHsTopType, tcHsTopBoxedType, + tcContext, tcHsTopTypeKind ) +import TcType ( zonkTcTyVarToTyVar, zonkTcClassConstraints ) +import TcEnv ( tcLookupTy, TcTyThing(..) ) import TcMonad -import TcKind ( TcKind, unifyKind, mkArrowKind, mkBoxedTypeKind ) - -import Class ( classInstEnv, Class ) -import MkId ( mkDataCon, mkRecordSelId ) -import Id ( dataConSig, idType, - dataConFieldLabels, dataConStrictMarks, - StrictnessMark(..), getIdUnfolding, - Id +import TcUnify ( unifyKind ) + +import Class ( Class ) +import DataCon ( DataCon, mkDataCon, isNullaryDataCon, + dataConFieldLabels, dataConId, dataConWrapId, + markedStrict, notMarkedStrict, markedUnboxed, dataConRepType ) -import CoreUnfold ( getUnfoldingTemplate ) +import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId ) import FieldLabel -import Kind ( Kind, mkArrowKind, mkBoxedTypeKind ) -import Name ( nameSrcLoc, isLocallyDefined, getSrcLoc, - OccName(..), - NamedThing(..) - ) +import Var ( Id, TyVar ) +import Name ( Name, isLocallyDefined, OccName, NamedThing(..), nameUnique ) import Outputable -import TyCon ( TyCon, mkSynTyCon, mkDataTyCon, isAlgTyCon, - isSynTyCon, tyConDataCons +import TyCon ( TyCon, AlgTyConFlavour(..), ArgVrcs, mkSynTyCon, mkAlgTyCon, + tyConDataCons, tyConTyVars, + isSynTyCon, isNewTyCon ) -import Type ( typeKind, getTyVar, tyVarsOfTypes, splitSigmaTy, +import Type ( getTyVar, tyVarsOfTypes, splitFunTy, applyTys, mkTyConApp, mkTyVarTys, mkForAllTys, mkFunTy, - splitFunTys, mkTyVarTy, getTyVar_maybe, - isUnboxedType, Type, ThetaType + mkTyVarTy, splitAlgTyConApp_maybe, + mkArrowKind, mkArrowKinds, boxedTypeKind, + isUnboxedType, Type, ThetaType, classesOfPreds ) -import TyVar ( tyVarKind, elementOfTyVarSet, intersectTyVarSets, isEmptyTyVarSet, - TyVar ) -import Unique ( evalClassKey ) -import UniqSet ( emptyUniqSet, mkUniqSet, uniqSetToList, unionManyUniqSets, UniqSet ) -import Util ( equivClasses, zipEqual, nOfThem, panic, assertPanic ) +import TysWiredIn ( unitTy ) +import Var ( tyVarKind ) +import VarSet ( intersectVarSet, isEmptyVarSet ) +import Util ( equivClasses ) +import FiniteMap ( FiniteMap, lookupWithDefaultFM ) +import CmdLineOpts ( opt_GlasgowExts ) \end{code} +%************************************************************************ +%* * +\subsection{Kind checking} +%* * +%************************************************************************ + \begin{code} -tcTyDecl :: RecFlag -> RenamedTyDecl -> TcM s TyCon +kcTyDecl :: RenamedTyClDecl -> TcM s () + +kcTyDecl (TySynonym name tyvar_names rhs src_loc) + = tcLookupTy name `thenNF_Tc` \ (kind, _, _) -> + tcExtendTopTyVarScope kind tyvar_names $ \ _ result_kind -> + tcHsTypeKind rhs `thenTc` \ (rhs_kind, _) -> + unifyKind result_kind rhs_kind + +kcTyDecl (TyData _ context tycon_name tyvar_names con_decls _ _ src_loc) + = tcLookupTy tycon_name `thenNF_Tc` \ (kind, _, _) -> + tcExtendTopTyVarScope kind tyvar_names $ \ result_kind _ -> + tcContext context `thenTc_` + mapTc kcConDecl con_decls `thenTc_` + returnTc () + +kcConDecl (ConDecl _ _ ex_tvs ex_ctxt details loc) + = tcAddSrcLoc loc ( + tcExtendTyVarScope ex_tvs ( \ tyvars -> + tcContext ex_ctxt `thenTc_` + kc_con details `thenTc_` + returnTc () + )) + where + kc_con (VanillaCon btys) = mapTc kc_bty btys `thenTc_` returnTc () + kc_con (InfixCon bty1 bty2) = mapTc kc_bty [bty1,bty2] `thenTc_` returnTc () + kc_con (NewCon ty _) = kcHsType ty + kc_con (RecCon flds) = mapTc kc_field flds `thenTc_` returnTc () + + kc_bty (Banged ty) = kcHsType ty + kc_bty (Unbanged ty) = kcHsType ty + kc_bty (Unpacked ty) = kcHsType ty + + kc_field (_, bty) = kc_bty bty \end{code} -Type synonym decls -~~~~~~~~~~~~~~~~~~ + +%************************************************************************ +%* * +\subsection{Type checking} +%* * +%************************************************************************ \begin{code} -tcTyDecl is_rec (TySynonym tycon_name tyvar_names rhs src_loc) - = tcAddSrcLoc src_loc $ - tcAddErrCtxt (tySynCtxt tycon_name) $ - - -- Look up the pieces - tcLookupTyCon tycon_name `thenTc` \ (tycon_kind, _, rec_tycon) -> - mapAndUnzipNF_Tc (tcLookupTyVar.getTyVarName) tyvar_names - `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) -> - - -- Look at the rhs - tcHsTypeKind rhs `thenTc` \ (rhs_kind, rhs_ty) -> - - -- Unify tycon kind with (k1->...->kn->rhs) - unifyKind tycon_kind - (foldr mkArrowKind rhs_kind tyvar_kinds) - `thenTc_` +tcTyDecl :: RecFlag -> FiniteMap Name ArgVrcs -> RenamedTyClDecl -> TcM s TyCon + +tcTyDecl is_rec rec_vrcs (TySynonym tycon_name tyvar_names rhs src_loc) + = tcLookupTy tycon_name `thenNF_Tc` \ (tycon_kind, Just arity, _) -> + tcExtendTopTyVarScope tycon_kind tyvar_names $ \ tyvars _ -> + tcHsTopTypeKind rhs `thenTc` \ (_, rhs_ty) -> + -- If the RHS mentions tyvars that aren't in scope, we'll + -- quantify over them. With gla-exts that's right, but for H98 + -- we should complain. We can't do that here without falling into + -- a black hole, so we do it in rnDecl (TySynonym case) let - -- Getting the TyCon's kind is a bit of a nuisance. We can't use the tycon_kind, - -- because that's a TcKind and may not yet be fully unified with other kinds. - -- We could have augmented the tycon environment with a knot-tied kind, - -- but the simplest thing to do seems to be to get the Kind by (lazily) - -- looking at the tyvars and rhs_ty. - result_kind, final_tycon_kind :: Kind -- NB not TcKind! - result_kind = typeKind rhs_ty - final_tycon_kind = foldr (mkArrowKind . tyVarKind) result_kind rec_tyvars + -- Construct the tycon + argvrcs = lookupWithDefaultFM rec_vrcs (pprPanic "tcTyDecl: argvrcs:" $ ppr tycon_name) + tycon_name + tycon = mkSynTyCon tycon_name tycon_kind arity tyvars rhs_ty argvrcs + in + returnTc tycon + +tcTyDecl is_rec rec_vrcs (TyData data_or_new context tycon_name tyvar_names con_decls derivings pragmas src_loc) + = -- Lookup the pieces + tcLookupTy tycon_name `thenNF_Tc` \ (tycon_kind, _, ATyCon rec_tycon) -> + tcExtendTopTyVarScope tycon_kind tyvar_names $ \ tyvars _ -> + + -- Typecheck the pieces + tcContext context `thenTc` \ ctxt -> + let ctxt' = classesOfPreds ctxt in + mapTc (tcConDecl rec_tycon tyvars ctxt') con_decls `thenTc` \ data_cons -> + tc_derivs derivings `thenTc` \ derived_classes -> + + let -- Construct the tycon - tycon = mkSynTyCon (getName tycon_name) - final_tycon_kind - (length tyvar_names) - rec_tyvars - rhs_ty + flavour = case data_or_new of + NewType -> NewTyCon (mkNewTyConRep tycon) + DataType | all isNullaryDataCon data_cons -> EnumTyCon + | otherwise -> DataTyCon + + argvrcs = lookupWithDefaultFM rec_vrcs (pprPanic "tcTyDecl: argvrcs:" $ ppr tycon_name) + tycon_name + + tycon = mkAlgTyCon tycon_name tycon_kind tyvars ctxt' argvrcs + data_cons + derived_classes + flavour is_rec in returnTc tycon -\end{code} + where + tc_derivs Nothing = returnTc [] + tc_derivs (Just ds) = mapTc tc_deriv ds -Algebraic data and newtype decls -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + tc_deriv name = tcLookupTy name `thenTc` \ (_, _, AClass clas) -> + returnTc clas +\end{code} \begin{code} -tcTyDecl is_rec (TyData data_or_new context tycon_name tyvar_names con_decls derivings pragmas src_loc) - = tcAddSrcLoc src_loc $ - let ctxt = case data_or_new of - NewType -> tyNewCtxt tycon_name - DataType -> tyDataCtxt tycon_name - in - tcAddErrCtxt ctxt $ +mkNewTyConRep :: TyCon -> Type +-- Find the representation type for this newtype TyCon +-- The trick is to to deal correctly with recursive newtypes +-- such as newtype T = MkT T - -- Lookup the pieces - tcLookupTyCon tycon_name `thenTc` \ (tycon_kind, _, rec_tycon) -> - mapAndUnzipNF_Tc (tcLookupTyVar.getTyVarName) - tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) -> - tc_derivs derivings `thenTc` \ derived_classes -> +mkNewTyConRep tc + = mkForAllTys tvs (loop [] (mkTyConApp tc (mkTyVarTys tvs))) + where + tvs = tyConTyVars tc + loop tcs ty = case splitAlgTyConApp_maybe ty of { + Nothing -> ty ; + Just (tc, tys, data_cons) | not (isNewTyCon tc) -> ty + | tc `elem` tcs -> unitTy + | otherwise -> + + case splitFunTy (applyTys (dataConRepType (head data_cons)) tys) of + (rep_ty, _) -> loop (tc:tcs) rep_ty + } +\end{code} - -- Typecheck the context - tcContext context `thenTc` \ ctxt -> - -- Unify tycon kind with (k1->...->kn->Type) - unifyKind tycon_kind - (foldr mkArrowKind mkBoxedTypeKind tyvar_kinds) - `thenTc_` +%************************************************************************ +%* * +\subsection{Type check constructors} +%* * +%************************************************************************ - -- Walk the condecls - mapTc (tcConDecl rec_tycon rec_tyvars ctxt) con_decls - `thenTc` \ con_ids -> - let - -- Construct the tycon - final_tycon_kind :: Kind -- NB not TcKind! - final_tycon_kind = foldr (mkArrowKind . tyVarKind) mkBoxedTypeKind rec_tyvars - - tycon = mkDataTyCon (getName tycon_name) - final_tycon_kind - rec_tyvars - ctxt - con_ids - derived_classes - Nothing -- Not a dictionary - data_or_new - is_rec +\begin{code} +tcConDecl :: TyCon -> [TyVar] -> [(Class,[Type])] -> RenamedConDecl -> TcM s DataCon + +tcConDecl tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ctxt details src_loc) + = tcAddSrcLoc src_loc $ + tcExtendTyVarScope ex_tvs $ \ ex_tyvars -> + tcContext ex_ctxt `thenTc` \ ex_theta -> + let + ex_ctxt' = classesOfPreds ex_theta in - returnTc tycon + tc_con_decl_help tycon tyvars ctxt name wkr_name ex_tyvars ex_ctxt' details + +tc_con_decl_help tycon tyvars ctxt name wkr_name ex_tyvars ex_theta details + = case details of + VanillaCon btys -> tc_datacon btys + InfixCon bty1 bty2 -> tc_datacon [bty1,bty2] + NewCon ty mb_f -> tc_newcon ty mb_f + RecCon fields -> tc_rec_con fields + where + tc_datacon btys + = let + arg_stricts = map get_strictness btys + tys = map get_pty btys + in + mapTc tcHsTopType tys `thenTc` \ arg_tys -> + mk_data_con arg_stricts arg_tys [] + + tc_newcon ty mb_f + = tcHsTopBoxedType ty `thenTc` \ arg_ty -> + -- can't allow an unboxed type here, because we're effectively + -- going to remove the constructor while coercing it to a boxed type. + let + field_label = + case mb_f of + Nothing -> [] + Just f -> [mkFieldLabel (getName f) tycon arg_ty (head allFieldLabelTags)] + in + mk_data_con [notMarkedStrict] [arg_ty] field_label + + tc_rec_con fields + = checkTc (null ex_tyvars) (exRecConErr name) `thenTc_` + mapTc tc_field fields `thenTc` \ field_label_infos_s -> + let + field_label_infos = concat field_label_infos_s + arg_stricts = [strict | (_, _, strict) <- field_label_infos] + arg_tys = [ty | (_, ty, _) <- field_label_infos] + + field_labels = [ mkFieldLabel (getName name) tycon ty tag + | ((name, ty, _), tag) <- field_label_infos `zip` allFieldLabelTags ] + in + mk_data_con arg_stricts arg_tys field_labels + + tc_field (field_label_names, bty) + = tcHsTopType (get_pty bty) `thenTc` \ field_ty -> + returnTc [(name, field_ty, get_strictness bty) | name <- field_label_names] + + mk_data_con arg_stricts arg_tys fields + = -- Now we've checked all the field types we must + -- zonk the existential tyvars to finish the kind + -- inference on their kinds, and commit them to being + -- immutable type variables. (The top-level tyvars are + -- already fixed, by the preceding kind-inference pass.) + mapNF_Tc zonkTcTyVarToTyVar ex_tyvars `thenNF_Tc` \ ex_tyvars' -> + zonkTcClassConstraints ex_theta `thenNF_Tc` \ ex_theta' -> + let + data_con = mkDataCon name arg_stricts fields + tyvars (thinContext arg_tys ctxt) + ex_tyvars' ex_theta' + arg_tys + tycon data_con_id data_con_wrap_id + data_con_id = mkDataConId wkr_name data_con + data_con_wrap_id = mkDataConWrapId data_con + in + returnNF_Tc data_con -tc_derivs Nothing = returnTc [] -tc_derivs (Just ds) = mapTc tc_deriv ds +-- The context for a data constructor should be limited to +-- the type variables mentioned in the arg_tys +thinContext arg_tys ctxt + = filter in_arg_tys ctxt + where + arg_tyvars = tyVarsOfTypes arg_tys + in_arg_tys (clas,tys) = not $ isEmptyVarSet $ + tyVarsOfTypes tys `intersectVarSet` arg_tyvars + +get_strictness (Banged _) = markedStrict +get_strictness (Unbanged _) = notMarkedStrict +get_strictness (Unpacked _) = markedUnboxed -tc_deriv name - = tcLookupClass name `thenTc` \ (_, clas) -> - returnTc clas +get_pty (Banged ty) = ty +get_pty (Unbanged ty) = ty +get_pty (Unpacked ty) = ty \end{code} -Generating constructor/selector bindings for data declarations -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + +%************************************************************************ +%* * +\subsection{Generating constructor/selector bindings for data declarations} +%* * +%************************************************************************ \begin{code} -mkDataBinds :: [TyCon] -> TcM s ([Id], TcMonoBinds s) -mkDataBinds [] = returnTc ([], EmptyMonoBinds) -mkDataBinds (tycon : tycons) - | isSynTyCon tycon = mkDataBinds tycons - | otherwise = mkDataBinds_one tycon `thenTc` \ (ids1, b1) -> - mkDataBinds tycons `thenTc` \ (ids2, b2) -> +mkImplicitDataBinds :: [TyCon] -> TcM s ([Id], TcMonoBinds) +mkImplicitDataBinds [] = returnTc ([], EmptyMonoBinds) +mkImplicitDataBinds (tycon : tycons) + | isSynTyCon tycon = mkImplicitDataBinds tycons + | otherwise = mkImplicitDataBinds_one tycon `thenTc` \ (ids1, b1) -> + mkImplicitDataBinds tycons `thenTc` \ (ids2, b2) -> returnTc (ids1++ids2, b1 `AndMonoBinds` b2) -mkDataBinds_one tycon - = ASSERT( isAlgTyCon tycon ) - mapTc checkConstructorContext data_cons `thenTc_` - mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids -> +mkImplicitDataBinds_one tycon + = mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids -> let - data_ids = data_cons ++ sel_ids + unf_ids = sel_ids ++ data_con_wrapper_ids + all_ids = map dataConId data_cons ++ unf_ids -- For the locally-defined things - -- we need to turn the unfoldings inside the Ids into bindings, - binds = [ CoreMonoBind (RealId data_id) (getUnfoldingTemplate (getIdUnfolding data_id)) - | data_id <- data_ids, isLocallyDefined data_id - ] + -- we need to turn the unfoldings inside the selector Ids into bindings, + -- and build bindigns for the constructor wrappers + binds | isLocallyDefined tycon = idsToMonoBinds unf_ids + | otherwise = EmptyMonoBinds in - returnTc (data_ids, andMonoBinds binds) + returnTc (all_ids, binds) where data_cons = tyConDataCons tycon + + data_con_wrapper_ids = map dataConWrapId data_cons + fields = [ (con, field) | con <- data_cons, field <- dataConFieldLabels con ] @@ -200,28 +327,6 @@ mkDataBinds_one tycon = fieldLabelName field1 `compare` fieldLabelName field2 \end{code} --- Check that all the types of all the strict arguments are in Eval - -\begin{code} -checkConstructorContext con_id - | not (isLocallyDefined con_id) - = returnTc () - - | otherwise -- It is locally defined - = tcLookupClassByKey evalClassKey `thenNF_Tc` \ eval_clas -> - let - strict_marks = dataConStrictMarks con_id - (tyvars, theta, ext_tyvars, ext_theta, arg_tys, _) = dataConSig con_id - - eval_theta = [ (eval_clas, [arg_ty]) - | (arg_ty, MarkedStrict) <- zipEqual "strict_args" - arg_tys strict_marks - ] - in - tcAddErrCtxt (evalCtxt con_id eval_theta) $ - tcSimplifyCheckThetas theta eval_theta -\end{code} - \begin{code} mkRecordSelector tycon fields@((first_con, first_field_label) : other_fields) -- These fields all have the same name, but are from @@ -231,138 +336,22 @@ mkRecordSelector tycon fields@((first_con, first_field_label) : other_fields) -- data type use the same type variables = checkTc (all (== field_ty) other_tys) (fieldTypeMisMatch field_name) `thenTc_` - returnTc selector_id + returnTc (mkRecordSelId tycon first_field_label) where field_ty = fieldLabelType first_field_label field_name = fieldLabelName first_field_label other_tys = [fieldLabelType fl | (_, fl) <- other_fields] - (tyvars, _, _, _, _, _) = dataConSig first_con - data_ty = mkTyConApp tycon (mkTyVarTys tyvars) - -- tyvars of first_con may be free in field_ty - -- Now build the selector - - selector_ty :: Type - selector_ty = mkForAllTys tyvars $ - mkFunTy data_ty $ - field_ty - - selector_id :: Id - selector_id = mkRecordSelId first_field_label selector_ty \end{code} -Constructors -~~~~~~~~~~~~ -\begin{code} -tcConDecl :: TyCon -> [TyVar] -> ThetaType -> RenamedConDecl -> TcM s Id - -tcConDecl tycon tyvars ctxt (ConDecl name ex_ctxt (VanillaCon btys) src_loc) - = tcDataCon tycon tyvars ctxt name btys src_loc - -tcConDecl tycon tyvars ctxt (ConDecl op ex_ctxt (InfixCon bty1 bty2) src_loc) - = tcDataCon tycon tyvars ctxt op [bty1,bty2] src_loc - -tcConDecl tycon tyvars ctxt (ConDecl name ex_ctxt (NewCon ty) src_loc) - = tcAddSrcLoc src_loc $ - tcHsType ty `thenTc` \ arg_ty -> - -- can't allow an unboxed type here, because we're effectively - -- going to remove the constructor while coercing it to a boxed type. - checkTc (not (isUnboxedType arg_ty)) (newTypeUnboxedField ty) `thenTc_` - let - data_con = mkDataCon (getName name) - [NotMarkedStrict] - [{- No labelled fields -}] - tyvars - ctxt - [] [] -- Temporary; existential chaps - [arg_ty] - tycon - in - returnTc data_con - -tcConDecl tycon tyvars ctxt (ConDecl name ex_ctxt (RecCon fields) src_loc) - = tcAddSrcLoc src_loc $ - mapTc tcField fields `thenTc` \ field_label_infos_s -> - let - field_label_infos = concat field_label_infos_s - stricts = [strict | (_, _, strict) <- field_label_infos] - arg_tys = [ty | (_, ty, _) <- field_label_infos] - - field_labels = [ mkFieldLabel (getName name) ty tag - | ((name, ty, _), tag) <- field_label_infos `zip` allFieldLabelTags ] - - data_con = mkDataCon (getName name) - stricts - field_labels - tyvars - (thinContext arg_tys ctxt) - [] [] -- Temporary; existential chaps - arg_tys - tycon - in - returnTc data_con - -tcField (field_label_names, bty) - = tcHsType (get_pty bty) `thenTc` \ field_ty -> - returnTc [(name, field_ty, get_strictness bty) | name <- field_label_names] - -tcDataCon tycon tyvars ctxt name btys src_loc - = tcAddSrcLoc src_loc $ - let - stricts = map get_strictness btys - tys = map get_pty btys - in - mapTc tcHsType tys `thenTc` \ arg_tys -> - let - data_con = mkDataCon (getName name) - stricts - [{- No field labels -}] - tyvars - (thinContext arg_tys ctxt) - [] [] -- Temporary existential chaps - arg_tys - tycon - in - returnTc data_con - --- The context for a data constructor should be limited to --- the type variables mentioned in the arg_tys -thinContext arg_tys ctxt - = filter in_arg_tys ctxt - where - arg_tyvars = tyVarsOfTypes arg_tys - in_arg_tys (clas,tys) = not $ isEmptyTyVarSet $ - tyVarsOfTypes tys `intersectTyVarSets` arg_tyvars - -get_strictness (Banged _) = MarkedStrict -get_strictness (Unbanged _) = NotMarkedStrict - -get_pty (Banged ty) = ty -get_pty (Unbanged ty) = ty -\end{code} - - Errors and contexts ~~~~~~~~~~~~~~~~~~~ \begin{code} -tySynCtxt tycon_name - = hsep [ptext SLIT("In the type declaration for"), quotes (ppr tycon_name)] - -tyDataCtxt tycon_name - = hsep [ptext SLIT("In the data declaration for"), quotes (ppr tycon_name)] - -tyNewCtxt tycon_name - = hsep [ptext SLIT("In the newtype declaration for"), quotes (ppr tycon_name)] - fieldTypeMisMatch field_name = sep [ptext SLIT("Declared types differ for field"), quotes (ppr field_name)] -newTypeUnboxedField ty - = sep [ptext SLIT("Newtype constructor field has an unboxed type:"), - quotes (ppr ty)] - -evalCtxt con eval_theta - = hsep [ptext SLIT("When checking the Eval context for constructor:"), - ppr con, - text "::", ppr eval_theta] +exRecConErr name + = ptext SLIT("Can't combine named fields with locally-quantified type variables") + $$ + (ptext SLIT("In the declaration of data constructor") <+> ppr name) \end{code}