X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=ee847f5ec8257f1e0623961b06aacda5f72eb861;hp=0474581f61178be2d9e2a936a45c523b0a6f0921;hb=b1086a0798f69f437d9546062878619a3681313a;hpb=cd2c71bb9bfe5dd3582263468712c29192c7340e diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs index 0474581..ee847f5 100644 --- a/compiler/typecheck/TcTyClsDecls.lhs +++ b/compiler/typecheck/TcTyClsDecls.lhs @@ -133,7 +133,7 @@ tcTyAndClassDecls :: ModDetails -> [LTyClDecl Name] -> TcM TcGblEnv -- Input env extended by types and classes -- and their implicit Ids,DataCons tcTyAndClassDecls boot_details allDecls - = do { -- Omit instances of indexed types; they are handled together + = do { -- Omit instances of type families; they are handled together -- with the *heads* of class instances ; let decls = filter (not . isFamInstDecl . unLoc) allDecls @@ -239,9 +239,9 @@ tcFamInstDecl (L loc decl) recoverM (returnM Nothing) $ setSrcSpan loc $ tcAddDeclCtxt decl $ - do { -- type families require -findexed-types and can't be in an + do { -- type families require -ftype-families and can't be in an -- hs-boot file - ; gla_exts <- doptM Opt_IndexedTypes + ; gla_exts <- doptM Opt_TypeFamilies ; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file? ; checkTc gla_exts $ badFamInstDecl (tcdLName decl) ; checkTc (not is_boot) $ badBootFamInstDeclErr @@ -252,7 +252,8 @@ tcFamInstDecl (L loc decl) tcFamInstDecl1 :: TyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error -tcFamInstDecl1 (decl@TySynonym {}) + -- "type instance" +tcFamInstDecl1 (decl@TySynonym {tcdLName = L loc tc_name}) = kcIdxTyPats decl $ \k_tvs k_typats resKind family -> do { -- check that the family declaration is for a synonym unless (isSynTyCon family) $ @@ -266,16 +267,20 @@ tcFamInstDecl1 (decl@TySynonym {}) ; t_typats <- mappM tcHsKindedType k_typats ; t_rhs <- tcHsKindedType k_rhs - -- !!!of the form: forall t_tvs. (tcdLName decl) t_typats = t_rhs - ; return Nothing -- !!!TODO: need TyThing for indexed synonym + -- (3) construct representation tycon + ; rep_tc_name <- newFamInstTyConName tc_name loc + ; tycon <- buildSynTyCon rep_tc_name t_tvs (SynonymTyCon t_rhs) + (Just (family, t_typats)) + + ; return $ Just (ATyCon tycon) }} - + + -- "newtype instance" and "data instance" tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, tcdCons = cons}) = kcIdxTyPats decl $ \k_tvs k_typats resKind family -> do { -- check that the family declaration is for the right kind - unless (new_or_data == NewType && isNewTyCon family || - new_or_data == DataType && isDataTyCon family) $ + unless (isAlgTyCon family) $ addErr (wrongKindOfFamily family) ; -- (1) kind check the data declaration as usual @@ -300,10 +305,10 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, ; t_typats <- mappM tcHsKindedType k_typats ; stupid_theta <- tcHsKindedContext k_ctxt - ; rep_tc_name <- newFamInstTyConName tc_name (srcSpanStart loc) + -- (3) construct representation tycon + ; rep_tc_name <- newFamInstTyConName tc_name loc ; tycon <- fixM (\ tycon -> do - { data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data - tycon t_tvs)) + { data_cons <- mappM (addLocM (tcConDecl unbox_strict tycon t_tvs)) k_cons ; tc_rhs <- case new_or_data of @@ -387,7 +392,7 @@ So we must infer their kinds from their right-hand sides *first* and then use them, whereas for the mutually recursive data types D we bring into scope kind bindings D -> k, where k is a kind variable, and do inference. -Indexed Types +Type families ~~~~~~~~~~~~~ This treatment of type synonyms only applies to Haskell 98-style synonyms. General type functions can be recursive, and hence, appear in `alg_decls'. @@ -588,12 +593,15 @@ tcSynDecls (decl : decls) ; syn_tcs <- tcExtendGlobalEnv [syn_tc] (tcSynDecls decls) ; return (syn_tc : syn_tcs) } + -- "type" tcSynDecl (TySynonym {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty}) = tcTyVarBndrs tvs $ \ tvs' -> do { traceTc (text "tcd1" <+> ppr tc_name) ; rhs_ty' <- tcHsKindedType rhs_ty - ; return (ATyCon (buildSynTyCon tc_name tvs' (SynonymTyCon rhs_ty'))) } + ; tycon <- buildSynTyCon tc_name tvs' (SynonymTyCon rhs_ty') Nothing + ; return (ATyCon tycon) + } -------------------- tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing] @@ -610,37 +618,35 @@ tcTyClDecl1 _calc_isrec -- kind checking = tcTyVarBndrs tvs $ \ tvs' -> do { traceTc (text "type family: " <+> ppr tc_name) - ; idx_tys <- doptM Opt_IndexedTypes + ; idx_tys <- doptM Opt_TypeFamilies - -- Check that we don't use families without -findexed-types + -- Check that we don't use families without -ftype-families ; checkTc idx_tys $ badFamInstDecl tc_name - ; return [ATyCon $ buildSynTyCon tc_name tvs' (OpenSynTyCon kind)] + ; tycon <- buildSynTyCon tc_name tvs' (OpenSynTyCon kind Nothing) Nothing + ; return [ATyCon tycon] } -- "newtype family" or "data family" declaration tcTyClDecl1 _calc_isrec - (TyFamily {tcdFlavour = DataFamily new_or_data, + (TyFamily {tcdFlavour = DataFamily, tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = mb_kind}) = tcTyVarBndrs tvs $ \ tvs' -> do - { traceTc (text "data/newtype family: " <+> ppr tc_name) + { traceTc (text "data family: " <+> ppr tc_name) ; extra_tvs <- tcDataKindSig mb_kind ; let final_tvs = tvs' ++ extra_tvs -- we may not need these - ; idx_tys <- doptM Opt_IndexedTypes + ; idx_tys <- doptM Opt_TypeFamilies - -- Check that we don't use families without -findexed-types + -- Check that we don't use families without -ftype-families ; checkTc idx_tys $ badFamInstDecl tc_name ; tycon <- buildAlgTyCon tc_name final_tvs [] - (case new_or_data of - DataType -> OpenDataTyCon - NewType -> OpenNewTyCon) - Recursive False True Nothing + mkOpenDataTyConRhs Recursive False True Nothing ; return [ATyCon tycon] } - -- "newtype", "data", "newtype instance", "data instance" + -- "newtype" and "data" tcTyClDecl1 calc_isrec (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs, tcdLName = L _ tc_name, tcdKindSig = mb_ksig, tcdCons = cons}) @@ -672,8 +678,7 @@ tcTyClDecl1 calc_isrec (newtypeConError tc_name (length cons)) ; tycon <- fixM (\ tycon -> do - { data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data - tycon final_tvs)) + { data_cons <- mappM (addLocM (tcConDecl unbox_strict tycon final_tvs)) cons ; tc_rhs <- if null cons && is_boot -- In a hs-boot file, empty cons means @@ -742,38 +747,11 @@ tcTyClDecl1 calc_isrec ----------------------------------- tcConDecl :: Bool -- True <=> -funbox-strict_fields - -> NewOrData -> TyCon -> [TyVar] -> ConDecl Name -> TcM DataCon -tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes - (ConDecl name _ tvs ex_ctxt details res_ty _) - = tcTyVarBndrs tvs $ \ tvs' -> do - do { (univ_tvs, ex_tvs, eq_preds, data_tc) <- tcResultType tycon tc_tvs tvs' res_ty - - -- Check that a newtype has no existential stuff - ; checkTc (null ex_tvs && null (unLoc ex_ctxt)) (newtypeExError name) - - ; let tc_datacon field_lbls arg_ty - = do { arg_ty' <- tcHsKindedType arg_ty -- No bang on newtype - ; buildDataCon (unLoc name) False {- Prefix -} - [NotMarkedStrict] - (map unLoc field_lbls) - univ_tvs [] -- No existentials - [] [] -- No equalities, predicates - [arg_ty'] - data_tc } - - ; case details of - PrefixCon [arg_ty] -> tc_datacon [] arg_ty - RecCon [HsRecField field_lbl arg_ty _] -> tc_datacon [field_lbl] arg_ty - other -> - failWithTc (newtypeFieldErr name (length (hsConArgs details))) - -- Check that the constructor has exactly one field - } - -tcConDecl unbox_strict DataType tycon tc_tvs -- Data types +tcConDecl unbox_strict tycon tc_tvs -- Data types (ConDecl name _ tvs ctxt details res_ty _) = tcTyVarBndrs tvs $ \ tvs' -> do { ctxt' <- tcHsKindedContext ctxt @@ -945,8 +923,8 @@ checkValidTyCon :: TyCon -> TcM () checkValidTyCon tc | isSynTyCon tc = case synTyConRhs tc of - OpenSynTyCon _ -> return () - SynonymTyCon ty -> checkValidType syn_ctxt ty + OpenSynTyCon _ _ -> return () + SynonymTyCon ty -> checkValidType syn_ctxt ty | otherwise = -- Check the context on the data decl checkValidTheta (DataTyCtxt name) (tyConStupidTheta tc) `thenM_` @@ -989,23 +967,23 @@ checkValidTyCon tc -- NB: this check assumes that all the constructors of a given -- data type use the same type variables where - tvs1 = mkVarSet (dataConAllTyVars con1) - res1 = dataConResTys con1 + (tvs1, _, _, res1) = dataConSig con1 + ts1 = mkVarSet tvs1 fty1 = dataConFieldType con1 label checkOne (_, con2) -- Do it bothways to ensure they are structurally identical - = do { checkFieldCompat label con1 con2 tvs1 res1 res2 fty1 fty2 - ; checkFieldCompat label con2 con1 tvs2 res2 res1 fty2 fty1 } + = do { checkFieldCompat label con1 con2 ts1 res1 res2 fty1 fty2 + ; checkFieldCompat label con2 con1 ts2 res2 res1 fty2 fty1 } where - tvs2 = mkVarSet (dataConAllTyVars con2) - res2 = dataConResTys con2 + (tvs2, _, _, res2) = dataConSig con2 + ts2 = mkVarSet tvs2 fty2 = dataConFieldType con2 label checkFieldCompat fld con1 con2 tvs1 res1 res2 fty1 fty2 = do { checkTc (isJust mb_subst1) (resultTypeMisMatch fld con1 con2) ; checkTc (isJust mb_subst2) (fieldTypeMisMatch fld con1 con2) } where - mb_subst1 = tcMatchTys tvs1 res1 res2 + mb_subst1 = tcMatchTy tvs1 res1 res2 mb_subst2 = tcMatchTyX tvs1 (expectJust "checkFieldCompat" mb_subst1) fty1 fty2 ------------------------------- @@ -1014,11 +992,30 @@ checkValidDataCon tc con = setSrcSpan (srcLocSpan (getSrcLoc con)) $ addErrCtxt (dataConCtxt con) $ do { checkTc (dataConTyCon con == tc) (badDataConTyCon con) - ; checkValidType ctxt (dataConUserType con) } + ; checkValidType ctxt (dataConUserType con) + ; ifM (isNewTyCon tc) (checkNewDataCon con) + } where ctxt = ConArgCtxt (dataConName con) ------------------------------- +checkNewDataCon :: DataCon -> TcM () +-- Checks for the data constructor of a newtype +checkNewDataCon con + = do { checkTc (isSingleton arg_tys) (newtypeFieldErr con (length arg_tys)) + -- One argument + ; checkTc (null eq_spec) (newtypePredError con) + -- Return type is (T a b c) + ; checkTc (null ex_tvs && null theta) (newtypeExError con) + -- No existentials + ; checkTc (not (any isMarkedStrict (dataConStrictMarks con))) + (newtypeStrictError con) + -- No strictness + } + where + (_univ_tvs, ex_tvs, eq_spec, theta, arg_tys, _res_ty) = dataConFullSig con + +------------------------------- checkValidClass :: Class -> TcM () checkValidClass cls = do { -- CHECK ARITY 1 FOR HASKELL 1.4 @@ -1158,6 +1155,14 @@ newtypeExError con = sep [ptext SLIT("A newtype constructor cannot have an existential context,"), nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")] +newtypeStrictError con + = sep [ptext SLIT("A newtype constructor cannot have a strictness annotation,"), + nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")] + +newtypePredError con + = sep [ptext SLIT("A newtype constructor must have a return type of form T a1 ... an"), + nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does not")] + newtypeFieldErr con_name n_flds = sep [ptext SLIT("The constructor of a newtype must have exactly one field"), nest 2 $ ptext SLIT("but") <+> quotes (ppr con_name) <+> ptext SLIT("has") <+> speakN n_flds] @@ -1170,7 +1175,7 @@ badSigTyDecl tc_name badFamInstDecl tc_name = vcat [ ptext SLIT("Illegal family instance for") <+> quotes (ppr tc_name) - , nest 2 (parens $ ptext SLIT("Use -findexed-types to allow indexed type families")) ] + , nest 2 (parens $ ptext SLIT("Use -ftype-families to allow indexed type families")) ] badGadtIdxTyDecl tc_name = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> @@ -1192,9 +1197,9 @@ wrongKindOfFamily family = ptext SLIT("Wrong category of family instance; declaration was for a") <+> kindOfFamily where - kindOfFamily | isSynTyCon family = ptext SLIT("type synonym") - | isDataTyCon family = ptext SLIT("data type") - | isNewTyCon family = ptext SLIT("newtype") + kindOfFamily | isSynTyCon family = ptext SLIT("type synonym") + | isAlgTyCon family = ptext SLIT("data type") + | otherwise = pprPanic "wrongKindOfFamily" (ppr family) emptyConDeclsErr tycon = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),