X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyDecls.lhs;h=0eff0ad51c5bf9ba73d099aaeaa86ed5b200df60;hb=f7ecf7234c224489be8a5e63fced903b655d92ee;hp=83a4c96732fdc6e93592cf0ec6617d3e272ff21e;hpb=6c381e873e222417d9a67aeec77b9555eca7b7a8;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyDecls.lhs b/ghc/compiler/typecheck/TcTyDecls.lhs index 83a4c96..0eff0ad 100644 --- a/ghc/compiler/typecheck/TcTyDecls.lhs +++ b/ghc/compiler/typecheck/TcTyDecls.lhs @@ -8,29 +8,63 @@ module TcTyDecls ( tcTyDecl, - tcConDecl + tcConDecl, + mkDataBinds ) where -import Ubiq{-uitous-} - -import HsSyn ( TyDecl(..), ConDecl(..), BangType(..), MonoType ) -import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..) ) - -import TcMonoType ( tcMonoTypeKind, tcMonoType, tcContext ) -import TcEnv ( tcLookupTyCon, tcLookupTyVar, tcLookupClass ) -import TcMonad +IMP_Ubiq(){-uitous-} + +import HsSyn ( TyDecl(..), ConDecl(..), BangType(..), HsExpr(..), + Match(..), GRHSsAndBinds(..), GRHS(..), OutPat(..), + HsBinds(..), HsLit, Stmt, Qualifier, ArithSeqInfo, + PolyType, Fake, InPat, + Bind(..), MonoBinds(..), Sig, + MonoType ) +import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..), + RnName{-instance Outputable-} + ) +import TcHsSyn ( mkHsTyLam, mkHsDictLam, tcIdType, + SYN_IE(TcHsBinds), TcIdOcc(..) + ) +import Inst ( newDicts, InstOrigin(..), Inst ) +import TcMonoType ( tcMonoTypeKind, tcMonoType, tcPolyType, tcContext ) +import TcSimplify ( tcSimplifyThetas ) +import TcType ( tcInstTyVars, tcInstType, tcInstId ) +import TcEnv ( tcLookupTyCon, tcLookupTyVar, tcLookupClass, + newLocalId, newLocalIds, tcLookupClassByKey + ) +import TcMonad hiding ( rnMtoTcM ) import TcKind ( TcKind, unifyKind, mkTcArrowKind, mkTcTypeKind ) -import Id ( mkDataCon, StrictnessMark(..) ) +import PprType ( GenClass, GenType{-instance Outputable-}, + GenTyVar{-instance Outputable-}{-ToDo:possibly rm-} + ) +import Class ( GenClass{-instance Eq-}, classInstEnv ) +import Id ( mkDataCon, dataConSig, mkRecordSelId, idType, + dataConFieldLabels, dataConStrictMarks, + StrictnessMark(..), + GenId{-instance NamedThing-} + ) +import FieldLabel import Kind ( Kind, mkArrowKind, mkBoxedTypeKind ) -import SpecEnv ( SpecEnv(..), nullSpecEnv ) -import Name ( getNameFullName, Name(..) ) +import SpecEnv ( SpecEnv, nullSpecEnv ) +import Name ( nameSrcLoc, isLocallyDefinedName, getSrcLoc, + Name{-instance Ord3-} + ) +import Outputable ( Outputable(..), interpp'SP ) import Pretty -import TyCon ( TyCon, ConsVisible(..), NewOrData(..), mkSynTyCon, mkDataTyCon ) -import Type ( getTypeKind ) -import TyVar ( getTyVarKind ) -import Util ( panic ) - +import TyCon ( TyCon, NewOrData(..), mkSynTyCon, mkDataTyCon, isDataTyCon, + isNewTyCon, isSynTyCon, tyConDataCons + ) +import Type ( GenType, -- instances + typeKind, getTyVar, tyVarsOfTypes, eqTy, splitSigmaTy, + applyTyCon, mkTyVarTys, mkForAllTys, mkFunTy, + splitFunTy, mkTyVarTy, getTyVar_maybe + ) +import TyVar ( tyVarKind, elementOfTyVarSet, GenTyVar{-instance Eq-} ) +import Unique ( Unique {- instance Eq -}, evalClassKey ) +import UniqSet ( emptyUniqSet, mkUniqSet, uniqSetToList, unionManyUniqSets, SYN_IE(UniqSet) ) +import Util ( equivClasses, zipEqual, nOfThem, panic, assertPanic ) \end{code} \begin{code} @@ -46,7 +80,7 @@ tcTyDecl (TySynonym tycon_name tyvar_names rhs src_loc) tcAddErrCtxt (tySynCtxt tycon_name) $ -- Look up the pieces - tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, rec_tycon) -> + tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, _, rec_tycon) -> mapAndUnzipNF_Tc tcLookupTyVar tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) -> -- Look at the rhs @@ -57,13 +91,17 @@ tcTyDecl (TySynonym tycon_name tyvar_names rhs src_loc) (foldr mkTcArrowKind rhs_kind tyvar_kinds) `thenTc_` let - -- Construct the tycon + -- 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 = getTypeKind rhs_ty - final_tycon_kind = foldr (mkArrowKind . getTyVarKind) result_kind rec_tyvars + result_kind = typeKind rhs_ty + final_tycon_kind = foldr (mkArrowKind . tyVarKind) result_kind rec_tyvars - tycon = mkSynTyCon (getItsUnique tycon_name) - (getNameFullName tycon_name) + -- Construct the tycon + tycon = mkSynTyCon (getName tycon_name) final_tycon_kind (length tyvar_names) rec_tyvars @@ -88,7 +126,7 @@ tcTyDataOrNew data_or_new context tycon_name tyvar_names con_decls derivings pra tcAddErrCtxt (tyDataCtxt tycon_name) $ -- Lookup the pieces - tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, rec_tycon) -> + tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, _, rec_tycon) -> mapAndUnzipNF_Tc tcLookupTyVar tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) -> tc_derivs derivings `thenNF_Tc` \ derived_classes -> @@ -99,34 +137,213 @@ tcTyDataOrNew data_or_new context tycon_name tyvar_names con_decls derivings pra unifyKind tycon_kind (foldr mkTcArrowKind mkTcTypeKind tyvar_kinds) `thenTc_` + -- 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 . getTyVarKind) mkBoxedTypeKind rec_tyvars + final_tycon_kind = foldr (mkArrowKind . tyVarKind) mkBoxedTypeKind rec_tyvars - tycon = mkDataTyCon (getItsUnique tycon_name) + tycon = mkDataTyCon (getName tycon_name) final_tycon_kind - (getNameFullName tycon_name) rec_tyvars ctxt con_ids derived_classes - ConsVisible -- For now; if constrs are from pragma we are *abstract* data_or_new in returnTc tycon + +tc_derivs Nothing = returnNF_Tc [] +tc_derivs (Just ds) = mapNF_Tc tc_deriv ds + +tc_deriv name + = tcLookupClass name `thenNF_Tc` \ (_, clas) -> + returnNF_Tc clas +\end{code} + +Generating constructor/selector bindings for data declarations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +\begin{code} +mkDataBinds :: [TyCon] -> TcM s ([Id], TcHsBinds s) +mkDataBinds [] = returnTc ([], EmptyBinds) +mkDataBinds (tycon : tycons) + | isSynTyCon tycon = mkDataBinds tycons + | otherwise = mkDataBinds_one tycon `thenTc` \ (ids1, b1) -> + mkDataBinds tycons `thenTc` \ (ids2, b2) -> + returnTc (ids1++ids2, b1 `ThenBinds` b2) + +mkDataBinds_one tycon + = ASSERT( isDataTyCon tycon || isNewTyCon tycon ) + mapAndUnzipTc mkConstructor data_cons `thenTc` \ (con_ids, con_binds) -> + mapAndUnzipTc (mkRecordSelector tycon) groups `thenTc` \ (sel_ids, sel_binds) -> + returnTc (con_ids ++ sel_ids, + SingleBind $ NonRecBind $ + foldr AndMonoBinds + (foldr AndMonoBinds EmptyMonoBinds sel_binds) + con_binds + ) where - tc_derivs Nothing = returnNF_Tc [] - tc_derivs (Just ds) = mapNF_Tc tc_deriv ds + data_cons = tyConDataCons tycon + fields = [ (con, field) | con <- data_cons, + field <- dataConFieldLabels con + ] + + -- groups is list of fields that share a common name + groups = equivClasses cmp_name fields + cmp_name (_, field1) (_, field2) + = fieldLabelName field1 `cmp` fieldLabelName field2 +\end{code} + +We're going to build a constructor that looks like: + + data (Data a, C b) => T a b = T1 !a !Int b + + T1 = /\ a b -> + \d1::Data a, d2::C b -> + \p q r -> case p of { p -> + case q of { q -> + HsCon T1 [a,b] [p,q,r]}} + +Notice that + +* d2 is thrown away --- a context in a data decl is used to make sure + one *could* construct dictionaries at the site the constructor + is used, but the dictionary isn't actually used. + +* We have to check that we can construct Data dictionaries for + the types a and Int. Once we've done that we can throw d1 away too. - tc_deriv name - = tcLookupClass name `thenNF_Tc` \ (_, clas) -> - returnNF_Tc clas +* We use (case p of ...) to evaluate p, rather than "seq" because + all that matters is that the arguments are evaluated. "seq" is + very careful to preserve evaluation order, which we don't need + to be here. + +\begin{code} +mkConstructor con_id + | not (isLocallyDefinedName (getName con_id)) + = returnTc (con_id, EmptyMonoBinds) + + | otherwise -- It is locally defined + = tcInstId con_id `thenNF_Tc` \ (tc_tyvars, tc_theta, tc_tau) -> + newDicts DataDeclOrigin tc_theta `thenNF_Tc` \ (_, dicts) -> + let + (tc_arg_tys, tc_result_ty) = splitFunTy tc_tau + n_args = length tc_arg_tys + in + newLocalIds (nOfThem n_args SLIT("con")) tc_arg_tys `thenNF_Tc` \ args -> + + -- Check that all the types of all the strict arguments are in Eval + tcLookupClassByKey evalClassKey `thenNF_Tc` \ eval_clas -> + let + (_,theta,tau) = splitSigmaTy (idType con_id) + (arg_tys, _) = splitFunTy tau + strict_marks = dataConStrictMarks con_id + eval_theta = [ (eval_clas,arg_ty) + | (arg_ty, MarkedStrict) <- zipEqual "strict_args" + arg_tys strict_marks + ] + in + tcSimplifyThetas classInstEnv theta eval_theta `thenTc` \ eval_theta' -> + checkTc (null eval_theta') + (missingEvalErr con_id eval_theta') `thenTc_` + + -- Build the data constructor + let + con_rhs = mkHsTyLam tc_tyvars $ + mkHsDictLam dicts $ + mk_pat_match args $ + mk_case (zipEqual "strict_args" args strict_marks) $ + HsCon con_id (mkTyVarTys tc_tyvars) (map HsVar args) + + mk_pat_match [] body = body + mk_pat_match (arg:args) body = HsLam $ + PatMatch (VarPat arg) $ + SimpleMatch (mk_pat_match args body) + + mk_case [] body = body + mk_case ((arg,MarkedStrict):args) body = HsCase (HsVar arg) + [PatMatch (VarPat arg) $ + SimpleMatch (mk_case args body)] + src_loc + mk_case (_:args) body = mk_case args body + + src_loc = nameSrcLoc (getName con_id) + in + + returnTc (con_id, VarMonoBind (RealId con_id) con_rhs) \end{code} +We're going to build a record selector that looks like this: + + data T a b c = T1 { op :: a, ...} + | T2 { op :: a, ...} + | T3 + + sel :: forall a b c. T a b c -> a + sel = /\ a b c -> \ T1 { sel = x } -> x + T2 { sel = 2 } -> x + +Note that the selector Id itself is used as the field +label; it has to be an Id, you see! + +\begin{code} +mkRecordSelector tycon fields@((first_con, first_field_label) : other_fields) + = let + 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 = applyTyCon tycon (mkTyVarTys tyvars) + -- tyvars of first_con may be free in field_ty + in + + -- Check that all the fields in the group have the same type + -- This check assumes that all the constructors of a given + -- data type use the same type variables + checkTc (all (eqTy field_ty) other_tys) + (fieldTypeMisMatch field_name) `thenTc_` + + -- Create an Id for the field itself + tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', tyvar_tys, tenv) -> + tcInstType tenv field_ty `thenNF_Tc` \ field_ty' -> + let + data_ty' = applyTyCon tycon tyvar_tys + in + newLocalId SLIT("x") field_ty' `thenNF_Tc` \ field_id -> + newLocalId SLIT("r") data_ty' `thenNF_Tc` \ record_id -> + + -- Now build the selector + let + selector_ty :: Type + selector_ty = mkForAllTys tyvars $ + mkFunTy data_ty $ + field_ty + + selector_id :: Id + selector_id = mkRecordSelId first_field_label selector_ty + + -- HsSyn is dreadfully verbose for defining the selector! + selector_rhs = mkHsTyLam tyvars' $ + HsLam $ + PatMatch (VarPat record_id) $ + SimpleMatch $ + selector_body + + selector_body = HsCase (HsVar record_id) (map mk_match fields) (getSrcLoc tycon) + + mk_match (con_id, field_label) + = PatMatch (RecPat con_id data_ty' [(selector_id, VarPat field_id, False)]) $ + SimpleMatch $ + HsVar field_id + in + returnTc (selector_id, if isLocallyDefinedName (getName tycon) + then VarMonoBind (RealId selector_id) selector_rhs + else EmptyMonoBinds) +\end{code} Constructors ~~~~~~~~~~~~ @@ -134,65 +351,84 @@ Constructors tcConDecl :: TyCon -> [TyVar] -> [(Class,Type)] -> RenamedConDecl -> TcM s Id tcConDecl tycon tyvars ctxt (ConDecl name btys src_loc) + = tcDataCon tycon tyvars ctxt name btys src_loc + +tcConDecl tycon tyvars ctxt (ConOpDecl bty1 op bty2 src_loc) + = tcDataCon tycon tyvars ctxt op [bty1,bty2] src_loc + +tcConDecl tycon tyvars ctxt (NewConDecl name ty src_loc) = tcAddSrcLoc src_loc $ + tcMonoType ty `thenTc` \ arg_ty -> let - (stricts, tys) = sep_bangs btys - in - mapTc tcMonoType tys `thenTc` \ arg_tys -> - let - data_con = mkDataCon (getItsUnique name) - (getNameFullName name) - stricts + data_con = mkDataCon (getName name) + [NotMarkedStrict] + [{- No labelled fields -}] tyvars - [] -- ToDo: ctxt; limited to tyvars in arg_tys - arg_tys + ctxt + [arg_ty] tycon -- nullSpecEnv in returnTc data_con -tcConDecl tycon tyvars ctxt (ConOpDecl bty1 op bty2 src_loc) +tcConDecl tycon tyvars ctxt (RecConDecl name fields src_loc) = tcAddSrcLoc src_loc $ + mapTc tcField fields `thenTc` \ field_label_infos_s -> let - (stricts, tys) = sep_bangs [bty1, bty2] - in - mapTc tcMonoType tys `thenTc` \ arg_tys -> - let - data_con = mkDataCon (getItsUnique op) - (getNameFullName op) + 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 - [] -- ToDo: ctxt + (thinContext arg_tys ctxt) arg_tys tycon -- nullSpecEnv in returnTc data_con -tcConDecl tycon tyvars ctxt (NewConDecl name ty src_loc) +tcField (field_label_names, bty) + = tcPolyType (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 $ - tcMonoType ty `thenTc` \ arg_ty -> let - data_con = mkDataCon (getItsUnique name) - (getNameFullName name) - [NotMarkedStrict] + stricts = map get_strictness btys + tys = map get_pty btys + in + mapTc tcPolyType tys `thenTc` \ arg_tys -> + let + data_con = mkDataCon (getName name) + stricts + [{- No field labels -}] tyvars - [] -- ToDo: ctxt - [arg_ty] + (thinContext arg_tys ctxt) + arg_tys tycon -- nullSpecEnv in returnTc data_con -tcConDecl tycon tyvars ctxt (RecConDecl con fields src_loc) - = panic "tcConDecls:RecConDecl" - - -sep_bangs btys - = unzip (map sep_bang btys) - where - sep_bang (Banged ty) = (MarkedStrict, ty) - sep_bang (Unbanged ty) = (NotMarkedStrict, ty) +-- 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,ty) = getTyVar "tcDataCon" ty `elementOfTyVarSet` arg_tyvars + +get_strictness (Banged _) = MarkedStrict +get_strictness (Unbanged _) = NotMarkedStrict + +get_pty (Banged ty) = ty +get_pty (Unbanged ty) = ty \end{code} @@ -208,4 +444,12 @@ tyDataCtxt tycon_name sty tyNewCtxt tycon_name sty = ppCat [ppStr "In the newtype declaration for", ppr sty tycon_name] + +fieldTypeMisMatch field_name sty + = ppSep [ppStr "Declared types differ for field", ppr sty field_name] + +missingEvalErr con eval_theta sty + = ppCat [ppStr "Missing Eval context for constructor", + ppQuote (ppr sty con), + ppStr ":", ppr sty eval_theta] \end{code}