%
-% (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
) 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 )
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, tcHsType, tcHsTopType, tcHsTopBoxedType,
+ tcContext, tcHsTopTypeKind
)
+import TcType ( zonkTcTyVarToTyVar, zonkTcThetaType )
+import TcEnv ( tcLookupTy, TcTyThing(..) )
import TcMonad
-import TcKind ( TcKind, unifyKind, mkArrowKind, mkBoxedTypeKind )
+import TcUnify ( unifyKind )
-import Class ( classInstEnv, Class )
-import Id ( mkDataCon, dataConSig, mkRecordSelId, idType,
- dataConFieldLabels, dataConStrictMarks,
- StrictnessMark(..), getIdUnfolding,
- Id
+import Class ( Class )
+import DataCon ( DataCon, dataConSig, mkDataCon, isNullaryDataCon,
+ dataConFieldLabels, dataConId,
+ markedStrict, notMarkedStrict, markedUnboxed
)
-import CoreUnfold ( getUnfoldingTemplate )
+import MkId ( mkDataConId, mkRecordSelId, mkNewTySelId )
+import Id ( getIdUnfolding )
+import CoreUnfold ( unfoldingTemplate )
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, ArgVrcs, mkSynTyCon, mkAlgTyCon, isAlgTyCon,
+ isSynTyCon, tyConDataCons, isNewTyCon
)
-import Type ( typeKind, getTyVar, tyVarsOfTypes, splitSigmaTy,
+import Type ( getTyVar, tyVarsOfTypes,
mkTyConApp, mkTyVarTys, mkForAllTys, mkFunTy,
- splitFunTys, mkTyVarTy, getTyVar_maybe,
+ mkTyVarTy,
+ mkArrowKind, mkArrowKinds, boxedTypeKind,
isUnboxedType, Type, ThetaType
)
-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 Var ( tyVarKind )
+import VarSet ( intersectVarSet, isEmptyVarSet )
+import Util ( equivClasses )
+import FiniteMap ( FiniteMap, lookupWithDefaultFM )
\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 _) = tcHsType ty `thenTc_` returnTc ()
+ kc_con (RecCon flds) = mapTc kc_field flds `thenTc_` returnTc ()
+
+ kc_bty (Banged ty) = tcHsType ty
+ kc_bty (Unbanged ty) = tcHsType ty
+ kc_bty (Unpacked ty) = tcHsType 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_`
- 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
+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) ->
+ let
-- Construct the tycon
- tycon = mkSynTyCon (getName tycon_name)
- final_tycon_kind
- (length tyvar_names)
- rec_tyvars
- rhs_ty
+ 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
-\end{code}
-Algebraic data and newtype decls
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-\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 $
-
- -- 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 ->
+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 context
- tcContext context `thenTc` \ ctxt ->
+ -- Typecheck the pieces
+ tcContext context `thenTc` \ ctxt ->
+ mapTc (tcConDecl rec_tycon tyvars ctxt) con_decls `thenTc` \ data_cons ->
+ tc_derivs derivings `thenTc` \ derived_classes ->
- -- Unify tycon kind with (k1->...->kn->Type)
- unifyKind tycon_kind
- (foldr mkArrowKind mkBoxedTypeKind 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 . 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
+ real_data_or_new = case data_or_new of
+ NewType -> NewType
+ DataType | all isNullaryDataCon data_cons -> EnumType
+ | otherwise -> DataType
+
+ 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
+ Nothing -- Not a dictionary
+ real_data_or_new is_rec
in
returnTc tycon
+ where
+ tc_derivs Nothing = returnTc []
+ tc_derivs (Just ds) = mapTc tc_deriv ds
-tc_derivs Nothing = returnTc []
-tc_derivs (Just ds) = mapTc tc_deriv ds
+ tc_deriv name = tcLookupTy name `thenTc` \ (_, _, AClass clas) ->
+ returnTc clas
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Type check constructors}
+%* *
+%************************************************************************
-tc_deriv name
- = tcLookupClass name `thenTc` \ (_, clas) ->
- returnTc clas
+\begin{code}
+tcConDecl :: TyCon -> [TyVar] -> ThetaType -> RenamedConDecl -> TcM s DataCon
+
+tcConDecl tycon tyvars ctxt (ConDecl name ex_tvs ex_ctxt details src_loc)
+ = tcAddSrcLoc src_loc $
+ tcExtendTyVarScope ex_tvs $ \ ex_tyvars ->
+ tcContext ex_ctxt `thenTc` \ ex_theta ->
+ tc_con_decl_help tycon tyvars ctxt name ex_tyvars ex_theta details
+
+tc_con_decl_help tycon tyvars ctxt 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) 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) 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' ->
+ zonkTcThetaType 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_id = mkDataConId data_con
+ in
+ returnNF_Tc 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 $ isEmptyVarSet $
+ tyVarsOfTypes tys `intersectVarSet` arg_tyvars
+
+get_strictness (Banged _) = markedStrict
+get_strictness (Unbanged _) = notMarkedStrict
+get_strictness (Unpacked _) = markedUnboxed
+
+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 :: [TyCon] -> TcM s ([Id], TcMonoBinds)
mkDataBinds [] = returnTc ([], EmptyMonoBinds)
mkDataBinds (tycon : tycons)
| isSynTyCon tycon = mkDataBinds tycons
returnTc (ids1++ids2, b1 `AndMonoBinds` b2)
mkDataBinds_one tycon
- = ASSERT( isAlgTyCon tycon )
- mapTc checkConstructorContext data_cons `thenTc_`
- mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids ->
+ = mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids ->
let
- data_ids = data_cons ++ sel_ids
+ data_ids = map dataConId data_cons ++ sel_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))
+ binds | isLocallyDefined tycon
+ = [ CoreMonoBind data_id (unfoldingTemplate (getIdUnfolding data_id))
| data_id <- data_ids, isLocallyDefined data_id
]
+ | otherwise
+ = []
in
- returnTc (data_ids, andMonoBinds binds)
+ returnTc (data_ids, andMonoBindList binds)
where
data_cons = tyConDataCons tycon
fields = [ (con, field) | con <- data_cons,
= 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
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
+ selector_id
+ | isNewTyCon tycon = mkNewTySelId first_field_label selector_ty
+ | otherwise = mkRecordSelId first_field_label selector_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}