\section[TcTyDecls]{Typecheck type declarations}
\begin{code}
-module TcTyDecls (
- tcTyDecl, kcTyDecl,
- tcConDecl,
- mkImplicitDataBinds
- ) where
+module TcTyDecls ( tcTyDecl, kcConDetails, tcMkDataCon ) where
#include "HsVersions.h"
-import HsSyn ( MonoBinds(..),
- TyClDecl(..), ConDecl(..), ConDetails(..), BangType(..),
- andMonoBindList
+import HsSyn ( TyClDecl(..), ConDecl(..), HsConDetails(..), BangType,
+ getBangType, getBangStrictness, conDetailsTys
)
-import RnHsSyn ( RenamedTyClDecl, RenamedConDecl )
-import TcHsSyn ( TcMonoBinds, idsToMonoBinds )
-import BasicTypes ( RecFlag(..), NewOrData(..) )
+import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext )
+import BasicTypes ( NewOrData(..), StrictnessMark(..) )
-import TcMonoType ( tcExtendTopTyVarScope, tcExtendTyVarScope,
- tcHsTypeKind, kcHsType, tcHsTopType, tcHsTopBoxedType,
- tcContext, tcHsTopTypeKind
+import TcMonoType ( tcHsTyVars, tcHsTheta, tcHsType,
+ kcHsContext, kcHsSigType, kcHsLiftedSigType
)
-import TcType ( zonkTcTyVarToTyVar, zonkTcClassConstraints )
-import TcEnv ( tcLookupTy, TcTyThing(..) )
-import TcMonad
-import TcUnify ( unifyKind )
-
-import Class ( Class )
-import DataCon ( DataCon, dataConSig, mkDataCon, isNullaryDataCon,
- dataConFieldLabels, dataConId, dataConWrapId,
- markedStrict, notMarkedStrict, markedUnboxed
- )
-import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId )
-import FieldLabel
-import Var ( Id, TyVar )
-import Name ( Name, isLocallyDefined, OccName, NamedThing(..), nameUnique )
+import TcEnv ( tcExtendTyVarEnv, tcLookupTyCon, TyThingDetails(..) )
+import TcType ( Type, tyVarsOfTypes, tyVarsOfPred, ThetaType )
+import RnEnv ( lookupSysName )
+import TcRnMonad
+
+import DataCon ( DataCon, mkDataCon, dataConFieldLabels )
+import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType, allFieldLabelTags, mkFieldLabel )
+import MkId ( mkDataConWorkId, mkDataConWrapId, mkRecordSelId )
+import Var ( TyVar )
+import Name ( Name )
+import OccName ( mkDataConWrapperOcc, mkDataConWorkerOcc, mkGenOcc1, mkGenOcc2 )
import Outputable
-import TyCon ( TyCon, ArgVrcs, mkSynTyCon, mkAlgTyCon,
- isSynTyCon, tyConDataCons, isNewTyCon
- )
-import Type ( getTyVar, tyVarsOfTypes,
- mkTyConApp, mkTyVarTys, mkForAllTys, mkFunTy,
- mkTyVarTy, splitForAllTys, isForAllTy,
- mkArrowKind, mkArrowKinds, boxedTypeKind,
- isUnboxedType, Type, ThetaType, classesOfPreds
- )
-import Var ( tyVarKind )
+import TyCon ( TyCon, DataConDetails(..), visibleDataCons,
+ tyConTyVars, tyConName )
import VarSet ( intersectVarSet, isEmptyVarSet )
-import Util ( equivClasses )
-import FiniteMap ( FiniteMap, lookupWithDefaultFM )
-import CmdLineOpts ( opt_GlasgowExts )
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Kind checking}
-%* *
-%************************************************************************
-
-\begin{code}
-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
+import Generics ( mkTyConGenInfo )
+import CmdLineOpts ( DynFlag(..) )
+import List ( nubBy )
\end{code}
-
%************************************************************************
%* *
\subsection{Type checking}
%************************************************************************
\begin{code}
-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)
+tcTyDecl :: RenamedTyClDecl -> TcM (Name, TyThingDetails)
+tcTyDecl (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs})
+ = tcLookupTyCon tycon_name `thenM` \ tycon ->
+ tcExtendTyVarEnv (tyConTyVars tycon) $
+ tcHsType rhs `thenM` \ rhs_ty ->
+ returnM (tycon_name, SynTyDetails rhs_ty)
+
+tcTyDecl (TyData {tcdND = new_or_data, tcdCtxt = context,
+ tcdName = tycon_name, tcdCons = con_decls,
+ tcdGeneric = generic})
+ = tcLookupTyCon tycon_name `thenM` \ tycon ->
let
- -- 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
+ tyvars = tyConTyVars tycon
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 ->
-
+ tcExtendTyVarEnv tyvars $
+ tcHsTheta context `thenM` \ ctxt ->
+ tcConDecls new_or_data tycon tyvars ctxt con_decls `thenM` \ data_cons ->
let
- -- Construct the tycon
- real_data_or_new = case data_or_new of
- NewType -> NewType
- DataType | all isNullaryDataCon data_cons -> EnumType
- | otherwise -> DataType
+ sel_ids = mkRecordSelectors tycon data_cons
+ in
+ tcGenericInfo tycon generic `thenM` \ gen_info ->
+ returnM (tycon_name, DataTyDetails ctxt data_cons sel_ids gen_info)
- argvrcs = lookupWithDefaultFM rec_vrcs (pprPanic "tcTyDecl: argvrcs:" $ ppr tycon_name)
- tycon_name
+tcTyDecl (ForeignType {tcdName = tycon_name})
+ = returnM (tycon_name, ForeignTyDetails)
- 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_deriv name = tcLookupTy name `thenTc` \ (_, _, AClass clas) ->
- returnTc clas
+tcGenericInfo tycon generics -- Source code decl: consult the flag
+ = do_we_want generics `thenM` \ want_generics ->
+ if want_generics then
+ mapM (lookupSysName (tyConName tycon))
+ [mkGenOcc1, mkGenOcc2] `thenM` \ gen_sys_names ->
+ returnM (mkTyConGenInfo tycon gen_sys_names)
+ else
+ returnM Nothing
+ where
+ do_we_want (Just g) = returnM g -- Interface file decl
+ -- so look at decl
+ do_we_want Nothing = doptM Opt_Generics -- Source code decl
+ -- so look at flag
+
+mkRecordSelectors tycon data_cons
+ = -- We'll check later that fields with the same name
+ -- from different constructors have the same type.
+ [ mkRecordSelId tycon field
+ | field <- nubBy eq_name fields ]
+ where
+ fields = [ field | con <- visibleDataCons data_cons,
+ field <- dataConFieldLabels con ]
+ eq_name field1 field2 = fieldLabelName field1 == fieldLabelName field2
\end{code}
%************************************************************************
%* *
-\subsection{Type check constructors}
+\subsection{Kind and type check constructors}
%* *
%************************************************************************
\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
- 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
+kcConDetails :: NewOrData -> RenamedContext
+ -> HsConDetails Name (BangType Name) -> TcM ()
+kcConDetails new_or_data ex_ctxt details
+ = kcHsContext ex_ctxt `thenM_`
+ mappM_ kc_sig_type (conDetailsTys details)
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]
+ kc_sig_type = case new_or_data of
+ DataType -> kcHsSigType
+ NewType -> kcHsLiftedSigType
+ -- Can't allow an unlifted type here, because we're effectively
+ -- going to remove the constructor while coercing it to a lifted type.
+
+
+tcConDecls :: NewOrData -> TyCon -> [TyVar] -> ThetaType
+ -> DataConDetails RenamedConDecl -> TcM (DataConDetails DataCon)
+
+tcConDecls new_or_data tycon tyvars ctxt con_decls
+ = case con_decls of
+ Unknown -> returnM Unknown
+ HasCons n -> returnM (HasCons n)
+ DataCons cs -> mappM tc_con_decl cs `thenM` \ data_cons ->
+ returnM (DataCons data_cons)
+ where
+ tc_con_decl (ConDecl name ex_tvs ex_ctxt details src_loc)
+ = addSrcLoc src_loc $
+ tcHsTyVars ex_tvs (kcConDetails new_or_data ex_ctxt details) $ \ ex_tyvars ->
+ tcHsTheta ex_ctxt `thenM` \ ex_theta ->
+ case details of
+ PrefixCon btys -> tc_datacon ex_tyvars ex_theta btys
+ InfixCon bty1 bty2 -> tc_datacon ex_tyvars ex_theta [bty1,bty2]
+ RecCon fields -> tc_rec_con ex_tyvars ex_theta fields
+ where
+
+ tc_datacon ex_tyvars ex_theta btys
+ = mappM tcHsType (map getBangType btys) `thenM` \ arg_tys ->
+ tcMkDataCon name
+ (map getBangStrictness btys)
+ [{- No field labels -}]
+ tyvars ctxt ex_tyvars ex_theta
+ arg_tys tycon
+
+ tc_rec_con ex_tyvars ex_theta fields
+ = checkTc (null ex_tyvars) (exRecConErr name) `thenM_`
+ mappM tc_field (fields `zip` allFieldLabelTags) `thenM` \ field_labels ->
+ let
+ arg_stricts = [getBangStrictness bty | (n, bty) <- fields]
+ arg_tys = map fieldLabelType field_labels
+ in
+ tcMkDataCon name arg_stricts field_labels
+ tyvars ctxt ex_tyvars ex_theta
+ arg_tys tycon
+
+ tc_field ((field_label_name, bty), tag)
+ = tcHsType (getBangType bty) `thenM` \ field_ty ->
+ returnM (mkFieldLabel field_label_name tycon field_ty tag)
+
+tcMkDataCon :: Name
+ -> [StrictnessMark] -> [FieldLabel]
+ -> [TyVar] -> ThetaType
+ -> [TyVar] -> ThetaType
+ -> [Type] -> TyCon
+ -> TcM DataCon
+-- A wrapper for DataCon.mkDataCon that
+-- a) makes the worker Id
+-- b) makes the wrapper Id if necessary, including
+-- allocating its unique (hence monadic)
+tcMkDataCon src_name arg_stricts fields
+ tyvars ctxt ex_tyvars ex_theta
+ arg_tys tycon
+ = lookupSysName src_name mkDataConWrapperOcc `thenM` \ wrap_name ->
+ lookupSysName src_name mkDataConWorkerOcc `thenM` \ work_name ->
+ -- This last one takes the name of the data constructor in the source
+ -- code, which (for Haskell source anyway) will be in the SrcDataName name
+ -- space, and makes it into a "real data constructor name"
+
+ doptM Opt_UnboxStrictFields `thenM` \ unbox_strict_fields ->
- 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
+ let
+ real_stricts
+ | unbox_strict_fields = map unboxUserStrict arg_stricts
+ | otherwise = arg_stricts
+
+ unboxUserStrict MarkedUserStrict = MarkedUserUnboxed
+ unboxUserStrict other = other
+
+ data_con = mkDataCon src_name real_stricts fields
+ tyvars (thinContext arg_tys ctxt)
+ ex_tyvars ex_theta
+ arg_tys tycon
+ data_con_work_id data_con_wrap_id
+ data_con_work_id = mkDataConWorkId work_name data_con
+ data_con_wrap_id = mkDataConWrapId wrap_name data_con
+ in
+ returnM data_con
-- The context for a data constructor should be limited to
-- the type variables mentioned in the arg_tys
= 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
+ in_arg_tys pred = not $ isEmptyVarSet $
+ tyVarsOfPred pred `intersectVarSet` arg_tyvars
\end{code}
-
%************************************************************************
%* *
-\subsection{Generating constructor/selector bindings for data declarations}
+\subsection{Errors and contexts}
%* *
%************************************************************************
-\begin{code}
-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)
-
-mkImplicitDataBinds_one tycon
- = mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids ->
- let
- 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 selector Ids into bindings,
- -- and build bindigns for the constructor wrappers
- binds | isLocallyDefined tycon = idsToMonoBinds unf_ids
- | otherwise = EmptyMonoBinds
- in
- 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
- ]
-
- -- groups is list of fields that share a common name
- groups = equivClasses cmp_name fields
- cmp_name (_, field1) (_, field2)
- = fieldLabelName field1 `compare` fieldLabelName field2
-\end{code}
\begin{code}
-mkRecordSelector tycon fields@((first_con, 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
- -- This check assumes that all the constructors of a given
- -- data type use the same type variables
- = checkTc (all (== field_ty) other_tys)
- (fieldTypeMisMatch field_name) `thenTc_`
- 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]
-\end{code}
-
-
-Errors and contexts
-~~~~~~~~~~~~~~~~~~~
-\begin{code}
-fieldTypeMisMatch field_name
- = sep [ptext SLIT("Declared types differ for field"), quotes (ppr field_name)]
-
exRecConErr name
= ptext SLIT("Can't combine named fields with locally-quantified type variables")
$$