\begin{code}
module TcTyDecls (
- tcTyDecl1,
- kcConDetails,
- mkImplicitDataBinds, mkNewTyConRep
+ tcTyDecl1, kcConDetails, mkNewTyConRep
) where
#include "HsVersions.h"
-import HsSyn ( MonoBinds(..),
- TyClDecl(..), ConDecl(..), ConDetails(..), BangType(..),
- andMonoBindList, getBangType
+import HsSyn ( TyClDecl(..), ConDecl(..), ConDetails(..),
+ getBangType, getBangStrictness, conDetailsTys
)
import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext )
-import TcHsSyn ( TcMonoBinds, idsToMonoBinds )
-import BasicTypes ( RecFlag(..), NewOrData(..) )
+import BasicTypes ( NewOrData(..), RecFlag, isRec )
-import TcMonoType ( tcHsSigType, tcHsBoxedSigType, kcTyVarScope, tcClassContext,
- kcHsContext, kcHsSigType
+import TcMonoType ( tcHsRecType, tcHsTyVars, tcRecTheta,
+ kcHsContext, kcHsSigType, kcHsLiftedSigType
+ )
+import TcEnv ( tcExtendTyVarEnv,
+ tcLookupTyCon, tcLookupRecId,
+ TyThingDetails(..), RecTcEnv
)
-import TcEnv ( tcExtendTyVarEnv, tcLookupTy, tcLookupValueByKey, TyThing(..), TyThingDetails(..) )
import TcMonad
-import TcUnify ( unifyKind )
-import Class ( Class, ClassContext )
-import DataCon ( DataCon, mkDataCon,
- dataConFieldLabels, dataConId, dataConWrapId,
- markedStrict, notMarkedStrict, markedUnboxed, dataConRepType
- )
+import DataCon ( DataCon, mkDataCon, dataConFieldLabels, dataConRepType )
import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId )
import FieldLabel
-import Var ( Id, TyVar )
-import Name ( Name, isLocallyDefined, OccName, NamedThing(..), nameUnique )
+import Var ( TyVar )
+import Name ( Name, NamedThing(..) )
import Outputable
-import TyCon ( TyCon, AlgTyConFlavour(..), ArgVrcs, mkSynTyCon, mkAlgTyCon,
- tyConDataConsIfAvailable, tyConTyVars,
- isSynTyCon, isNewTyCon
- )
-import Type ( getTyVar, tyVarsOfTypes, splitFunTy, applyTys,
- mkTyConApp, mkTyVarTys, mkForAllTys, mkFunTy,
- mkTyVarTy, splitAlgTyConApp_maybe,
- mkArrowKind, mkArrowKinds, boxedTypeKind,
- isUnboxedType, Type, ThetaType, classesOfPreds
+import TyCon ( TyCon, isNewTyCon, tyConTyVars )
+import Type ( tyVarsOfTypes, tyVarsOfPred, splitFunTy, applyTys,
+ mkTyConApp, mkTyVarTys, mkForAllTys,
+ splitAlgTyConApp_maybe, Type, ThetaType
)
import TysWiredIn ( unitTy )
-import Var ( tyVarKind )
import VarSet ( intersectVarSet, isEmptyVarSet )
-import Unique ( unpackCStringIdKey )
-import Util ( equivClasses )
-import FiniteMap ( FiniteMap, lookupWithDefaultFM )
+import PrelNames ( unpackCStringName, unpackCStringUtf8Name )
+import ListSetOps ( equivClasses )
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-tcTyDecl1 :: RenamedTyClDecl -> TcM s (Name, TyThingDetails)
-tcTyDecl1 (TySynonym tycon_name tyvar_names rhs src_loc)
- = tcLookupTy tycon_name `thenNF_Tc` \ (ATyCon tycon) ->
+tcTyDecl1 :: RecFlag -> RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails)
+tcTyDecl1 is_rec unf_env (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs})
+ = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon ->
tcExtendTyVarEnv (tyConTyVars tycon) $
- tcHsSigType rhs `thenTc` \ rhs_ty ->
+ tcHsRecType is_rec rhs `thenTc` \ rhs_ty ->
+ -- Note tcHsRecType not tcHsRecSigType; we allow type synonyms
+ -- that aren't types; e.g. type List = []
+ --
-- 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 now do that here without falling into
+ -- quantify over them:
+ -- e.g. type T = a->a
+ -- will become type T = forall a. a->a
+ --
+ -- With gla-exts that's right, but for H98 we should complain.
+ -- We can now do that here without falling into
-- a black hole, we still do it in rnDecl (TySynonym case)
+
returnTc (tycon_name, SynTyDetails rhs_ty)
-tcTyDecl1 (TyData _ context tycon_name _ con_decls _ derivings _ src_loc)
- = tcLookupTy tycon_name `thenNF_Tc` \ (ATyCon tycon) ->
+tcTyDecl1 is_rec unf_env (TyData {tcdND = new_or_data, tcdCtxt = context,
+ tcdName = tycon_name, tcdCons = con_decls})
+ = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon ->
let
tyvars = tyConTyVars tycon
in
tcExtendTyVarEnv tyvars $
-- Typecheck the pieces
- tcClassContext context `thenTc` \ ctxt ->
- tc_derivs derivings `thenTc` \ derived_classes ->
- mapTc (tcConDecl tycon tyvars ctxt) con_decls `thenTc` \ data_cons ->
-
- returnTc (tycon_name, DataTyDetails ctxt data_cons derived_classes)
- where
- tc_derivs Nothing = returnTc []
- tc_derivs (Just ds) = mapTc tc_deriv ds
-
- tc_deriv name = tcLookupTy name `thenTc` \ (AClass clas) ->
- returnTc clas
+ tcRecTheta is_rec context `thenTc` \ ctxt ->
+ mapTc (tcConDecl is_rec new_or_data tycon tyvars ctxt) con_decls `thenTc` \ data_cons ->
+ tcRecordSelectors is_rec unf_env tycon data_cons `thenTc` \ sel_ids ->
+ returnTc (tycon_name, DataTyDetails ctxt data_cons sel_ids)
\end{code}
\begin{code}
%************************************************************************
\begin{code}
-kcConDetails :: RenamedContext -> ConDetails Name -> TcM s ()
-kcConDetails ex_ctxt details
+kcConDetails :: NewOrData -> RenamedContext -> ConDetails Name -> TcM ()
+kcConDetails new_or_data ex_ctxt details
= kcHsContext ex_ctxt `thenTc_`
- kc_con_details details
+ mapTc_ kc_sig_type (conDetailsTys details)
where
- kc_con_details (VanillaCon btys) = mapTc_ kc_bty btys
- kc_con_details (InfixCon bty1 bty2) = mapTc_ kc_bty [bty1,bty2]
- kc_con_details (NewCon ty _) = kcHsSigType ty
- kc_con_details (RecCon flds) = mapTc_ kc_field flds
-
- kc_field (_, bty) = kc_bty bty
+ 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.
- kc_bty bty = kcHsSigType (getBangType bty)
-tcConDecl :: TyCon -> [TyVar] -> ClassContext -> RenamedConDecl -> TcM s DataCon
+tcConDecl :: RecFlag -> NewOrData -> TyCon -> [TyVar] -> ThetaType -> RenamedConDecl -> TcM DataCon
-tcConDecl tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ctxt details src_loc)
- = tcAddSrcLoc src_loc $
- kcTyVarScope ex_tvs (kcConDetails ex_ctxt details) `thenTc` \ ex_tyvars ->
- tcExtendTyVarEnv ex_tyvars $
- tcClassContext ex_ctxt `thenTc` \ ex_theta ->
+tcConDecl is_rec new_or_data tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ctxt details src_loc)
+ = tcAddSrcLoc src_loc $
+ tcHsTyVars ex_tvs (kcConDetails new_or_data ex_ctxt details) $ \ ex_tyvars ->
+ tcRecTheta is_rec ex_ctxt `thenTc` \ ex_theta ->
case details of
VanillaCon btys -> tc_datacon ex_tyvars ex_theta btys
InfixCon bty1 bty2 -> tc_datacon ex_tyvars ex_theta [bty1,bty2]
- NewCon ty mb_f -> tc_newcon ex_tyvars ex_theta ty mb_f
RecCon fields -> tc_rec_con ex_tyvars ex_theta fields
where
tc_datacon ex_tyvars ex_theta btys
arg_stricts = map getBangStrictness btys
tys = map getBangType btys
in
- mapTc tcHsSigType tys `thenTc` \ arg_tys ->
+ mapTc (tcHsRecType is_rec) tys `thenTc` \ arg_tys ->
mk_data_con ex_tyvars ex_theta arg_stricts arg_tys []
- tc_newcon ex_tyvars ex_theta ty mb_f
- = tcHsBoxedSigType 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 ex_tyvars ex_theta [notMarkedStrict] [arg_ty] field_label
-
tc_rec_con ex_tyvars ex_theta fields
= checkTc (null ex_tyvars) (exRecConErr name) `thenTc_`
mapTc tc_field (fields `zip` allFieldLabelTags) `thenTc` \ field_labels_s ->
let
field_labels = concat field_labels_s
arg_stricts = [str | (ns, bty) <- fields,
- let str = getBangStrictness bty,
- n <- ns -- One for each. E.g x,y,z :: !Int
+ let str = getBangStrictness bty,
+ n <- ns -- One for each. E.g x,y,z :: !Int
]
in
mk_data_con ex_tyvars ex_theta arg_stricts
(map fieldLabelType field_labels) field_labels
tc_field ((field_label_names, bty), tag)
- = tcHsSigType (getBangType bty) `thenTc` \ field_ty ->
+ = tcHsRecType is_rec (getBangType bty) `thenTc` \ field_ty ->
returnTc [mkFieldLabel (getName name) tycon field_ty tag | name <- field_label_names]
mk_data_con ex_tyvars ex_theta arg_stricts arg_tys fields
= filter in_arg_tys ctxt
where
arg_tyvars = tyVarsOfTypes arg_tys
- in_arg_tys (clas,tys) = not $ isEmptyVarSet $
- tyVarsOfTypes tys `intersectVarSet` arg_tyvars
-
-getBangStrictness (Banged _) = markedStrict
-getBangStrictness (Unbanged _) = notMarkedStrict
-getBangStrictness (Unpacked _) = markedUnboxed
+ in_arg_tys pred = not $ isEmptyVarSet $
+ tyVarsOfPred pred `intersectVarSet` arg_tyvars
\end{code}
-
%************************************************************************
%* *
-\subsection{Generating constructor/selector bindings for data declarations}
+\subsection{Record selectors}
%* *
%************************************************************************
\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)
+tcRecordSelectors is_rec unf_env tycon data_cons
+ -- Omit the check that the fields have consistent types if
+ -- the group is recursive; TcTyClsDecls.tcGroup will repeat
+ -- with NonRecursive once we have tied the knot
+ | isRec is_rec = returnTc sel_ids
+ | otherwise = mapTc check groups `thenTc_`
+ returnTc sel_ids
where
- data_cons = tyConDataConsIfAvailable tycon
- -- Abstract types mean we don't bring the
- -- data cons into scope, which should be fine
-
- data_con_wrapper_ids = map dataConWrapId data_cons
-
- fields = [ (con, field) | con <- data_cons,
- field <- dataConFieldLabels con
- ]
+ fields = [ 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
+ groups = equivClasses cmp_name fields
+ cmp_name field1 field2 = fieldLabelName field1 `compare` fieldLabelName field2
+
+ sel_ids = [ mkRecordSelId tycon field unpack_id unpackUtf8_id
+ | (field : _) <- groups ]
+
+ check fields@(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
+ -- NB: 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)
+ where
+ field_ty = fieldLabelType first_field_label
+ field_name = fieldLabelName first_field_label
+ other_tys = map fieldLabelType other_fields
+
+ unpack_id = tcLookupRecId unf_env unpackCStringName
+ unpackUtf8_id = tcLookupRecId unf_env unpackCStringUtf8Name
\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_`
- tcLookupValueByKey unpackCStringIdKey `thenTc` \ unpack_id ->
- returnTc (mkRecordSelId tycon first_field_label unpack_id)
- 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
-~~~~~~~~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{Errors and contexts}
+%* *
+%************************************************************************
+
+
\begin{code}
fieldTypeMisMatch field_name
- = sep [ptext SLIT("Declared types differ for field"), quotes (ppr field_name)]
+ = sep [ptext SLIT("Different constructors give different types for field"), quotes (ppr field_name)]
exRecConErr name
= ptext SLIT("Can't combine named fields with locally-quantified type variables")
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