%
-% (c) The AQUA Project, Glasgow University, 1996
+% (c) The AQUA Project, Glasgow University, 1996-1998
%
\section[TcTyDecls]{Typecheck type declarations}
\begin{code}
-#include "HsVersions.h"
-
-module TcTyDecls (
- tcTyDecl,
- tcConDecl
- ) where
-
-import Ubiq{-uitous-}
+module TcTyDecls ( tcTyDecl, kcConDetails ) where
-import HsSyn ( TyDecl(..), ConDecl(..), BangType(..), MonoType )
-import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..) )
+#include "HsVersions.h"
-import TcMonoType ( tcMonoTypeKind, tcMonoType, tcContext )
-import TcEnv ( tcLookupTyCon, tcLookupTyVar, tcLookupClass )
+import HsSyn ( TyClDecl(..), ConDecl(..), ConDetails(..),
+ getBangType, getBangStrictness, conDetailsTys
+ )
+import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext )
+import BasicTypes ( NewOrData(..) )
+
+import TcMonoType ( tcHsTyVars, tcHsTheta, tcHsType,
+ kcHsContext, kcHsSigType, kcHsLiftedSigType
+ )
+import TcEnv ( tcExtendTyVarEnv,
+ tcLookupTyCon, tcLookupRecId,
+ TyThingDetails(..), RecTcEnv
+ )
+import TcType ( tyVarsOfTypes, tyVarsOfPred, ThetaType )
import TcMonad
-import TcKind ( TcKind, unifyKind, mkTcArrowKind, mkTcTypeKind )
-
-import Id ( mkDataCon, StrictnessMark(..) )
-import Kind ( Kind, mkArrowKind, mkBoxedTypeKind )
-import SpecEnv ( SpecEnv(..), nullSpecEnv )
-import Name ( getNameFullName, Name(..) )
-import Pretty
-import TyCon ( TyCon, ConsVisible(..), NewOrData(..), mkSynTyCon, mkDataTyCon )
-import Type ( getTypeKind )
-import TyVar ( getTyVarKind )
-import Util ( panic )
-
-\end{code}
-\begin{code}
-tcTyDecl :: RenamedTyDecl -> TcM s TyCon
+import DataCon ( DataCon, mkDataCon, dataConFieldLabels )
+import FieldLabel ( fieldLabelName, fieldLabelType, allFieldLabelTags, mkFieldLabel )
+import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId )
+import Var ( TyVar )
+import Name ( Name, NamedThing(..) )
+import Outputable
+import TyCon ( TyCon, DataConDetails(..), visibleDataCons,
+ tyConTyVars )
+import VarSet ( intersectVarSet, isEmptyVarSet )
+import PrelNames ( unpackCStringName, unpackCStringUtf8Name )
+import List ( nubBy )
\end{code}
-Type synonym decls
-~~~~~~~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{Type checking}
+%* *
+%************************************************************************
\begin{code}
-tcTyDecl (TySynonym tycon_name tyvar_names rhs src_loc)
- = tcAddSrcLoc src_loc $
- tcAddErrCtxt (tySynCtxt tycon_name) $
-
- -- Look up the pieces
- tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, rec_tycon) ->
- mapAndUnzipNF_Tc tcLookupTyVar tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) ->
-
- -- Look at the rhs
- tcMonoTypeKind rhs `thenTc` \ (rhs_kind, rhs_ty) ->
-
- -- Unify tycon kind with (k1->...->kn->rhs)
- unifyKind tycon_kind
- (foldr mkTcArrowKind rhs_kind tyvar_kinds)
- `thenTc_`
+tcTyDecl :: RenamedTyClDecl -> TcM (Name, TyThingDetails)
+tcTyDecl (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs})
+ = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon ->
+ tcExtendTyVarEnv (tyConTyVars tycon) $
+ tcHsType rhs `thenTc` \ rhs_ty ->
+ returnTc (tycon_name, SynTyDetails rhs_ty)
+
+tcTyDecl (TyData {tcdND = new_or_data, tcdCtxt = context,
+ tcdName = tycon_name, tcdCons = con_decls})
+ = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon ->
let
- -- Construct the tycon
- result_kind, final_tycon_kind :: Kind -- NB not TcKind!
- result_kind = getTypeKind rhs_ty
- final_tycon_kind = foldr (mkArrowKind . getTyVarKind) result_kind rec_tyvars
-
- tycon = mkSynTyCon (getItsUnique tycon_name)
- (getNameFullName tycon_name)
- final_tycon_kind
- (length tyvar_names)
- rec_tyvars
- rhs_ty
+ tyvars = tyConTyVars tycon
in
- returnTc tycon
-\end{code}
-
-Algebraic data and newtype decls
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-\begin{code}
-tcTyDecl (TyData context tycon_name tyvar_names con_decls derivings pragmas src_loc)
- = tcTyDataOrNew DataType context tycon_name tyvar_names con_decls derivings pragmas src_loc
-
-tcTyDecl (TyNew context tycon_name tyvar_names con_decl derivings pragmas src_loc)
- = tcTyDataOrNew NewType context tycon_name tyvar_names con_decl derivings pragmas src_loc
-
-
-tcTyDataOrNew data_or_new context tycon_name tyvar_names con_decls derivings pragmas src_loc
- = tcAddSrcLoc src_loc $
- tcAddErrCtxt (tyDataCtxt tycon_name) $
-
- -- Lookup the pieces
- 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 ->
-
- -- Typecheck the context
- tcContext context `thenTc` \ ctxt ->
-
- -- Unify tycon kind with (k1->...->kn->Type)
- unifyKind tycon_kind
- (foldr mkTcArrowKind mkTcTypeKind tyvar_kinds)
- `thenTc_`
- -- Walk the condecls
- mapTc (tcConDecl rec_tycon rec_tyvars ctxt) con_decls
- `thenTc` \ con_ids ->
+ tcExtendTyVarEnv tyvars $
+ tcHsTheta context `thenTc` \ ctxt ->
+ tcConDecls new_or_data tycon tyvars ctxt con_decls `thenTc` \ data_cons ->
let
- -- Construct the tycon
- final_tycon_kind :: Kind -- NB not TcKind!
- final_tycon_kind = foldr (mkArrowKind . getTyVarKind) mkBoxedTypeKind rec_tyvars
-
- tycon = mkDataTyCon (getItsUnique 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
+ sel_ids = mkRecordSelectors tycon data_cons
in
- returnTc tycon
- where
- tc_derivs Nothing = returnNF_Tc []
- tc_derivs (Just ds) = mapNF_Tc tc_deriv ds
+ returnTc (tycon_name, DataTyDetails ctxt data_cons sel_ids)
- tc_deriv name
- = tcLookupClass name `thenNF_Tc` \ (_, clas) ->
- returnNF_Tc clas
-\end{code}
+tcTyDecl (ForeignType {tcdName = tycon_name})
+ = returnTc (tycon_name, ForeignTyDetails)
-Constructors
-~~~~~~~~~~~~
-\begin{code}
-tcConDecl :: TyCon -> [TyVar] -> [(Class,Type)] -> RenamedConDecl -> TcM s Id
-
-tcConDecl tycon tyvars ctxt (ConDecl name btys src_loc)
- = tcAddSrcLoc src_loc $
- let
- (stricts, tys) = sep_bangs btys
- in
- mapTc tcMonoType tys `thenTc` \ arg_tys ->
- let
- data_con = mkDataCon (getItsUnique name)
- (getNameFullName name)
- stricts
- tyvars
- [] -- ToDo: ctxt; limited to tyvars in arg_tys
- arg_tys
- tycon
- -- nullSpecEnv
- in
- returnTc data_con
-
-tcConDecl tycon tyvars ctxt (ConOpDecl bty1 op bty2 src_loc)
- = tcAddSrcLoc src_loc $
- let
- (stricts, tys) = sep_bangs [bty1, bty2]
- in
- mapTc tcMonoType tys `thenTc` \ arg_tys ->
- let
- data_con = mkDataCon (getItsUnique op)
- (getNameFullName op)
- stricts
- tyvars
- [] -- ToDo: ctxt
- arg_tys
- tycon
- -- nullSpecEnv
- in
- returnTc data_con
-
-tcConDecl tycon tyvars ctxt (NewConDecl name ty src_loc)
- = tcAddSrcLoc src_loc $
- tcMonoType ty `thenTc` \ arg_ty ->
- let
- data_con = mkDataCon (getItsUnique name)
- (getNameFullName name)
- [NotMarkedStrict]
- tyvars
- [] -- ToDo: ctxt
- [arg_ty]
- tycon
- -- nullSpecEnv
- in
- returnTc data_con
+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}
-tcConDecl tycon tyvars ctxt (RecConDecl con fields src_loc)
- = panic "tcConDecls:RecConDecl"
+%************************************************************************
+%* *
+\subsection{Kind and type check constructors}
+%* *
+%************************************************************************
-sep_bangs btys
- = unzip (map sep_bang btys)
- where
- sep_bang (Banged ty) = (MarkedStrict, ty)
- sep_bang (Unbanged ty) = (NotMarkedStrict, ty)
+\begin{code}
+kcConDetails :: NewOrData -> RenamedContext -> ConDetails Name -> TcM ()
+kcConDetails new_or_data ex_ctxt details
+ = kcHsContext ex_ctxt `thenTc_`
+ mapTc_ kc_sig_type (conDetailsTys details)
+ where
+ 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 -> returnTc Unknown
+ HasCons n -> returnTc (HasCons n)
+ DataCons cs -> mapTc tc_con_decl cs `thenTc` \ data_cons ->
+ returnTc (DataCons data_cons)
+ where
+ tc_con_decl (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 ->
+ tcHsTheta 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]
+ RecCon fields -> tc_rec_con ex_tyvars ex_theta fields
+ where
+
+ tc_datacon ex_tyvars ex_theta btys
+ = mapTc tcHsType (map getBangType btys) `thenTc` \ arg_tys ->
+ mk_data_con ex_tyvars ex_theta (map getBangStrictness btys) arg_tys []
+
+ 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
+ ]
+ in
+ mk_data_con ex_tyvars ex_theta arg_stricts
+ (map fieldLabelType field_labels) field_labels
+
+ tc_field ((field_label_names, bty), tag)
+ = tcHsType (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
+ = 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
+
+-- 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 pred = not $ isEmptyVarSet $
+ tyVarsOfPred pred `intersectVarSet` arg_tyvars
\end{code}
+%************************************************************************
+%* *
+\subsection{Errors and contexts}
+%* *
+%************************************************************************
-Errors and contexts
-~~~~~~~~~~~~~~~~~~~
-\begin{code}
-tySynCtxt tycon_name sty
- = ppCat [ppStr "In the type declaration for", ppr sty tycon_name]
-tyDataCtxt tycon_name sty
- = ppCat [ppStr "In the data declaration for", ppr sty tycon_name]
-
-tyNewCtxt tycon_name sty
- = ppCat [ppStr "In the newtype declaration for", ppr sty tycon_name]
+\begin{code}
+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}
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