\section[TcTyDecls]{Typecheck type declarations}
\begin{code}
-#include "HsVersions.h"
-
module TcTyDecls (
tcTyDecl,
tcConDecl,
mkDataBinds
) where
-IMP_Ubiq(){-uitous-}
+#include "HsVersions.h"
-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 HsSyn ( MonoBinds(..),
+ TyDecl(..), ConDecl(..), ConDetails(..), BangType(..),
+ andMonoBinds
)
+import HsTypes ( getTyVarName )
+import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..) )
import TcHsSyn ( mkHsTyLam, mkHsDictLam, tcIdType,
- SYN_IE(TcHsBinds), TcIdOcc(..)
+ TcHsBinds, TcMonoBinds
)
+import BasicTypes ( RecFlag(..), NewOrData(..) )
+
import Inst ( newDicts, InstOrigin(..), Inst )
-import TcMonoType ( tcMonoTypeKind, tcMonoType, tcPolyType, tcContext )
-import TcSimplify ( tcSimplifyThetas )
-import TcType ( tcInstTyVars, tcInstType, tcInstId )
-import TcEnv ( tcLookupTyCon, tcLookupTyVar, tcLookupClass,
+import TcMonoType ( tcHsTypeKind, tcHsType, tcContext )
+import TcSimplify ( tcSimplifyCheckThetas )
+import TcType ( tcInstTyVars )
+import TcEnv ( TcIdOcc(..), tcInstId,
+ tcLookupTyCon, tcLookupTyVar, tcLookupClass,
newLocalId, newLocalIds, tcLookupClassByKey
)
-import TcMonad hiding ( rnMtoTcM )
-import TcKind ( TcKind, unifyKind, mkTcArrowKind, mkTcTypeKind )
+import TcMonad
+import TcKind ( TcKind, unifyKind, mkArrowKind, mkBoxedTypeKind )
-import PprType ( GenClass, GenType{-instance Outputable-},
- GenTyVar{-instance Outputable-}{-ToDo:possibly rm-}
- )
-import Class ( GenClass{-instance Eq-}, classInstEnv )
+import Class ( classInstEnv, Class )
import Id ( mkDataCon, dataConSig, mkRecordSelId, idType,
dataConFieldLabels, dataConStrictMarks,
- StrictnessMark(..),
- GenId{-instance NamedThing-}
+ StrictnessMark(..), getIdUnfolding,
+ Id
)
+import CoreUnfold ( getUnfoldingTemplate )
import FieldLabel
import Kind ( Kind, mkArrowKind, mkBoxedTypeKind )
-import SpecEnv ( SpecEnv, nullSpecEnv )
-import Name ( nameSrcLoc, isLocallyDefinedName, getSrcLoc,
- Name{-instance Ord3-}
+import Name ( nameSrcLoc, isLocallyDefined, getSrcLoc,
+ OccName(..),
+ NamedThing(..)
)
-import Outputable ( Outputable(..), interpp'SP )
-import Pretty
-import TyCon ( TyCon, NewOrData(..), mkSynTyCon, mkDataTyCon, isDataTyCon,
- isNewTyCon, isSynTyCon, tyConDataCons
+import Outputable
+import TyCon ( TyCon, mkSynTyCon, mkDataTyCon, isAlgTyCon,
+ isSynTyCon, tyConDataCons
)
-import Type ( GenType, -- instances
- typeKind, getTyVar, tyVarsOfTypes, eqTy, splitSigmaTy,
- applyTyCon, mkTyVarTys, mkForAllTys, mkFunTy,
- splitFunTy, mkTyVarTy, getTyVar_maybe
+import Type ( typeKind, getTyVar, tyVarsOfTypes, splitSigmaTy,
+ mkTyConApp, mkTyVarTys, mkForAllTys, mkFunTy,
+ splitFunTys, mkTyVarTy, getTyVar_maybe,
+ isUnboxedType, Type, ThetaType
)
-import TyVar ( tyVarKind, elementOfTyVarSet, GenTyVar{-instance Eq-} )
-import Unique ( Unique {- instance Eq -}, evalClassKey )
-import UniqSet ( emptyUniqSet, mkUniqSet, uniqSetToList, unionManyUniqSets, SYN_IE(UniqSet) )
+import TyVar ( tyVarKind, elementOfTyVarSet, intersectTyVarSets, isEmptyTyVarSet,
+ TyVar )
+import Unique ( evalClassKey )
+import UniqSet ( emptyUniqSet, mkUniqSet, uniqSetToList, unionManyUniqSets, UniqSet )
import Util ( equivClasses, zipEqual, nOfThem, panic, assertPanic )
\end{code}
\begin{code}
-tcTyDecl :: RenamedTyDecl -> TcM s TyCon
+tcTyDecl :: RecFlag -> RenamedTyDecl -> TcM s TyCon
\end{code}
Type synonym decls
~~~~~~~~~~~~~~~~~~
\begin{code}
-tcTyDecl (TySynonym tycon_name tyvar_names rhs src_loc)
+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 `thenNF_Tc` \ (tycon_kind, _, rec_tycon) ->
- mapAndUnzipNF_Tc tcLookupTyVar tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) ->
+ tcLookupTyCon tycon_name `thenTc` \ (tycon_kind, _, rec_tycon) ->
+ mapAndUnzipNF_Tc (tcLookupTyVar.getTyVarName) tyvar_names
+ `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) ->
-- Look at the rhs
- tcMonoTypeKind rhs `thenTc` \ (rhs_kind, rhs_ty) ->
+ tcHsTypeKind rhs `thenTc` \ (rhs_kind, rhs_ty) ->
-- Unify tycon kind with (k1->...->kn->rhs)
unifyKind tycon_kind
- (foldr mkTcArrowKind rhs_kind tyvar_kinds)
+ (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,
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\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
+tcTyDecl is_rec (TyData data_or_new context tycon_name tyvar_names con_decls derivings pragmas src_loc)
= tcAddSrcLoc src_loc $
- tcAddErrCtxt (tyDataCtxt tycon_name) $
+ let ctxt = case data_or_new of
+ NewType -> tyNewCtxt tycon_name
+ DataType -> tyDataCtxt tycon_name
+ in
+ tcAddErrCtxt ctxt $
-- 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 ->
+ 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 ->
-- Typecheck the context
tcContext context `thenTc` \ ctxt ->
-- Unify tycon kind with (k1->...->kn->Type)
unifyKind tycon_kind
- (foldr mkTcArrowKind mkTcTypeKind tyvar_kinds)
+ (foldr mkArrowKind mkBoxedTypeKind tyvar_kinds)
`thenTc_`
-- Walk the condecls
ctxt
con_ids
derived_classes
+ Nothing -- Not a dictionary
data_or_new
+ is_rec
in
returnTc tycon
-tc_derivs Nothing = returnNF_Tc []
-tc_derivs (Just ds) = mapNF_Tc tc_deriv ds
+tc_derivs Nothing = returnTc []
+tc_derivs (Just ds) = mapTc tc_deriv ds
tc_deriv name
- = tcLookupClass name `thenNF_Tc` \ (_, clas) ->
- returnNF_Tc clas
+ = tcLookupClass name `thenTc` \ (_, clas) ->
+ returnTc clas
\end{code}
Generating constructor/selector bindings for data declarations
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-mkDataBinds :: [TyCon] -> TcM s ([Id], TcHsBinds s)
-mkDataBinds [] = returnTc ([], EmptyBinds)
+mkDataBinds :: [TyCon] -> TcM s ([Id], TcMonoBinds s)
+mkDataBinds [] = returnTc ([], EmptyMonoBinds)
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)
+ returnTc (ids1++ids2, b1 `AndMonoBinds` 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
- )
+ = ASSERT( isAlgTyCon tycon )
+ mapTc checkConstructorContext data_cons `thenTc_`
+ mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids ->
+ let
+ data_ids = 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))
+ | data_id <- data_ids, isLocallyDefined data_id
+ ]
+ in
+ returnTc (data_ids, andMonoBinds binds)
where
data_cons = tyConDataCons tycon
fields = [ (con, field) | con <- data_cons,
-- groups is list of fields that share a common name
groups = equivClasses cmp_name fields
cmp_name (_, field1) (_, field2)
- = fieldLabelName field1 `cmp` fieldLabelName field2
+ = fieldLabelName field1 `compare` 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.
-
-* 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.
+-- Check that all the types of all the strict arguments are in Eval
\begin{code}
-mkConstructor con_id
- | not (isLocallyDefinedName (getName con_id))
- = returnTc (con_id, EmptyMonoBinds)
+checkConstructorContext con_id
+ | not (isLocallyDefined con_id)
+ = returnTc ()
| 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 ->
+ = 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_`
+ strict_marks = dataConStrictMarks con_id
+ (tyvars, theta, ext_tyvars, ext_theta, arg_tys, _) = dataConSig con_id
- -- 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)
+ eval_theta = [ (eval_clas, [arg_ty])
+ | (arg_ty, MarkedStrict) <- zipEqual "strict_args"
+ arg_tys strict_marks
+ ]
in
-
- returnTc (con_id, VarMonoBind (RealId con_id) con_rhs)
+ tcAddErrCtxt (evalCtxt con_id eval_theta) $
+ tcSimplifyCheckThetas theta eval_theta
\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
-
+ -- 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 (eqTy field_ty) other_tys)
+ = checkTc (all (== 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
+ returnTc selector_id
+ where
+ 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 = mkTyConApp tycon (mkTyVarTys tyvars)
+ -- tyvars of first_con may be free in field_ty
+ -- Now build the selector
+
+ 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)
+ selector_id :: Id
+ selector_id = mkRecordSelId first_field_label selector_ty
\end{code}
Constructors
~~~~~~~~~~~~
\begin{code}
-tcConDecl :: TyCon -> [TyVar] -> [(Class,Type)] -> RenamedConDecl -> TcM s Id
+tcConDecl :: TyCon -> [TyVar] -> ThetaType -> RenamedConDecl -> TcM s Id
-tcConDecl tycon tyvars ctxt (ConDecl name btys src_loc)
+tcConDecl tycon tyvars ctxt (ConDecl name ex_ctxt (VanillaCon btys) src_loc)
= tcDataCon tycon tyvars ctxt name btys src_loc
-tcConDecl tycon tyvars ctxt (ConOpDecl bty1 op bty2 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 (NewConDecl name ty src_loc)
+tcConDecl tycon tyvars ctxt (ConDecl name ex_ctxt (NewCon ty) src_loc)
= tcAddSrcLoc src_loc $
- tcMonoType ty `thenTc` \ arg_ty ->
+ 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
- -- nullSpecEnv
in
returnTc data_con
-tcConDecl tycon tyvars ctxt (RecConDecl name fields src_loc)
+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_labels
tyvars
(thinContext arg_tys ctxt)
+ [] [] -- Temporary; existential chaps
arg_tys
tycon
- -- nullSpecEnv
in
returnTc data_con
tcField (field_label_names, bty)
- = tcPolyType (get_pty bty) `thenTc` \ field_ty ->
+ = 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
stricts = map get_strictness btys
tys = map get_pty btys
in
- mapTc tcPolyType tys `thenTc` \ arg_tys ->
+ 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
- -- nullSpecEnv
in
returnTc data_con
= filter in_arg_tys ctxt
where
arg_tyvars = tyVarsOfTypes arg_tys
- in_arg_tys (clas,ty) = getTyVar "tcDataCon" ty `elementOfTyVarSet` arg_tyvars
+ in_arg_tys (clas,tys) = not $ isEmptyTyVarSet $
+ tyVarsOfTypes tys `intersectTyVarSets` arg_tyvars
get_strictness (Banged _) = MarkedStrict
get_strictness (Unbanged _) = NotMarkedStrict
Errors and contexts
~~~~~~~~~~~~~~~~~~~
\begin{code}
-tySynCtxt tycon_name sty
- = ppCat [ppStr "In the type declaration for", ppr sty tycon_name]
+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)]
-tyDataCtxt tycon_name sty
- = ppCat [ppStr "In the data declaration for", ppr sty tycon_name]
+tyNewCtxt tycon_name
+ = hsep [ptext SLIT("In the newtype declaration for"), quotes (ppr tycon_name)]
-tyNewCtxt tycon_name sty
- = ppCat [ppStr "In the newtype declaration for", ppr sty tycon_name]
+fieldTypeMisMatch field_name
+ = sep [ptext SLIT("Declared types differ for field"), quotes (ppr field_name)]
-fieldTypeMisMatch field_name sty
- = ppSep [ppStr "Declared types differ for field", ppr sty field_name]
+newTypeUnboxedField ty
+ = sep [ptext SLIT("Newtype constructor field has an unboxed type:"),
+ quotes (ppr ty)]
-missingEvalErr con eval_theta sty
- = ppCat [ppStr "Missing Eval context for constructor",
- ppQuote (ppr sty con),
- ppStr ":", ppr sty eval_theta]
+evalCtxt con eval_theta
+ = hsep [ptext SLIT("When checking the Eval context for constructor:"),
+ ppr con,
+ text "::", ppr eval_theta]
\end{code}
projects / ghc-hetmet.git / blobdiff