ConDecl(..), Sig(..), NewOrData(..), ResType(..),
tyClDeclTyVars, isSynDecl, isClassDecl, isIdxTyDecl,
isKindSigDecl, hsConArgs, LTyClDecl, tcdName,
- hsTyVarName, LHsTyVarBndr, LHsType
+ hsTyVarName, LHsTyVarBndr, LHsType, HsType(..),
+ mkHsAppTy
)
-import HsTypes ( HsBang(..), getBangStrictness )
+import HsTypes ( HsBang(..), getBangStrictness, hsLTyVarNames )
import BasicTypes ( RecFlag(..), StrictnessMark(..) )
import HscTypes ( implicitTyThings, ModDetails )
import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon,
import TcRnMonad
import TcEnv ( TyThing(..),
tcLookupLocated, tcLookupLocatedGlobal,
- tcExtendGlobalEnv, tcExtendKindEnv, tcExtendKindEnvTvs,
- tcExtendRecEnv, tcLookupTyVar, InstInfo )
+ tcExtendGlobalEnv, tcExtendKindEnv,
+ tcExtendKindEnvTvs, newFamInstTyConName,
+ tcExtendRecEnv, tcLookupTyVar, tcLookupLocatedTyCon )
import TcTyDecls ( calcRecFlags, calcClassCycles, calcSynCycles )
import TcClassDcl ( tcClassSigs, tcAddDeclCtxt )
import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType,
mkArrowKind, liftedTypeKind, mkTyVarTys,
tcSplitSigmaTy, tcEqTypes, tcGetTyVar_maybe )
import Type ( PredType(..), splitTyConApp_maybe, mkTyVarTy,
- newTyConInstRhs, isLiftedTypeKind, Kind
+ newTyConInstRhs, isLiftedTypeKind, Kind,
+ splitKindFunTys, mkArrowKinds
-- pprParendType, pprThetaArrow
)
import Generics ( validGenericMethodType, canDoGenerics )
tyConDataCons, mkForeignTyCon, isProductTyCon,
isRecursiveTyCon, isOpenTyCon,
tyConStupidTheta, synTyConRhs, isSynTyCon, tyConName,
- isNewTyCon, tyConKind )
+ isNewTyCon, isDataTyCon, tyConKind,
+ setTyConArgPoss )
import DataCon ( DataCon, dataConUserType, dataConName,
dataConFieldLabels, dataConTyCon, dataConAllTyVars,
dataConFieldType, dataConResTys )
import VarSet ( elemVarSet, mkVarSet )
import Name ( Name, getSrcLoc )
import Outputable
-import Maybe ( isJust, fromJust, isNothing )
+import Maybe ( isJust, fromJust, isNothing, catMaybes )
import Maybes ( expectJust )
+import Monad ( unless )
import Unify ( tcMatchTys, tcMatchTyX )
import Util ( zipLazy, isSingleton, notNull, sortLe )
-import List ( partition )
-import SrcLoc ( Located(..), unLoc, getLoc, srcLocSpan )
+import List ( partition, elemIndex )
+import SrcLoc ( Located(..), unLoc, getLoc, srcLocSpan,
+ srcSpanStart )
import ListSetOps ( equivClasses, minusList )
-import List ( delete )
import Digraph ( SCC(..) )
import DynFlags ( DynFlag( Opt_GlasgowExts, Opt_Generics,
- Opt_UnboxStrictFields ) )
+ Opt_UnboxStrictFields, Opt_IndexedTypes ) )
\end{code}
; mod <- getModule
; traceTc (text "tcTyAndCl" <+> ppr mod)
; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) ->
- do { let { -- Calculate variances and rec-flag
+ do { let { -- Seperate ordinary synonyms from all other type and
+ -- class declarations and add all associated type
+ -- declarations from type classes. The latter is
+ -- required so that the temporary environment for the
+ -- knot includes all associated family declarations.
; (syn_decls, alg_decls) = partition (isSynDecl . unLoc)
- decls }
+ decls
+ ; alg_at_decls = concatMap addATs alg_decls
+ }
-- Extend the global env with the knot-tied results
-- for data types and classes
--
- -- We must populate the environment with the loop-tied T's right
- -- away, because the kind checker may "fault in" some type
- -- constructors that recursively mention T
- ; let { gbl_things = mkGlobalThings alg_decls rec_alg_tyclss }
+ -- We must populate the environment with the loop-tied
+ -- T's right away, because the kind checker may "fault
+ -- in" some type constructors that recursively
+ -- mention T
+ ; let gbl_things = mkGlobalThings alg_at_decls rec_alg_tyclss
; tcExtendRecEnv gbl_things $ do
-- Kind-check the declarations
{ (kc_syn_decls, kc_alg_decls) <- kcTyClDecls syn_decls alg_decls
- ; let { calc_rec = calcRecFlags boot_details rec_alg_tyclss
+ ; let { -- Calculate rec-flag
+ ; calc_rec = calcRecFlags boot_details rec_alg_tyclss
; tc_decl = addLocM (tcTyClDecl calc_rec) }
-- Type-check the type synonyms, and extend the envt
; syn_tycons <- tcSynDecls kc_syn_decls
-- Type-check the data types and classes
{ alg_tyclss <- mappM tc_decl kc_alg_decls
- ; return (syn_tycons, alg_tyclss)
+ ; return (syn_tycons, concat alg_tyclss)
}}})
-- Finished with knot-tying now
-- Extend the environment with the finished things
-- Add the implicit things;
-- we want them in the environment because
-- they may be mentioned in interface files
+ -- NB: All associated types and their implicit things will be added a
+ -- second time here. This doesn't matter as the definitions are
+ -- the same.
; let { implicit_things = concatMap implicitTyThings alg_tyclss }
- ; traceTc ((text "Adding" <+> ppr alg_tyclss) $$ (text "and" <+> ppr implicit_things))
+ ; traceTc ((text "Adding" <+> ppr alg_tyclss)
+ $$ (text "and" <+> ppr implicit_things))
; tcExtendGlobalEnv implicit_things getGblEnv
}}
+ where
+ -- Pull associated types out of class declarations, to tie them into the
+ -- knot above.
+ -- NB: We put them in the same place in the list as `tcTyClDecl' will
+ -- eventually put the matching `TyThing's. That's crucial; otherwise,
+ -- the two argument lists of `mkGlobalThings' don't match up.
+ addATs decl@(L _ (ClassDecl {tcdATs = ats})) = decl : ats
+ addATs decl = [decl]
mkGlobalThings :: [LTyClDecl Name] -- The decls
-> [TyThing] -- Knot-tied, in 1-1 correspondence with the decls
data types (and GADTs).
\begin{code}
-tcIdxTyInstDecl :: LTyClDecl Name -> TcM (Maybe InstInfo) -- Nothing if error
+tcIdxTyInstDecl :: LTyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error
tcIdxTyInstDecl (L loc decl)
= -- Prime error recovery, set source location
- recoverM (returnM Nothing) $
- setSrcSpan loc $
- tcAddDeclCtxt decl $
- do { -- indexed data types require -fglasgow-exts and can't be in an
+ recoverM (returnM Nothing) $
+ setSrcSpan loc $
+ tcAddDeclCtxt decl $
+ do { -- indexed data types require -findexed-types and can't be in an
-- hs-boot file
- ; gla_exts <- doptM Opt_GlasgowExts
+ ; gla_exts <- doptM Opt_IndexedTypes
; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file?
; checkTc gla_exts $ badIdxTyDecl (tcdLName decl)
; checkTc (not is_boot) $ badBootTyIdxDeclErr
; tcIdxTyInstDecl1 decl
}
-tcIdxTyInstDecl1 :: TyClDecl Name -> TcM (Maybe InstInfo) -- Nothing if error
+tcIdxTyInstDecl1 :: TyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error
tcIdxTyInstDecl1 (decl@TySynonym {})
- = kcIdxTyPats decl $ \k_tvs k_typats resKind ->
- do { -- (1) kind check the right hand side of the type equation
+ = kcIdxTyPats decl $ \k_tvs k_typats resKind family ->
+ do { -- check that the family declaration is for a synonym
+ unless (isSynTyCon family) $
+ addErr (wrongKindOfFamily family)
+
+ ; -- (1) kind check the right hand side of the type equation
; k_rhs <- kcCheckHsType (tcdSynRhs decl) resKind
-- (2) type check type equation
; t_typats <- mappM tcHsKindedType k_typats
; t_rhs <- tcHsKindedType k_rhs
- -- construct type rewrite rule
-- !!!of the form: forall t_tvs. (tcdLName decl) t_typats = t_rhs
- ; return Nothing -- !!!TODO: need InstInfo for indexed types
+ ; return Nothing -- !!!TODO: need TyThing for indexed synonym
}}
-tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L _ tc_name,
+tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name,
tcdCons = cons})
- = kcIdxTyPats decl $ \k_tvs k_typats resKind ->
- do { -- (1) kind check the data declaration as usual
+ = kcIdxTyPats decl $ \k_tvs k_typats resKind family ->
+ do { -- check that the family declaration is for the right kind
+ unless (new_or_data == NewType && isNewTyCon family ||
+ new_or_data == DataType && isDataTyCon family) $
+ addErr (wrongKindOfFamily family)
+
+ ; -- (1) kind check the data declaration as usual
; k_decl <- kcDataDecl decl k_tvs
- ; let k_ctxt = tcdCtxt decl
- k_cons = tcdCons decl
+ ; let k_ctxt = tcdCtxt k_decl
+ k_cons = tcdCons k_decl
-- result kind must be '*' (otherwise, we have too few patterns)
; checkTc (isLiftedTypeKind resKind) $ tooFewParmsErr tc_name
; checkTc h98_syntax (badGadtIdxTyDecl tc_name)
-- Check that a newtype has exactly one constructor
- ; checkTc (new_or_data == DataType || isSingleton cons) $
- newtypeConError tc_name (length cons)
+ ; checkTc (new_or_data == DataType || isSingleton k_cons) $
+ newtypeConError tc_name (length k_cons)
; t_typats <- mappM tcHsKindedType k_typats
; stupid_theta <- tcHsKindedContext k_ctxt
+
+ ; rep_tc_name <- newFamInstTyConName tc_name (srcSpanStart loc)
; tycon <- fixM (\ tycon -> do
{ data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data
- tycon t_tvs))
+ tycon t_tvs))
k_cons
; tc_rhs <-
case new_or_data of
DataType -> return (mkDataTyConRhs data_cons)
- NewType ->
- ASSERT( isSingleton data_cons )
- mkNewTyConRhs tc_name tycon (head data_cons)
- --vvvvvvv !!! need a new derived tc_name here
- ; buildAlgTyCon tc_name t_tvs stupid_theta tc_rhs Recursive
- False h98_syntax
+ NewType -> ASSERT( isSingleton data_cons )
+ mkNewTyConRhs tc_name tycon (head data_cons)
+ ; buildAlgTyCon rep_tc_name t_tvs stupid_theta tc_rhs Recursive
+ False h98_syntax (Just (family, t_typats))
-- We always assume that indexed types are recursive. Why?
-- (1) Due to their open nature, we can never be sure that a
-- further instance might not introduce a new recursive
})
-- construct result
- -- !!!twofold: (1) (ATyCon tycon) and (2) an equality axiom
- ; return Nothing -- !!!TODO: need InstInfo for indexed types
+ ; return $ Just (ATyCon tycon)
}}
where
h98_syntax = case cons of -- All constructors have same shape
-- check is only required for type functions.
--
kcIdxTyPats :: TyClDecl Name
- -> ([LHsTyVarBndr Name] -> [LHsType Name] -> Kind -> TcM a)
+ -> ([LHsTyVarBndr Name] -> [LHsType Name] -> Kind -> TyCon -> TcM a)
-- ^^kinded tvs ^^kinded ty pats ^^res kind
-> TcM a
kcIdxTyPats decl thing_inside
= kcHsTyVars (tcdTyVars decl) $ \tvs ->
- do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
- ; let { tc_kind = case tc_ty_thing of
- AGlobal (ATyCon tycon) -> tyConKind tycon
- ; (kinds, resKind) = splitKindFunTys tc_kind
+ do { family <- tcLookupLocatedTyCon (tcdLName decl)
+ ; let { (kinds, resKind) = splitKindFunTys (tyConKind family)
; hs_typats = fromJust $ tcdTyPats decl }
-- we may not have more parameters than the kind indicates
-- type functions can have a higher-kinded result
; let resultKind = mkArrowKinds (drop (length hs_typats) kinds) resKind
; typats <- zipWithM kcCheckHsType hs_typats kinds
- ; thing_inside tvs typats resultKind
+ ; thing_inside tvs typats resultKind family
}
where
\end{code}
; return (ATyCon (buildSynTyCon tc_name tvs' (SynonymTyCon rhs_ty'))) }
--------------------
-tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM TyThing
+tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing]
tcTyClDecl calc_isrec decl
= tcAddDeclCtxt decl (tcTyClDecl1 calc_isrec decl)
tcTyClDecl1 _calc_isrec
(TyFunction {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = kind})
= tcTyVarBndrs tvs $ \ tvs' -> do
- { gla_exts <- doptM Opt_GlasgowExts
+ { traceTc (text "type family: " <+> ppr tc_name)
+ ; gla_exts <- doptM Opt_IndexedTypes
-- Check that we don't use kind signatures without Glasgow extensions
; checkTc gla_exts $ badSigTyDecl tc_name
- ; return (ATyCon (buildSynTyCon tc_name tvs' (OpenSynTyCon kind)))
+ ; return [ATyCon $ buildSynTyCon tc_name tvs' (OpenSynTyCon kind)]
}
-- kind signature for an indexed data type
tcTyClDecl1 _calc_isrec
(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs,
- tcdLName = L _ tc_name, tcdKindSig = mb_ksig, tcdCons = []})
+ tcdLName = L _ tc_name, tcdKindSig = Just ksig, tcdCons = []})
= tcTyVarBndrs tvs $ \ tvs' -> do
- { extra_tvs <- tcDataKindSig mb_ksig
+ { traceTc (text "data/newtype family: " <+> ppr tc_name)
+ ; extra_tvs <- tcDataKindSig (Just ksig)
; let final_tvs = tvs' ++ extra_tvs -- we may not need these
; checkTc (null . unLoc $ ctxt) $ badKindSigCtxt tc_name
- ; gla_exts <- doptM Opt_GlasgowExts
+ ; gla_exts <- doptM Opt_IndexedTypes
-- Check that we don't use kind signatures without Glasgow extensions
; checkTc gla_exts $ badSigTyDecl tc_name
(case new_or_data of
DataType -> OpenDataTyCon
NewType -> OpenNewTyCon)
- Recursive False True
- ; return (ATyCon tycon)
+ Recursive False True Nothing
+ ; return [ATyCon tycon]
}
tcTyClDecl1 calc_isrec
ASSERT( isSingleton data_cons )
mkNewTyConRhs tc_name tycon (head data_cons)
; buildAlgTyCon tc_name final_tvs stupid_theta tc_rhs is_rec
- (want_generic && canDoGenerics data_cons) h98_syntax
+ (want_generic && canDoGenerics data_cons) h98_syntax Nothing
})
- ; return (ATyCon tycon)
+ ; return [ATyCon tycon]
}
where
is_rec = calc_isrec tc_name
= tcTyVarBndrs tvs $ \ tvs' -> do
{ ctxt' <- tcHsKindedContext ctxt
; fds' <- mappM (addLocM tc_fundep) fundeps
- ; ats' <- mappM (addLocM (tcTyClDecl1 (const Recursive))) ats
+ ; atss <- mappM (addLocM (tcTyClDecl1 (const Recursive))) ats
+ ; let ats' = zipWith setTyThingPoss atss (map (tcdTyVars . unLoc) ats)
; sig_stuff <- tcClassSigs class_name sigs meths
; clas <- fixM (\ clas ->
let -- This little knot is just so we can get
in
buildClass class_name tvs' ctxt' fds' ats'
sig_stuff tc_isrec)
- ; return (AClass clas) }
+ ; return (AClass clas : ats')
+ -- NB: Order is important due to the call to `mkGlobalThings' when
+ -- tying the the type and class declaration type checking knot.
+ }
where
tc_fundep (tvs1, tvs2) = do { tvs1' <- mappM tcLookupTyVar tvs1 ;
; tvs2' <- mappM tcLookupTyVar tvs2 ;
; return (tvs1', tvs2') }
+ -- For each AT argument compute the position of the corresponding class
+ -- parameter in the class head. This will later serve as a permutation
+ -- vector when checking the validity of instance declarations.
+ setTyThingPoss [ATyCon tycon] atTyVars =
+ let classTyVars = hsLTyVarNames tvs
+ poss = catMaybes
+ . map (`elemIndex` classTyVars)
+ . hsLTyVarNames
+ $ atTyVars
+ -- There will be no Nothing, as we already passed renaming
+ in
+ ATyCon (setTyConArgPoss tycon poss)
+ setTyThingPoss _ _ = panic "TcTyClsDecls.setTyThingPoss"
tcTyClDecl1 calc_isrec
(ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name})
- = returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0))
+ = returnM [ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0)]
-----------------------------------
tcConDecl :: Bool -- True <=> -funbox-strict_fields
- -> NewOrData -> TyCon -> [TyVar]
- -> ConDecl Name -> TcM DataCon
+ -> NewOrData
+ -> TyCon -> [TyVar]
+ -> ConDecl Name
+ -> TcM DataCon
tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes
(ConDecl name _ ex_tvs ex_ctxt details ResTyH98)
; checkTc (null ex_tvs && null (unLoc ex_ctxt)) (newtypeExError name)
; case details of
- PrefixCon [arg_ty] -> tc_datacon [] arg_ty
+ PrefixCon [arg_ty] -> tc_datacon [] arg_ty
RecCon [(field_lbl, arg_ty)] -> tc_datacon [field_lbl] arg_ty
- other -> failWithTc (newtypeFieldErr name (length (hsConArgs details)))
+ other ->
+ failWithTc (newtypeFieldErr name (length (hsConArgs details)))
-- Check that the constructor has exactly one field
}
(map unLoc field_lbls)
univ_tvs ex_tvs eq_preds ctxt' arg_tys
data_tc }
- -- NB: we put data_tc, the type constructor gotten from the constructor
- -- type signature into the data constructor; that way
- -- checkValidDataCon can complain if it's wrong.
+ -- NB: we put data_tc, the type constructor gotten from the
+ -- constructor type signature into the data constructor;
+ -- that way checkValidDataCon can complain if it's wrong.
; case details of
PrefixCon btys -> tc_datacon False [] btys
= ptext SLIT("Indexed type instance has too few parameters:") <+>
quotes (ppr tc_name)
-badBootTyIdxDeclErr = ptext SLIT("Illegal indexed type instance in hs-boot file")
+badBootTyIdxDeclErr =
+ ptext SLIT("Illegal indexed type instance in hs-boot file")
+
+wrongKindOfFamily family =
+ ptext SLIT("Wrong category of type instance; declaration was for a") <+>
+ kindOfFamily
+ where
+ kindOfFamily | isSynTyCon family = ptext SLIT("type synonym")
+ | isDataTyCon family = ptext SLIT("data type")
+ | isNewTyCon family = ptext SLIT("newtype")
emptyConDeclsErr tycon
= sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),