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}
-- 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))
; 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]
data types (and GADTs).
\begin{code}
-tcIdxTyInstDecl :: LTyClDecl Name
- -> TcM (Maybe InstInfo, Maybe TyThing) -- 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, Nothing)) $
+ recoverM (returnM Nothing) $
setSrcSpan loc $
tcAddDeclCtxt decl $
- do { -- indexed data types require -fglasgow-exts and can't be in an
+ 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, Maybe TyThing) -- 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, Nothing) -- !!!TODO: need InstInfo for eq axioms
+ ; return Nothing -- !!!TODO: need TyThing for indexed synonym
}}
tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name,
tcdCons = cons})
= kcIdxTyPats decl $ \k_tvs k_typats resKind family ->
- do { -- (1) kind check the data declaration as usual
+ 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 k_decl
k_cons = tcdCons k_decl
; 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 (Just t_typats)))
+ 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)
- ; buildAlgTyCon tc_name t_tvs stupid_theta tc_rhs Recursive
- False h98_syntax (Just family)
+ 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
- -- !!!TODO: missing eq axiom
- ; return (Nothing, Just (ATyCon tycon))
+ ; return $ Just (ATyCon tycon)
}}
where
h98_syntax = case cons of -- All constructors have same shape
-> TcM a
kcIdxTyPats decl thing_inside
= kcHsTyVars (tcdTyVars decl) $ \tvs ->
- do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
- ; let { family = case tc_ty_thing of
- AGlobal (ATyCon family) -> family
- ; (kinds, resKind) = splitKindFunTys (tyConKind family)
+ 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
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
; tycon <- fixM (\ tycon -> do
{ data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data
- tycon final_tvs Nothing))
+ tycon final_tvs))
cons
; tc_rhs <-
if null cons && is_boot -- In a hs-boot file, empty cons means
{ ctxt' <- tcHsKindedContext ctxt
; fds' <- mappM (addLocM tc_fundep) fundeps
; atss <- mappM (addLocM (tcTyClDecl1 (const Recursive))) ats
- ; let ats' = concat atss
+ ; 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
; 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})
tcConDecl :: Bool -- True <=> -funbox-strict_fields
-> NewOrData
-> TyCon -> [TyVar]
- -> Maybe [Type] -- Just ts <=> type patterns of instance type
-> ConDecl Name
-> TcM DataCon
-tcConDecl unbox_strict NewType tycon tc_tvs mb_typats -- Newtypes
+tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes
(ConDecl name _ ex_tvs ex_ctxt details ResTyH98)
= do { let tc_datacon field_lbls arg_ty
= do { arg_ty' <- tcHsKindedType arg_ty -- No bang on newtype
tc_tvs [] -- No existentials
[] [] -- No equalities, predicates
[arg_ty']
- tycon
- mb_typats}
+ tycon }
-- Check that a newtype has no existential stuff
; checkTc (null ex_tvs && null (unLoc ex_ctxt)) (newtypeExError name)
-- Check that the constructor has exactly one field
}
-tcConDecl unbox_strict DataType tycon tc_tvs mb_typats -- Data types
+tcConDecl unbox_strict DataType tycon tc_tvs -- Data types
(ConDecl name _ tvs ctxt details res_ty)
= tcTyVarBndrs tvs $ \ tvs' -> do
{ ctxt' <- tcHsKindedContext ctxt
(argStrictness unbox_strict tycon bangs arg_tys)
(map unLoc field_lbls)
univ_tvs ex_tvs eq_preds ctxt' arg_tys
- data_tc
- mb_typats}
+ 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.
= 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"),