import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon,
mkDataTyConRhs, mkNewTyConRhs )
import TcRnMonad
-import TcEnv ( TcTyThing(..), TyThing(..),
+import TcEnv ( TyThing(..),
tcLookupLocated, tcLookupLocatedGlobal,
tcExtendGlobalEnv, tcExtendKindEnv,
tcExtendRecEnv, tcLookupTyVar )
import TcClassDcl ( tcClassSigs, tcAddDeclCtxt )
import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType,
kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext,
- kcHsSigType, tcHsBangType, tcLHsConSig )
+ kcHsSigType, tcHsBangType, tcLHsConSig, tcDataKindSig )
import TcMType ( newKindVar, checkValidTheta, checkValidType, checkFreeness,
UserTypeCtxt(..), SourceTyCtxt(..) )
import TcUnify ( unifyKind )
import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars )
import TyCon ( TyCon, ArgVrcs,
tyConDataCons, mkForeignTyCon, isProductTyCon, isRecursiveTyCon,
- tyConStupidTheta, getSynTyConDefn, tyConDataCons, isSynTyCon, tyConName )
+ tyConStupidTheta, getSynTyConDefn, isSynTyCon, tyConName )
import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig,
dataConFieldLabels, dataConOrigArgTys, dataConTyCon )
import Type ( zipTopTvSubst, substTys )
= do { -- First check for cyclic type synonysm or classes
-- See notes with checkCycleErrs
checkCycleErrs decls
-
+ ; mod <- getModule
+ ; traceTc (text "tcTyAndCl" <+> ppr mod <+> ppr boot_names)
; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) ->
do { let { -- Calculate variances and rec-flag
; (syn_decls, alg_decls) = partition (isSynDecl . unLoc) decls }
; thing_inside kinded_tvs }
where
result_kind (TyData { tcdKindSig = Just kind }) = kind
- result_kind other = liftedTypeKind
+ result_kind other = liftedTypeKind
-- On GADT-style declarations we allow a kind signature
-- data T :: *->* where { ... }
tcTyClDecl1 calc_vrcs calc_isrec
(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs,
- tcdLName = L _ tc_name, tcdCons = cons})
- = tcTyVarBndrs tvs $ \ tvs' -> do
- { stupid_theta <- tcStupidTheta ctxt cons
+ tcdLName = L _ tc_name, tcdKindSig = mb_ksig, tcdCons = cons})
+ = tcTyVarBndrs tvs $ \ tvs' -> do
+ { extra_tvs <- tcDataKindSig mb_ksig
+ ; let final_tvs = tvs' ++ extra_tvs
+ ; stupid_theta <- tcStupidTheta ctxt cons
; want_generic <- doptM Opt_Generics
; tycon <- fixM (\ tycon -> do
{ unbox_strict <- doptM Opt_UnboxStrictFields
- ; data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data tycon tvs')) cons
+ ; gla_exts <- doptM Opt_GlasgowExts
+ ; checkTc (gla_exts || h98_syntax) (badGadtDecl tc_name)
+
+ ; data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data tycon final_tvs)) cons
; let tc_rhs = case new_or_data of
DataType -> mkDataTyConRhs stupid_theta data_cons
NewType -> ASSERT( isSingleton data_cons )
mkNewTyConRhs tycon (head data_cons)
- ; buildAlgTyCon tc_name tvs' tc_rhs arg_vrcs is_rec
+ ; buildAlgTyCon tc_name final_tvs tc_rhs arg_vrcs is_rec
(want_generic && canDoGenerics data_cons)
})
; return (ATyCon tycon)
where
arg_vrcs = calc_vrcs tc_name
is_rec = calc_isrec tc_name
+ h98_syntax = case cons of -- All constructors have same shape
+ L _ (GadtDecl {}) : _ -> False
+ other -> True
tcTyClDecl1 calc_vrcs calc_isrec
(ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs,
-> NewOrData -> TyCon -> [TyVar]
-> ConDecl Name -> TcM DataCon
-tcConDecl unbox_strict new_or_data tycon tc_tvs
+tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes
+ (ConDecl name ex_tvs ex_ctxt details)
+ = ASSERT( null ex_tvs && null (unLoc ex_ctxt) )
+ do { let tc_datacon field_lbls arg_ty
+ = do { arg_ty' <- tcHsKindedType arg_ty -- No bang on newtype
+ ; buildDataCon (unLoc name) False {- Prefix -}
+ True {- Vanilla -} [NotMarkedStrict]
+ (map unLoc field_lbls)
+ tc_tvs [] [arg_ty']
+ tycon (mkTyVarTys tc_tvs) }
+ ; case details of
+ PrefixCon [arg_ty] -> tc_datacon [] arg_ty
+ RecCon [(field_lbl, arg_ty)] -> tc_datacon [field_lbl] arg_ty }
+
+tcConDecl unbox_strict DataType tycon tc_tvs -- Ordinary data types
(ConDecl name ex_tvs ex_ctxt details)
= tcTyVarBndrs ex_tvs $ \ ex_tvs' -> do
{ ex_ctxt' <- tcHsKindedContext ex_ctxt
; let
is_vanilla = null ex_tvs && null (unLoc ex_ctxt)
-- Vanilla iff no ex_tvs and no context
+ -- Must check the context too because of
+ -- implicit params; e.g.
+ -- data T = (?x::Int) => MkT Int
tc_datacon is_infix field_lbls btys
= do { let { bangs = map getBangStrictness btys }
; case details of
PrefixCon btys -> tc_datacon False [] btys
InfixCon bty1 bty2 -> tc_datacon True [] [bty1,bty2]
- RecCon fields -> do { checkTc is_vanilla (exRecConErr name)
+ RecCon fields -> do { checkTc (null ex_tvs) (exRecConErr name)
+ -- It's ok to have an implicit-parameter context
+ -- for the data constructor, provided it binds
+ -- no type variables
; let { (field_names, btys) = unzip fields }
; tc_datacon False field_names btys } }
-tcConDecl unbox_strict new_or_data tycon tc_tvs
+tcConDecl unbox_strict DataType tycon tc_tvs -- GADTs
decl@(GadtDecl name con_ty)
= do { traceTc (text "tcConDecl" <+> ppr name)
; (tvs, theta, bangs, arg_tys, tc, res_tys) <- tcLHsConSig con_ty
[{- No field labels -}]
tvs' theta arg_tys' tycon res_tys' }
+-------------------
tcStupidTheta :: LHsContext Name -> [LConDecl Name] -> TcM (Maybe ThetaType)
-- For GADTs we don't allow a context on the data declaration
-- whereas for standard Haskell style data declarations, we do
-- ; checkFreeness tvs ex_theta }
where
ctxt = ConArgCtxt (dataConName con)
- (tvs, ex_theta, _, _, _) = dataConSig con
+-- (tvs, ex_theta, _, _, _) = dataConSig con
-------------------------------
-- Check that for a generic method, the type of
-- the method is sufficiently simple
- ; checkTc (dm /= GenDefMeth || validGenericMethodType op_ty)
+ ; checkTc (dm /= GenDefMeth || validGenericMethodType tau)
(badGenericMethodType op_name op_ty)
}
where
badGenericMethodType op op_ty
= hang (ptext SLIT("Generic method type is too complex"))
4 (vcat [ppr op <+> dcolon <+> ppr op_ty,
- ptext SLIT("You can only use type variables, arrows, and tuples")])
+ ptext SLIT("You can only use type variables, arrows, lists, and tuples")])
recSynErr syn_decls
= setSrcSpan (getLoc (head sorted_decls)) $
badDataConTyCon data_con
= hang (ptext SLIT("Data constructor does not return its parent type:"))
2 (ppr data_con)
+
+badGadtDecl tc_name
+ = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name)
+ , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow GADTs")) ]
\end{code}
projects / ghc-hetmet.git / blobdiff