X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcClassDcl.lhs;h=2f7f6bc3f41ae92776570c8a90cb99a97608fb7e;hp=0fb82cb76a305eafc156c0f1da378b377857e1f1;hb=786932468faac49aafe20b65eabc8bdf465fbc9d;hpb=f03b9562a92c6ef94c603a334d5d5e1cd2165c92 diff --git a/compiler/typecheck/TcClassDcl.lhs b/compiler/typecheck/TcClassDcl.lhs index 0fb82cb..2f7f6bc 100644 --- a/compiler/typecheck/TcClassDcl.lhs +++ b/compiler/typecheck/TcClassDcl.lhs @@ -8,7 +8,7 @@ Typechecking class declarations \begin{code} module TcClassDcl ( tcClassSigs, tcClassDecl2, findMethodBind, instantiateMethod, tcInstanceMethodBody, - mkGenericDefMethBind, getGenericInstances, mkDefMethRdrName, + mkGenericDefMethBind, getGenericInstances, tcAddDeclCtxt, badMethodErr, badATErr, omittedATWarn ) where @@ -17,7 +17,6 @@ module TcClassDcl ( tcClassSigs, tcClassDecl2, import HsSyn import RnHsSyn import RnExpr -import RnEnv import Inst import InstEnv import TcEnv @@ -27,6 +26,7 @@ import TcHsType import TcMType import TcType import TcRnMonad +import BuildTyCl( TcMethInfo ) import Generics import Class import TyCon @@ -36,7 +36,6 @@ import Name import Var import NameEnv import NameSet -import RdrName import Outputable import PrelNames import DynFlags @@ -99,54 +98,44 @@ tcClassSigs :: Name -- Name of the class -> LHsBinds Name -> TcM [TcMethInfo] -type TcMethInfo = (Name, DefMeth, Type) -- A temporary intermediate, to communicate - -- between tcClassSigs and buildClass tcClassSigs clas sigs def_methods - = do { dm_env <- checkDefaultBinds clas op_names def_methods - ; mapM (tcClassSig dm_env) op_sigs } + = do { dm_env <- mapM (addLocM (checkDefaultBind clas op_names)) + (bagToList def_methods) + ; mapM (tcClassSig (mkNameEnv dm_env)) op_sigs } where op_sigs = [sig | sig@(L _ (TypeSig _ _)) <- sigs] op_names = [n | (L _ (TypeSig (L _ n) _)) <- op_sigs] - -checkDefaultBinds :: Name -> [Name] -> LHsBinds Name -> TcM (NameEnv Bool) +checkDefaultBind :: Name -> [Name] -> HsBindLR Name Name -> TcM (Name, DefMethSpec) -- Check default bindings -- a) must be for a class op for this class -- b) must be all generic or all non-generic - -- and return a mapping from class-op to Bool - -- where True <=> it's a generic default method -checkDefaultBinds clas ops binds - = do dm_infos <- mapM (addLocM (checkDefaultBind clas ops)) (bagToList binds) - return (mkNameEnv dm_infos) - -checkDefaultBind :: Name -> [Name] -> HsBindLR Name Name -> TcM (Name, Bool) checkDefaultBind clas ops (FunBind {fun_id = L _ op, fun_matches = MatchGroup matches _ }) = do { -- Check that the op is from this class - checkTc (op `elem` ops) (badMethodErr clas op) + checkTc (op `elem` ops) (badMethodErr clas op) -- Check that all the defns ar generic, or none are - ; checkTc (all_generic || none_generic) (mixedGenericErr op) - - ; return (op, all_generic) + ; case (none_generic, all_generic) of + (True, _) -> return (op, VanillaDM) + (_, True) -> return (op, GenericDM) + _ -> failWith (mixedGenericErr op) } where n_generic = count (isJust . maybeGenericMatch) matches none_generic = n_generic == 0 all_generic = matches `lengthIs` n_generic + checkDefaultBind _ _ b = pprPanic "checkDefaultBind" (ppr b) -tcClassSig :: NameEnv Bool -- Info about default methods; +tcClassSig :: NameEnv DefMethSpec -- Info about default methods; -> LSig Name -> TcM TcMethInfo tcClassSig dm_env (L loc (TypeSig (L _ op_name) op_hs_ty)) = setSrcSpan loc $ do { op_ty <- tcHsKindedType op_hs_ty -- Class tyvars already in scope - ; let dm = case lookupNameEnv dm_env op_name of - Nothing -> NoDefMeth - Just False -> DefMeth - Just True -> GenDefMeth + ; let dm = lookupNameEnv dm_env op_name `orElse` NoDM ; return (op_name, dm, op_ty) } tcClassSig _ s = pprPanic "tcClassSig" (ppr s) \end{code} @@ -189,32 +178,32 @@ tcClassDecl2 (L loc (ClassDecl {tcdLName = class_name, tcdSigs = sigs, ; let tc_dm = tcDefMeth clas clas_tyvars this_dict default_binds sig_fn prag_fn - -- tc_dm is called only for a sel_id - -- that has a binding in default_binds - - dm_sel_ids = [sel_id | (sel_id, DefMeth) <- op_items] - -- Generate code for polymorphic default methods only (hence DefMeth) - -- (Generic default methods have turned into instance decls by now.) - -- This is incompatible with Hugs, which expects a polymorphic - -- default method for every class op, regardless of whether or not - -- the programmer supplied an explicit default decl for the class. - -- (If necessary we can fix that, but we don't have a convenient Id to hand.) - ; (dm_ids, defm_binds) <- tcExtendTyVarEnv clas_tyvars $ - mapAndUnzipM tc_dm dm_sel_ids + ; dm_stuff <- tcExtendTyVarEnv clas_tyvars $ + mapM tc_dm op_items + ; let (dm_ids, defm_binds) = unzip (catMaybes dm_stuff) ; return (dm_ids, listToBag defm_binds) } tcClassDecl2 d = pprPanic "tcClassDecl2" (ppr d) tcDefMeth :: Class -> [TyVar] -> Inst -> LHsBinds Name - -> TcSigFun -> TcPragFun -> Id - -> TcM (Id, LHsBind Id) -tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn sel_id - = do { let sel_name = idName sel_id - ; dm_name <- lookupTopBndrRn (mkDefMethRdrName sel_name) - ; local_dm_name <- newLocalName sel_name - -- Base the local_dm_name on the selector name, becuase + -> TcSigFun -> TcPragFun -> ClassOpItem + -> TcM (Maybe (Id, LHsBind Id)) +-- Generate code for polymorphic default methods only (hence DefMeth) +-- (Generic default methods have turned into instance decls by now.) +-- This is incompatible with Hugs, which expects a polymorphic +-- default method for every class op, regardless of whether or not +-- the programmer supplied an explicit default decl for the class. +-- (If necessary we can fix that, but we don't have a convenient Id to hand.) +tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn (sel_id, dm_info) + = case dm_info of + NoDefMeth -> return Nothing + GenDefMeth -> return Nothing + DefMeth dm_name -> do + { let sel_name = idName sel_id + ; local_dm_name <- newLocalName sel_name + -- Base the local_dm_name on the selector name, because -- type errors from tcInstanceMethodBody come from here -- See Note [Silly default-method bind] @@ -222,8 +211,7 @@ tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn sel_id ; let meth_bind = findMethodBind sel_name local_dm_name binds_in `orElse` pprPanic "tcDefMeth" (ppr sel_id) - -- We only call tcDefMeth on selectors for which - -- there is a binding in binds_in + -- dm_info = DefMeth dm_name only if there is a binding in binds_in dm_sig_fn _ = sig_fn sel_name dm_ty = idType sel_id @@ -238,7 +226,8 @@ tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn sel_id (ptext (sLit "Ignoring SPECIALISE pragmas on default method") <+> quotes (ppr sel_name)) - ; tcInstanceMethodBody (instLoc this_dict) + ; liftM Just $ + tcInstanceMethodBody (instLoc this_dict) tyvars [this_dict] ([], emptyBag) dm_id_w_inline local_dm_id @@ -282,9 +271,6 @@ tcInstanceMethodBody inst_loc tyvars dfun_dicts \end{code} \begin{code} -mkDefMethRdrName :: Name -> RdrName -mkDefMethRdrName sel_name = mkDerivedRdrName sel_name mkDefaultMethodOcc - instantiateMethod :: Class -> Id -> [TcType] -> TcType -- Take a class operation, say -- op :: forall ab. C a => forall c. Ix c => (b,c) -> a