X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcClassDcl.lhs;h=839a5a276b999810597512b152e4e000d22d707d;hb=14a496fd0b3aa821b69eb02736d5f41086576761;hp=2f7f6bc3f41ae92776570c8a90cb99a97608fb7e;hpb=786932468faac49aafe20b65eabc8bdf465fbc9d;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcClassDcl.lhs b/compiler/typecheck/TcClassDcl.lhs index 2f7f6bc..839a5a2 100644 --- a/compiler/typecheck/TcClassDcl.lhs +++ b/compiler/typecheck/TcClassDcl.lhs @@ -19,9 +19,10 @@ import RnHsSyn import RnExpr import Inst import InstEnv +import TcPat( addInlinePrags ) import TcEnv import TcBinds -import TcSimplify +import TcUnify import TcHsType import TcMType import TcType @@ -149,12 +150,12 @@ tcClassSig _ s = pprPanic "tcClassSig" (ppr s) \begin{code} tcClassDecl2 :: LTyClDecl Name -- The class declaration - -> TcM ([Id], LHsBinds Id) + -> TcM (LHsBinds Id) tcClassDecl2 (L loc (ClassDecl {tcdLName = class_name, tcdSigs = sigs, tcdMeths = default_binds})) - = recoverM (return ([], emptyLHsBinds)) $ - setSrcSpan loc $ + = recoverM (return emptyLHsBinds) $ + setSrcSpan loc $ do { clas <- tcLookupLocatedClass class_name -- We make a separate binding for each default method. @@ -169,27 +170,25 @@ tcClassDecl2 (L loc (ClassDecl {tcdLName = class_name, tcdSigs = sigs, (tyvars, _, _, op_items) = classBigSig clas rigid_info = ClsSkol clas prag_fn = mkPragFun sigs default_binds - sig_fn = mkTcSigFun sigs + sig_fn = mkSigFun sigs clas_tyvars = tcSkolSigTyVars rigid_info tyvars pred = mkClassPred clas (mkTyVarTys clas_tyvars) - ; inst_loc <- getInstLoc (SigOrigin rigid_info) - ; this_dict <- newDictBndr inst_loc pred + ; this_dict <- newEvVar pred ; let tc_dm = tcDefMeth clas clas_tyvars this_dict default_binds sig_fn prag_fn - ; dm_stuff <- tcExtendTyVarEnv clas_tyvars $ + ; dm_binds <- tcExtendTyVarEnv clas_tyvars $ mapM tc_dm op_items - ; let (dm_ids, defm_binds) = unzip (catMaybes dm_stuff) - ; return (dm_ids, listToBag defm_binds) } + ; return (listToBag (catMaybes dm_binds)) } tcClassDecl2 d = pprPanic "tcClassDecl2" (ppr d) -tcDefMeth :: Class -> [TyVar] -> Inst -> LHsBinds Name - -> TcSigFun -> TcPragFun -> ClassOpItem - -> TcM (Maybe (Id, LHsBind Id)) +tcDefMeth :: Class -> [TyVar] -> EvVar -> LHsBinds Name + -> SigFun -> PragFun -> ClassOpItem + -> TcM (Maybe (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 @@ -209,62 +208,69 @@ tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn (sel_id, dm_info) -- See Note [Silly default-method bind] -- (possibly out of date) - ; let meth_bind = findMethodBind sel_name local_dm_name binds_in + ; let meth_bind = findMethodBind sel_name binds_in `orElse` pprPanic "tcDefMeth" (ppr sel_id) -- 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 - dm_id = mkDefaultMethodId dm_name dm_ty + dm_sig_fn _ = sig_fn sel_name + dm_id = mkDefaultMethodId sel_id dm_name local_dm_type = instantiateMethod clas sel_id (mkTyVarTys tyvars) local_dm_id = mkLocalId local_dm_name local_dm_type + prags = prag_fn sel_name - ; (dm_id_w_inline, spec_prags) - <- tcPrags NonRecursive False True dm_id (prag_fn sel_name) + ; dm_id_w_inline <- addInlinePrags dm_id prags + ; spec_prags <- tcSpecPrags dm_id prags ; warnTc (not (null spec_prags)) (ptext (sLit "Ignoring SPECIALISE pragmas on default method") <+> quotes (ppr sel_name)) ; liftM Just $ - tcInstanceMethodBody (instLoc this_dict) - tyvars [this_dict] - ([], emptyBag) + tcInstanceMethodBody (ClsSkol clas) + tyvars + [this_dict] + Nothing dm_id_w_inline local_dm_id dm_sig_fn IsDefaultMethod meth_bind } --------------- -tcInstanceMethodBody :: InstLoc -> [TcTyVar] -> [Inst] - -> ([Inst], LHsBinds Id) -> Id -> Id - -> TcSigFun -> TcSpecPrags -> LHsBind Name - -> TcM (Id, LHsBind Id) -tcInstanceMethodBody inst_loc tyvars dfun_dicts - (this_dict, this_bind) meth_id local_meth_id - meth_sig_fn spec_prags bind@(L loc _) +tcInstanceMethodBody :: SkolemInfo -> [TcTyVar] -> [EvVar] + -> Maybe EvBind + -> Id -> Id + -> SigFun -> TcSpecPrags -> LHsBind Name + -> TcM (LHsBind Id) +tcInstanceMethodBody skol_info tyvars dfun_ev_vars + this_dict meth_id local_meth_id + meth_sig_fn specs + (L loc bind) = do { -- Typecheck the binding, first extending the envt -- so that when tcInstSig looks up the local_meth_id to find -- its signature, we'll find it in the environment - ; ((tc_bind, _), lie) <- getLIE $ - tcExtendIdEnv [local_meth_id] $ - tcPolyBinds TopLevel meth_sig_fn no_prag_fn - NonRecursive NonRecursive - (unitBag bind) - - ; let avails = this_dict ++ dfun_dicts - -- Only need the this_dict stuff if there are type - -- variables involved; otherwise overlap is not possible - -- See Note [Subtle interaction of recursion and overlap] - -- in TcInstDcls - ; lie_binds <- tcSimplifyCheck inst_loc tyvars avails lie - - ; let full_bind = AbsBinds tyvars dfun_lam_vars - [(tyvars, meth_id, local_meth_id, spec_prags)] - (this_bind `unionBags` lie_binds - `unionBags` tc_bind) - - dfun_lam_vars = map instToVar dfun_dicts -- Includes equalities - - ; return (meth_id, L loc full_bind) } + let full_given = case this_dict of + Nothing -> dfun_ev_vars + Just (EvBind dict _) -> dict : dfun_ev_vars + lm_bind = L loc (bind { fun_id = L loc (idName local_meth_id) }) + -- Substitue the local_meth_name for the binder + -- NB: the binding is always a FunBind + + ; (ev_binds, (tc_bind, _)) + <- checkConstraints skol_info tyvars full_given $ + tcExtendIdEnv [local_meth_id] $ + tcPolyBinds TopLevel meth_sig_fn no_prag_fn + NonRecursive NonRecursive + [lm_bind] + + -- Add the binding for this_dict, if we have one + ; ev_binds' <- case this_dict of + Nothing -> return ev_binds + Just (EvBind self rhs) -> extendTcEvBinds ev_binds self rhs + + ; let full_bind = AbsBinds { abs_tvs = tyvars, abs_ev_vars = dfun_ev_vars + , abs_exports = [(tyvars, meth_id, local_meth_id, specs)] + , abs_ev_binds = ev_binds' + , abs_binds = tc_bind } + + ; return (L loc full_bind) } where no_prag_fn _ = [] -- No pragmas for local_meth_id; -- they are all for meth_id @@ -295,18 +301,16 @@ instantiateMethod clas sel_id inst_tys --------------------------- --- The renamer just puts the selector ID as the binder in the method binding --- but we must use the method name; so we substitute it here. Crude but simple. -findMethodBind :: Name -> Name -- Selector and method name +findMethodBind :: Name -- Selector name -> LHsBinds Name -- A group of bindings - -> Maybe (LHsBind Name) -- The binding, with meth_name replacing sel_name -findMethodBind sel_name meth_name binds + -> Maybe (LHsBind Name) -- The binding +findMethodBind sel_name binds = foldlBag mplus Nothing (mapBag f binds) where - f (L loc1 bind@(FunBind { fun_id = L loc2 op_name })) - | op_name == sel_name - = Just (L loc1 (bind { fun_id = L loc2 meth_name })) - f _other = Nothing + f bind@(L _ (FunBind { fun_id = L _ op_name })) + | op_name == sel_name + = Just bind + f _other = Nothing \end{code} Note [Polymorphic methods] @@ -366,8 +370,8 @@ gives rise to the instance declarations op Unit = ... \begin{code} -mkGenericDefMethBind :: Class -> [Type] -> Id -> Name -> TcM (LHsBind Name) -mkGenericDefMethBind clas inst_tys sel_id meth_name +mkGenericDefMethBind :: Class -> [Type] -> Id -> TcM (LHsBind Name) +mkGenericDefMethBind clas inst_tys sel_id = -- A generic default method -- If the method is defined generically, we can only do the job if the -- instance declaration is for a single-parameter type class with @@ -385,7 +389,8 @@ mkGenericDefMethBind clas inst_tys sel_id meth_name -- Rename it before returning it ; (rn_rhs, _) <- rnLExpr rhs - ; return (noLoc $ mkFunBind (noLoc meth_name) [mkSimpleMatch [] rn_rhs]) } + ; return (noLoc $ mkFunBind (noLoc (idName sel_id)) + [mkSimpleMatch [] rn_rhs]) } where rhs = mkGenericRhs sel_id clas_tyvar tycon @@ -597,7 +602,7 @@ notGeneric tycon badGenericInstanceType :: LHsBinds Name -> SDoc badGenericInstanceType binds = vcat [ptext (sLit "Illegal type pattern in the generic bindings"), - nest 4 (ppr binds)] + nest 2 (ppr binds)] missingGenericInstances :: [Name] -> SDoc missingGenericInstances missing @@ -606,7 +611,7 @@ missingGenericInstances missing dupGenericInsts :: [(TyCon, InstInfo a)] -> SDoc dupGenericInsts tc_inst_infos = vcat [ptext (sLit "More than one type pattern for a single generic type constructor:"), - nest 4 (vcat (map ppr_inst_ty tc_inst_infos)), + nest 2 (vcat (map ppr_inst_ty tc_inst_infos)), ptext (sLit "All the type patterns for a generic type constructor must be identical") ] where