From 2eb105009654588b2130997509645841800681b9 Mon Sep 17 00:00:00 2001 From: Twan van Laarhoven Date: Thu, 17 Jan 2008 21:32:42 +0000 Subject: [PATCH] Monadify typecheck/TcMType: use do, return, applicative, standard monad functions --- compiler/typecheck/TcMType.lhs | 197 +++++++++++++++++++--------------------- 1 file changed, 94 insertions(+), 103 deletions(-) diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs index f7cbb2c..a6a9634 100644 --- a/compiler/typecheck/TcMType.lhs +++ b/compiler/typecheck/TcMType.lhs @@ -163,7 +163,7 @@ checkKinds swapped tv1 ty2 -- We're about to unify a type variable tv1 with a non-tyvar-type ty2. -- ty2 has been zonked at this stage, which ensures that -- its kind has as much boxity information visible as possible. - | tk2 `isSubKind` tk1 = returnM () + | tk2 `isSubKind` tk1 = return () | otherwise -- Either the kinds aren't compatible @@ -220,7 +220,7 @@ checkTauTvUpdate orig_tv orig_ty -- closed type synonym that expands to a tau type. go (TyConApp tc tys) | isSynTyCon tc = go_syn tc tys - | otherwise = do { tys' <- mappM go tys + | otherwise = do { tys' <- mapM go tys ; return $ occurs (TyConApp tc) tys' } go (NoteTy _ ty2) = go ty2 -- Discard free-tyvar annotations go (PredTy p) = do { p' <- go_pred p @@ -344,20 +344,19 @@ Rather, we should bind t to () (= non_var_ty2). Error mesages in case of kind mismatch. \begin{code} -unifyKindMisMatch ty1 ty2 - = zonkTcKind ty1 `thenM` \ ty1' -> - zonkTcKind ty2 `thenM` \ ty2' -> +unifyKindMisMatch ty1 ty2 = do + ty1' <- zonkTcKind ty1 + ty2' <- zonkTcKind ty2 let msg = hang (ptext SLIT("Couldn't match kind")) 2 (sep [quotes (ppr ty1'), ptext SLIT("against"), quotes (ppr ty2')]) - in failWithTc msg unifyKindCtxt swapped tv1 ty2 tidy_env -- not swapped => tv1 expected, ty2 inferred -- tv1 and ty2 are zonked already - = returnM msg + = return msg where msg = (env2, ptext SLIT("When matching the kinds of") <+> sep [quotes pp_expected <+> ptext SLIT("and"), quotes pp_actual]) @@ -409,7 +408,7 @@ newKindVar = do { uniq <- newUnique ; return (mkTyVarTy (mkKindVar uniq ref)) } newKindVars :: Int -> TcM [TcKind] -newKindVars n = mappM (\ _ -> newKindVar) (nOfThem n ()) +newKindVars n = mapM (\ _ -> newKindVar) (nOfThem n ()) \end{code} @@ -514,7 +513,7 @@ writeMetaTyVar tyvar ty = writeMutVar (metaTvRef tyvar) (Indirect ty) writeMetaTyVar tyvar ty | not (isMetaTyVar tyvar) = pprTrace "writeMetaTyVar" (ppr tyvar) $ - returnM () + return () | otherwise = ASSERT( isMetaTyVar tyvar ) @@ -540,12 +539,12 @@ newFlexiTyVar :: Kind -> TcM TcTyVar newFlexiTyVar kind = newMetaTyVar TauTv kind newFlexiTyVarTy :: Kind -> TcM TcType -newFlexiTyVarTy kind - = newFlexiTyVar kind `thenM` \ tc_tyvar -> - returnM (TyVarTy tc_tyvar) +newFlexiTyVarTy kind = do + tc_tyvar <- newFlexiTyVar kind + return (TyVarTy tc_tyvar) newFlexiTyVarTys :: Int -> Kind -> TcM [TcType] -newFlexiTyVarTys n kind = mappM newFlexiTyVarTy (nOfThem n kind) +newFlexiTyVarTys n kind = mapM newFlexiTyVarTy (nOfThem n kind) tcInstTyVar :: TyVar -> TcM TcTyVar -- Instantiate with a META type variable @@ -556,7 +555,7 @@ tcInstTyVars :: [TyVar] -> TcM ([TcTyVar], [TcType], TvSubst) tcInstTyVars tyvars = do { tc_tvs <- mapM tcInstTyVar tyvars ; let tys = mkTyVarTys tc_tvs - ; returnM (tc_tvs, tys, zipTopTvSubst tyvars tys) } + ; return (tc_tvs, tys, zipTopTvSubst tyvars tys) } -- Since the tyvars are freshly made, -- they cannot possibly be captured by -- any existing for-alls. Hence zipTopTvSubst @@ -657,33 +656,33 @@ lookupTcTyVar tyvar getTcTyVar tyvar | not (isTcTyVar tyvar) = pprTrace "getTcTyVar" (ppr tyvar) $ - returnM (Just (mkTyVarTy tyvar)) + return (Just (mkTyVarTy tyvar)) | otherwise - = ASSERT2( isTcTyVar tyvar, ppr tyvar ) - readMetaTyVar tyvar `thenM` \ maybe_ty -> + = ASSERT2( isTcTyVar tyvar, ppr tyvar ) do + maybe_ty <- readMetaTyVar tyvar case maybe_ty of - Just ty -> short_out ty `thenM` \ ty' -> - writeMetaTyVar tyvar (Just ty') `thenM_` - returnM (Just ty') + Just ty -> do ty' <- short_out ty + writeMetaTyVar tyvar (Just ty') + return (Just ty') - Nothing -> returnM Nothing + Nothing -> return Nothing short_out :: TcType -> TcM TcType short_out ty@(TyVarTy tyvar) | not (isTcTyVar tyvar) - = returnM ty + = return ty - | otherwise - = readMetaTyVar tyvar `thenM` \ maybe_ty -> + | otherwise = do + maybe_ty <- readMetaTyVar tyvar case maybe_ty of - Just ty' -> short_out ty' `thenM` \ ty' -> - writeMetaTyVar tyvar (Just ty') `thenM_` - returnM ty' + Just ty' -> do ty' <- short_out ty' + writeMetaTyVar tyvar (Just ty') + return ty' - other -> returnM ty + other -> return ty -short_out other_ty = returnM other_ty +short_out other_ty = return other_ty -} \end{code} @@ -698,45 +697,37 @@ short_out other_ty = returnM other_ty \begin{code} zonkTcTyVars :: [TcTyVar] -> TcM [TcType] -zonkTcTyVars tyvars = mappM zonkTcTyVar tyvars +zonkTcTyVars tyvars = mapM zonkTcTyVar tyvars zonkTcTyVarsAndFV :: [TcTyVar] -> TcM TcTyVarSet -zonkTcTyVarsAndFV tyvars = mappM zonkTcTyVar tyvars `thenM` \ tys -> - returnM (tyVarsOfTypes tys) +zonkTcTyVarsAndFV tyvars = tyVarsOfTypes <$> mapM zonkTcTyVar tyvars zonkTcTyVar :: TcTyVar -> TcM TcType zonkTcTyVar tyvar = ASSERT2( isTcTyVar tyvar, ppr tyvar) - zonk_tc_tyvar (\ tv -> returnM (TyVarTy tv)) tyvar + zonk_tc_tyvar (\ tv -> return (TyVarTy tv)) tyvar \end{code} ----------------- Types \begin{code} zonkTcType :: TcType -> TcM TcType -zonkTcType ty = zonkType (\ tv -> returnM (TyVarTy tv)) ty +zonkTcType ty = zonkType (\ tv -> return (TyVarTy tv)) ty zonkTcTypes :: [TcType] -> TcM [TcType] -zonkTcTypes tys = mappM zonkTcType tys +zonkTcTypes tys = mapM zonkTcType tys -zonkTcClassConstraints cts = mappM zonk cts - where zonk (clas, tys) - = zonkTcTypes tys `thenM` \ new_tys -> - returnM (clas, new_tys) +zonkTcClassConstraints cts = mapM zonk cts + where zonk (clas, tys) = do + new_tys <- zonkTcTypes tys + return (clas, new_tys) zonkTcThetaType :: TcThetaType -> TcM TcThetaType -zonkTcThetaType theta = mappM zonkTcPredType theta +zonkTcThetaType theta = mapM zonkTcPredType theta zonkTcPredType :: TcPredType -> TcM TcPredType -zonkTcPredType (ClassP c ts) - = zonkTcTypes ts `thenM` \ new_ts -> - returnM (ClassP c new_ts) -zonkTcPredType (IParam n t) - = zonkTcType t `thenM` \ new_t -> - returnM (IParam n new_t) -zonkTcPredType (EqPred t1 t2) - = zonkTcType t1 `thenM` \ new_t1 -> - zonkTcType t2 `thenM` \ new_t2 -> - returnM (EqPred new_t1 new_t2) +zonkTcPredType (ClassP c ts) = ClassP c <$> zonkTcTypes ts +zonkTcPredType (IParam n t) = IParam n <$> zonkTcType t +zonkTcPredType (EqPred t1 t2) = EqPred <$> zonkTcType t1 <*> zonkTcType t2 \end{code} ------------------- These ...ToType, ...ToKind versions @@ -768,7 +759,7 @@ zonkTopTyVar tv default_k = defaultKind k zonkQuantifiedTyVars :: [TcTyVar] -> TcM [TcTyVar] -zonkQuantifiedTyVars = mappM zonkQuantifiedTyVar +zonkQuantifiedTyVars = mapM zonkQuantifiedTyVar zonkQuantifiedTyVar :: TcTyVar -> TcM TcTyVar -- zonkQuantifiedTyVar is applied to the a TcTyVar when quantifying over it. @@ -898,20 +889,20 @@ zonkType unbound_var_fn ty = go ty where go (NoteTy _ ty2) = go ty2 -- Discard free-tyvar annotations - - go (TyConApp tc tys) = mappM go tys `thenM` \ tys' -> - returnM (TyConApp tc tys') - - go (PredTy p) = go_pred p `thenM` \ p' -> - returnM (PredTy p') - - go (FunTy arg res) = go arg `thenM` \ arg' -> - go res `thenM` \ res' -> - returnM (FunTy arg' res') - - go (AppTy fun arg) = go fun `thenM` \ fun' -> - go arg `thenM` \ arg' -> - returnM (mkAppTy fun' arg') + + go (TyConApp tc tys) = do tys' <- mapM go tys + return (TyConApp tc tys') + + go (PredTy p) = do p' <- go_pred p + return (PredTy p') + + go (FunTy arg res) = do arg' <- go arg + res' <- go res + return (FunTy arg' res') + + go (AppTy fun arg) = do fun' <- go fun + arg' <- go arg + return (mkAppTy fun' arg') -- NB the mkAppTy; we might have instantiated a -- type variable to a type constructor, so we need -- to pull the TyConApp to the top. @@ -921,23 +912,23 @@ zonkType unbound_var_fn ty | otherwise = return (TyVarTy tyvar) -- Ordinary (non Tc) tyvars occur inside quantified types - go (ForAllTy tyvar ty) = ASSERT( isImmutableTyVar tyvar ) - go ty `thenM` \ ty' -> - returnM (ForAllTy tyvar ty') + go (ForAllTy tyvar ty) = ASSERT( isImmutableTyVar tyvar ) do + ty' <- go ty + return (ForAllTy tyvar ty') - go_pred (ClassP c tys) = mappM go tys `thenM` \ tys' -> - returnM (ClassP c tys') - go_pred (IParam n ty) = go ty `thenM` \ ty' -> - returnM (IParam n ty') - go_pred (EqPred ty1 ty2) = go ty1 `thenM` \ ty1' -> - go ty2 `thenM` \ ty2' -> - returnM (EqPred ty1' ty2') + go_pred (ClassP c tys) = do tys' <- mapM go tys + return (ClassP c tys') + go_pred (IParam n ty) = do ty' <- go ty + return (IParam n ty') + go_pred (EqPred ty1 ty2) = do ty1' <- go ty1 + ty2' <- go ty2 + return (EqPred ty1' ty2') zonk_tc_tyvar :: (TcTyVar -> TcM Type) -- What to do for an unbound mutable variable -> TcTyVar -> TcM TcType zonk_tc_tyvar unbound_var_fn tyvar | not (isMetaTyVar tyvar) -- Skolems - = returnM (TyVarTy tyvar) + = return (TyVarTy tyvar) | otherwise -- Mutables = do { cts <- readMetaTyVar tyvar @@ -1008,12 +999,12 @@ This might not necessarily show up in kind checking. \begin{code} checkValidType :: UserTypeCtxt -> Type -> TcM () -- Checks that the type is valid for the given context -checkValidType ctxt ty - = traceTc (text "checkValidType" <+> ppr ty) `thenM_` - doptM Opt_UnboxedTuples `thenM` \ unboxed -> - doptM Opt_Rank2Types `thenM` \ rank2 -> - doptM Opt_RankNTypes `thenM` \ rankn -> - doptM Opt_PolymorphicComponents `thenM` \ polycomp -> +checkValidType ctxt ty = do + traceTc (text "checkValidType" <+> ppr ty) + unboxed <- doptM Opt_UnboxedTuples + rank2 <- doptM Opt_Rank2Types + rankn <- doptM Opt_RankNTypes + polycomp <- doptM Opt_PolymorphicComponents let rank | rankn = Arbitrary | rank2 = Rank 2 @@ -1049,12 +1040,12 @@ checkValidType ctxt ty TySynCtxt _ | unboxed -> UT_Ok ExprSigCtxt | unboxed -> UT_Ok _ -> UT_NotOk - in + -- Check that the thing has kind Type, and is lifted if necessary - checkTc kind_ok (kindErr actual_kind) `thenM_` + checkTc kind_ok (kindErr actual_kind) -- Check the internal validity of the type itself - check_type rank ubx_tup ty `thenM_` + check_type rank ubx_tup ty traceTc (text "checkValidType done" <+> ppr ty) @@ -1112,7 +1103,7 @@ check_type rank ubx_tup (PredTy sty) = do { dflags <- getDOpts ; check_pred_ty dflags TypeCtxt sty } -check_type rank ubx_tup (TyVarTy _) = returnM () +check_type rank ubx_tup (TyVarTy _) = return () check_type rank ubx_tup ty@(FunTy arg_ty res_ty) = do { check_type (decRank rank) UT_NotOk arg_ty ; check_type rank UT_Ok res_ty } @@ -1138,7 +1129,7 @@ check_type rank ubx_tup ty@(TyConApp tc tys) ; liberal <- doptM Opt_LiberalTypeSynonyms ; if not liberal || isOpenSynTyCon tc then -- For H98 and synonym families, do check the type args - mappM_ check_mono_type tys + mapM_ check_mono_type tys else -- In the liberal case (only for closed syns), expand then check case tcView ty of @@ -1155,10 +1146,10 @@ check_type rank ubx_tup ty@(TyConApp tc tys) -- c.f. check_arg_type -- However, args are allowed to be unlifted, or -- more unboxed tuples, so can't use check_arg_ty - ; mappM_ (check_type rank' UT_Ok) tys } + ; mapM_ (check_type rank' UT_Ok) tys } | otherwise - = mappM_ (check_arg_type rank) tys + = mapM_ (check_arg_type rank) tys where ubx_tup_ok ub_tuples_allowed = case ubx_tup of { UT_Ok -> ub_tuples_allowed; other -> False } @@ -1270,11 +1261,11 @@ checkValidTheta ctxt theta ------------------------- check_valid_theta ctxt [] - = returnM () -check_valid_theta ctxt theta - = getDOpts `thenM` \ dflags -> - warnTc (notNull dups) (dupPredWarn dups) `thenM_` - mappM_ (check_pred_ty dflags ctxt) theta + = return () +check_valid_theta ctxt theta = do + dflags <- getDOpts + warnTc (notNull dups) (dupPredWarn dups) + mapM_ (check_pred_ty dflags ctxt) theta where (_,dups) = removeDups tcCmpPred theta @@ -1285,7 +1276,7 @@ check_pred_ty dflags ctxt pred@(ClassP cls tys) ; checkTc (arity == n_tys) arity_err -- Check the form of the argument types - ; mappM_ check_mono_type tys + ; mapM_ check_mono_type tys ; checkTc (check_class_pred_tys dflags ctxt tys) (predTyVarErr pred $$ how_to_allow) } @@ -1376,7 +1367,7 @@ don't need to check for ambiguity either, because the test can't fail \begin{code} checkAmbiguity :: [TyVar] -> ThetaType -> TyVarSet -> TcM () checkAmbiguity forall_tyvars theta tau_tyvars - = mappM_ complain (filter is_ambig theta) + = mapM_ complain (filter is_ambig theta) where complain pred = addErrTc (ambigErr pred) extended_tau_vars = grow theta tau_tyvars @@ -1402,7 +1393,7 @@ even in a scope where b is in scope. \begin{code} checkFreeness forall_tyvars theta = do { flexible_contexts <- doptM Opt_FlexibleContexts - ; unless flexible_contexts $ mappM_ complain (filter is_free theta) } + ; unless flexible_contexts $ mapM_ complain (filter is_free theta) } where is_free pred = not (isIPPred pred) && not (any bound_var (varSetElems (tyVarsOfPred pred))) @@ -1482,12 +1473,12 @@ checkValidInstHead ty -- Should be a source type case getClassPredTys_maybe pred of { Nothing -> failWithTc (instTypeErr (pprPred pred) empty) ; - Just (clas,tys) -> + Just (clas,tys) -> do - getDOpts `thenM` \ dflags -> - mappM_ check_mono_type tys `thenM_` - check_inst_head dflags clas tys `thenM_` - returnM (clas, tys) + dflags <- getDOpts + mapM_ check_mono_type tys + check_inst_head dflags clas tys + return (clas, tys) }} check_inst_head dflags clas tys @@ -1679,7 +1670,7 @@ checkValidTypeInst :: [Type] -> Type -> TcM () checkValidTypeInst typats rhs = do { -- left-hand side contains no type family applications -- (vanilla synonyms are fine, though) - ; mappM_ checkTyFamFreeness typats + ; mapM_ checkTyFamFreeness typats -- the right-hand side is a tau type ; checkTc (isTauTy rhs) $ -- 1.7.10.4