*** compiler/typecheck/TcMatches.lhs 2010-11-08 17:39:22.000000000 -0500 --- compiler/typecheck/TcMatches.lhs 2010-11-05 15:57:18.958067000 -0400 *************** *** 12,18 **** tcDoStmt, tcMDoStmt, tcGuardStmt ) where ! import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRhoNC, tcMonoExpr, tcMonoExprNC, tcPolyExpr ) import HsSyn --- 12,18 ---- tcDoStmt, tcMDoStmt, tcGuardStmt ) where ! import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRhoNC, tcCheckId, tcMonoExpr, tcMonoExprNC, tcPolyExpr ) import HsSyn *************** *** 24,37 **** import TcType import TcBinds import TcUnify - import TcSimplify import Name import TysWiredIn import PrelNames import Id import TyCon import TysPrim import Outputable import Util import SrcLoc import FastString --- 24,38 ---- import TcType import TcBinds import TcUnify import Name import TysWiredIn import PrelNames import Id import TyCon import TysPrim + import Coercion ( mkSymCoercion ) import Outputable + import BasicTypes ( Arity ) import Util import SrcLoc import FastString *************** *** 52,63 **** is used in error messages. It checks that all the equations have the same number of arguments before using @tcMatches@ to do the work. \begin{code} tcMatchesFun :: Name -> Bool -> MatchGroup Name ! -> BoxyRhoType -- Expected type of function ! -> TcM (HsWrapper, MatchGroup TcId) -- Returns type of body ! tcMatchesFun fun_name inf matches exp_ty = do { -- Check that they all have the same no of arguments -- Location is in the monad, set the caller so that --- 53,69 ---- is used in error messages. It checks that all the equations have the same number of arguments before using @tcMatches@ to do the work. + Note [Polymorphic expected type for tcMatchesFun] + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + tcMatchesFun may be given a *sigma* (polymorphic) type + so it must be prepared to use tcGen to skolemise it. + See Note [sig_tau may be polymorphic] in TcPat. + \begin{code} tcMatchesFun :: Name -> Bool -> MatchGroup Name ! -> TcSigmaType -- Expected type of function ! -> TcM (HsWrapper, MatchGroup TcId) -- Returns type of body tcMatchesFun fun_name inf matches exp_ty = do { -- Check that they all have the same no of arguments -- Location is in the monad, set the caller so that *************** *** 68,87 **** traceTc (text "tcMatchesFun" <+> (ppr fun_name $$ ppr exp_ty)) ; checkArgs fun_name matches ! -- ToDo: Don't use "expected" stuff if there ain't a type signature ! -- because inconsistency between branches ! -- may show up as something wrong with the (non-existent) type signature ! ! -- This is one of two places places we call subFunTys ! -- The point is that if expected_y is a "hole", we want ! -- to make pat_tys and rhs_ty as "holes" too. ! ; subFunTys doc n_pats exp_ty (Just (FunSigCtxt fun_name)) $ \ pat_tys rhs_ty -> ! tcMatches match_ctxt pat_tys rhs_ty matches ! } where ! doc = ptext (sLit "The equation(s) for") <+> quotes (ppr fun_name) ! <+> ptext (sLit "have") <+> speakNOf n_pats (ptext (sLit "argument")) ! n_pats = matchGroupArity matches match_ctxt = MC { mc_what = FunRhs fun_name inf, mc_body = tcBody } \end{code} --- 74,89 ---- traceTc (text "tcMatchesFun" <+> (ppr fun_name $$ ppr exp_ty)) ; checkArgs fun_name matches ! ; (wrap_gen, (wrap_fun, group)) ! <- tcGen (SigSkol (FunSigCtxt fun_name)) exp_ty $ \ _ exp_rho -> ! -- Note [Polymorphic expected type for tcMatchesFun] ! matchFunTys herald arity exp_rho $ \ pat_tys rhs_ty -> ! tcMatches match_ctxt pat_tys rhs_ty matches ! ; return (wrap_gen <.> wrap_fun, group) } where ! arity = matchGroupArity matches ! herald = ptext (sLit "The equation(s) for") ! <+> quotes (ppr fun_name) <+> ptext (sLit "have") match_ctxt = MC { mc_what = FunRhs fun_name inf, mc_body = tcBody } \end{code} *************** *** 92,113 **** tcMatchesCase :: TcMatchCtxt -- Case context -> TcRhoType -- Type of scrutinee -> MatchGroup Name -- The case alternatives ! -> BoxyRhoType -- Type of whole case expressions -> TcM (MatchGroup TcId) -- Translated alternatives tcMatchesCase ctxt scrut_ty matches res_ty ! | isEmptyMatchGroup matches ! = -- Allow empty case expressions ! do { -- Make sure we follow the invariant that res_ty is filled in ! res_ty' <- refineBoxToTau res_ty ! ; return (MatchGroup [] (mkFunTys [scrut_ty] res_ty')) } | otherwise = tcMatches ctxt [scrut_ty] res_ty matches ! tcMatchLambda :: MatchGroup Name -> BoxyRhoType -> TcM (HsWrapper, MatchGroup TcId) tcMatchLambda match res_ty ! = subFunTys doc n_pats res_ty Nothing $ \ pat_tys rhs_ty -> tcMatches match_ctxt pat_tys rhs_ty match where n_pats = matchGroupArity match --- 94,112 ---- tcMatchesCase :: TcMatchCtxt -- Case context -> TcRhoType -- Type of scrutinee -> MatchGroup Name -- The case alternatives ! -> TcRhoType -- Type of whole case expressions -> TcM (MatchGroup TcId) -- Translated alternatives tcMatchesCase ctxt scrut_ty matches res_ty ! | isEmptyMatchGroup matches -- Allow empty case expressions ! = return (MatchGroup [] (mkFunTys [scrut_ty] res_ty)) | otherwise = tcMatches ctxt [scrut_ty] res_ty matches ! tcMatchLambda :: MatchGroup Name -> TcRhoType -> TcM (HsWrapper, MatchGroup TcId) tcMatchLambda match res_ty ! = matchFunTys doc n_pats res_ty $ \ pat_tys rhs_ty -> tcMatches match_ctxt pat_tys rhs_ty match where n_pats = matchGroupArity match *************** *** 123,129 **** @tcGRHSsPat@ typechecks @[GRHSs]@ that occur in a @PatMonoBind@. \begin{code} ! tcGRHSsPat :: GRHSs Name -> BoxyRhoType -> TcM (GRHSs TcId) -- Used for pattern bindings tcGRHSsPat grhss res_ty = tcGRHSs match_ctxt grhss res_ty where --- 122,128 ---- @tcGRHSsPat@ typechecks @[GRHSs]@ that occur in a @PatMonoBind@. \begin{code} ! tcGRHSsPat :: GRHSs Name -> TcRhoType -> TcM (GRHSs TcId) -- Used for pattern bindings tcGRHSsPat grhss res_ty = tcGRHSs match_ctxt grhss res_ty where *************** *** 132,137 **** \end{code} %************************************************************************ %* * \subsection{tcMatch} --- 131,153 ---- \end{code} + \begin{code} + matchFunTys + :: SDoc -- See Note [Herald for matchExpecteFunTys] in TcUnify + -> Arity + -> TcRhoType + -> ([TcSigmaType] -> TcRhoType -> TcM a) + -> TcM (HsWrapper, a) + + -- Written in CPS style for historical reasons; + -- could probably be un-CPSd, like matchExpectedTyConApp + + matchFunTys herald arity res_ty thing_inside + = do { (coi, pat_tys, res_ty) <- matchExpectedFunTys herald arity res_ty + ; res <- thing_inside pat_tys res_ty + ; return (coToHsWrapper (mkSymCoercion coi), res) } + \end{code} + %************************************************************************ %* * \subsection{tcMatch} *************** *** 140,147 **** \begin{code} tcMatches :: TcMatchCtxt ! -> [BoxySigmaType] -- Expected pattern types ! -> BoxyRhoType -- Expected result-type of the Match. -> MatchGroup Name -> TcM (MatchGroup TcId) --- 156,163 ---- \begin{code} tcMatches :: TcMatchCtxt ! -> [TcSigmaType] -- Expected pattern types ! -> TcRhoType -- Expected result-type of the Match. -> MatchGroup Name -> TcM (MatchGroup TcId) *************** *** 149,155 **** = MC { mc_what :: HsMatchContext Name, -- What kind of thing this is mc_body :: LHsExpr Name -- Type checker for a body of -- an alternative ! -> BoxyRhoType -> TcM (LHsExpr TcId) } tcMatches ctxt pat_tys rhs_ty (MatchGroup matches _) --- 165,171 ---- = MC { mc_what :: HsMatchContext Name, -- What kind of thing this is mc_body :: LHsExpr Name -- Type checker for a body of -- an alternative ! -> TcRhoType -> TcM (LHsExpr TcId) } tcMatches ctxt pat_tys rhs_ty (MatchGroup matches _) *************** *** 159,166 **** ------------- tcMatch :: TcMatchCtxt ! -> [BoxySigmaType] -- Expected pattern types ! -> BoxyRhoType -- Expected result-type of the Match. -> LMatch Name -> TcM (LMatch TcId) --- 175,182 ---- ------------- tcMatch :: TcMatchCtxt ! -> [TcSigmaType] -- Expected pattern types ! -> TcRhoType -- Expected result-type of the Match. -> LMatch Name -> TcM (LMatch TcId) *************** *** 170,176 **** tc_match ctxt pat_tys rhs_ty match@(Match pats maybe_rhs_sig grhss) = add_match_ctxt match $ do { (pats', grhss') <- tcPats (mc_what ctxt) pats pat_tys rhs_ty $ ! tc_grhss ctxt maybe_rhs_sig grhss ; return (Match pats' Nothing grhss') } tc_grhss ctxt Nothing grhss rhs_ty --- 186,192 ---- tc_match ctxt pat_tys rhs_ty match@(Match pats maybe_rhs_sig grhss) = add_match_ctxt match $ do { (pats', grhss') <- tcPats (mc_what ctxt) pats pat_tys rhs_ty $ ! tc_grhss ctxt maybe_rhs_sig grhss rhs_ty ; return (Match pats' Nothing grhss') } tc_grhss ctxt Nothing grhss rhs_ty *************** *** 188,194 **** m_ctxt -> addErrCtxt (pprMatchInCtxt m_ctxt match) thing_inside ------------- ! tcGRHSs :: TcMatchCtxt -> GRHSs Name -> BoxyRhoType -> TcM (GRHSs TcId) -- Notice that we pass in the full res_ty, so that we get --- 204,210 ---- m_ctxt -> addErrCtxt (pprMatchInCtxt m_ctxt match) thing_inside ------------- ! tcGRHSs :: TcMatchCtxt -> GRHSs Name -> TcRhoType -> TcM (GRHSs TcId) -- Notice that we pass in the full res_ty, so that we get *************** *** 204,210 **** ; return (GRHSs grhss' binds') } ------------- ! tcGRHS :: TcMatchCtxt -> BoxyRhoType -> GRHS Name -> TcM (GRHS TcId) tcGRHS ctxt res_ty (GRHS guards rhs) = do { (guards', rhs') <- tcStmts stmt_ctxt tcGuardStmt guards res_ty $ --- 220,226 ---- ; return (GRHSs grhss' binds') } ------------- ! tcGRHS :: TcMatchCtxt -> TcRhoType -> GRHS Name -> TcM (GRHS TcId) tcGRHS ctxt res_ty (GRHS guards rhs) = do { (guards', rhs') <- tcStmts stmt_ctxt tcGuardStmt guards res_ty $ *************** *** 225,246 **** tcDoStmts :: HsStmtContext Name -> [LStmt Name] -> LHsExpr Name ! -> BoxyRhoType -> TcM (HsExpr TcId) -- Returns a HsDo tcDoStmts ListComp stmts body res_ty ! = do { (elt_ty, coi) <- boxySplitListTy res_ty ; (stmts', body') <- tcStmts ListComp (tcLcStmt listTyCon) stmts elt_ty $ tcBody body ! ; return $ mkHsWrapCoI coi (HsDo ListComp stmts' body' (mkListTy elt_ty)) } tcDoStmts PArrComp stmts body res_ty ! = do { (elt_ty, coi) <- boxySplitPArrTy res_ty ; (stmts', body') <- tcStmts PArrComp (tcLcStmt parrTyCon) stmts elt_ty $ tcBody body ! ; return $ mkHsWrapCoI coi (HsDo PArrComp stmts' body' (mkPArrTy elt_ty)) } tcDoStmts DoExpr stmts body res_ty --- 241,262 ---- tcDoStmts :: HsStmtContext Name -> [LStmt Name] -> LHsExpr Name ! -> TcRhoType -> TcM (HsExpr TcId) -- Returns a HsDo tcDoStmts ListComp stmts body res_ty ! = do { (coi, elt_ty) <- matchExpectedListTy res_ty ; (stmts', body') <- tcStmts ListComp (tcLcStmt listTyCon) stmts elt_ty $ tcBody body ! ; return $ mkHsWrapCo coi (HsDo ListComp stmts' body' (mkListTy elt_ty)) } tcDoStmts PArrComp stmts body res_ty ! = do { (coi, elt_ty) <- matchExpectedPArrTy res_ty ; (stmts', body') <- tcStmts PArrComp (tcLcStmt parrTyCon) stmts elt_ty $ tcBody body ! ; return $ mkHsWrapCo coi (HsDo PArrComp stmts' body' (mkPArrTy elt_ty)) } tcDoStmts DoExpr stmts body res_ty *************** *** 249,272 **** ; return (HsDo DoExpr stmts' body' res_ty) } tcDoStmts ctxt@(MDoExpr _) stmts body res_ty ! = do { ((m_ty, elt_ty), coi) <- boxySplitAppTy res_ty ! ; let res_ty' = mkAppTy m_ty elt_ty -- The boxySplit consumes res_ty ! tc_rhs rhs = withBox liftedTypeKind $ \ pat_ty -> tcMonoExpr rhs (mkAppTy m_ty pat_ty) ! ; (stmts', body') <- tcStmts ctxt (tcMDoStmt tc_rhs) stmts ! res_ty' $ tcBody body ; let names = [mfixName, bindMName, thenMName, returnMName, failMName] ! ; insts <- mapM (newMethodFromName DoOrigin m_ty) names ! ; return $ ! mkHsWrapCoI coi ! (HsDo (MDoExpr (names `zip` insts)) stmts' body' res_ty') } tcDoStmts ctxt _ _ _ = pprPanic "tcDoStmts" (pprStmtContext ctxt) ! tcBody :: LHsExpr Name -> BoxyRhoType -> TcM (LHsExpr TcId) tcBody body res_ty = do { traceTc (text "tcBody" <+> ppr res_ty) ; body' <- tcMonoExpr body res_ty --- 265,286 ---- ; return (HsDo DoExpr stmts' body' res_ty) } tcDoStmts ctxt@(MDoExpr _) stmts body res_ty ! = do { (coi, (m_ty, elt_ty)) <- matchExpectedAppTy res_ty ! ; let res_ty' = mkAppTy m_ty elt_ty -- The matchExpected consumes res_ty ! tc_rhs rhs = tcInfer $ \ pat_ty -> tcMonoExpr rhs (mkAppTy m_ty pat_ty) ! ; (stmts', body') <- tcStmts ctxt (tcMDoStmt tc_rhs) stmts res_ty' $ tcBody body ; let names = [mfixName, bindMName, thenMName, returnMName, failMName] ! ; insts <- mapM (\name -> newMethodFromName DoOrigin name m_ty) names ! ; return $ mkHsWrapCo coi $ ! HsDo (MDoExpr (names `zip` insts)) stmts' body' res_ty' } tcDoStmts ctxt _ _ _ = pprPanic "tcDoStmts" (pprStmtContext ctxt) ! tcBody :: LHsExpr Name -> TcRhoType -> TcM (LHsExpr TcId) tcBody body res_ty = do { traceTc (text "tcBody" <+> ppr res_ty) ; body' <- tcMonoExpr body res_ty *************** *** 285,299 **** type TcStmtChecker = forall thing. HsStmtContext Name -> Stmt Name ! -> BoxyRhoType -- Result type for comprehension ! -> (BoxyRhoType -> TcM thing) -- Checker for what follows the stmt -> TcM (Stmt TcId, thing) tcStmts :: HsStmtContext Name -> TcStmtChecker -- NB: higher-rank type -> [LStmt Name] ! -> BoxyRhoType ! -> (BoxyRhoType -> TcM thing) -> TcM ([LStmt TcId], thing) -- Note the higher-rank type. stmt_chk is applied at different --- 299,313 ---- type TcStmtChecker = forall thing. HsStmtContext Name -> Stmt Name ! -> TcRhoType -- Result type for comprehension ! -> (TcRhoType -> TcM thing) -- Checker for what follows the stmt -> TcM (Stmt TcId, thing) tcStmts :: HsStmtContext Name -> TcStmtChecker -- NB: higher-rank type -> [LStmt Name] ! -> TcRhoType ! -> (TcRhoType -> TcM thing) -> TcM ([LStmt TcId], thing) -- Note the higher-rank type. stmt_chk is applied at different *************** *** 330,336 **** tcGuardStmt ctxt (BindStmt pat rhs _ _) res_ty thing_inside = do { (rhs', rhs_ty) <- tcInferRhoNC rhs -- Stmt has a context already ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat rhs_ty res_ty thing_inside ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } tcGuardStmt _ stmt _ _ --- 344,351 ---- tcGuardStmt ctxt (BindStmt pat rhs _ _) res_ty thing_inside = do { (rhs', rhs_ty) <- tcInferRhoNC rhs -- Stmt has a context already ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat rhs_ty res_ty $ ! thing_inside res_ty ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } tcGuardStmt _ stmt _ _ *************** *** 345,353 **** -- A generator, pat <- rhs tcLcStmt m_tc ctxt (BindStmt pat rhs _ _) res_ty thing_inside ! = do { (rhs', pat_ty) <- withBox liftedTypeKind $ \ ty -> ! tcMonoExpr rhs (mkTyConApp m_tc [ty]) ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty res_ty thing_inside ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } -- A boolean guard --- 360,369 ---- -- A generator, pat <- rhs tcLcStmt m_tc ctxt (BindStmt pat rhs _ _) res_ty thing_inside ! = do { pat_ty <- newFlexiTyVarTy liftedTypeKind ! ; rhs' <- tcMonoExpr rhs (mkTyConApp m_tc [pat_ty]) ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty res_ty $ ! thing_inside res_ty ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } -- A boolean guard *************** *** 361,367 **** -- | ... ; let h v = ... ] -- -- It's possible that g,h are overloaded, so we need to feed the LIE from the ! -- (g x, h x) up through both lots of bindings (so we get the bindInstsOfLocalFuns). -- Similarly if we had an existential pattern match: -- -- data T = forall a. Show a => C a --- 377,383 ---- -- | ... ; let h v = ... ] -- -- It's possible that g,h are overloaded, so we need to feed the LIE from the ! -- (g x, h x) up through both lots of bindings (so we get the bindLocalMethods). -- Similarly if we had an existential pattern match: -- -- data T = forall a. Show a => C a *************** *** 477,488 **** -- (see Note [Treat rebindable syntax first], but that breaks -- the rigidity info for GADTs. When we move to the new story -- for GADTs, we can move this after tcSyntaxOp ! (rhs', rhs_ty) <- tcInferRhoNC rhs ! ! ; ((bind_op', new_res_ty), pat_ty) <- ! withBox liftedTypeKind $ \ pat_ty -> ! withBox liftedTypeKind $ \ new_res_ty -> ! tcSyntaxOp DoOrigin bind_op (mkFunTys [rhs_ty, mkFunTy pat_ty new_res_ty] res_ty) -- If (but only if) the pattern can fail, --- 493,502 ---- -- (see Note [Treat rebindable syntax first], but that breaks -- the rigidity info for GADTs. When we move to the new story -- for GADTs, we can move this after tcSyntaxOp ! rhs_ty <- newFlexiTyVarTy liftedTypeKind ! ; pat_ty <- newFlexiTyVarTy liftedTypeKind ! ; new_res_ty <- newFlexiTyVarTy liftedTypeKind ! ; bind_op' <- tcSyntaxOp DoOrigin bind_op (mkFunTys [rhs_ty, mkFunTy pat_ty new_res_ty] res_ty) -- If (but only if) the pattern can fail, *************** *** 491,505 **** then return noSyntaxExpr else tcSyntaxOp DoOrigin fail_op (mkFunTy stringTy new_res_ty) ! -- We should typecheck the RHS *before* the pattern, ! -- because of GADTs. ! -- do { pat <- rhs; } ! -- is rather like ! -- case rhs of { pat -> } ! -- We do inference on rhs, so that information about its type ! -- can be refined when type-checking the pattern. ! ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty new_res_ty thing_inside ; return (BindStmt pat' rhs' bind_op' fail_op', thing) } --- 505,513 ---- then return noSyntaxExpr else tcSyntaxOp DoOrigin fail_op (mkFunTy stringTy new_res_ty) ! ; rhs' <- tcMonoExpr rhs rhs_ty ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty new_res_ty $ ! thing_inside new_res_ty ; return (BindStmt pat' rhs' bind_op' fail_op', thing) } *************** *** 508,517 **** = do { -- Deal with rebindable syntax; -- (>>) :: rhs_ty -> new_res_ty -> res_ty -- See also Note [Treat rebindable syntax first] ! ((then_op', rhs_ty), new_res_ty) <- ! withBox liftedTypeKind $ \ new_res_ty -> ! withBox liftedTypeKind $ \ rhs_ty -> ! tcSyntaxOp DoOrigin then_op (mkFunTys [rhs_ty, new_res_ty] res_ty) ; rhs' <- tcMonoExprNC rhs rhs_ty --- 516,524 ---- = do { -- Deal with rebindable syntax; -- (>>) :: rhs_ty -> new_res_ty -> res_ty -- See also Note [Treat rebindable syntax first] ! rhs_ty <- newFlexiTyVarTy liftedTypeKind ! ; new_res_ty <- newFlexiTyVarTy liftedTypeKind ! ; then_op' <- tcSyntaxOp DoOrigin then_op (mkFunTys [rhs_ty, new_res_ty] res_ty) ; rhs' <- tcMonoExprNC rhs rhs_ty *************** *** 528,550 **** tup_ty = mkBoxedTupleTy tup_elt_tys ; tcExtendIdEnv tup_ids $ do ! { ((stmts', (ret_op', tup_rets)), stmts_ty) ! <- withBox liftedTypeKind $ \ stmts_ty -> ! tcStmts ctxt tcDoStmt stmts stmts_ty $ \ inner_res_ty -> ! do { tup_rets <- zipWithM tc_ret tup_names tup_elt_tys ; ret_op' <- tcSyntaxOp DoOrigin ret_op (mkFunTy tup_ty inner_res_ty) ; return (ret_op', tup_rets) } ! ; (mfix_op', mfix_res_ty) <- withBox liftedTypeKind $ \ mfix_res_ty -> ! tcSyntaxOp DoOrigin mfix_op ! (mkFunTy (mkFunTy tup_ty stmts_ty) mfix_res_ty) ! ! ; (bind_op', new_res_ty) <- withBox liftedTypeKind $ \ new_res_ty -> ! tcSyntaxOp DoOrigin bind_op ! (mkFunTys [mfix_res_ty, mkFunTy tup_ty new_res_ty] res_ty) ! ; (thing,lie) <- getLIE (thing_inside new_res_ty) ! ; lie_binds <- bindInstsOfLocalFuns lie tup_ids ; let rec_ids = takeList rec_names tup_ids ; later_ids <- tcLookupLocalIds later_names --- 535,559 ---- tup_ty = mkBoxedTupleTy tup_elt_tys ; tcExtendIdEnv tup_ids $ do ! { stmts_ty <- newFlexiTyVarTy liftedTypeKind ! ; (stmts', (ret_op', tup_rets)) ! <- tcStmts ctxt tcDoStmt stmts stmts_ty $ \ inner_res_ty -> ! do { tup_rets <- zipWithM tcCheckId tup_names tup_elt_tys ! -- Unify the types of the "final" Ids (which may ! -- be polymorphic) with those of "knot-tied" Ids ; ret_op' <- tcSyntaxOp DoOrigin ret_op (mkFunTy tup_ty inner_res_ty) ; return (ret_op', tup_rets) } ! ; mfix_res_ty <- newFlexiTyVarTy liftedTypeKind ! ; mfix_op' <- tcSyntaxOp DoOrigin mfix_op ! (mkFunTy (mkFunTy tup_ty stmts_ty) mfix_res_ty) ! ! ; new_res_ty <- newFlexiTyVarTy liftedTypeKind ! ; bind_op' <- tcSyntaxOp DoOrigin bind_op ! (mkFunTys [mfix_res_ty, mkFunTy tup_ty new_res_ty] res_ty) ! ; thing <- thing_inside new_res_ty ! -- ; lie_binds <- bindLocalMethods lie tup_ids ; let rec_ids = takeList rec_names tup_ids ; later_ids <- tcLookupLocalIds later_names *************** *** 553,568 **** ; return (RecStmt { recS_stmts = stmts', recS_later_ids = later_ids , recS_rec_ids = rec_ids, recS_ret_fn = ret_op' , recS_mfix_fn = mfix_op', recS_bind_fn = bind_op' ! , recS_rec_rets = tup_rets, recS_dicts = lie_binds }, thing) }} - where - -- Unify the types of the "final" Ids with those of "knot-tied" Ids - tc_ret rec_name mono_ty - = do { poly_id <- tcLookupId rec_name - -- poly_id may have a polymorphic type - -- but mono_ty is just a monomorphic type variable - ; co_fn <- tcSubExp DoOrigin (idType poly_id) mono_ty - ; return (mkHsWrap co_fn (HsVar poly_id)) } tcDoStmt _ stmt _ _ = pprPanic "tcDoStmt: unexpected Stmt" (ppr stmt) --- 562,569 ---- ; return (RecStmt { recS_stmts = stmts', recS_later_ids = later_ids , recS_rec_ids = rec_ids, recS_ret_fn = ret_op' , recS_mfix_fn = mfix_op', recS_bind_fn = bind_op' ! , recS_rec_rets = tup_rets, recS_dicts = emptyTcEvBinds }, thing) }} tcDoStmt _ stmt _ _ = pprPanic "tcDoStmt: unexpected Stmt" (ppr stmt) *************** *** 589,595 **** -> TcStmtChecker tcMDoStmt tc_rhs ctxt (BindStmt pat rhs _ _) res_ty thing_inside = do { (rhs', pat_ty) <- tc_rhs rhs ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty res_ty thing_inside ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } tcMDoStmt tc_rhs _ (ExprStmt rhs _ _) res_ty thing_inside --- 590,597 ---- -> TcStmtChecker tcMDoStmt tc_rhs ctxt (BindStmt pat rhs _ _) res_ty thing_inside = do { (rhs', pat_ty) <- tc_rhs rhs ! ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty res_ty $ ! thing_inside res_ty ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } tcMDoStmt tc_rhs _ (ExprStmt rhs _ _) res_ty thing_inside *************** *** 604,634 **** { (stmts', (later_ids, rec_rets)) <- tcStmts ctxt (tcMDoStmt tc_rhs) stmts res_ty $ \ _res_ty' -> -- ToDo: res_ty not really right ! do { rec_rets <- zipWithM tc_ret recNames rec_tys ; later_ids <- tcLookupLocalIds laterNames ; return (later_ids, rec_rets) } ! ; (thing,lie) <- tcExtendIdEnv later_ids (getLIE (thing_inside res_ty)) -- NB: The rec_ids for the recursive things -- already scope over this part. This binding may shadow -- some of them with polymorphic things with the same Name -- (see note [RecStmt] in HsExpr) ! ; lie_binds <- bindInstsOfLocalFuns lie later_ids ; return (RecStmt stmts' later_ids rec_ids noSyntaxExpr noSyntaxExpr noSyntaxExpr rec_rets lie_binds, thing) }} - where - -- Unify the types of the "final" Ids with those of "knot-tied" Ids - tc_ret rec_name mono_ty - = do { poly_id <- tcLookupId rec_name - -- poly_id may have a polymorphic type - -- but mono_ty is just a monomorphic type variable - ; co_fn <- tcSubExp DoOrigin (idType poly_id) mono_ty - ; return (mkHsWrap co_fn (HsVar poly_id)) } tcMDoStmt _ _ stmt _ _ = pprPanic "tcMDoStmt: unexpected Stmt" (ppr stmt) - \end{code} --- 606,630 ---- { (stmts', (later_ids, rec_rets)) <- tcStmts ctxt (tcMDoStmt tc_rhs) stmts res_ty $ \ _res_ty' -> -- ToDo: res_ty not really right ! do { rec_rets <- zipWithM tcCheckId recNames rec_tys ; later_ids <- tcLookupLocalIds laterNames ; return (later_ids, rec_rets) } ! ; thing <- tcExtendIdEnv later_ids (thing_inside res_ty) -- NB: The rec_ids for the recursive things -- already scope over this part. This binding may shadow -- some of them with polymorphic things with the same Name -- (see note [RecStmt] in HsExpr) ! ! -- Need the bindLocalMethods if we re-add Method constraints ! -- ; lie_binds <- bindLocalMethods lie later_ids ! ; let lie_binds = emptyTcEvBinds ; return (RecStmt stmts' later_ids rec_ids noSyntaxExpr noSyntaxExpr noSyntaxExpr rec_rets lie_binds, thing) }} tcMDoStmt _ _ stmt _ _ = pprPanic "tcMDoStmt: unexpected Stmt" (ppr stmt) \end{code}