X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcMatches.lhs;h=820e5172ce1130d45c1866ee2bfb15bac7602e4f;hp=31aa555b728907b53931bb3b55360ddadce3e434;hb=d76d9636aeebe933d160157331b8c8c0087e73ac;hpb=478e69b303eb2e653a2ebf5c888b5efdfef1fb9d diff --git a/compiler/typecheck/TcMatches.lhs b/compiler/typecheck/TcMatches.lhs index 31aa555..820e517 100644 --- a/compiler/typecheck/TcMatches.lhs +++ b/compiler/typecheck/TcMatches.lhs @@ -8,7 +8,7 @@ TcMatches: Typecheck some @Matches@ \begin{code} module TcMatches ( tcMatchesFun, tcGRHSsPat, tcMatchesCase, tcMatchLambda, TcMatchCtxt(..), - tcStmts, tcDoStmts, tcBody, + tcStmts, tcStmtsAndThen, tcDoStmts, tcBody, tcDoStmt, tcMDoStmt, tcGuardStmt ) where @@ -224,7 +224,7 @@ tcGRHSs ctxt (GRHSs grhss binds) res_ty 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 $ + = do { (guards', rhs') <- tcStmtsAndThen stmt_ctxt tcGuardStmt guards res_ty $ mc_body ctxt rhs ; return (GRHS guards' rhs') } where @@ -241,43 +241,33 @@ tcGRHS ctxt res_ty (GRHS guards rhs) \begin{code} tcDoStmts :: HsStmtContext Name -> [LStmt Name] - -> LHsExpr Name - -> SyntaxExpr Name -- 'return' function for monad - -- comprehensions -> TcRhoType -> TcM (HsExpr TcId) -- Returns a HsDo -tcDoStmts ListComp stmts body _ res_ty +tcDoStmts ListComp stmts res_ty = do { (coi, elt_ty) <- matchExpectedListTy res_ty - ; (stmts', body') <- tcStmts ListComp (tcLcStmt listTyCon) stmts - elt_ty $ - tcBody body + ; stmts' <- tcStmts ListComp (tcLcStmt listTyCon) stmts elt_ty ; return $ mkHsWrapCoI coi - (HsDo ListComp stmts' body' noSyntaxExpr (mkListTy elt_ty)) } + (HsDo ListComp stmts' (mkListTy elt_ty)) } -tcDoStmts PArrComp stmts body _ res_ty +tcDoStmts PArrComp stmts res_ty = do { (coi, elt_ty) <- matchExpectedPArrTy res_ty - ; (stmts', body') <- tcStmts PArrComp (tcLcStmt parrTyCon) stmts - elt_ty $ - tcBody body + ; stmts' <- tcStmts PArrComp (tcLcStmt parrTyCon) stmts elt_ty ; return $ mkHsWrapCoI coi - (HsDo PArrComp stmts' body' noSyntaxExpr (mkPArrTy elt_ty)) } + (HsDo PArrComp stmts' (mkPArrTy elt_ty)) } -tcDoStmts DoExpr stmts body _ res_ty - = do { (stmts', body') <- tcStmts DoExpr tcDoStmt stmts res_ty $ - tcBody body - ; return (HsDo DoExpr stmts' body' noSyntaxExpr res_ty) } +tcDoStmts DoExpr stmts res_ty + = do { stmts' <- tcStmts DoExpr tcDoStmt stmts res_ty + ; return (HsDo DoExpr stmts' res_ty) } -tcDoStmts MDoExpr stmts body _ res_ty - = do { (stmts', body') <- tcStmts MDoExpr tcDoStmt stmts res_ty $ - tcBody body - ; return (HsDo MDoExpr stmts' body' noSyntaxExpr res_ty) } +tcDoStmts MDoExpr stmts res_ty + = do { stmts' <- tcStmts MDoExpr tcDoStmt stmts res_ty + ; return (HsDo MDoExpr stmts' res_ty) } -tcDoStmts MonadComp stmts body return_op res_ty - = do { (stmts', (body', return_op')) <- tcStmts MonadComp tcMcStmt stmts res_ty $ - tcMcBody body return_op - ; return $ HsDo MonadComp stmts' body' return_op' res_ty } +tcDoStmts MonadComp stmts res_ty + = do { stmts' <- tcStmts MonadComp tcMcStmt stmts res_ty + ; return (HsDo MonadComp stmts' res_ty) } -tcDoStmts ctxt _ _ _ _ = pprPanic "tcDoStmts" (pprStmtContext ctxt) +tcDoStmts ctxt _ _ = pprPanic "tcDoStmts" (pprStmtContext ctxt) tcBody :: LHsExpr Name -> TcRhoType -> TcM (LHsExpr TcId) tcBody body res_ty @@ -306,30 +296,40 @@ tcStmts :: HsStmtContext Name -> TcStmtChecker -- NB: higher-rank type -> [LStmt Name] -> TcRhoType - -> (TcRhoType -> TcM thing) - -> TcM ([LStmt TcId], thing) + -> TcM [LStmt TcId] +tcStmts ctxt stmt_chk stmts res_ty + = do { (stmts', _) <- tcStmtsAndThen ctxt stmt_chk stmts res_ty $ + const (return ()) + ; return stmts' } + +tcStmtsAndThen :: 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 -- types in the equations for tcStmts -tcStmts _ _ [] res_ty thing_inside +tcStmtsAndThen _ _ [] res_ty thing_inside = do { thing <- thing_inside res_ty ; return ([], thing) } -- LetStmts are handled uniformly, regardless of context -tcStmts ctxt stmt_chk (L loc (LetStmt binds) : stmts) res_ty thing_inside +tcStmtsAndThen ctxt stmt_chk (L loc (LetStmt binds) : stmts) res_ty thing_inside = do { (binds', (stmts',thing)) <- tcLocalBinds binds $ - tcStmts ctxt stmt_chk stmts res_ty thing_inside + tcStmtsAndThen ctxt stmt_chk stmts res_ty thing_inside ; return (L loc (LetStmt binds') : stmts', thing) } -- For the vanilla case, handle the location-setting part -tcStmts ctxt stmt_chk (L loc stmt : stmts) res_ty thing_inside +tcStmtsAndThen ctxt stmt_chk (L loc stmt : stmts) res_ty thing_inside = do { (stmt', (stmts', thing)) <- - setSrcSpan loc $ - addErrCtxt (pprStmtInCtxt ctxt stmt) $ - stmt_chk ctxt stmt res_ty $ \ res_ty' -> - popErrCtxt $ - tcStmts ctxt stmt_chk stmts res_ty' $ + setSrcSpan loc $ + addErrCtxt (pprStmtInCtxt ctxt stmt) $ + stmt_chk ctxt stmt res_ty $ \ res_ty' -> + popErrCtxt $ + tcStmtsAndThen ctxt stmt_chk stmts res_ty' $ thing_inside ; return (L loc stmt' : stmts', thing) } @@ -357,18 +357,23 @@ tcGuardStmt _ stmt _ _ tcLcStmt :: TyCon -- The list/Parray type constructor ([] or PArray) -> TcStmtChecker +tcLcStmt _ _ (LastStmt body _) elt_ty thing_inside + = do { body' <- tcMonoExpr body elt_ty + ; thing <- thing_inside (panic "tcLcStmt: thing_inside") + ; return (LastStmt body' noSyntaxExpr, thing) } + -- A generator, pat <- rhs -tcLcStmt m_tc ctxt (BindStmt pat rhs _ _) res_ty thing_inside +tcLcStmt m_tc ctxt (BindStmt pat rhs _ _) elt_ty thing_inside = do { pat_ty <- newFlexiTyVarTy liftedTypeKind ; rhs' <- tcMonoExpr rhs (mkTyConApp m_tc [pat_ty]) ; (pat', thing) <- tcPat (StmtCtxt ctxt) pat pat_ty $ - thing_inside res_ty + thing_inside elt_ty ; return (BindStmt pat' rhs' noSyntaxExpr noSyntaxExpr, thing) } -- A boolean guard -tcLcStmt _ _ (ExprStmt rhs _ _ _) res_ty thing_inside +tcLcStmt _ _ (ExprStmt rhs _ _ _) elt_ty thing_inside = do { rhs' <- tcMonoExpr rhs boolTy - ; thing <- thing_inside res_ty + ; thing <- thing_inside elt_ty ; return (ExprStmt rhs' noSyntaxExpr noSyntaxExpr boolTy, thing) } -- A parallel set of comprehensions @@ -402,7 +407,7 @@ tcLcStmt m_tc ctxt (ParStmt bndr_stmts_s _ _ _) elt_ty thing_inside loop ((stmts, names) : pairs) = do { (stmts', (ids, pairs', thing)) - <- tcStmts ctxt (tcLcStmt m_tc) stmts elt_ty $ \ _elt_ty' -> + <- tcStmtsAndThen ctxt (tcLcStmt m_tc) stmts elt_ty $ \ _elt_ty' -> do { ids <- tcLookupLocalIds names ; (pairs', thing) <- loop pairs ; return (ids, pairs', thing) } @@ -410,7 +415,7 @@ tcLcStmt m_tc ctxt (ParStmt bndr_stmts_s _ _ _) elt_ty thing_inside tcLcStmt m_tc ctxt (TransformStmt stmts binders usingExpr maybeByExpr _ _) elt_ty thing_inside = do (stmts', (binders', usingExpr', maybeByExpr', thing)) <- - tcStmts (TransformStmtCtxt ctxt) (tcLcStmt m_tc) stmts elt_ty $ \elt_ty' -> do + tcStmtsAndThen (TransformStmtCtxt ctxt) (tcLcStmt m_tc) stmts elt_ty $ \elt_ty' -> do let alphaListTy = mkTyConApp m_tc [alphaTy] (usingExpr', maybeByExpr') <- @@ -437,11 +442,13 @@ tcLcStmt m_tc ctxt (TransformStmt stmts binders usingExpr maybeByExpr _ _) elt_t return (TransformStmt stmts' binders' usingExpr' maybeByExpr' noSyntaxExpr noSyntaxExpr, thing) -tcLcStmt m_tc ctxt (GroupStmt stmts bindersMap by using _ _ _) elt_ty thing_inside +tcLcStmt m_tc ctxt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = bindersMap + , grpS_by = by, grpS_using = using + , grpS_explicit = explicit }) elt_ty thing_inside = do { let (bndr_names, list_bndr_names) = unzip bindersMap ; (stmts', (bndr_ids, by', using_ty, elt_ty')) <- - tcStmts (TransformStmtCtxt ctxt) (tcLcStmt m_tc) stmts elt_ty $ \elt_ty' -> do + tcStmtsAndThen (TransformStmtCtxt ctxt) (tcLcStmt m_tc) stmts elt_ty $ \elt_ty' -> do (by', using_ty) <- case by of Nothing -> -- check that using :: forall a. [a] -> [[a]] @@ -466,14 +473,14 @@ tcLcStmt m_tc ctxt (GroupStmt stmts bindersMap by using _ _ _) elt_ty thing_insi bindersMap' = bndr_ids `zip` list_bndr_ids -- See Note [GroupStmt binder map] in HsExpr - ; using' <- case using of - Left e -> do { e' <- tcPolyExpr e using_ty; return (Left e') } - Right e -> do { e' <- tcPolyExpr (noLoc e) using_ty; return (Right (unLoc e')) } + ; using' <- tcPolyExpr using using_ty -- Type check the thing in the environment with -- these new binders and return the result ; thing <- tcExtendIdEnv list_bndr_ids (thing_inside elt_ty') - ; return (GroupStmt stmts' bindersMap' by' using' noSyntaxExpr noSyntaxExpr noSyntaxExpr, thing) } + ; return (emptyGroupStmt { grpS_stmts = stmts', grpS_bndrs = bindersMap' + , grpS_by = by', grpS_using = using' + , grpS_explicit = explicit }, thing) } where alphaListTy = mkTyConApp m_tc [alphaTy] alphaListListTy = mkTyConApp m_tc [alphaListTy] @@ -491,20 +498,30 @@ tcLcStmt _ _ stmt _ _ tcMcStmt :: TcStmtChecker +tcMcStmt _ (LastStmt body return_op) res_ty thing_inside + = do { a_ty <- newFlexiTyVarTy liftedTypeKind + ; return_op' <- tcSyntaxOp MCompOrigin return_op + (a_ty `mkFunTy` res_ty) + ; body' <- tcMonoExpr body a_ty + ; thing <- thing_inside (panic "tcMcStmt: thing_inside") + ; return (LastStmt body' return_op', thing) } + -- Generators for monad comprehensions ( pat <- rhs ) -- -- [ body | q <- gen ] -> gen :: m a -- q :: a -- + tcMcStmt ctxt (BindStmt pat rhs bind_op fail_op) res_ty thing_inside = do { rhs_ty <- newFlexiTyVarTy liftedTypeKind ; pat_ty <- newFlexiTyVarTy liftedTypeKind ; new_res_ty <- newFlexiTyVarTy liftedTypeKind + + -- (>>=) :: rhs_ty -> (pat_ty -> new_res_ty) -> res_ty ; bind_op' <- tcSyntaxOp MCompOrigin bind_op (mkFunTys [rhs_ty, mkFunTy pat_ty new_res_ty] res_ty) - -- If (but only if) the pattern can fail, - -- typecheck the 'fail' operator + -- If (but only if) the pattern can fail, typecheck the 'fail' operator ; fail_op' <- if isIrrefutableHsPat pat then return noSyntaxExpr else tcSyntaxOp MCompOrigin fail_op (mkFunTy stringTy new_res_ty) @@ -540,15 +557,15 @@ tcMcStmt _ (ExprStmt rhs then_op guard_op _) res_ty thing_inside -- [ body | stmts, then f ] -> f :: forall a. m a -> m a -- [ body | stmts, then f by e ] -> f :: forall a. (a -> t) -> m a -> m a -- -tcMcStmt ctxt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_op) elt_ty thing_inside +tcMcStmt ctxt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_op) res_ty thing_inside = do { -- We don't know the types of binders yet, so we use this dummy and -- later unify this type with the `m_bndr_ty` ty_dummy <- newFlexiTyVarTy liftedTypeKind ; (stmts', (binders', usingExpr', maybeByExpr', return_op', bind_op', thing)) <- - tcStmts (TransformStmtCtxt ctxt) tcMcStmt stmts ty_dummy $ \elt_ty' -> do - { (_, (m_ty, _)) <- matchExpectedAppTy elt_ty' + tcStmtsAndThen (TransformStmtCtxt ctxt) tcMcStmt stmts ty_dummy $ \res_ty' -> do + { (_, (m_ty, _)) <- matchExpectedAppTy res_ty' ; (usingExpr', maybeByExpr') <- case maybeByExpr of Nothing -> do @@ -582,22 +599,22 @@ tcMcStmt ctxt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_ -- -> ( (a,b,c,..) -> m (a,b,c,..) ) -- -> m (a,b,c,..) -- - ; let bndr_ty = mkChunkified mkBoxedTupleTy $ map idType bndr_ids + ; let bndr_ty = mkBigCoreVarTupTy bndr_ids m_bndr_ty = m_ty `mkAppTy` bndr_ty ; return_op' <- tcSyntaxOp MCompOrigin return_op (bndr_ty `mkFunTy` m_bndr_ty) ; bind_op' <- tcSyntaxOp MCompOrigin bind_op $ - m_bndr_ty `mkFunTy` (bndr_ty `mkFunTy` elt_ty) - `mkFunTy` elt_ty + m_bndr_ty `mkFunTy` (bndr_ty `mkFunTy` res_ty) + `mkFunTy` res_ty -- Unify types of the inner comprehension and the binders type - ; _ <- unifyType elt_ty' m_bndr_ty + ; _ <- unifyType res_ty' m_bndr_ty -- Typecheck the `thing` with out old type (which is the type -- of the final result of our comprehension) - ; thing <- thing_inside elt_ty + ; thing <- thing_inside res_ty ; return (bndr_ids, usingExpr', maybeByExpr', return_op', bind_op', thing) } @@ -613,32 +630,27 @@ tcMcStmt ctxt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_ -- [ body | stmts, then group using f ] -- -> f :: forall a. m a -> m (m a) -- -tcMcStmt ctxt (GroupStmt stmts bindersMap by using return_op bind_op liftM_op) elt_ty thing_inside - = do { let (bndr_names, m_bndr_names) = unzip bindersMap - - ; (_,(m_ty,_)) <- matchExpectedAppTy elt_ty - ; let alphaMTy = m_ty `mkAppTy` alphaTy - alphaMMTy = m_ty `mkAppTy` alphaMTy - - -- We don't know the type of the bindings yet. It's not elt_ty! - ; bndr_ty_dummy <- newFlexiTyVarTy liftedTypeKind - - ; (stmts', (bndr_ids, by', using_ty, return_op', bind_op')) <- - tcStmts (TransformStmtCtxt ctxt) tcMcStmt stmts bndr_ty_dummy $ \elt_ty' -> do - { (by', using_ty) <- - case by of - Nothing -> -- check that using :: forall a. m a -> m (m a) - return (Nothing, mkForAllTy alphaTyVar $ - alphaMTy `mkFunTy` alphaMMTy) - - Just by_e -> -- check that using :: forall a. (a -> t) -> m a -> m (m a) - -- where by :: t - do { (by_e', t_ty) <- tcInferRhoNC by_e - ; return (Just by_e', mkForAllTy alphaTyVar $ - (alphaTy `mkFunTy` t_ty) - `mkFunTy` alphaMTy - `mkFunTy` alphaMMTy) } - +tcMcStmt ctxt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = bindersMap + , grpS_by = by, grpS_using = using, grpS_explicit = explicit + , grpS_ret = return_op, grpS_bind = bind_op + , grpS_fmap = fmap_op }) res_ty thing_inside + = do { let star_star_kind = liftedTypeKind `mkArrowKind` liftedTypeKind + ; m1_ty <- newFlexiTyVarTy star_star_kind + ; m2_ty <- newFlexiTyVarTy star_star_kind + ; n_ty <- newFlexiTyVarTy star_star_kind + ; tup_ty_var <- newFlexiTyVarTy liftedTypeKind + ; new_res_ty <- newFlexiTyVarTy liftedTypeKind + ; let (bndr_names, n_bndr_names) = unzip bindersMap + m1_tup_ty = m1_ty `mkAppTy` tup_ty_var + + -- 'stmts' returns a result of type (m1_ty tuple_ty), + -- typically something like [(Int,Bool,Int)] + -- We don't know what tuple_ty is yet, so we use a variable + ; (stmts', (bndr_ids, by_e_ty, return_op')) <- + tcStmtsAndThen (TransformStmtCtxt ctxt) tcMcStmt stmts m1_tup_ty $ \res_ty' -> do + { by_e_ty <- case by of + Nothing -> return Nothing + Just e -> do { e_ty <- tcInferRhoNC e; return (Just e_ty) } -- Find the Ids (and hence types) of all old binders ; bndr_ids <- tcLookupLocalIds bndr_names @@ -646,60 +658,71 @@ tcMcStmt ctxt (GroupStmt stmts bindersMap by using return_op bind_op liftM_op) e -- 'return' is only used for the binders, so we know its type. -- -- return :: (a,b,c,..) -> m (a,b,c,..) - -- - ; let bndr_ty = mkChunkified mkBoxedTupleTy $ map idType bndr_ids - m_bndr_ty = m_ty `mkAppTy` bndr_ty - ; return_op' <- tcSyntaxOp MCompOrigin return_op $ bndr_ty `mkFunTy` m_bndr_ty - - -- '>>=' is used to pass the grouped binders to the rest of the - -- comprehension. - -- - -- (>>=) :: m (m a, m b, m c, ..) - -- -> ( (m a, m b, m c, ..) -> new_elt_ty ) - -- -> elt_ty - -- - ; let bndr_m_ty = mkChunkified mkBoxedTupleTy $ map (mkAppTy m_ty . idType) bndr_ids - m_bndr_m_ty = m_ty `mkAppTy` bndr_m_ty - ; new_elt_ty <- newFlexiTyVarTy liftedTypeKind - ; bind_op' <- tcSyntaxOp MCompOrigin bind_op $ - m_bndr_m_ty `mkFunTy` (bndr_m_ty `mkFunTy` new_elt_ty) - `mkFunTy` elt_ty - - -- Finally make sure the type of the inner comprehension - -- represents the types of our binders - ; _ <- unifyType elt_ty' m_bndr_ty - - ; return (bndr_ids, by', using_ty, return_op', bind_op') } + ; return_op' <- tcSyntaxOp MCompOrigin return_op $ + (mkBigCoreVarTupTy bndr_ids) `mkFunTy` res_ty' + + ; return (bndr_ids, by_e_ty, return_op') } + + + + ; let tup_ty = mkBigCoreVarTupTy bndr_ids -- (a,b,c) + using_arg_ty = m1_ty `mkAppTy` tup_ty -- m1 (a,b,c) + n_tup_ty = n_ty `mkAppTy` tup_ty -- n (a,b,c) + using_res_ty = m2_ty `mkAppTy` n_tup_ty -- m2 (n (a,b,c)) + using_fun_ty = using_arg_ty `mkFunTy` using_arg_ty + + -- (>>=) :: m2 (n (a,b,c)) -> ( n (a,b,c) -> new_res_ty ) -> res_ty + -- using :: ((a,b,c)->t) -> m1 (a,b,c) -> m2 (n (a,b,c)) + + --------------- Typecheck the 'bind' function ------------- + ; bind_op' <- tcSyntaxOp MCompOrigin bind_op $ + using_res_ty `mkFunTy` (n_tup_ty `mkFunTy` new_res_ty) + `mkFunTy` res_ty + + --------------- Typecheck the 'using' function ------------- + ; let poly_fun_ty = (m1_ty `mkAppTy` alphaTy) `mkFunTy` + (m2_ty `mkAppTy` (n_ty `mkAppTy` alphaTy)) + using_poly_ty = case by_e_ty of + Nothing -> mkForAllTy alphaTyVar poly_fun_ty + -- using :: forall a. m1 a -> m2 (n a) + + Just (_,t_ty) -> mkForAllTy alphaTyVar $ + (alphaTy `mkFunTy` t_ty) `mkFunTy` poly_fun_ty + -- using :: forall a. (a->t) -> m1 a -> m2 (n a) + -- where by :: t + + ; using' <- tcPolyExpr using using_poly_ty + ; coi <- unifyType (applyTy using_poly_ty tup_ty) + (case by_e_ty of + Nothing -> using_fun_ty + Just (_,t_ty) -> (tup_ty `mkFunTy` t_ty) `mkFunTy` using_fun_ty) + ; let final_using = fmap (mkHsWrapCoI coi . HsWrap (WpTyApp tup_ty)) using' + + --------------- Typecheck the 'fmap' function ------------- + ; fmap_op' <- fmap unLoc . tcPolyExpr (noLoc fmap_op) $ + mkForAllTy alphaTyVar $ mkForAllTy betaTyVar $ + (alphaTy `mkFunTy` betaTy) + `mkFunTy` (n_ty `mkAppTy` alphaTy) + `mkFunTy` (n_ty `mkAppTy` betaTy) - ; let mk_m_bndr :: Name -> TcId -> TcId - mk_m_bndr m_bndr_name bndr_id = - mkLocalId m_bndr_name (m_ty `mkAppTy` idType bndr_id) + ; let mk_n_bndr :: Name -> TcId -> TcId + mk_n_bndr n_bndr_name bndr_id + = mkLocalId n_bndr_name (n_ty `mkAppTy` idType bndr_id) -- Ensure that every old binder of type `b` is linked up with its - -- new binder which should have type `m b` - m_bndr_ids = zipWith mk_m_bndr m_bndr_names bndr_ids - bindersMap' = bndr_ids `zip` m_bndr_ids - + -- new binder which should have type `n b` -- See Note [GroupStmt binder map] in HsExpr - - ; using' <- case using of - Left e -> do { e' <- tcPolyExpr e using_ty; return (Left e') } - Right e -> do { e' <- tcPolyExpr (noLoc e) using_ty; return (Right (unLoc e')) } - - -- Type check 'liftM' with 'forall a b. (a -> b) -> m_ty a -> m_ty b' - ; liftM_op' <- fmap unLoc . tcPolyExpr (noLoc liftM_op) $ - mkForAllTy alphaTyVar $ mkForAllTy betaTyVar $ - (alphaTy `mkFunTy` betaTy) - `mkFunTy` - (m_ty `mkAppTy` alphaTy) - `mkFunTy` - (m_ty `mkAppTy` betaTy) + n_bndr_ids = zipWith mk_n_bndr n_bndr_names bndr_ids + bindersMap' = bndr_ids `zip` n_bndr_ids -- Type check the thing in the environment with these new binders and -- return the result - ; thing <- tcExtendIdEnv m_bndr_ids (thing_inside elt_ty) + ; thing <- tcExtendIdEnv n_bndr_ids (thing_inside res_ty) - ; return (GroupStmt stmts' bindersMap' by' using' return_op' bind_op' liftM_op', thing) } + ; return (GroupStmt { grpS_stmts = stmts', grpS_bndrs = bindersMap' + , grpS_by = fmap fst by_e_ty, grpS_using = final_using + , grpS_ret = return_op', grpS_bind = bind_op' + , grpS_fmap = fmap_op', grpS_explicit = explicit }, thing) } -- Typecheck `ParStmt`. See `tcLcStmt` for more informations about typechecking -- of `ParStmt`s. @@ -712,8 +735,10 @@ tcMcStmt ctxt (GroupStmt stmts bindersMap by using return_op bind_op liftM_op) e -- -> (m st2 -> m st3 -> m (st2, st3)) -- recursive call -- -> m (st1, (st2, st3)) -- -tcMcStmt ctxt (ParStmt bndr_stmts_s mzip_op bind_op return_op) elt_ty thing_inside - = do { (_,(m_ty,_)) <- matchExpectedAppTy elt_ty +tcMcStmt ctxt (ParStmt bndr_stmts_s mzip_op bind_op return_op) res_ty thing_inside + = do { (_,(m_ty,_)) <- matchExpectedAppTy res_ty + -- ToDo: what if the coercion isn't the identity? + ; (pairs', thing) <- loop m_ty bndr_stmts_s ; let mzip_ty = mkForAllTys [alphaTyVar, betaTyVar] $ @@ -725,36 +750,37 @@ tcMcStmt ctxt (ParStmt bndr_stmts_s mzip_op bind_op return_op) elt_ty thing_insi ; mzip_op' <- unLoc `fmap` tcPolyExpr (noLoc mzip_op) mzip_ty -- Typecheck bind: - ; let tys = map (mkChunkified mkBoxedTupleTy . map idType . snd) pairs' + ; let tys = map (mkBigCoreVarTupTy . snd) pairs' tuple_ty = mk_tuple_ty tys ; bind_op' <- tcSyntaxOp MCompOrigin bind_op $ (m_ty `mkAppTy` tuple_ty) `mkFunTy` - (tuple_ty `mkFunTy` elt_ty) + (tuple_ty `mkFunTy` res_ty) `mkFunTy` - elt_ty + res_ty ; return_op' <- fmap unLoc . tcPolyExpr (noLoc return_op) $ mkForAllTy alphaTyVar $ alphaTy `mkFunTy` (m_ty `mkAppTy` alphaTy) + ; return (ParStmt pairs' mzip_op' bind_op' return_op', thing) } - where mk_tuple_ty tys = foldr (\tn tm -> mkBoxedTupleTy [tn, tm]) (last tys) (init tys) + where mk_tuple_ty tys = foldr1 (\tn tm -> mkBoxedTupleTy [tn, tm]) tys -- loop :: Type -- m_ty -- -> [([LStmt Name], [Name])] -- -> TcM ([([LStmt TcId], [TcId])], thing) - loop _ [] = do { thing <- thing_inside elt_ty + loop _ [] = do { thing <- thing_inside res_ty ; return ([], thing) } -- matching in the branches loop m_ty ((stmts, names) : pairs) = do { -- type dummy since we don't know all binder types yet ty_dummy <- newFlexiTyVarTy liftedTypeKind ; (stmts', (ids, pairs', thing)) - <- tcStmts ctxt tcMcStmt stmts ty_dummy $ \elt_ty' -> + <- tcStmtsAndThen ctxt tcMcStmt stmts ty_dummy $ \res_ty' -> do { ids <- tcLookupLocalIds names - ; _ <- unifyType elt_ty' (m_ty `mkAppTy` (mkChunkified mkBoxedTupleTy) (map idType ids)) + ; _ <- unifyType res_ty' (m_ty `mkAppTy` mkBigCoreVarTupTy ids) ; (pairs', thing) <- loop m_ty pairs ; return (ids, pairs', thing) } ; return ( (stmts', ids) : pairs', thing ) } @@ -762,27 +788,17 @@ tcMcStmt ctxt (ParStmt bndr_stmts_s mzip_op bind_op return_op) elt_ty thing_insi tcMcStmt _ stmt _ _ = pprPanic "tcMcStmt: unexpected Stmt" (ppr stmt) --- Typecheck 'body' with type 'a' instead of 'm a' like the rest of the --- statements, ignore the second type argument coming from the tcStmts loop -tcMcBody :: LHsExpr Name - -> SyntaxExpr Name - -> TcRhoType - -> TcM (LHsExpr TcId, SyntaxExpr TcId) -tcMcBody body return_op res_ty - = do { (_, (_, a_ty)) <- matchExpectedAppTy res_ty - ; body' <- tcMonoExpr body a_ty - ; return_op' <- tcSyntaxOp MCompOrigin return_op - (a_ty `mkFunTy` res_ty) - ; return (body', return_op') - } - - -------------------------------- -- Do-notation -- The main excitement here is dealing with rebindable syntax tcDoStmt :: TcStmtChecker +tcDoStmt _ (LastStmt body _) res_ty thing_inside + = do { body' <- tcMonoExprNC body res_ty + ; thing <- thing_inside (panic "tcDoStmt: thing_inside") + ; return (LastStmt body' noSyntaxExpr, thing) } + tcDoStmt ctxt (BindStmt pat rhs bind_op fail_op) res_ty thing_inside = do { -- Deal with rebindable syntax: -- (>>=) :: rhs_ty -> (pat_ty -> new_res_ty) -> res_ty @@ -837,7 +853,7 @@ tcDoStmt ctxt (RecStmt { recS_stmts = stmts, recS_later_ids = later_names ; tcExtendIdEnv tup_ids $ do { stmts_ty <- newFlexiTyVarTy liftedTypeKind ; (stmts', (ret_op', tup_rets)) - <- tcStmts ctxt tcDoStmt stmts stmts_ty $ \ inner_res_ty -> + <- tcStmtsAndThen 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 @@ -862,7 +878,7 @@ tcDoStmt ctxt (RecStmt { recS_stmts = stmts, recS_later_ids = later_names ; 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 }, thing) + , recS_rec_rets = tup_rets, recS_ret_ty = stmts_ty }, thing) }} tcDoStmt _ stmt _ _ @@ -888,6 +904,7 @@ the expected/inferred stuff is back to front (see Trac #3613). tcMDoStmt :: (LHsExpr Name -> TcM (LHsExpr TcId, TcType)) -- RHS inference -> TcStmtChecker +-- Used only by TcArrows... should be gotten rid of 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 $ @@ -903,9 +920,9 @@ tcMDoStmt tc_rhs ctxt (RecStmt { recS_stmts = stmts, recS_later_ids = laterNames , recS_rec_ids = recNames }) res_ty thing_inside = do { rec_tys <- newFlexiTyVarTys (length recNames) liftedTypeKind ; let rec_ids = zipWith mkLocalId recNames rec_tys - ; tcExtendIdEnv rec_ids $ do + ; tcExtendIdEnv rec_ids $ do { (stmts', (later_ids, rec_rets)) - <- tcStmts ctxt (tcMDoStmt tc_rhs) stmts res_ty $ \ _res_ty' -> + <- tcStmtsAndThen 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 @@ -917,12 +934,13 @@ tcMDoStmt tc_rhs ctxt (RecStmt { recS_stmts = stmts, recS_later_ids = laterNames -- some of them with polymorphic things with the same Name -- (see note [RecStmt] in HsExpr) - ; return (RecStmt stmts' later_ids rec_ids noSyntaxExpr noSyntaxExpr noSyntaxExpr rec_rets, thing) + ; return (emptyRecStmt { recS_stmts = stmts', recS_later_ids = later_ids + , recS_rec_ids = rec_ids, recS_rec_rets = rec_rets + , recS_ret_ty = res_ty }, thing) }} tcMDoStmt _ _ stmt _ _ = pprPanic "tcMDoStmt: unexpected Stmt" (ppr stmt) - \end{code}