\begin{code}
module TcMatches ( tcMatchesFun, tcGRHSsPat, tcMatchesCase, tcMatchLambda,
TcMatchCtxt(..),
- tcStmts, tcDoStmts, tcBody,
+ tcStmts, tcStmtsAndThen, tcDoStmts, tcBody,
tcDoStmt, tcMDoStmt, tcGuardStmt
) where
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
\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
-> 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) }
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
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) }
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') <-
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]]
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]
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)
-- [ 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
-- -> ( (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) }
-- [ 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
-- '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.
-- -> (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] $
; 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 ) }
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
; 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
; 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 _ _
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 $
, 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
-- 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}
projects / ghc-hetmet.git / blobdiff