tcDoStmt, tcMDoStmt, tcGuardStmt
) where
-import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRhoNC, tcCheckId,
+import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRhoNC, tcInferRho, tcCheckId,
tcMonoExpr, tcMonoExprNC, tcPolyExpr )
import HsSyn
; return (ids, pairs', thing) }
; return ( (stmts', ids) : pairs', thing ) }
-tcLcStmt m_tc ctxt (TransformStmt stmts binders usingExpr maybeByExpr _ _) elt_ty thing_inside = do
- (stmts', (binders', usingExpr', maybeByExpr', thing)) <-
- tcStmtsAndThen (TransformStmtCtxt ctxt) (tcLcStmt m_tc) stmts elt_ty $ \elt_ty' -> do
- let alphaListTy = mkTyConApp m_tc [alphaTy]
-
- (usingExpr', maybeByExpr') <-
- case maybeByExpr of
- Nothing -> do
- -- We must validate that usingExpr :: forall a. [a] -> [a]
- let using_ty = mkForAllTy alphaTyVar (alphaListTy `mkFunTy` alphaListTy)
- usingExpr' <- tcPolyExpr usingExpr using_ty
- return (usingExpr', Nothing)
- Just byExpr -> do
- -- We must infer a type such that e :: t and then check that
- -- usingExpr :: forall a. (a -> t) -> [a] -> [a]
- (byExpr', tTy) <- tcInferRhoNC byExpr
- let using_ty = mkForAllTy alphaTyVar $
- (alphaTy `mkFunTy` tTy)
- `mkFunTy` alphaListTy `mkFunTy` alphaListTy
- usingExpr' <- tcPolyExpr usingExpr using_ty
- return (usingExpr', Just byExpr')
-
- binders' <- tcLookupLocalIds binders
- thing <- thing_inside elt_ty'
-
- return (binders', usingExpr', maybeByExpr', thing)
-
- return (TransformStmt stmts' binders' usingExpr' maybeByExpr' noSyntaxExpr noSyntaxExpr, thing)
-
-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')) <-
- 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]]
- return (Nothing, mkForAllTy alphaTyVar $
- alphaListTy `mkFunTy` alphaListListTy)
-
- Just by_e -> -- check that using :: forall a. (a -> t) -> [a] -> [[a]]
- -- where by :: t
- do { (by_e', t_ty) <- tcInferRhoNC by_e
- ; return (Just by_e', mkForAllTy alphaTyVar $
- (alphaTy `mkFunTy` t_ty)
- `mkFunTy` alphaListTy
- `mkFunTy` alphaListListTy) }
- -- Find the Ids (and hence types) of all old binders
- bndr_ids <- tcLookupLocalIds bndr_names
-
- return (bndr_ids, by', using_ty, elt_ty')
-
- -- Ensure that every old binder of type b is linked up with
- -- its new binder which should have type [b]
- ; let list_bndr_ids = zipWith mk_list_bndr list_bndr_names bndr_ids
- bindersMap' = bndr_ids `zip` list_bndr_ids
+tcLcStmt m_tc ctxt (TransStmt { trS_form = form, trS_stmts = stmts
+ , trS_bndrs = bindersMap
+ , trS_by = by, trS_using = using }) elt_ty thing_inside
+ = do { let (bndr_names, n_bndr_names) = unzip bindersMap
+ unused_ty = pprPanic "tcLcStmt: inner ty" (ppr bindersMap)
+ -- The inner 'stmts' lack a LastStmt, so the element type
+ -- passed in to tcStmtsAndThen is never looked at
+ ; (stmts', (bndr_ids, by'))
+ <- tcStmtsAndThen (TransformStmtCtxt ctxt) (tcLcStmt m_tc) stmts unused_ty $ \_ -> do
+ { by' <- case by of
+ Nothing -> return Nothing
+ Just e -> do { e_ty <- tcInferRho e; return (Just e_ty) }
+ ; bndr_ids <- tcLookupLocalIds bndr_names
+ ; return (bndr_ids, by') }
+
+ ; let m_app ty = mkTyConApp m_tc [ty]
+
+ --------------- Typecheck the 'using' function -------------
+ -- using :: ((a,b,c)->t) -> m (a,b,c) -> m (a,b,c)m (ThenForm)
+ -- :: ((a,b,c)->t) -> m (a,b,c) -> m (m (a,b,c))) (GroupForm)
+
+ -- n_app :: Type -> Type -- Wraps a 'ty' into '[ty]' for GroupForm
+ ; let n_app = case form of
+ ThenForm -> (\ty -> ty)
+ _ -> m_app
+
+ by_arrow :: Type -> Type -- Wraps 'ty' to '(a->t) -> ty' if the By is present
+ by_arrow = case by' of
+ Nothing -> \ty -> ty
+ Just (_,e_ty) -> \ty -> e_ty `mkFunTy` ty
+
+ tup_ty = mkBigCoreVarTupTy bndr_ids
+ poly_arg_ty = m_app alphaTy
+ poly_res_ty = m_app (n_app alphaTy)
+ using_poly_ty = mkForAllTy alphaTyVar $ by_arrow $
+ poly_arg_ty `mkFunTy` poly_res_ty
+
+ ; using' <- tcPolyExpr using using_poly_ty
+ ; let final_using = fmap (HsWrap (WpTyApp tup_ty)) using'
+
+ -- '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
+ ; let mk_n_bndr :: Name -> TcId -> TcId
+ mk_n_bndr n_bndr_name bndr_id = mkLocalId n_bndr_name (n_app (idType bndr_id))
+
+ -- Ensure that every old binder of type `b` is linked up with its
+ -- new binder which should have type `n b`
-- See Note [GroupStmt binder map] in HsExpr
-
- ; 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 (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]
-
- mk_list_bndr :: Name -> TcId -> TcId
- mk_list_bndr list_bndr_name bndr_id
- = mkLocalId list_bndr_name (mkTyConApp m_tc [idType bndr_id])
+ 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 n_bndr_ids (thing_inside elt_ty)
+
+ ; return (emptyTransStmt { trS_stmts = stmts', trS_bndrs = bindersMap'
+ , trS_by = fmap fst by', trS_using = final_using
+ , trS_form = form }, thing) }
tcLcStmt _ _ stmt _ _
= pprPanic "tcLcStmt: unexpected Stmt" (ppr stmt)
; thing <- thing_inside new_res_ty
; return (ExprStmt rhs' then_op' guard_op' rhs_ty, thing) }
--- Transform statements.
---
--- [ 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) 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 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', (binders', usingExpr', maybeByExpr', return_op', bind_op', thing)) <-
- tcStmtsAndThen (TransformStmtCtxt ctxt) tcMcStmt stmts m1_tup_ty $ \res_ty' -> do
- { (usingExpr', maybeByExpr') <-
- case maybeByExpr of
- Nothing -> do
- -- We must validate that usingExpr :: forall a. m a -> m a
- let using_ty = mkForAllTy alphaTyVar $
- (m_ty `mkAppTy` alphaTy)
- `mkFunTy`
- (m_ty `mkAppTy` alphaTy)
- usingExpr' <- tcPolyExpr usingExpr using_ty
- return (usingExpr', Nothing)
- Just byExpr -> do
- -- We must infer a type such that e :: t and then check that
- -- usingExpr :: forall a. (a -> t) -> m a -> m a
- (byExpr', tTy) <- tcInferRhoNC byExpr
- let using_ty = mkForAllTy alphaTyVar $
- (alphaTy `mkFunTy` tTy)
- `mkFunTy`
- (m_ty `mkAppTy` alphaTy)
- `mkFunTy`
- (m_ty `mkAppTy` alphaTy)
- usingExpr' <- tcPolyExpr usingExpr using_ty
- return (usingExpr', Just byExpr')
-
- ; bndr_ids <- tcLookupLocalIds binders
-
- -- `return` and `>>=` are used to pass around/modify our
- -- binders, so we know their types:
- --
- -- return :: (a,b,c,..) -> m (a,b,c,..)
- -- (>>=) :: m (a,b,c,..)
- -- -> ( (a,b,c,..) -> m (a,b,c,..) )
- -- -> m (a,b,c,..)
- --
- ; 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` res_ty)
- `mkFunTy` res_ty
-
- -- Unify types of the inner comprehension and the binders type
- ; _ <- 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 res_ty
-
- ; return (bndr_ids, usingExpr', maybeByExpr', return_op', bind_op', thing) }
-
- ; return (TransformStmt stmts' binders' usingExpr' maybeByExpr' return_op' bind_op', thing) }
-
-- Grouping statements
--
-- [ body | stmts, then group by e ]
-- f :: forall a. (a -> t) -> m a -> m (m a)
-- [ body | stmts, then group using f ]
-- -> f :: forall a. m a -> m (m a)
+
+-- We type [ body | (stmts, group by e using f), ... ]
+-- f <optional by> [ (a,b,c) | stmts ] >>= \(a,b,c) -> ...body....
--
-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
+-- We type the functions as follows:
+-- f <optional by> :: m1 (a,b,c) -> m2 (a,b,c) (ThenForm)
+-- :: m1 (a,b,c) -> m2 (n (a,b,c)) (GroupForm)
+-- (>>=) :: m2 (a,b,c) -> ((a,b,c) -> res) -> res (ThenForm)
+-- :: m2 (n (a,b,c)) -> (n (a,b,c) -> res) -> res (GroupForm)
+--
+tcMcStmt ctxt (TransStmt { trS_stmts = stmts, trS_bndrs = bindersMap
+ , trS_by = by, trS_using = using, trS_form = form
+ , trS_ret = return_op, trS_bind = bind_op
+ , trS_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
+ ; m1_ty <- newFlexiTyVarTy star_star_kind
+ ; m2_ty <- newFlexiTyVarTy star_star_kind
+ ; tup_ty <- newFlexiTyVarTy liftedTypeKind
+ ; by_e_ty <- newFlexiTyVarTy liftedTypeKind -- The type of the 'by' expression (if any)
+
+ --------------- Typecheck the 'using' function -------------
+ -- using :: ((a,b,c)->t) -> m1 (a,b,c) -> m2 (n (a,b,c))
+
+ -- n_app :: Type -> Type -- Wraps a 'ty' into '(n ty)' for GroupForm
+ ; n_app <- case form of
+ ThenForm -> return (\ty -> ty)
+ _ -> do { n_ty <- newFlexiTyVarTy star_star_kind
+ ; return (n_ty `mkAppTy`) }
+ ; let by_arrow :: Type -> Type -- Wraps 'ty' to '(a->t) -> ty' if the By is present
+ by_arrow = case by of
+ Nothing -> \ty -> ty
+ Just {} -> \ty -> by_e_ty `mkFunTy` ty
+
+ poly_arg_ty = m1_ty `mkAppTy` alphaTy
+ using_arg_ty = m1_ty `mkAppTy` tup_ty
+ poly_res_ty = m2_ty `mkAppTy` n_app alphaTy
+ using_res_ty = m2_ty `mkAppTy` n_app tup_ty
+ using_poly_ty = mkForAllTy alphaTyVar $ by_arrow $
+ poly_arg_ty `mkFunTy` poly_res_ty
+
+ ; using' <- tcPolyExpr using using_poly_ty
+ ; let final_using = fmap (HsWrap (WpTyApp tup_ty)) using'
+
+ --------------- Typecheck the 'bind' function -------------
+ -- (>>=) :: m2 (n (a,b,c)) -> ( n (a,b,c) -> new_res_ty ) -> res_ty
; new_res_ty <- newFlexiTyVarTy liftedTypeKind
- ; let (bndr_names, n_bndr_names) = unzip bindersMap
- m1_tup_ty = m1_ty `mkAppTy` tup_ty_var
-
+ ; let n_tup_ty = n_app tup_ty -- n (a,b,c)
+ ; bind_op' <- tcSyntaxOp MCompOrigin bind_op $
+ using_res_ty `mkFunTy` (n_tup_ty `mkFunTy` new_res_ty)
+ `mkFunTy` res_ty
+
+ --------------- Typecheck the 'fmap' function -------------
+ ; fmap_op' <- case form of
+ ThenForm -> return noSyntaxExpr
+ _ -> fmap unLoc . tcPolyExpr (noLoc fmap_op) $
+ mkForAllTy alphaTyVar $ mkForAllTy betaTyVar $
+ (alphaTy `mkFunTy` betaTy)
+ `mkFunTy` (n_app alphaTy)
+ `mkFunTy` (n_app betaTy)
+
-- '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) }
+ ; let (bndr_names, n_bndr_names) = unzip bindersMap
+ ; (stmts', (bndr_ids, by', return_op')) <-
+ tcStmtsAndThen (TransformStmtCtxt ctxt) tcMcStmt stmts using_arg_ty $ \res_ty' -> do
+ { by' <- case by of
+ Nothing -> return Nothing
+ Just e -> do { e' <- tcMonoExpr e by_e_ty; return (Just e') }
-- 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,..)
; 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)
+ ; return (bndr_ids, by', return_op') }
; 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)
+ mk_n_bndr n_bndr_name bndr_id = mkLocalId n_bndr_name (n_app (idType bndr_id))
-- Ensure that every old binder of type `b` is linked up with its
-- new binder which should have type `n b`
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
+ -- Type check the thing in the environment with
+ -- these new binders and return the result
; thing <- tcExtendIdEnv n_bndr_ids (thing_inside res_ty)
- ; 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) }
+ ; return (TransStmt { trS_stmts = stmts', trS_bndrs = bindersMap'
+ , trS_by = by', trS_using = final_using
+ , trS_ret = return_op', trS_bind = bind_op'
+ , trS_fmap = fmap_op', trS_form = form }, thing) }
-- Typecheck `ParStmt`. See `tcLcStmt` for more informations about typechecking
-- of `ParStmt`s.
projects / ghc-hetmet.git / blobdiff