X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcMatches.lhs;fp=compiler%2Ftypecheck%2FTcMatches.lhs;h=579e5d486ecd3049611b6c65221278f30f283a97;hp=87449b6d5c703750e3f1a43ccd0c55327a9513d6;hb=e01036f89a0d3949ea642dd42b29bc8e31658f0f;hpb=f6d254cccd3dc25fff9ff50c2e1bea52b10345e4 diff --git a/compiler/typecheck/TcMatches.lhs b/compiler/typecheck/TcMatches.lhs index 87449b6..579e5d4 100644 --- a/compiler/typecheck/TcMatches.lhs +++ b/compiler/typecheck/TcMatches.lhs @@ -12,7 +12,7 @@ module TcMatches ( tcMatchesFun, tcGRHSsPat, tcMatchesCase, tcMatchLambda, tcDoStmt, tcMDoStmt, tcGuardStmt ) where -import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRhoNC, tcCheckId, +import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRhoNC, tcInferRho, tcCheckId, tcMonoExpr, tcMonoExprNC, tcPolyExpr ) import HsSyn @@ -413,81 +413,65 @@ tcLcStmt m_tc ctxt (ParStmt bndr_stmts_s _ _ _) elt_ty thing_inside ; 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) @@ -552,79 +536,6 @@ tcMcStmt _ (ExprStmt rhs then_op guard_op _) res_ty thing_inside ; 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 ] @@ -634,85 +545,88 @@ tcMcStmt ctxt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_ -- 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 [ (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 :: 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` @@ -720,14 +634,14 @@ tcMcStmt ctxt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = bindersMap 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.