X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FdeSugar%2FDsListComp.lhs;h=aabd6b0d0d0776ed06632f65f321f55182f9e9b1;hp=63cae938d083cf5b061ccd87a272e3fc69999801;hb=c0687066474aa4ce4912f31a5c09c1bcd673fb06;hpb=d76d9636aeebe933d160157331b8c8c0087e73ac diff --git a/compiler/deSugar/DsListComp.lhs b/compiler/deSugar/DsListComp.lhs index 63cae93..aabd6b0 100644 --- a/compiler/deSugar/DsListComp.lhs +++ b/compiler/deSugar/DsListComp.lhs @@ -91,45 +91,19 @@ dsInnerListComp (stmts, bndrs) where bndrs_tuple_type = mkBigCoreVarTupTy bndrs --- This function factors out commonality between the desugaring strategies for TransformStmt. --- Given such a statement it gives you back an expression representing how to compute the transformed --- list and the tuple that you need to bind from that list in order to proceed with your desugaring -dsTransformStmt :: Stmt Id -> DsM (CoreExpr, LPat Id) -dsTransformStmt (TransformStmt stmts binders usingExpr maybeByExpr _ _) - = do { (expr, binders_tuple_type) <- dsInnerListComp (stmts, binders) - ; usingExpr' <- dsLExpr usingExpr - - ; using_args <- - case maybeByExpr of - Nothing -> return [expr] - Just byExpr -> do - byExpr' <- dsLExpr byExpr - - us <- newUniqueSupply - [tuple_binder] <- newSysLocalsDs [binders_tuple_type] - let byExprWrapper = mkTupleCase us binders byExpr' tuple_binder (Var tuple_binder) - - return [Lam tuple_binder byExprWrapper, expr] - - ; let inner_list_expr = mkApps usingExpr' ((Type binders_tuple_type) : using_args) - pat = mkBigLHsVarPatTup binders - ; return (inner_list_expr, pat) } - -- This function factors out commonality between the desugaring strategies for GroupStmt. -- Given such a statement it gives you back an expression representing how to compute the transformed -- list and the tuple that you need to bind from that list in order to proceed with your desugaring -dsGroupStmt :: Stmt Id -> DsM (CoreExpr, LPat Id) -dsGroupStmt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = binderMap - , grpS_by = by, grpS_using = using }) = do - let (fromBinders, toBinders) = unzip binderMap - - fromBindersTypes = map idType fromBinders - toBindersTypes = map idType toBinders - - toBindersTupleType = mkBigCoreTupTy toBindersTypes +dsTransStmt :: Stmt Id -> DsM (CoreExpr, LPat Id) +dsTransStmt (TransStmt { trS_form = form, trS_stmts = stmts, trS_bndrs = binderMap + , trS_by = by, trS_using = using }) = do + let (from_bndrs, to_bndrs) = unzip binderMap + from_bndrs_tys = map idType from_bndrs + to_bndrs_tys = map idType to_bndrs + to_bndrs_tup_ty = mkBigCoreTupTy to_bndrs_tys -- Desugar an inner comprehension which outputs a list of tuples of the "from" binders - (expr, from_tup_ty) <- dsInnerListComp (stmts, fromBinders) + (expr, from_tup_ty) <- dsInnerListComp (stmts, from_bndrs) -- Work out what arguments should be supplied to that expression: i.e. is an extraction -- function required? If so, create that desugared function and add to arguments @@ -137,31 +111,34 @@ dsGroupStmt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = binderMap usingArgs <- case by of Nothing -> return [expr] Just by_e -> do { by_e' <- dsLExpr by_e - ; us <- newUniqueSupply - ; [from_tup_id] <- newSysLocalsDs [from_tup_ty] - ; let by_wrap = mkTupleCase us fromBinders by_e' - from_tup_id (Var from_tup_id) - ; return [Lam from_tup_id by_wrap, expr] } + ; lam <- matchTuple from_bndrs by_e' + ; return [lam, expr] } -- Create an unzip function for the appropriate arity and element types and find "map" - (unzip_fn, unzip_rhs) <- mkUnzipBind fromBindersTypes + unzip_stuff <- mkUnzipBind form from_bndrs_tys map_id <- dsLookupGlobalId mapName -- Generate the expressions to build the grouped list let -- First we apply the grouping function to the inner list - inner_list_expr = mkApps usingExpr' ((Type from_tup_ty) : usingArgs) + inner_list_expr = mkApps usingExpr' usingArgs -- Then we map our "unzip" across it to turn the lists of tuples into tuples of lists -- We make sure we instantiate the type variable "a" to be a list of "from" tuples and -- the "b" to be a tuple of "to" lists! - unzipped_inner_list_expr = mkApps (Var map_id) - [Type (mkListTy from_tup_ty), Type toBindersTupleType, Var unzip_fn, inner_list_expr] -- Then finally we bind the unzip function around that expression - bound_unzipped_inner_list_expr = Let (Rec [(unzip_fn, unzip_rhs)]) unzipped_inner_list_expr - - -- Build a pattern that ensures the consumer binds into the NEW binders, which hold lists rather than single values - let pat = mkBigLHsVarPatTup toBinders + bound_unzipped_inner_list_expr + = case unzip_stuff of + Nothing -> inner_list_expr + Just (unzip_fn, unzip_rhs) -> Let (Rec [(unzip_fn, unzip_rhs)]) $ + mkApps (Var map_id) $ + [ Type (mkListTy from_tup_ty) + , Type to_bndrs_tup_ty + , Var unzip_fn + , inner_list_expr] + + -- Build a pattern that ensures the consumer binds into the NEW binders, + -- which hold lists rather than single values + let pat = mkBigLHsVarPatTup to_bndrs return (bound_unzipped_inner_list_expr, pat) - \end{code} %************************************************************************ @@ -251,12 +228,8 @@ deListComp (LetStmt binds : quals) list = do core_rest <- deListComp quals list dsLocalBinds binds core_rest -deListComp (stmt@(TransformStmt {}) : quals) list = do - (inner_list_expr, pat) <- dsTransformStmt stmt - deBindComp pat inner_list_expr quals list - -deListComp (stmt@(GroupStmt {}) : quals) list = do - (inner_list_expr, pat) <- dsGroupStmt stmt +deListComp (stmt@(TransStmt {}) : quals) list = do + (inner_list_expr, pat) <- dsTransStmt stmt deBindComp pat inner_list_expr quals list deListComp (BindStmt pat list1 _ _ : quals) core_list2 = do -- rule A' above @@ -264,16 +237,14 @@ deListComp (BindStmt pat list1 _ _ : quals) core_list2 = do -- rule A' above deBindComp pat core_list1 quals core_list2 deListComp (ParStmt stmtss_w_bndrs _ _ _ : quals) list - = do - exps_and_qual_tys <- mapM dsInnerListComp stmtss_w_bndrs - let (exps, qual_tys) = unzip exps_and_qual_tys + = do { exps_and_qual_tys <- mapM dsInnerListComp stmtss_w_bndrs + ; let (exps, qual_tys) = unzip exps_and_qual_tys - (zip_fn, zip_rhs) <- mkZipBind qual_tys + ; (zip_fn, zip_rhs) <- mkZipBind qual_tys -- Deal with [e | pat <- zip l1 .. ln] in example above - deBindComp pat (Let (Rec [(zip_fn, zip_rhs)]) (mkApps (Var zip_fn) exps)) - quals list - + ; deBindComp pat (Let (Rec [(zip_fn, zip_rhs)]) (mkApps (Var zip_fn) exps)) + quals list } where bndrs_s = map snd stmtss_w_bndrs @@ -361,13 +332,8 @@ dfListComp c_id n_id (LetStmt binds : quals) = do core_rest <- dfListComp c_id n_id quals dsLocalBinds binds core_rest -dfListComp c_id n_id (stmt@(TransformStmt {}) : quals) = do - (inner_list_expr, pat) <- dsTransformStmt stmt - -- Anyway, we bind the newly transformed list via the generic binding function - dfBindComp c_id n_id (pat, inner_list_expr) quals - -dfListComp c_id n_id (stmt@(GroupStmt {}) : quals) = do - (inner_list_expr, pat) <- dsGroupStmt stmt +dfListComp c_id n_id (stmt@(TransStmt {}) : quals) = do + (inner_list_expr, pat) <- dsTransStmt stmt -- Anyway, we bind the newly grouped list via the generic binding function dfBindComp c_id n_id (pat, inner_list_expr) quals @@ -445,7 +411,7 @@ mkZipBind elt_tys = do -- Increasing order of tag -mkUnzipBind :: [Type] -> DsM (Id, CoreExpr) +mkUnzipBind :: TransForm -> [Type] -> DsM (Maybe (Id, CoreExpr)) -- mkUnzipBind [t1, t2] -- = (unzip, \ys :: [(t1, t2)] -> foldr (\ax :: (t1, t2) axs :: ([t1], [t2]) -- -> case ax of @@ -455,28 +421,29 @@ mkUnzipBind :: [Type] -> DsM (Id, CoreExpr) -- ys) -- -- We use foldr here in all cases, even if rules are turned off, because we may as well! -mkUnzipBind elt_tys = do - ax <- newSysLocalDs elt_tuple_ty - axs <- newSysLocalDs elt_list_tuple_ty - ys <- newSysLocalDs elt_tuple_list_ty - xs <- mapM newSysLocalDs elt_tys - xss <- mapM newSysLocalDs elt_list_tys +mkUnzipBind ThenForm _ + = return Nothing -- No unzipping for ThenForm +mkUnzipBind _ elt_tys + = do { ax <- newSysLocalDs elt_tuple_ty + ; axs <- newSysLocalDs elt_list_tuple_ty + ; ys <- newSysLocalDs elt_tuple_list_ty + ; xs <- mapM newSysLocalDs elt_tys + ; xss <- mapM newSysLocalDs elt_list_tys - unzip_fn <- newSysLocalDs unzip_fn_ty - - [us1, us2] <- sequence [newUniqueSupply, newUniqueSupply] - - let nil_tuple = mkBigCoreTup (map mkNilExpr elt_tys) - - concat_expressions = map mkConcatExpression (zip3 elt_tys (map Var xs) (map Var xss)) - tupled_concat_expression = mkBigCoreTup concat_expressions - - folder_body_inner_case = mkTupleCase us1 xss tupled_concat_expression axs (Var axs) - folder_body_outer_case = mkTupleCase us2 xs folder_body_inner_case ax (Var ax) - folder_body = mkLams [ax, axs] folder_body_outer_case - - unzip_body <- mkFoldrExpr elt_tuple_ty elt_list_tuple_ty folder_body nil_tuple (Var ys) - return (unzip_fn, mkLams [ys] unzip_body) + ; unzip_fn <- newSysLocalDs unzip_fn_ty + + ; [us1, us2] <- sequence [newUniqueSupply, newUniqueSupply] + + ; let nil_tuple = mkBigCoreTup (map mkNilExpr elt_tys) + concat_expressions = map mkConcatExpression (zip3 elt_tys (map Var xs) (map Var xss)) + tupled_concat_expression = mkBigCoreTup concat_expressions + + folder_body_inner_case = mkTupleCase us1 xss tupled_concat_expression axs (Var axs) + folder_body_outer_case = mkTupleCase us2 xs folder_body_inner_case ax (Var ax) + folder_body = mkLams [ax, axs] folder_body_outer_case + + ; unzip_body <- mkFoldrExpr elt_tuple_ty elt_list_tuple_ty folder_body nil_tuple (Var ys) + ; return (Just (unzip_fn, mkLams [ys] unzip_body)) } where elt_tuple_ty = mkBigCoreTupTy elt_tys elt_tuple_list_ty = mkListTy elt_tuple_ty @@ -730,30 +697,6 @@ dsMcStmt (ExprStmt exp then_exp guard_exp _) stmts ; return $ mkApps then_exp' [ mkApps guard_exp' [exp'] , rest ] } --- Transform statements desugar like this: --- --- [ .. | qs, then f by e ] -> f (\q_v -> e) [| qs |] --- --- where [| qs |] is the desugared inner monad comprehenion generated by the --- statements `qs`. -dsMcStmt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_op) stmts_rest - = do { expr <- dsInnerMonadComp stmts binders return_op - ; let binders_tup_type = mkBigCoreTupTy $ map idType binders - ; usingExpr' <- dsLExpr usingExpr - ; using_args <- case maybeByExpr of - Nothing -> return [expr] - Just byExpr -> do - byExpr' <- dsLExpr byExpr - us <- newUniqueSupply - tup_binder <- newSysLocalDs binders_tup_type - let byExprWrapper = mkTupleCase us binders byExpr' tup_binder (Var tup_binder) - return [Lam tup_binder byExprWrapper, expr] - - ; let pat = mkBigLHsVarPatTup binders - rhs = mkApps usingExpr' ((Type binders_tup_type) : using_args) - - ; dsMcBindStmt pat rhs bind_op noSyntaxExpr stmts_rest } - -- Group statements desugar like this: -- -- [| (q, then group by e using f); rest |] @@ -768,10 +711,10 @@ dsMcStmt (TransformStmt stmts binders usingExpr maybeByExpr return_op bind_op) s -- n_tup :: n qt -- unzip :: n qt -> (n t1, ..., n tk) (needs Functor n) -dsMcStmt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = bndrs - , grpS_by = by, grpS_using = using - , grpS_ret = return_op, grpS_bind = bind_op - , grpS_fmap = fmap_op }) stmts_rest +dsMcStmt (TransStmt { trS_stmts = stmts, trS_bndrs = bndrs + , trS_by = by, trS_using = using + , trS_ret = return_op, trS_bind = bind_op + , trS_fmap = fmap_op, trS_form = form }) stmts_rest = do { let (from_bndrs, to_bndrs) = unzip bndrs from_bndr_tys = map idType from_bndrs -- Types ty @@ -790,16 +733,15 @@ dsMcStmt (GroupStmt { grpS_stmts = stmts, grpS_bndrs = bndrs -- Generate the expressions to build the grouped list -- Build a pattern that ensures the consumer binds into the NEW binders, -- which hold monads rather than single values - ; fmap_op' <- dsExpr fmap_op ; bind_op' <- dsExpr bind_op - ; let bind_ty = exprType bind_op' -- m2 (n (a,b,c)) -> (n (a,b,c) -> r1) -> r2 + ; let bind_ty = exprType bind_op' -- m2 (n (a,b,c)) -> (n (a,b,c) -> r1) -> r2 n_tup_ty = funArgTy $ funArgTy $ funResultTy bind_ty -- n (a,b,c) tup_n_ty = mkBigCoreVarTupTy to_bndrs ; body <- dsMcStmts stmts_rest ; n_tup_var <- newSysLocalDs n_tup_ty ; tup_n_var <- newSysLocalDs tup_n_ty - ; tup_n_expr <- mkMcUnzipM fmap_op' n_tup_var from_bndr_tys + ; tup_n_expr <- mkMcUnzipM form fmap_op n_tup_var from_bndr_tys ; us <- newUniqueSupply ; let rhs' = mkApps usingExpr' usingArgs body' = mkTupleCase us to_bndrs body tup_n_var tup_n_expr @@ -908,17 +850,22 @@ dsInnerMonadComp stmts bndrs ret_op -- = ( fmap (selN1 :: (t1, t2) -> t1) ys -- , fmap (selN2 :: (t1, t2) -> t2) ys ) -mkMcUnzipM :: CoreExpr -- fmap +mkMcUnzipM :: TransForm + -> SyntaxExpr TcId -- fmap -> Id -- Of type n (a,b,c) -> [Type] -- [a,b,c] -> DsM CoreExpr -- Of type (n a, n b, n c) -mkMcUnzipM fmap_op ys elt_tys - = do { xs <- mapM newSysLocalDs elt_tys - ; tup_xs <- newSysLocalDs (mkBigCoreTupTy elt_tys) - - ; let arg_ty = idType ys - mk_elt i = mkApps fmap_op -- fmap :: forall a b. (a -> b) -> n a -> n b - [ Type arg_ty, Type (elt_tys !! i) +mkMcUnzipM ThenForm _ ys _ + = return (Var ys) -- No unzipping to do + +mkMcUnzipM _ fmap_op ys elt_tys + = do { fmap_op' <- dsExpr fmap_op + ; xs <- mapM newSysLocalDs elt_tys + ; let tup_ty = mkBigCoreTupTy elt_tys + ; tup_xs <- newSysLocalDs tup_ty + + ; let mk_elt i = mkApps fmap_op' -- fmap :: forall a b. (a -> b) -> n a -> n b + [ Type tup_ty, Type (elt_tys !! i) , mk_sel i, Var ys] mk_sel n = Lam tup_xs $