diff options
Diffstat (limited to 'lib/stdlib/src/maps.erl')
-rw-r--r-- | lib/stdlib/src/maps.erl | 128 |
1 files changed, 99 insertions, 29 deletions
diff --git a/lib/stdlib/src/maps.erl b/lib/stdlib/src/maps.erl index 5dafdb282a..60463feec2 100644 --- a/lib/stdlib/src/maps.erl +++ b/lib/stdlib/src/maps.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2013-2016. All Rights Reserved. +%% Copyright Ericsson AB 2013-2018. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -23,7 +23,8 @@ -export([get/3, filter/2,fold/3, map/2, size/1, update_with/3, update_with/4, - without/2, with/2]). + without/2, with/2, + iterator/1, next/1]). %% BIFs -export([get/2, find/2, from_list/1, @@ -31,6 +32,15 @@ new/0, put/3, remove/2, take/2, to_list/1, update/3, values/1]). +-opaque iterator() :: {term(), term(), iterator()} + | none | nonempty_improper_list(integer(),map()). + +-export_type([iterator/0]). + +-dialyzer({no_improper_lists, iterator/1}). + +-define(IS_ITERATOR(I), is_tuple(I) andalso tuple_size(I) == 3; I == none; is_integer(hd(I)) andalso is_map(tl(I))). + %% Shadowed by erl_bif_types: maps:get/2 -spec get(Key,Map) -> Value when Key :: term(), @@ -39,7 +49,6 @@ get(_,_) -> erlang:nif_error(undef). - -spec find(Key,Map) -> {ok, Value} | error when Key :: term(), Map :: map(), @@ -114,14 +123,20 @@ remove(_,_) -> erlang:nif_error(undef). take(_,_) -> erlang:nif_error(undef). -%% Shadowed by erl_bif_types: maps:to_list/1 -spec to_list(Map) -> [{Key,Value}] when Map :: map(), Key :: term(), Value :: term(). -to_list(_) -> erlang:nif_error(undef). +to_list(Map) when is_map(Map) -> + to_list_internal(erts_internal:map_next(0, Map, [])); +to_list(Map) -> + erlang:error({badmap,Map},[Map]). +to_list_internal([Iter, Map | Acc]) when is_integer(Iter) -> + to_list_internal(erts_internal:map_next(Iter, Map, Acc)); +to_list_internal(Acc) -> + Acc. %% Shadowed by erl_bif_types: maps:update/3 -spec update(Key,Value,Map1) -> Map2 when @@ -192,47 +207,80 @@ get(Key,Map,Default) -> erlang:error({badmap,Map},[Key,Map,Default]). --spec filter(Pred,Map1) -> Map2 when +-spec filter(Pred,MapOrIter) -> Map when Pred :: fun((Key, Value) -> boolean()), Key :: term(), Value :: term(), - Map1 :: map(), - Map2 :: map(). + MapOrIter :: map() | iterator(), + Map :: map(). filter(Pred,Map) when is_function(Pred,2), is_map(Map) -> - maps:from_list([{K,V}||{K,V}<-maps:to_list(Map),Pred(K,V)]); + maps:from_list(filter_1(Pred, iterator(Map))); +filter(Pred,Iterator) when is_function(Pred,2), ?IS_ITERATOR(Iterator) -> + maps:from_list(filter_1(Pred, Iterator)); filter(Pred,Map) -> erlang:error(error_type(Map),[Pred,Map]). - --spec fold(Fun,Init,Map) -> Acc when +filter_1(Pred, Iter) -> + case next(Iter) of + {K, V, NextIter} -> + case Pred(K,V) of + true -> + [{K,V} | filter_1(Pred, NextIter)]; + false -> + filter_1(Pred, NextIter) + end; + none -> + [] + end. + +-spec fold(Fun,Init,MapOrIter) -> Acc when Fun :: fun((K, V, AccIn) -> AccOut), Init :: term(), Acc :: term(), AccIn :: term(), AccOut :: term(), - Map :: map(), + MapOrIter :: map() | iterator(), K :: term(), V :: term(). fold(Fun,Init,Map) when is_function(Fun,3), is_map(Map) -> - lists:foldl(fun({K,V},A) -> Fun(K,V,A) end,Init,maps:to_list(Map)); + fold_1(Fun,Init,iterator(Map)); +fold(Fun,Init,Iterator) when is_function(Fun,3), ?IS_ITERATOR(Iterator) -> + fold_1(Fun,Init,Iterator); fold(Fun,Init,Map) -> - erlang:error(error_type(Map),[Fun,Init,Map]). + erlang:error(error_type_iter(Map),[Fun,Init,Map]). + +fold_1(Fun, Acc, Iter) -> + case next(Iter) of + {K, V, NextIter} -> + fold_1(Fun, Fun(K,V,Acc), NextIter); + none -> + Acc + end. --spec map(Fun,Map1) -> Map2 when +-spec map(Fun,MapOrIter) -> Map when Fun :: fun((K, V1) -> V2), - Map1 :: map(), - Map2 :: map(), + MapOrIter :: map() | iterator(), + Map :: map(), K :: term(), V1 :: term(), V2 :: term(). map(Fun,Map) when is_function(Fun, 2), is_map(Map) -> - maps:from_list([{K,Fun(K,V)}||{K,V}<-maps:to_list(Map)]); + maps:from_list(map_1(Fun, iterator(Map))); +map(Fun,Iterator) when is_function(Fun, 2), ?IS_ITERATOR(Iterator) -> + maps:from_list(map_1(Fun, Iterator)); map(Fun,Map) -> - erlang:error(error_type(Map),[Fun,Map]). + erlang:error(error_type_iter(Map),[Fun,Map]). +map_1(Fun, Iter) -> + case next(Iter) of + {K, V, NextIter} -> + [{K, Fun(K, V)} | map_1(Fun, NextIter)]; + none -> + [] + end. -spec size(Map) -> non_neg_integer() when Map :: map(). @@ -242,6 +290,26 @@ size(Map) when is_map(Map) -> size(Val) -> erlang:error({badmap,Val},[Val]). +-spec iterator(Map) -> Iterator when + Map :: map(), + Iterator :: iterator(). + +iterator(M) when is_map(M) -> [0 | M]; +iterator(M) -> erlang:error({badmap, M}, [M]). + +-spec next(Iterator) -> {Key, Value, NextIterator} | 'none' when + Iterator :: iterator(), + Key :: term(), + Value :: term(), + NextIterator :: iterator(). +next({K, V, I}) -> + {K, V, I}; +next([Path | Map]) when is_integer(Path), is_map(Map) -> + erts_internal:map_next(Path, Map, iterator); +next(none) -> + none; +next(Iter) -> + erlang:error(badarg, [Iter]). -spec without(Ks,Map1) -> Map2 when Ks :: [K], @@ -250,11 +318,10 @@ size(Val) -> K :: term(). without(Ks,M) when is_list(Ks), is_map(M) -> - lists:foldl(fun(K, M1) -> ?MODULE:remove(K, M1) end, M, Ks); + lists:foldl(fun(K, M1) -> maps:remove(K, M1) end, M, Ks); without(Ks,M) -> erlang:error(error_type(M),[Ks,M]). - -spec with(Ks, Map1) -> Map2 when Ks :: [K], Map1 :: map(), @@ -263,17 +330,20 @@ without(Ks,M) -> with(Ks,Map1) when is_list(Ks), is_map(Map1) -> Fun = fun(K, List) -> - case ?MODULE:find(K, Map1) of - {ok, V} -> - [{K, V} | List]; - error -> - List - end - end, - ?MODULE:from_list(lists:foldl(Fun, [], Ks)); + case maps:find(K, Map1) of + {ok, V} -> + [{K, V} | List]; + error -> + List + end + end, + maps:from_list(lists:foldl(Fun, [], Ks)); with(Ks,M) -> erlang:error(error_type(M),[Ks,M]). error_type(M) when is_map(M) -> badarg; error_type(V) -> {badmap, V}. + +error_type_iter(M) when is_map(M); ?IS_ITERATOR(M) -> badarg; +error_type_iter(V) -> {badmap, V}. |