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-rw-r--r--lib/stdlib/src/maps.erl121
1 files changed, 94 insertions, 27 deletions
diff --git a/lib/stdlib/src/maps.erl b/lib/stdlib/src/maps.erl
index 5dafdb282a..a13f340709 100644
--- a/lib/stdlib/src/maps.erl
+++ b/lib/stdlib/src/maps.erl
@@ -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]).
--spec map(Fun,Map1) -> Map2 when
+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,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]).
+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 +330,17 @@ 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(M) when is_map(M); ?IS_ITERATOR(M) -> badarg;
error_type(V) -> {badmap, V}.
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 22:44:16 +0000