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|
%%
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2013-2021. 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.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% backport of OTP 24 map functions not present in 23.
-module(nouveau_maps).
-export([merge_with/3, foreach/2]).
-if(?OTP_RELEASE >= 24).
merge_with(Combiner, Map1, Map2) ->
maps:merge_with(Combiner, Map1, Map2).
foreach(Fun, MapOrIter) ->
maps:foreach(Fun, MapOrIter).
-else.
merge_with(Combiner, Map1, Map2) when
is_map(Map1),
is_map(Map2),
is_function(Combiner, 3)
->
case map_size(Map1) > map_size(Map2) of
true ->
Iterator = maps:iterator(Map2),
merge_with_1(
maps:next(Iterator),
Map1,
Map2,
Combiner
);
false ->
Iterator = maps:iterator(Map1),
merge_with_1(
maps:next(Iterator),
Map2,
Map1,
fun(K, V1, V2) -> Combiner(K, V2, V1) end
)
end;
merge_with(Combiner, Map1, Map2) ->
error_with_info(
error_type_merge_intersect(Map1, Map2, Combiner),
[Combiner, Map1, Map2]
).
merge_with_1({K, V2, Iterator}, Map1, Map2, Combiner) ->
case Map1 of
#{K := V1} ->
NewMap1 = Map1#{K := Combiner(K, V1, V2)},
merge_with_1(maps:next(Iterator), NewMap1, Map2, Combiner);
#{} ->
merge_with_1(maps:next(Iterator), maps:put(K, V2, Map1), Map2, Combiner)
end;
merge_with_1(none, Result, _, _) ->
Result.
foreach(Fun, MapOrIter) when is_function(Fun, 2) ->
Iter =
if
is_map(MapOrIter) -> maps:iterator(MapOrIter);
true -> MapOrIter
end,
try maps:next(Iter) of
Next ->
foreach_1(Fun, Next)
catch
error:_ ->
error_with_info({badmap, MapOrIter}, [Fun, MapOrIter])
end;
foreach(Pred, Map) ->
badarg_with_info([Pred, Map]).
foreach_1(Fun, {K, V, Iter}) ->
Fun(K, V),
foreach_1(Fun, maps:next(Iter));
foreach_1(_Fun, none) ->
ok.
%% We must inline these functions so that the stacktrace points to
%% the correct function.
-compile({inline, [badarg_with_info/1, error_with_info/2]}).
badarg_with_info(Args) ->
erlang:error(badarg, Args, [{error_info, #{module => erl_stdlib_errors}}]).
error_with_info(Reason, Args) ->
erlang:error(Reason, Args, [{error_info, #{module => erl_stdlib_errors}}]).
error_type_two_maps(M1, M2) when is_map(M1) ->
{badmap, M2};
error_type_two_maps(M1, _M2) ->
{badmap, M1}.
error_type_merge_intersect(M1, M2, Combiner) when is_function(Combiner, 3) ->
error_type_two_maps(M1, M2);
error_type_merge_intersect(_M1, _M2, _Combiner) ->
badarg.
-endif.
|
