在erlang中获取嵌套映射的值

-module(map_utils).
-export([get_nested_value/2]).

get_nested_value(#{Key := Value}, Key) ->
    Value;
get_nested_value(#{_ := _} = Map, Key) ->
    lists:foldl(fun({K, V}, Acc) ->
        case Acc of
            undefined ->
                case K of
                    Key ->
                        get_nested_value(V, Key);
                    _ ->
                        undefined
                end;
            _ ->
                Acc
        end
    end, undefined, maps:to_list(Map)).