Erlang delete double values in arrays (dict vs orddict vs sets vs ordsets vs maps vs gb_sets benchmark)

list_bench.erl

-module(list_bench).

-compile([export_all]).

main(Count) ->
    Values = lists:foldl(fun(C, Acc) ->
        [C, C, C, C, C, C, C, C, C, C | Acc]
    end, [], lists:seq(1, Count)),

    {TimeDict0, ResultDict} = timer:tc(?MODULE, count_dict, [Values]),
    TimeDict = TimeDict0 / 1000000,
    io:format("DICT (~p): ~p sec~n", [ResultDict, TimeDict]),

    {TimeOrdDict0, ResultOrdDict} = timer:tc(?MODULE, count_orddict, [Values]),
    TimeOrdDict = TimeOrdDict0 / 1000000,
    io:format("ORDDICT (~p): ~p sec~n", [ResultOrdDict, TimeOrdDict]),

    {TimeSets0, ResultSets} = timer:tc(?MODULE, count_sets, [Values]),
    TimeSets = TimeSets0 / 1000000,
    io:format("SETS (~p): ~p sec~n", [ResultSets, TimeSets]),

    {TimeOrdSets0, ResultOrdSets} = timer:tc(?MODULE, count_ordsets, [Values]),
    TimeOrdSets = TimeOrdSets0 / 1000000,
    io:format("ORDSETS (~p): ~p sec~n", [ResultOrdSets, TimeOrdSets]),

    {TimeMap0, ResultMap} = timer:tc(?MODULE, count_maps, [Values]),
    TimeMap = TimeMap0 / 1000000,
    io:format("MAP (~p): ~p sec~n", [ResultMap, TimeMap]),

    {TimeGBSets0, ResultGBSets} = timer:tc(?MODULE, count_gb_sets, [Values]),
    TimeGBSets = TimeGBSets0 / 1000000,
    io:format("GB_SETS (~p): ~p sec~n", [ResultGBSets, TimeGBSets]).

count_dict(Values) ->
    ValuesKV = lists:map(fun(V) -> {V, undefined} end, Values),
    Dict = dict:from_list(ValuesKV),
    dict:size(Dict).

count_orddict(Values) ->
    ValuesKV = lists:map(fun(V) -> {V, undefined} end, Values),
    Dict = orddict:from_list(ValuesKV),
    orddict:size(Dict).

count_sets(Values) ->
    Set = sets:from_list(Values),
    sets:size(Set).

count_ordsets(Values) ->
    Set = ordsets:from_list(Values),
    ordsets:size(Set).

count_maps(Values) ->
    Map = maps:from_keys(Values, undefined),
    maps:size(Map).

count_gb_sets(Values) ->
    GbSet = gb_sets:from_list(Values),
    gb_sets:size(GbSet).

%% RESULTS for 1_000_000 (large list)
%%
%% 1> list_bench:main(1000000).
%% DICT (1000000): 430.271907 sec
%% ORDDICT (1000000): 1.912428 sec
%% SETS (1000000): 60.717392 sec
%% ORDSETS (1000000): 0.089105 sec
%% MAP (1000000): 2.994229 sec
%% GB_SETS (1000000): 0.127389 sec

%% RESULTS for 10_000_000 (dict and sets omitted)
%% 
%% ORDDICT (10000000): 35.303066 sec
%% ORDSETS (10000000): 0.873909 sec
%% MAP (10000000): 38.187113 sec
%% GB_SETS (10000000): 1.528153 sec