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gleam_stdlib src gleam@set.erl
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src/gleam@set.erl

-module(gleam@set).
-compile(no_auto_import).
-export([new/0, size/1, insert/2, contains/2, delete/2, to_list/1, from_list/1, fold/3, filter/2, take/2, union/2, intersection/2]).
-export_type([set/1]).
-opaque set(CNK) :: {set, gleam@map:map_(CNK, list(nil))}.
-spec new() -> set(any()).
new() ->
{set, gleam@map:new()}.
-spec size(set(any())) -> integer().
size(Set) ->
gleam@map:size(erlang:element(2, Set)).
-spec insert(set(CNT), CNT) -> set(CNT).
insert(Set, Member) ->
{set, gleam@map:insert(erlang:element(2, Set), Member, [])}.
-spec contains(set(CNW), CNW) -> boolean().
contains(Set, Member) ->
_pipe = erlang:element(2, Set),
_pipe@1 = gleam@map:get(_pipe, Member),
gleam@result:is_ok(_pipe@1).
-spec delete(set(CNY), CNY) -> set(CNY).
delete(Set, Member) ->
{set, gleam@map:delete(erlang:element(2, Set), Member)}.
-spec to_list(set(COB)) -> list(COB).
to_list(Set) ->
gleam@map:keys(erlang:element(2, Set)).
-spec from_list(list(COE)) -> set(COE).
from_list(Members) ->
Map = gleam@list:fold(
Members,
gleam@map:new(),
fun(M, K) -> gleam@map:insert(M, K, []) end
),
{set, Map}.
-spec fold(set(COH), COJ, fun((COJ, COH) -> COJ)) -> COJ.
fold(Set, Initial, Reducer) ->
gleam@map:fold(
erlang:element(2, Set),
Initial,
fun(A, K, _) -> Reducer(A, K) end
).
-spec filter(set(COK), fun((COK) -> boolean())) -> set(COK).
filter(Set, Property) ->
{set,
gleam@map:filter(erlang:element(2, Set), fun(M, _) -> Property(M) end)}.
-spec take(set(CON), list(CON)) -> set(CON).
take(Set, Desired) ->
{set, gleam@map:take(erlang:element(2, Set), Desired)}.
-spec order(set(COR), set(COR)) -> {set(COR), set(COR)}.
order(First, Second) ->
case gleam@map:size(erlang:element(2, First))
> gleam@map:size(erlang:element(2, Second)) of
true ->
{First, Second};
false ->
{Second, First}
end.
-spec union(set(COW), set(COW)) -> set(COW).
union(First, Second) ->
{Larger, Smaller} = order(First, Second),
fold(Smaller, Larger, fun insert/2).
-spec intersection(set(CPA), set(CPA)) -> set(CPA).
intersection(First, Second) ->
{Larger, Smaller} = order(First, Second),
take(Larger, to_list(Smaller)).