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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, nowarn_unused_vars]).
-export([new/0, size/1, insert/2, contains/2, delete/2, to_list/1, from_list/1, fold/3, filter/2, drop/2, take/2, union/2, intersection/2]).
-export_type([set/1]).
-opaque set(ERX) :: {set, gleam@map:map_(ERX, 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(ESD), ESD) -> set(ESD).
insert(Set, Member) ->
{set, gleam@map:insert(erlang:element(2, Set), Member, [])}.
-spec contains(set(ESG), ESG) -> 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(ESI), ESI) -> set(ESI).
delete(Set, Member) ->
{set, gleam@map:delete(erlang:element(2, Set), Member)}.
-spec to_list(set(ESL)) -> list(ESL).
to_list(Set) ->
gleam@map:keys(erlang:element(2, Set)).
-spec from_list(list(ESO)) -> set(ESO).
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(ESR), EST, fun((EST, ESR) -> EST)) -> EST.
fold(Set, Initial, Reducer) ->
gleam@map:fold(
erlang:element(2, Set),
Initial,
fun(A, K, _) -> Reducer(A, K) end
).
-spec filter(set(ESU), fun((ESU) -> boolean())) -> set(ESU).
filter(Set, Property) ->
{set,
gleam@map:filter(erlang:element(2, Set), fun(M, _) -> Property(M) end)}.
-spec drop(set(ESX), list(ESX)) -> set(ESX).
drop(Set, Disallowed) ->
gleam@list:fold(Disallowed, Set, fun delete/2).
-spec take(set(ETB), list(ETB)) -> set(ETB).
take(Set, Desired) ->
{set, gleam@map:take(erlang:element(2, Set), Desired)}.
-spec order(set(ETF), set(ETF)) -> {set(ETF), set(ETF)}.
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(ETK), set(ETK)) -> set(ETK).
union(First, Second) ->
{Larger, Smaller} = order(First, Second),
fold(Smaller, Larger, fun insert/2).
-spec intersection(set(ETO), set(ETO)) -> set(ETO).
intersection(First, Second) ->
{Larger, Smaller} = order(First, Second),
take(Larger, to_list(Smaller)).