-module(gleam@pair).
-compile(no_auto_import).

-export([first/1, second/1, swap/1, map_first/2, map_second/2]).

-spec first({BZ, any()}) -> BZ.
first(Pair) ->
    {A, _@1} = Pair,
    A.

-spec second({any(), CC}) -> CC.
second(Pair) ->
    {_@1, A} = Pair,
    A.

-spec swap({CD, CE}) -> {CE, CD}.
swap(Pair) ->
    {A, B} = Pair,
    {B, A}.

-spec map_first({CF, CG}, fun((CF) -> CH)) -> {CH, CG}.
map_first(Pair, Fun) ->
    {A, B} = Pair,
    {Fun(A), B}.

-spec map_second({CI, CJ}, fun((CJ) -> CK)) -> {CI, CK}.
map_second(Pair, Fun) ->
    {A, B} = Pair,
    {A, Fun(B)}.