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

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

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

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

-spec swap({CG, CH}) -> {CH, CG}.
swap(Pair) ->
    {A, B} = Pair,
    {B, A}.

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

-spec map_second({CL, CM}, fun((CM) -> CN)) -> {CL, CN}.
map_second(Pair, Fun) ->
    {A, B} = Pair,
    {A, Fun(B)}.