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

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

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

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

-spec swap({M, N}) -> {N, M}.
swap(Pair) ->
    {A, B} = Pair,
    {B, A}.

-spec map_first({O, P}, fun((O) -> Q)) -> {Q, P}.
map_first(Pair, Fun) ->
    {A, B} = Pair,
    {Fun(A), B}.

-spec map_second({R, S}, fun((S) -> T)) -> {R, T}.
map_second(Pair, Fun) ->
    {A, B} = Pair,
    {A, Fun(B)}.