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

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

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

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

-spec swap({EC, ED}) -> {ED, EC}.
swap(Pair) ->
    {A, B} = Pair,
    {B, A}.

-spec map_first({EE, EF}, fun((EE) -> EG)) -> {EG, EF}.
map_first(Pair, Fun) ->
    {A, B} = Pair,
    {Fun(A), B}.

-spec map_second({EH, EI}, fun((EI) -> EJ)) -> {EH, EJ}.
map_second(Pair, Fun) ->
    {A, B} = Pair,
    {A, Fun(B)}.