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

-export([is_ok/1, is_error/1, map/2, map_error/2, flatten/1, then/2, unwrap/2, lazy_unwrap/2, nil_error/1, 'or'/2, lazy_or/2, all/1, replace_error/2, values/1]).

-spec is_ok({ok, any()} | {error, any()}) -> boolean().
is_ok(Result) ->
    case Result of
        {error, _} ->
            false;

        {ok, _} ->
            true
    end.

-spec is_error({ok, any()} | {error, any()}) -> boolean().
is_error(Result) ->
    case Result of
        {ok, _} ->
            false;

        {error, _} ->
            true
    end.

-spec map({ok, AZN} | {error, AZO}, fun((AZN) -> AZR)) -> {ok, AZR} |
    {error, AZO}.
map(Result, Fun) ->
    case Result of
        {ok, X} ->
            {ok, Fun(X)};

        {error, E} ->
            {error, E}
    end.

-spec map_error({ok, AZU} | {error, AZV}, fun((AZV) -> AZY)) -> {ok, AZU} |
    {error, AZY}.
map_error(Result, Fun) ->
    case Result of
        {ok, X} ->
            {ok, X};

        {error, Error} ->
            {error, Fun(Error)}
    end.

-spec flatten({ok, {ok, BAB} | {error, BAC}} | {error, BAC}) -> {ok, BAB} |
    {error, BAC}.
flatten(Result) ->
    case Result of
        {ok, X} ->
            X;

        {error, Error} ->
            {error, Error}
    end.

-spec then({ok, BAJ} | {error, BAK}, fun((BAJ) -> {ok, BAN} | {error, BAK})) -> {ok,
                                                                                 BAN} |
    {error, BAK}.
then(Result, Fun) ->
    case Result of
        {ok, X} ->
            Fun(X);

        {error, E} ->
            {error, E}
    end.

-spec unwrap({ok, BAS} | {error, any()}, BAS) -> BAS.
unwrap(Result, Default) ->
    case Result of
        {ok, V} ->
            V;

        {error, _} ->
            Default
    end.

-spec lazy_unwrap({ok, BAW} | {error, any()}, fun(() -> BAW)) -> BAW.
lazy_unwrap(Result, Default) ->
    case Result of
        {ok, V} ->
            V;

        {error, _} ->
            Default()
    end.

-spec nil_error({ok, BBA} | {error, any()}) -> {ok, BBA} | {error, nil}.
nil_error(Result) ->
    map_error(Result, fun(_) -> nil end).

-spec 'or'({ok, BBG} | {error, BBH}, {ok, BBG} | {error, BBH}) -> {ok, BBG} |
    {error, BBH}.
'or'(First, Second) ->
    case First of
        {ok, _} ->
            First;

        {error, _} ->
            Second
    end.

-spec lazy_or({ok, BBO} | {error, BBP}, fun(() -> {ok, BBO} | {error, BBP})) -> {ok,
                                                                                 BBO} |
    {error, BBP}.
lazy_or(First, Second) ->
    case First of
        {ok, _} ->
            First;

        {error, _} ->
            Second()
    end.

-spec all(list({ok, BBW} | {error, BBX})) -> {ok, list(BBW)} | {error, BBX}.
all(Results) ->
    gleam@list:try_map(Results, fun(X) -> X end).

-spec replace_error({ok, BCE} | {error, any()}, BCI) -> {ok, BCE} | {error, BCI}.
replace_error(Result, Error) ->
    map_error(Result, fun(_) -> Error end).

-spec values(list({ok, BCL} | {error, any()})) -> list(BCL).
values(Results) ->
    gleam@list:filter_map(Results, fun(R) -> R end).