PHP Widmogrod\Monad IO Examples

Example #1

File: functions.php Project: widmogrod/php-functional

/**
 * ioState :: IO a -> State IO a
 *
 * @param M\IO $io
 *
 * @return M\State
 */
function ioState(M\IO $io)
{
    return M\State::of(function ($state) use($io) {
        list($key, $data) = $state;
        $value = $io->run();
        $data[$key] = $value;
        $newState = [$key, $data];
        return [$value, $newState];
    });
}

Example #2

File: errors.php Project: widmogrod/php-functional

/**
 * tryCatch :: Exception e => IO a -> (e -> IO a) -> IO a
 *
 * @param M\IO $io
 * @param callable $catchFunction
 *
 * @return M\IO
 */
function tryCatch(M\IO $io = null, callable $catchFunction = null)
{
    return call_user_func_array(f\curryN(2, function (M\IO $io, callable $catchFunction) {
        return M\IO::of(function () use($io, $catchFunction) {
            try {
                return $io->run();
            } catch (\Exception $e) {
                return call_user_func($catchFunction, $e);
            }
        });
    }), func_get_args());
}

Example #3

File: IOTest.php Project: widmogrod/php-functional

 public function provideFunctorTestData()
 {
     return ['IO' => ['$f' => function ($x) {
         return $x + 1;
     }, '$g' => function ($x) {
         return $x + 5;
     }, '$x' => IO::of(function () {
         return 1;
     })]];
 }

Example #4

File: functions.php Project: widmogrod/php-functional

/**
 * getEnv :: String -> IO String
 *
 * @param string $name
 *
 * @throws IOError
 *
 * @return M\IO
 */
function getEnv($name)
{
    return M\IO::of(function () use($name) {
        $value = \getenv($name);
        if (false === $value) {
            throw userError(sprintf('Environment variable "%s" does not exists.', $name));
        }
        return $value;
    });
}