zicht / itertools

    // http://php.net/manual/en/functions.arguments.php#functions.variable-arg-list

    $args = func_get_args();

    switch (sizeof($args)) {

        case 1:

            $strategy = null;

            $iterable = $args[0];

            break;

        case 2:

            $strategy = $args[0];

            $iterable = $args[1];

            break;

        default:

            throw new \InvalidArgumentException('filter requires either one (iterable) or two (strategy, iterable) arguments');

    }

    $strategy = conversions\mixed_to_value_getter($strategy);

    $isValid = function ($value, $key) use ($strategy) {

function unique()

{

    $args = func_get_args();

    switch (sizeof($args)) {

        case 1:

            $strategy = null;

            $iterable = $args[0];

            break;

        case 2:

            $strategy = $args[0];

            $iterable = $args[1];

            break;

        default:

            throw new \InvalidArgumentException('unique requires either one (iterable) or two (strategy, iterable) arguments');

    }

    return new UniqueIterator(

        conversions\mixed_to_value_getter($strategy),