zicht / itertools

    $args = func_get_args();

    switch (sizeof($args)) {

        case 2:

            $strategy = conversions\mixed_to_value_getter($args[0]);

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

                $tempVarPhp54 = call_user_func($strategy, $value, $key);

                return !empty($tempVarPhp54);

            };

            $iterable = conversions\mixed_to_iterator($args[1]);

            break;

        case 3:

            $strategy = conversions\mixed_to_value_getter($args[0]);

            $iterable = conversions\mixed_to_iterator($args[1]);

            break;

        case 3:

            $strategy = conversions\mixed_to_value_getter($args[0]);

            $userClosure = $args[1];

            $closure = function ($value, $key) use ($strategy, $userClosure) {

                return call_user_func($userClosure, call_user_func($strategy, $value, $key));

            };

            $iterable = conversions\mixed_to_iterator($args[2]);

            break;

        default:

            throw new \InvalidArgumentException('filterBy requires either two (strategy, iterable) or three (strategy, closure, iterable) arguments');