zicht / itertools

     * @return \Closure

     * @throws \InvalidArgumentException

     */

    public function reducing($name)

    {

        // note, once we stop supporting php 5.5, we can rewrite the code below

        // to the reducing($name, ...$args) structure.

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

        $method = sprintf('\Zicht\Itertools\util\Reductions::%s', $name);

        if (!is_callable($method)) {

            throw new \InvalidArgumentException(sprintf('$name "%s" is not a valid reduction.', $name));

        }

        return call_user_func_array($method, array_slice(func_get_args(), 1));

    }

    /**

     * Returns a mapping closure

     * @return \Closure

     * @throws \InvalidArgumentException

     */

    public function mapping($name)

    {

        // note, once we stop supporting php 5.5, we can rewrite the code below

        // to the reducing($name, ...$args) structure.

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

        $method = sprintf('\Zicht\Itertools\util\Mappings::%s', $name);

        if (!is_callable($method)) {

            throw new \InvalidArgumentException(sprintf('$name "%s" is not a valid mapping.', $name));

        }

        return call_user_func_array($method, array_slice(func_get_args(), 1));

    }

    /**

     * Returns a filter closure

     * @return \Closure

     * @throws \InvalidArgumentException

     */

    public function filtering($name)

    {

        // note, once we stop supporting php 5.5, we can rewrite the code below

        // to the reducing($name, ...$args) structure.

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

        $method = sprintf('\Zicht\Itertools\util\Filters::%s', $name);

        if (!is_callable($method)) {

            throw new \InvalidArgumentException(sprintf('$name "%s" is not a valid filter.', $name));

        }

        return call_user_func_array($method, array_slice(func_get_args(), 1));

    }

    /**

     * Make an iterator that returns values from $iterable where the