get_functions
Github

    public function get_functions()
    {
        $data = [];
        foreach (_class('core_api')->get_functions() as $name) {
            $data[++$i] = [
                'name' => $name,
                'link' => './?object=' . __CLASS__ . '&action=get_function_source&id=' . $name,
            ];
        }
        return _class('html')->tree($data, [
            'opened_levels' => 0,
            'draggable' => false,
        ]);
    }