CodeIgniter -自定义配置文件中的验证规则

在CodeIgniter用户指南中，我读到我们可以将验证规则保存到application/config/form_validation.php中的数组

http://codeigniter.com/user_guide/libraries/form_validation.html savingtoconfig

我想知道是否有可能将这些规则保存到不同的配置文件中，如application/config/my_library.php

form_validate .php应该像这样:

<?php $config = array(
             'signup' => array(
                                array(
                                        'field' => 'username',
                                        'label' => 'Username',
                                        'rules' => 'required'
                                     ),
                                array(
                                        'field' => 'password',
                                        'label' => 'Password',
                                        'rules' => 'required'
                                     ),
                                array(
                                        'field' => 'passconf',
                                        'label' => 'PasswordConfirmation',
                                        'rules' => 'required'
                                     ),
                                array(
                                        'field' => 'email',
                                        'label' => 'Email',
                                        'rules' => 'required'
                                     )
                                ),
             'email' => array(
                                array(
                                        'field' => 'emailaddress',
                                        'label' => 'EmailAddress',
                                        'rules' => 'required|valid_email'
                                     ),
                                array(
                                        'field' => 'name',
                                        'label' => 'Name',
                                        'rules' => 'required|alpha'
                                     ),
                                array(
                                        'field' => 'title',
                                        'label' => 'Title',
                                        'rules' => 'required'
                                     ),
                                array(
                                        'field' => 'message',
                                        'label' => 'MessageBody',
                                        'rules' => 'required'
                                     )
                                )                          
           );

，其中每个子数组，如'email'或'signup'，标识一个不同的表单