增加配置文件驱动接口，以便用户在遵循接口的前提下定义并使用自己的驱动，例如 YAML

library/think/config.php

@@ -11,6 +11,9 @@
 
 namespace think;
 
+use think\config\driver\DriverInterface;
+use think\config\driver\Ini;
+
 class Config
 {
     // 配置参数
@@ -27,15 +30,21 @@ class Config
         }
     }
 
-    // 解析其他格式的配置参数
-    public static function parse($config, $type = '', $range = '')
+    /**
+     * 解析配置文件或内容
+     *
+     * @param string               $config 配置文件路径或内容
+     * @param string               $range  作用域
+     * @param DriverInterface|null $driver 配置解析驱动
+     */
+    public static function parse($config, $range = '', DriverInterface $driver = null)
     {
-        if (empty($type)) {
-            $type = substr(strrchr($config, '.'), 1);
+        if ($driver === null) {
+            $driver = new Ini();
         }
+
         $range = $range ? $range : self::$range;
-        $class = '\\think\\config\\driver\\' . strtolower($type);
-        self::set((new $class())->parse($config), '', $range);
+        self::set($driver->parse($config), '', $range);
     }
 
     // 加载配置文件

library/think/config/driver/DriverInterface.php

@@ -0,0 +1,29 @@
+<?php
+// +----------------------------------------------------------------------
+// | ThinkPHP [ WE CAN DO IT JUST THINK ]
+// +----------------------------------------------------------------------
+// | Copyright (c) 2006~2015 http://thinkphp.cn All rights reserved.
+// +----------------------------------------------------------------------
+// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
+// +----------------------------------------------------------------------
+// | Author: dongww <dongww@gmail.com>
+// +----------------------------------------------------------------------
+
+namespace think\config\driver;
+
+/**
+ * 配置文件解析驱动接口
+ *
+ * @package think\config\driver
+ */
+interface DriverInterface
+{
+    /**
+     * 解析配置文件或内容，并以字符串形式返回
+     *
+     * @param string $config 配置文件路径或字符串
+     *
+     * @return array 以数组形式返回配置
+     */
+    public function parse($config);
+}

library/think/config/driver/ini.php

@@ -11,7 +11,7 @@
 
 namespace think\config\driver;
 
-class Ini
+class Ini implements DriverInterface
 {
     public function parse($config)
     {

library/think/config/driver/xml.php

@@ -11,7 +11,7 @@
 
 namespace think\config\driver;
 
-class Xml
+class Xml implements DriverInterface
 {
     public function parse($config)
     {