Refactor cache class. Fix driver instantiation bug. Allow closures as default parameter.

system/cache.php

@@ -17,19 +17,39 @@ class Cache {
 	 */
 	public static function driver($driver = null)
 	{
-		if ( ! array_key_exists($driver, static::$drivers))
+		if (is_null($driver))
 		{
-			if (is_null($driver))
-			{
-				$driver = Config::get('cache.driver');
-			}
+			$driver = Config::get('cache.driver');
+		}
 
+		if ( ! array_key_exists($driver, static::$drivers))
+		{
 			static::$drivers[$driver] = Cache\Factory::make($driver);
 		}
 
 		return static::$drivers[$driver];
 	}
 
+	/**
+	 * Get an item from the cache.
+	 *
+	 * @param  string  $key
+	 * @param  mixed   $default
+	 * @param  string  $driver
+	 * @return mixed
+	 */	
+	public static function get($key, $default = null, $driver = null)
+	{
+		$item = static::driver($driver)->get($key);
+
+		if (is_null($item))
+		{
+			return is_callable($default) ? call_user_func($default) : $default;
+		}
+
+		return $item;
+	}
+
 	/**
 	 * Pass all other methods to the default driver.
 	 *