public function add_path($path, $type = null)
	{
		is_null($type) and $type = $this->_path_folders;
		empty($path) and $path = DOCROOT;

		if( is_array($type))
		{
			foreach ($type as $key => $folder)
			{
				is_numeric($key) and $key = $folder;
				$folder = $this->_unify_path($path).ltrim($this->_unify_path($folder),DS);
				array_unshift($this->_asset_paths[$key], $folder);
			}
		}
		else
		{
			// create the asset type if it doesn't exist
			if ( ! isset($this->_asset_paths[$type]))
			{
				$this->_asset_paths[$type] = array();
				$this->_path_folders[$type] = $type.'/';
			}

			$path = $this->_unify_path($path);
			array_unshift($this->_asset_paths[$type], $path);
		}
		return $this;
	}