/// <summary>
/// 返回当前消息链的适用于发送形式, 去除仅用于接收的消息元素, 即去除了 <see cref="Source" /> 和 <see cref="Quote" />
/// </summary>
/// <param name="chain">原链</param>
/// <returns>包含不便发送元素的新链</returns>
public static MessageChain AsSendable(this MessageChain chain)
{
return(new(chain.Where(x => !(x is Source) && !(x is Quote))));
}
/// <summary>
/// 返回当前消息链的可读形式, 即去除了 <see cref="Source" /> 元素
/// </summary>
/// <param name="chain">原链</param>
/// <returns>不包含不便于程序阅读元素的新链</returns>
public static MessageChain AsReadable(this MessageChain chain)
{
return(new(chain.Where(x => !(x is Source))));
}