如果序列是空的，就返回初始值，否则函数会先接收初始值和序列的第一个元素，然后是返回值和下一个元素，依此类推。

In this case the starting value is returned for an empty sequence, and the function is first applied to the starting value and the first sequence item, then to the result and the next item, and so on.

youdao

函数实现创建、初始化服务元套接字，初始化服务元及服务元序列等。

Socket function mainly realizes setting up and initializing service unit socket, initializing service unit and service unit serial and so on.

youdao