Instead of implementing singly linked lists as we did earlier, I recommend implementing such lists with a class LinkedList that contains a field holding either an Empty or a Cons class.

我建议执行有着linkedlist类的链表，该类包含一个有empty类或cons类的域，而不是象我们前面做的那样，单个执行链接链表。

youdao

Instead of implementing singly linked lists as we did earlier, I recommend implementing such lists with a class LinkedList that contains a field holding either an Empty or a Cons class.

我建议执行有着linkedlist类的链表，该类包含一个有empty类或cons类的域，而不是象我们前面做的那样，单个执行链接链表。

youdao