Golang:List

List的接口

 func New() *List                                                    //创建List
 func (l *List) Back() *Element                                      //返回List的上一个元素
 func (l *List) Front() *Element                                     //返回List下一个元素
 func (l *List) Init() *List                                         //初始化List
 func (l *List) InsertAfter(v interface{}, mark *Element) *Element   //在指定节点后插入，成功返回插入节点的指针，失败返回nil, 时间复杂度O(1)
 func (l *List) InsertBefore(v interface{}, mark *Element) *Element  //在指定节点之前插入， 成功返回插入节点的指针，失败返回nil, 时间复杂度O(1)
 func (l *List) Len() int                                            //返回链表长度，时间复杂度O(1)
 func (l *List) MoveAfter(e, mark *Element)                          //移动节点e到mark节点之后，时间复杂度O(1), 处理方式：先删除然后再插入
 func (l *List) MoveBefore(e, mark *Element)                         //移动节点e到mark节点之前，时间复杂度O(1), 处理方式：先删除然后再插入
 func (l *List) MoveToBack(e *Element)                               //移动节点e到链表的尾部
 func (l *List) MoveToFront(e *Element)                              //移动节点e到链表的头部
 func (l *List) PushBack(v interface{}) *Element                     //在链表尾部追加值为v的新节点
 func (l *List) PushBackList(other *List)                            //把链表other所有节点追加到当前链表的尾部
 func (l *List) PushFront(v interface{}) *Element                    //在链表的头部插入新节点
 func (l *List) PushFrontList(other *List)                           //把链表other所有节点追加到当前链表头部
 func (l *List) Remove(e *Element) interface{}                       //删除指定节点

从这些接口我们可以看到Go的list应该是一个双向链表，不然InsertBefore这种操作应该不会放出来。

然后我们再从源码看看List的结构

 // Element is an element of a linked list.
 type Element struct {
     // Next and previous pointers in the doubly-linked list of elements.
     // To simplify the implementation, internally a list l is implemented
     // as a ring, such that &l.root is both the next element of the last
     // list element (l.Back()) and the previous element of the first list
     // element (l.Front()).
     next, prev *Element

     // The list to which this element belongs.
     list *List

     // The value stored with this element.
     Value interface{}
 }

 // List represents a doubly linked list.
 // The zero value for List is an empty list ready to use.
 type List struct {
     root Element // sentinel list element, only &root, root.prev, and root.next are used
     len  int     // current list length excluding (this) sentinel element
 }

从这里证实了上面的猜想，这是一个双向链表

List的使用

 package main

 import (
     "container/list"
     "fmt"
 )

 func main() {

     list0 := list.New()
     e4 := list0.PushBack()
     e1 := list0.PushFront()
     list0.InsertBefore(, e4)
     list0.InsertAfter(, e1)

     for e := list0.Front(); e != nil; e = e.Next() {
         fmt.Print(e.Value, " ")
     }
     fmt.Println("\r")

     front := list0.Front()
     back := list0.Back()

     fmt.Println("front is:", front.Value)
     fmt.Println("back is:", back.Value)
     fmt.Println("length is", list0.Len())

     list0.InsertBefore(, front)
     list0.InsertAfter(, back)

     list0.PushFront(-)
     list0.PushBack()
     for e := list0.Front(); e != nil; e = e.Next() {
         fmt.Print(e.Value, " ")
     }
     fmt.Println("\r")
     list0.Remove(list0.Front())
     for e := list0.Front(); e != nil; e = e.Next() {
         fmt.Print(e.Value, " ")
     }

     fmt.Println("\r")
     list1 := list.New()
     list1.PushBack()
     list1.PushBack()
     list0.PushBackList(list1)
     for e := list0.Front(); e != nil; e = e.Next() {
         fmt.Print(e.Value, " ")
     }
     fmt.Println("\r")
 }

10-14行往list写入1，2，3，4

16行遍历打印list

21-16行打印front 和back节点

42-48行把另一个list追加到list的back

运行结果是：

front is:
back is:
length is
-