5.1.4 glist (链表)

带并发安全开关的双向列表。
使用场景：
双向链表。
使用方式：

import "github.com/gogf/gf/container/glist"

接口文档：
https://godoc.org/github.com/gogf/gf/container/glist

基础使用

package main
import (
    "fmt"
    "github.com/gogf/gf/container/glist"
)
func main() {
    // Not concurrent-safe in default.
    l := glist.New()
    // Push
    l.PushBack(1)
    l.PushBack(2)
    e := l.PushFront(0)
    // Insert
    l.InsertBefore(e, -1)
    l.InsertAfter(e, "a")
    fmt.Println(l)
    // Pop
    fmt.Println(l.PopFront())
    fmt.Println(l.PopBack())
    fmt.Println(l)
}

执行后，输出结果：

[-1,0,"a",1,2]
-1
2
[0,"a",1]

链表遍历

该示例中我们将通过读锁和写锁遍历一个并发安全的链表，分别通过RLockFunc和LockFunc实现。

package main
import (
    "container/list"
    "fmt"
    "github.com/gogf/gf/container/garray"
    "github.com/gogf/gf/container/glist"
)
func main() {
    // concurrent-safe list.
    l := glist.NewFrom(garray.NewArrayRange(1, 10, 1).Slice(), true)
    // iterate reading from head.
    l.RLockFunc(func(list *list.List) {
        length := list.Len()
        if length > 0 {
            for i, e := 0, list.Front(); i < length; i, e = i+1, e.Next() {
                fmt.Print(e.Value)
            }
        }
    })
    fmt.Println()
    // iterate reading from tail.
    l.RLockFunc(func(list *list.List) {
        length := list.Len()
        if length > 0 {
            for i, e := 0, list.Back(); i < length; i, e = i+1, e.Prev() {
                fmt.Print(e.Value)
            }
        }
    })
    fmt.Println()
    // iterate reading from head using IteratorAsc.
    l.IteratorAsc(func(e *glist.Element) bool {
        fmt.Print(e.Value)
        return true
    })
    fmt.Println()
    // iterate reading from tail using IteratorDesc.
    l.IteratorDesc(func(e *glist.Element) bool {
        fmt.Print(e.Value)
        return true
    })
    fmt.Println()
    // iterate writing from head.
    l.LockFunc(func(list *list.List) {
        length := list.Len()
        if length > 0 {
            for i, e := 0, list.Front(); i < length; i, e = i+1, e.Next() {
                if e.Value == 6 {
                    e.Value = "M"
                    break
                }
            }
        }
    })
    fmt.Println(l)
}

执行后，输出结果为：

12345678910
10987654321
12345678910
10987654321
[1,2,3,4,5,"M",7,8,9,10]

Pop*元素项出栈

package main
import (
    "fmt"
    "github.com/gogf/gf/container/glist"
    "github.com/gogf/gf/frame/g"
)
func main() {
    l := glist.NewFrom(g.Slice{1, 2, 3, 4, 5, 6, 7, 8, 9})
    fmt.Println(l.PopBack())
    fmt.Println(l.PopBacks(2))
    fmt.Println(l.PopFront())
    fmt.Println(l.PopFronts(2))
    // Output:
    // 9
    // [8 7]
    // 1
    // [2 3]
}

Join元素项串连

package main
import (
    "fmt"
    "github.com/gogf/gf/container/glist"
    "github.com/gogf/gf/frame/g"
)
func main() {
    var l glist.List
    l.PushBacks(g.Slice{"a", "b", "c", "d"})
    fmt.Println(l.Join(","))
    // Output:
    // a,b,c,d
}

JSON序列化/反序列

glist容器实现了标准库json数据格式的序列化/反序列化接口。
1. Marshal

import (
    "encoding/json"
    "fmt"
    "github.com/gogf/gf/container/glist"
    "github.com/gogf/gf/frame/g"
)
func main() {
    type Student struct {
        Id     int
        Name   string
        Scores *glist.List
    }
    s := Student{
        Id:     1,
        Name:   "john",
        Scores: glist.NewFrom(g.Slice{100, 99, 98}),
    }
    b, _ := json.Marshal(s)
    fmt.Println(string(b))
}

执行后，输出结果：

{"Id":1,"Name":"john","Scores":[100,99,98]}

2.Unmarshal
```go
package main
import (
    "encoding/json"
    "fmt"
    "github.com/gogf/gf/container/glist"
)
func main() {
    b := []byte(`{"Id":1,"Name":"john","Scores":[100,99,98]}`)
    type Student struct {
        Id     int
        Name   string
        Scores *glist.List
    }
    s := Student{}
    json.Unmarshal(b, &s)
    fmt.Println(s)
}

执行后，输出结果：

{1 john [100,99,98]}