map之类数据集合的几个代码小例子

package main

/*
几个集合的小例子

Author: XCL
Date: 2017-6-25
*/

import (
"fmt"
"sort"
"sync"
"utils"

"golang.org/x/sync/syncmap"
)

var (
data = []string{"bb", "aa", "1d", "ee", "cc"}
)

func main() {
fmt.Println("---------------------------------")
fmt.Println(" 有序集合(map + sort) ")
fmt.Println("---------------------------------")
map1()
fmt.Println("---------------------------------")
fmt.Println(" 有序集合(左倾红黑树) ")
fmt.Println("---------------------------------")
map2()
fmt.Println("---------------------------------")
fmt.Println(" 并发map(golang.org/x/sync/syncmap) ")
fmt.Println("---------------------------------")
map3()
}

func map1() {
// map = c++ unordered_map = 哈希表
m := make(map[string]string)
for _, v := range data {
m[v] = v
}

keys := make([]string, 0, len(m))
for _, v := range m {
keys = append(keys, v)
}
sort.Strings(keys)

for _, k := range keys {
fmt.Println("map1:", k, " => ", m[k])
}
}

func map2() {
// <<Programming in Go>>中的omap = c++ map = 红黑树
// C++ http://www.teachsolaisgames.com/articles/balanced_left_leaning.html 
m := utils.NewCaseFoldedKeyed()
for _, v := range data {
m.Insert(v, v)
}

m.Do(func(k, v interface{}) {
fmt.Println("map2:", k, " => ", v)
})

}

func map3() {
// 并发map
// golang.org/x/sync/syncmap
m := new(syncmap.Map)
var wg sync.WaitGroup

for i := 0; i < 10; i++ {
wg.Add(1)
go func(v int) {
defer wg.Done()
m.Store(v, v*10)
}(i)
}
wg.Wait()

m.Range(func(ki, vi interface{}) bool {
k, v := ki.(int), vi.(int)
fmt.Println("map3.range:", k, " => ", v)
return true
})

}

/*
输出:

---------------------------------
有序集合(map + sort)
---------------------------------
map1: 1d  =>  1d
map1: aa  =>  aa
map1: bb  =>  bb
map1: cc  =>  cc
map1: ee  =>  ee
---------------------------------
有序集合(左倾红黑树)
---------------------------------
map2: 1d  =>  1d
map2: aa  =>  aa
map2: bb  =>  bb
map2: cc  =>  cc
map2: ee  =>  ee
---------------------------------
并发map(golang.org/x/sync/syncmap)
---------------------------------
map3.range: 1  =>  10
map3.range: 0  =>  0
map3.range: 5  =>  50
map3.range: 8  =>  80
map3.range: 3  =>  30
map3.range: 2  =>  20
map3.range: 4  =>  40
map3.range: 7  =>  70
map3.range: 6  =>  60
map3.range: 9  =>  90

*/