Go的几个小技巧

1.匿名结构体

1.全局配置结构体
var config struct {// 定义一个用于全局配置结构体
    APIKey      string
    OAuthConfig oauth.Config
}
config.APIKey = "BADC0C0A"

2.
data := struct {//匿名结构体的定义
  Title string
  Users []*User
}{//同时初始化
  title,
  users,
}
err := tmpl.Execute(w, data)
(比 map[string]interface{} 消耗更小和更安全)

2.select中使用空channel

func worker(i int, ch chan Work, quit chan struct{}) {
    for {
        select {
        case w := <-ch:
            if quit == nil {
                w.Refuse(); fmt.Println("worker", i, "refused", w)
                break
            }
            w.Do(); fmt.Println("worker", i, "processed", w)
        case <-quit:
            fmt.Println("worker", i, "quitting")
            quit = nil
        }
    }
}

func main() {
    ch, quit := make(chan Work), make(chan struct{})
    go makeWork(ch)
    for i := 0; i < 4; i++ { go worker(i, ch, quit) }
    time.Sleep(5 * time.Second)
    close(quit)
    time.Sleep(2 * time.Second)
}

3.使用close广播

func waiter(i int, block, done chan struct{}) {
    time.Sleep(time.Duration(rand.Intn(3000)) * time.Millisecond)
    fmt.Println(i, "waiting...")
    <-block
    fmt.Println(i, "done!")
    done <- struct{}{}
}

func main() {
    block, done := make(chan struct{}), make(chan struct{})
    for i := 0; i < 4; i++ {
        go waiter(i, block, done)
    }
    time.Sleep(5 * time.Second)
    close(block)
    for i := 0; i < 4; i++ {
        <-done
    }
}

4.使用channel接受发送消息。

package main

import "fmt"

var battle = make(chan string)

func warrior(name string, done chan struct{}) {
    select {
    case opponent := <-battle:
        fmt.Printf("%s beat %s\n", name, opponent)
    case battle <- name:
        // I lost :-(
    }
    done <- struct{}{}
}

func main() {
    done := make(chan struct{})
    langs := []string{"Go", "C", "C++", "Java", "Perl", "Python"}
    for _, l := range langs { go warrior(l, done) }
    for _ = range langs { <-done }
}