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 }

}