如何在Go中将函数存储在切片中

huangapple
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英文:

How to store functions in a slice in Go

问题

我正在尝试将以下Python功能移植到Golang中。特别是如何将函数存储在切片中并调用它们。在Golang中我该如何做到这一点？

  1. package main
  3. import "fmt"
  5. type Dispatcher struct {
  6. 	listeners []func()
  7. }
  9. func (d *Dispatcher) addListener(listener func()) {
  10. 	d.listeners = append(d.listeners, listener)
  11. }
  13. func (d *Dispatcher) notifyUpdate() {
  14. 	for _, f := range d.listeners {
  15. 		f()
  16. 	}
  17. }
  19. func beeper() {
  20. 	fmt.Println("beep...beep...beep")
  21. }
  23. func pinger() {
  24. 	fmt.Println("ping...ping...ping")
  25. }
  27. func main() {
  28. 	dispatch := &Dispatcher{}
  29. 	dispatch.addListener(beeper)
  30. 	dispatch.addListener(pinger)
  31. 	dispatch.notifyUpdate()
  32. }

输出：

  1. beep...beep...beep
  2. ping...ping...ping

以上是将Python代码转换为Golang的示例。在Golang中，我们使用函数类型的切片来存储函数，并通过循环调用它们。

英文:

I'm trying to port the following Python functionality to Golang.
Especially, how to store functions in a slice and then call them.
How can I do this in Golang?

  1. class Dispatcher(object):
  2.     def __init__(self):
  3. 	    self._listeners = []
  5.     def addlistener(self, listener):
  6. 	    self._listeners.append(listener)
  8.     def notifyupdate(self):
  9. 	    for f in self._listeners:
  10. 		    f()
  12. def beeper():
  13.     print "beep...beep...beep"
  15. def pinger():
  16.     print "ping...ping...ping"
  18. dispatch = Dispatcher()
  19. dispatch.addlistener(beeper)
  20. dispatch.addlistener(pinger)
  21. dispatch.notifyupdate()
  23. output:
  24. beep...beep...beep
  26. ping...ping...ping

答案1

得分: 22

这是一个相当简单的代码：

  1. package main
  3. import "fmt"
  5. func main() {
  6.     var fns []func()
  7.     fns = append(fns, beeper)
  8.     fns = append(fns, pinger)
  10.     for _, fn := range fns {
  11.         fn()
  12.     }
  13. }
  15. func beeper() {
  16.     fmt.Println("beep-beep")
  17. }
  19. func pinger() {
  20.     fmt.Println("ping-ping")
  21. }

Playground: http://play.golang.org/p/xuDsdeRQX3.

英文:

It's pretty easy actually:

  1. package main
  3. import "fmt"
  5. func main() {
  6. 	var fns []func()
  7. 	fns = append(fns, beeper)
  8. 	fns = append(fns, pinger)
  10. 	for _, fn := range fns {
  11. 		fn()
  12. 	}
  13. }
  15. func beeper() {
  16. 	fmt.Println("beep-beep")
  17. }
  19. func pinger() {
  20. 	fmt.Println("ping-ping")
  21. }

Playground: http://play.golang.org/p/xuDsdeRQX3.

答案2

得分: 1

以下是翻译好的内容：

或者，如果你想要一个更接近的结构（诚然，在这种情况下并不需要）：

  1. package main
  3. import "fmt"
  5. type dispatcher struct {
  6.     listeners []func()
  7. }
  9. func (d *dispatcher) addListener(f func()) {
  10.     d.listeners = append(d.listeners, f)
  11. }
  13. func (d *dispatcher) notify() {
  14.     for _, f := range d.listeners {
  15.         f()
  16.     }
  17. }
  19. func ping() {
  20.     fmt.Println("Ping... ping...")
  21. }
  23. func beep() {
  24.     fmt.Println("Beep... beep...")
  25. }
  27. func main() {
  28.     d := dispatcher{}
  29.     d.addListener(ping)
  30.     d.addListener(beep)
  31.     d.notify()
  32. }

Go playground

英文:

Alternatively, if you want an even closer structure (admittedly, not needed, at all, in this case):

  1. package main
  3. import "fmt"
  5. type dispatcher struct {
  6.     listeners []func()
  7. }
  9. func (d *dispatcher) addListener(f func()) {
  10.     d.listeners = append(d.listeners, f)
  11. }
  13. func (d *dispatcher) notify() {
  14.     for _, f := range d.listeners {
  15. 	    f()
  16.     }
  17. }
  19. func ping() {
  20.     fmt.Println("Ping... ping...")
  21. }
  23. func beep() {
  24.     fmt.Println("Beep... beep...")
  25. }
  27. func main() {
  28.     d := dispatcher{}
  29. 	d.addListener(ping)
  30.     d.addListener(beep)
  31.     d.notify()
  32. }

Go playground

答案3

得分: 0

  1. package main
  3. import "fmt"
  5. func main() {
  6.     var funcs = []func(){}
  7.     funcs = append(funcs, beeper)
  8.     funcs = append(funcs, pinger)
  9.     
  10.     for _, f := range funcs {
  11.         f()
  12.     }
  13. }
  15. func beeper() {
  16.     fmt.Println("I'm a beeper")
  17. }
  19. func pinger() {
  20.     fmt.Println("I'm a pinger")
  21. }

点击此处查看代码。

英文: 
  1. package main
  3. import "fmt"
  5. func main() {
  6. 	var funcs = []func(){}
  7. 	funcs = append(funcs, beeper)
  8. 	funcs = append(funcs, pinger)
  9. 	
  10. 	for _, f := range funcs {
  11. 		f()
  12. 	}
  13. }
  15. func beeper() {
  16. 	fmt.Println("I'm a beeper")
  17. }
  19. func pinger() {
  20. 	fmt.Println("I'm a pinger")
  21. }

http://play.golang.org/p/PaClU6Ri4n

答案4

得分: 0

func main(){
var funcSlice []func()
funcSlice = append(funcSlice, f1)
funcSlice = append(funcSlice, f2)
}

func f1(){
fmt.Println("")
}

func f2(){
fmt.Println("")
}

英文: 
  1. func main(){
  2.     var funcSlice []func()
  3.     funcSlice = append(funcSlice, f1)
  4.     funcSlice = append(funcSlice, f2)
  5. }
  7. func f1(){  
  8.     fmt.Println("")
  9. }
  11. func f2(){ 
  12.     fmt.Println("")
  13. }

答案5

得分: 0

如果你使用更复杂的函数，你可以这样做：

  1. func addr(instru, beforeg [4]int) [4]int {
  2.     beforeg[instru[3]] = beforeg[instru[1]] + beforeg[instru[2]]
  3.     return beforeg
  4. }
  6. func addi(instru, beforeg [4]int) [4]int {
  7.     beforeg[instru[3]] = beforeg[instru[1]] + instru[2]
  8.     return beforeg
  9. }
  11. func day16Run(isTest bool) {
  12.     arrayFunc := [16]func([4]int, [4]int) [4]int{addr, addi}
  13.     // 使用 arrayFunc
  14. }

如果你的函数具有不同的签名，可以使用切片并在需要时进行追加，但在调用函数时要小心：
https://stackoverflow.com/questions/37314365/golang-how-do-you-create-a-slice-of-functions-with-different-signatures

英文:

If you use more complexes functions you do this :

  1. func addr(instru, beforeg [4]int) [4]int {
  2. 	beforeg[instru[3]] = beforeg[instru[1]] + beforeg[instru[2]]
  3. 	return beforeg
  4. }
  6. func addi(instru, beforeg [4]int) [4]int {
  7. 	beforeg[instru[3]] = beforeg[instru[1]] + instru[2]
  8. 	return beforeg
  9. }
  11. func day16Run(isTest bool) {
  12. 	arrayFunc:= [16]func([4]int, [4]int) [4]int{addr, addi}
  13.     // use arrayFunc
  14. }

And if your functions have differnt signatures, use a slice and append as you go, but be careful when calling the functions :
https://stackoverflow.com/questions/37314365/golang-how-do-you-create-a-slice-of-functions-with-different-signatures

huangapple
  • 本文由 发表于 2016年2月26日 17:58:51
  • 转载请务必保留本文链接：https://go.coder-hub.com/35648561.html
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