How can I write an enum with "intellisence support"?

huangapple
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英文:

How can I write an enum with "intellisence support"?

问题

在Go语言中，你可以像这样编写一个枚举：

  1. type Direction int
  3. const (
  4.     North Direction = iota
  5.     South
  6.     East
  7.     West
  8. )
  10. func main() {
  12.     // 声明一个类型为Direction的变量myDirection
  13.     var myDirection Direction
  14.     myDirection = West
  16.     if myDirection == West {
  17.         fmt.Println("myDirection is West:", myDirection)
  18.     }
  19. }

现在假设你要编写一个不仅有4个选项，而是有100个选项的枚举。我想要的是一个能够提供"智能提示"的枚举：当我输入枚举类型，然后输入一个点号"."，我想知道该枚举有哪些选项。

下面是一个示例，展示了如何实现这个功能。是否有更好的方法呢？

  1. type direction struct{}
  3. func (d *direction) north() string {
  4.     return "north"
  5. }
  6. func (d *direction) east() string {
  7.     return "east"
  8. }
  9. func (d *direction) south() string {
  10.     return "south"
  11. }
  12. func (d *direction) west() string {
  13.     return "west"
  14. }
  16. func main() {
  17.     var d direction
  18.     d.east()
  19.     ...
  20. }
英文:

In go you can write an enum like this

  1. type Direction int
  3. const (
  4.     North Direction = iota
  5.     South
  6.     East
  7.     West
  8. )
  10. func main() {
  12.     // Declaring a variable myDirection with type Direction
  13.     var myDirection Direction
  14.     myDirection = West
  16.     if (myDirection == West) {
  17.       fmt.Println("myDirection is West:", myDirection)
  18.     }
  19. }

Now image you write an enum which not only has 4 option, but instead 100. What I want is an enum that gives me "Inellisence support": If I type the enum, type a ., I want to know what options are there for the enum.

An example how this could look like is this. Is there a better way?

  2. type direction struct{}
  4. func (d *direction) north() string {
  5. 	return "north"
  6. }
  7. func (d *direction) east() string {
  8. 	return "east"
  9. }
  10. func (d *direction) south() string {
  11. 	return "south"
  12. }
  13. func (d *direction) west() string {
  14. 	return "west"
  15. }
  17. func main() {
  18.     var d direction
  19.     d.east()
  20.     ...
  21. }

答案1

得分: 1

我建议使用一个共同的前缀来命名枚举值，例如Dir，像这样：

  1. const (
  2.     DirNorth Direction = iota
  3.     DirSouth
  4.     DirEast
  5.     DirWest
  6. )

这样做的好处是，当你输入packagename.Dir时，你将得到可能的值列表。

因此，除了应用良好的命名策略外，你还将同时获得改进的自动完成功能，使你的源代码更易读（特别是如果枚举值很多，并且它们之间有更多的共同单词）。

标准库也使用了这种方法，一个很好的例子是net/http包：

  1. const (
  2.     MethodGet  = "GET"
  3.     MethodHead = "HEAD"
  4.     MethodPost = "POST"
  5.     // ...
  6. )
  8. const (
  9.     StatusContinue           = 100 // RFC 7231, 6.2.1
  10.     StatusSwitchingProtocols = 101 // RFC 7231, 6.2.2
  11.     StatusProcessing         = 102 // RFC 2518, 10.1
  13.     StatusOK                 = 200 // RFC 7231, 6.3.1
  14.     StatusCreated            = 201 // RFC 7231, 6.3.2
  15.     // ...
  16. )

相关问题请参考：https://stackoverflow.com/questions/39830166/glued-acronyms-and-golang-naming-convention/39830270#39830270

英文:

I suggest to start the names of the enum values with a common prefix, e.g. Dir like this:

  1. const (
  2.     DirNorth Direction = iota
  3.     DirSouth
  4.     DirEast
  5.     DirWest
  6. )

Doing so, when you type packagename.Dir, you'll get a list of the possible values.

So beside applying a good naming strategy, you'll get improved auto-completion at the same time, and your source code becomes more readable (especially if there are a lot of enum values and you have more common words among them).

This is also used by the standard library, great examples are in the net/http package:

  1. const (
  2.     MethodGet  = "GET"
  3.     MethodHead = "HEAD"
  4.     MethodPost = "POST"
  5.     // ...
  6. )
  8. const (
  9.     StatusContinue           = 100 // RFC 7231, 6.2.1
  10.     StatusSwitchingProtocols = 101 // RFC 7231, 6.2.2
  11.     StatusProcessing         = 102 // RFC 2518, 10.1
  13.     StatusOK                 = 200 // RFC 7231, 6.3.1
  14.     StatusCreated            = 201 // RFC 7231, 6.3.2
  15.     // ...
  16. )

See related question: https://stackoverflow.com/questions/39830166/glued-acronyms-and-golang-naming-convention/39830270#39830270

huangapple
  • 本文由 发表于 2021年12月3日 21:19:45
  • 转载请务必保留本文链接：https://go.coder-hub.com/70214974.html
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