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

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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:

type Direction int

const (
    North Direction = iota
    South
    East
    West
)

func main() {

    // 声明一个类型为Direction的变量myDirection
    var myDirection Direction
    myDirection = West

    if myDirection == West {
        fmt.Println("myDirection is West:", myDirection)
    }
}

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?

type direction struct{}

func (d *direction) north() string {
    return "north"
}
func (d *direction) east() string {
    return "east"
}
func (d *direction) south() string {
    return "south"
}
func (d *direction) west() string {
    return "west"
}

func main() {
    var d direction
    d.east()
    ...
}
英文:

In go you can write an enum like this

type Direction int

const (
    North Direction = iota
    South
    East
    West
)

func main() {

    // Declaring a variable myDirection with type Direction
    var myDirection Direction
    myDirection = West

    if (myDirection == West) {
      fmt.Println("myDirection is West:", myDirection)
    }
}

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?


type direction struct{}

func (d *direction) north() string {
	return "north"
}
func (d *direction) east() string {
	return "east"
}
func (d *direction) south() string {
	return "south"
}
func (d *direction) west() string {
	return "west"
}

func main() {
    var d direction
    d.east()
    ...
}

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:

const (
    DirNorth Direction = iota
    DirSouth
    DirEast
    DirWest
)

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:

const (
    MethodGet  = "GET"
    MethodHead = "HEAD"
    MethodPost = "POST"
    // ...
)

const (
    StatusContinue           = 100 // RFC 7231, 6.2.1
    StatusSwitchingProtocols = 101 // RFC 7231, 6.2.2
    StatusProcessing         = 102 // RFC 2518, 10.1

    StatusOK                 = 200 // RFC 7231, 6.3.1
    StatusCreated            = 201 // RFC 7231, 6.3.2
    // ...
)

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:

const (
    DirNorth Direction = iota
    DirSouth
    DirEast
    DirWest
)

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:

const (
    MethodGet  = "GET"
    MethodHead = "HEAD"
    MethodPost = "POST"
    // ...
)

const (
    StatusContinue           = 100 // RFC 7231, 6.2.1
    StatusSwitchingProtocols = 101 // RFC 7231, 6.2.2
    StatusProcessing         = 102 // RFC 2518, 10.1

    StatusOK                 = 200 // RFC 7231, 6.3.1
    StatusCreated            = 201 // RFC 7231, 6.3.2
    // ...
)

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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