在任务中解压Golang切片？ [英] Unpack Golang slices on assignment?

问题描述

Golang有没有一种优雅的方式可以像Python一样从数组中进行多项赋值？这是我想要做的一个Python例子（分割一个字符串，然后将结果数组分配给两个变量）。

  python：
>>> a，b =foo; bar.split（;）
  

我目前的解决方案是：

  x：= strings.Split（foo; bar，;）
a，b：= x [0]，x [1] 
  

我可以看到这在一些结构中变得混乱。我目前面临的实际示例是书签文件解析并分配给地图：

 书签：= make（map [字符串]字符串）
x：= strings.Split（foo \thttps：// bar，\t）
 name，link：= x [0]，x [1] 
书签[name] = link 
  

现在我有一个无用的变量x我想做一些事情：

$ $ p $ $ $ $ $ $ $ $ line：= strings.Split（foo \thttps：// bar，\t）
bookmark [name] = link

但这是无效的。

不支持在Python中完成解包。我认为去那里的方法是使用多个返回值定义您自己的小型临时函数：

  func splitLink（s ，sep string）（string，string）{
x：= strings.Split（s，sep）
 return x [0]，x [1] 
} 
  

然后您可以编写：

  name，link：= splitLink（foo \thttps：// bar，\t）
  

但是，只有当至少有两个子字符串被分割时，这显然才起作用，并且如果两个以上的字符串被默默地忽略。如果这是你使用很多的东西，它可能会让你的代码更具可读性。

- 编辑 -

解包一个数组的另一种方法是通过variadic指针参数：

  func unpack（s [] string，vars ... * string）{
 for i，str：= range s {
 * vars [i] = str 
} 
} 
  

您可以写：

  var name，link string 
 unpack（strings.Split（foo\thttps：// bar，\ t），& name，&link）
书签[name] = link 
  

这适用于任何数组大小，但可以说它的可读性较差，你必须明确地声明你的变量。

Is there an elegant way in Golang to do multiple assignments from arrays like in Python? Here is a Python example of what I'm trying to do (split a string and then assign the resulting array into two variables).

python:
>>> a, b = "foo;bar".split(";")

My current solution is:

x := strings.Split("foo;bar", ";")
a, b := x[0], x[1]

I'm can see this getting messy in some constructs. The practical example I'm currently facing is a bookmark file parsing and assigning to a map:

bookmark := make(map[string]string)
x := strings.Split("foo\thttps://bar", "\t")
name, link := x[0], x[1]
bookmark[name] = link

Now I have a useless variable "x" sitting around. I'd like to do something like:

bookmark := make(map[string]string)
name, line := strings.Split("foo\thttps://bar", "\t")
bookmark[name] = link

but that's invalid.

解决方案

As Sergio Tulentsev mentioned, general packing/unpacking as is done in Python is not supported. I think the way to go there is to define your own small ad-hoc function using multiple return values:

func splitLink(s, sep string) (string, string) {
    x := strings.Split(s, sep)
    return x[0], x[1]
}

And you can then write:

name, link := splitLink("foo\thttps://bar", "\t")

But this will obviously work only when at least two substrings are being split, and silently ignore if more than two were. If this is something you use a lot, it might make your code more readable though.

--EDIT--

Another way to unpack an array is via variadic pointer arguments:

func unpack(s []string, vars... *string) {
    for i, str := range s {
        *vars[i] = str
    }
}

Which let you write:

var name, link string
unpack(strings.Split("foo\thttps://bar", "\t"), &name, &link)
bookmarks[name] = link

This will work for any array size, but it is arguably less readable, and you have to declare your variables explicitly.

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