在分配作业时解压切片? [英] Unpack slices on assignment?

问题描述

在Go中，有没有一种优雅的方法可以像在Python中那样从数组中进行多个赋值?这是我要尝试执行的Python示例(拆分一个字符串，然后将结果数组分配给两个变量).

Is there an elegant way in Go 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(";")

我当前的解决方案是:

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

在某些结构中，我会看到它变得凌乱.我当前面对的实际示例是一个书签文件，它解析并分配给地图:

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

现在我周围有一个无用的变量x.我想做类似的事情:

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

但这是无效的.

推荐答案

正如Sergio Tulentsev所述，不支持Python中的常规打包/解包.我认为方法是使用多个返回值定义自己的小型即席函数:

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]
}

然后您可以写:

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

但是，这显然仅在拆分至少两个子字符串时才有效，并且如果两个以上的子字符串被拆分，则默默地忽略.如果这是您经常使用的内容，则可能会使您的代码更具可读性.

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.

-编辑-

解数组的另一种方法是通过可变指针参数:

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
    }
}

您可以这样写:

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

这适用于任何数组大小，但可以说可读性较差，并且必须显式声明变量.

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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