英文:
Simplifying error handling in go
问题
在C和类似的语言中，可以使用以下快捷方式来检测错误并在第一个非零结果上停止：
(void)(result = dosomething() ||
result = dosomething() ||
result = dosomething()
)
if (result == 0 && ...
在Go语言中，似乎无法这样做。
例如：
if result = dosomething() ||
result = dosomething(); result < 0 {
fmt.Printf("Error occurred\n");
}
C语言可以将整数视为布尔表达式来检查非零。
例如，我可以写成：
if (result = dosomething() || ... )
而不是：
if ( (result = dosomething()) == 0 || ... )
但是在Go语言中，你不能这样做。
我以为我可以写成：
if result = dosomething() == 0 ||
result = dosomething() == 0; result < 0 {
fmt.Printf("Error occurred\n");
}
但是我得到了一个错误：
syntax error: result = dosomething() || result used as value
肯定有一种方法可以将它们链接在一起。或者按照JavaScript promises的风格，是否可以使用dosomething().doSomething.doSomething.error()的方法？
对于这个问题有什么创造性的解决方案吗？我只是想避免大量重复的代码，我想做很多事情，但如果在任何一点上出现错误，就停止执行。因为每个错误处理逻辑都完全相同。
英文:
In C and similar languages the following shortcuts can be applied to detect an error and stop on first non-zero result
(void)(result = dosomething() ||
result = dosomething() ||
result = dosomething()
)
if (result == 0 && ...
In golang, I can't seem to do that.
For example:
if result = dosomething() ||
result = dosomething(); result < 0 {
fmt.Printf("Error occurred\n");
}
C is able to treat integers as a boolean expression when checking for non-zero.
for example I can write
if (result = dosomething() || ... )
Instead of
if ( (result = dosomething()) == 0 || ... )
But in go, you can't do that.
I thought I could write:
if result = dosomething() == 0 ||
result = dosomething() == 0; result < 0 {
fmt.Printf("Error occurred\n");
}
But I get an error.
syntax error: result = dosomething() || result used as value
There has to be a way of chaining these together. Or in the style of
javascript promises could a dosomething().doSomething.doSomething.error() approach be possible?
Any creative solutions to this problem? I'm really just wanting to avoid
lots of repetitive code where I want to do a whole bunch of things, but if there is an error at any point stop. Because the error handling logic for each is exactly the same.
答案1
得分: 4
请参考错误即值这篇文章，它是由Rob Pike撰写的，介绍了一种处理函数组中错误的有趣而强大的方法，非常有效。
我之前多次使用过这种技术，确实很有效。
这种技术使用的代码示例如下（摘自文章）：
// 辅助类型
type errWriter struct {
w io.Writer
err error
}
func (ew *errWriter) write(buf []byte) {
if ew.err != nil {
return
}
_, ew.err = ew.w.Write(buf)
}
// 使用示例:
ew := &errWriter{w: fd}
ew.write(p0[a:b])
ew.write(p1[c:d])
ew.write(p2[e:f])
// 以此类推
if ew.err != nil {
return ew.err
}
英文:
See Errors are values on The Go Blog. This article, written by Rob Pike, has an interesting and powerful method of handling errors in a group of functions that works very well.
I have used this technique before several times, and it really works.
For reference, the code used for this technique looks like this (copied from the article):
> // Helper type
> type errWriter struct {
> w io.Writer
> err error
> }
>
> func (ew *errWriter) write(buf []byte) {
> if ew.err != nil {
> return
> }
> _, ew.err = ew.w.Write(buf)
> }
>
> //Usage:
> ew := &errWriter{w: fd}
> ew.write(p0[a:b])
> ew.write(p1[c:d])
> ew.write(p2[e:f])
> // and so on
> if ew.err != nil {
> return ew.err
> }
答案2
得分: 1
你可以使用slice和for循环。
s := []func() error{do1,do2,do3,do4}
for i := range s {
if err := s[i](); err != nil {
return err
}
}
return nil
不过，你可能应该遵循其他答案中的示例，因为它们直接来自文档。
英文:
You could use a slice and a for loop.
https://play.golang.org/p/NJaCliBydA
s := []func() error{do1,do2,do3,do4}
for i := range s {
if err := s[i](); err != nil {
return err
}
}
return nil
Really though, you probably SHOULD follow the examples in the other answer as they come directly from documentation.
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