More idiomatic way in Go to encode a []byte slice int an int64?

huangapple
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英文:

More idiomatic way in Go to encode a []byte slice int an int64?

问题

在Go语言中，将[]byte切片编码为int64的更好或更惯用的方法是什么？

  1. package main
  3. import "fmt"
  5. func main() {
  6.     var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
  7.     var data int64
  8.     for i := 0; i < 8; i++ {
  9.         data |= int64(mySlice[i] & byte(255)) << uint((8*8)-((i+1)*8))
  10.     }
  11.     fmt.Println(data)
  12. }

链接：http://play.golang.org/p/VjaqeFkgBX

英文:

Is there a better or more idiomatic way in Go to encode a []byte slice into an int64?

  1. package main
  3. import &quot;fmt&quot;
  5. func main() {
  6.     var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
  7.     var data int64
  8.     for i := 0; i &lt; 8; i++ {
  9. 	        	data |= int64(mySlice[i] &amp; byte(255)) &lt;&lt; uint((8*8)-((i+1)*8))
  10.     }
  11.     fmt.Println(data)
  12. }

http://play.golang.org/p/VjaqeFkgBX

答案1

得分: 7

这是一小段代码，通过能够准确地看到正在发生的事情，可以获得一些清晰度。但这是一个非常有争议的观点，所以你自己的品味和判断可能会有所不同。

  1. func main() {
  2.     var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
  3.     data := int64(0)
  4.     for _, b := range mySlice {
  5.         data = (data << 8) | int64(b)
  6.     }
  7.     fmt.Printf("%d\n", data)
  8. }

输出结果为:

  1. -795741901218843404

Playground链接: https://go.dev/play/p/aemkEg7a6S5

英文:

It's such a tiny amount of code, there's some clarity gained by being able to see exactly what's going on. But this is a highly contentious opinion, so your own taste and judgement may differ.

  1. func main() {
  2. 	var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
  3. 	data := int64(0)
  4. 	for _, b := range mySlice {
  5. 	    data = (data &lt;&lt; 8) | int64(b)
  6. 	}
  7. 	fmt.Printf(&quot;%d\n&quot;, data)
  8. }

Prints:

  1. -795741901218843404

Playground: https://go.dev/play/p/aemkEg7a6S5

答案2

得分: 1

我不确定是否符合惯用语，但这里有一个使用encoding/binary包的替代方案：

  1. package main
  3. import (
  4. 	"bytes"
  5. 	"encoding/binary"
  6. 	"fmt"
  7. )
  9. func main() {
  10. 	var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
  11. 	buf := bytes.NewReader(mySlice)
  12. 	var data int64
  13. 	err := binary.Read(buf, binary.LittleEndian, &data)
  14. 	if err != nil {
  15. 		fmt.Println("binary.Read failed:", err)
  16. 	}
  17. 	fmt.Println(data)
  18. }

这里是一个可以运行的示例链接。

英文:

I'm not sure about idiomatic, but here's an alternative using the encoding/binary package:

  1. package main
  3. import (
  4.    &quot;bytes&quot;
  5.    &quot;encoding/binary&quot;
  6.    &quot;fmt&quot;
  7. )
  9. func main() {
  10.    var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
  11.    buf := bytes.NewReader(mySlice)
  12.    var data int64
  13.    err := binary.Read(buf, binary.LittleEndian, &amp;data)
  14.    if err != nil {
  15. 	  fmt.Println(&quot;binary.Read failed:&quot;, err)
  16.    }
  17.    fmt.Println(data)
  18. }

http://play.golang.org/p/MTyy5gIEp5

huangapple
  • 本文由 发表于 2014年1月2日 03:09:13
  • 转载请务必保留本文链接：https://go.coder-hub.com/20872173.html
  • bit-manipulation
  • go
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