在Go语言中遍历所有接口方法。

huangapple
go评论124阅读模式
英文:

iterate over all interface methods in go

问题

如何对一个 XML 文件运行一系列检查？每个检查都是一个返回两个字符串的方法：它的名称和通过或失败的结果。我尝试将所有的方法放在一个接口中，但是无法弄清如何进行迭代。

在这个代码示例中，尝试为注释"WANT"找到一些可行的解决方案：

  1. package main
  3. import (
  4.         "fmt"
  5.         "github.com/antchfx/xmlquery"
  6. )
  8. type node xmlquery.Node
  10. type XmlChecks interface {
  11.         checkUTC() (string, string)
  12.         checkSugPresDel() (string, string)
  13.         checkStartNum() (string, string)
  14.         // ... 还会有很多其他方法
  15. }
  17. type XmlVerify struct {
  18.         doc node
  19. }
  21. func (xver XmlVerify) checkUTC() (string, string) {
  22.         //TBD
  23.         return "cUTC", "pass"
  24. }
  26. func (xver XmlVerify) checkSugPresDel() (string, string) {
  27.         //TBD
  28.         return "cSugPresDel", "pass"
  29. }
  31. func (xver XmlVerify) checkStartNum() (string, string) {
  32.         //TBD
  33.         return "cStartNum", "pass"
  34. }
  36. func main() {
  37.         var vrfy XmlVerify
  38.         vrfy.doc, _ := xmlquery.Parse("myfile.xml")
  39.         for each_method := range "vrfy.XmlChecks 中的所有方法" { // <--WANT
  40.                 fmt.Printf("%s %s\n", vrfy.each_method()) // <--WANT
  41.         }
  43. }
英文:

How to run a suite of checks on an xml file? Each check is a method
that returns 2 strings: it's name and pass or fail.
Using xmlquery. I tried putting all the methods in an interface but
can't figure out how to iterate.

In this code sample, trying to get something to work for comment "WANT":

  1. package main
  3. import (
  4.         &quot;fmt&quot;
  5.         &quot;github.com/antchfx/xmlquery&quot;
  6. )
  8. type node xmlquery.Node
  10. type XmlChecks interface {
  11.         checkUTC() (string, string)
  12.         checkSugPresDel() (string, string)
  13.         checkStartNum() (string, string)
  14.         // ... there will be many
  15. }
  17. type XmlVerify struct {
  18.         doc node
  19. }
  21. func (xver XmlVerify) checkUTC() (string, string) {
  22.         //TBD
  23.         return &quot;cUTC&quot;, &quot;pass&quot;
  24. }
  26. func (xver XmlVerify) checkSugPresDel() (string, string) {
  27.         //TBD
  28.         return &quot;cSugPresDel&quot;, &quot;pass&quot;
  29. }
  31. func (xver XmlVerify) checkStartNum() (string, string) {
  32.         //TBD
  33.         return &quot;cStartNum&quot;, &quot;pass&quot;
  34. }
  36. func main() {
  37.         var vrfy XmlVerify
  38.         vrfy.doc, _ := xmlquery.Parse(&quot;myfile.xml&quot;)
  39.         for each_method := range &quot;all the methods in vrfy.XmlChecks&quot; { //&lt;--WANT
  40.                 fmt.Printf(&quot;%s %s\n&quot;, vrfy.each_method()) //&lt;--WANT
  41.         }
  43. }

答案1

得分: 2

这是一个使用reflect包的示例，展示了如何进行操作。只需更改XmlVerify内部的值，就可以使示例变得更简单一些。还要确保方法名是导出的（首字母大写）。

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"reflect"
  6. )
  8. type XmlVerify struct {
  9. 	value string
  10. }
  12. func (xver XmlVerify) CheckUTC() (string, bool) {
  13. 	return "cUTC", xver.value == "one"
  14. }
  16. func (xver XmlVerify) CheckSugPresDel() (string, bool) {
  17. 	return "cSugPresDel", xver.value == "two"
  18. }
  20. func (xver XmlVerify) CheckStartNum() (string, bool) {
  21. 	return "cStartNum", xver.value == "three"
  22. }
  24. func verify(xmlverify XmlVerify) {
  25. 	t := reflect.TypeOf(xmlverify)
  27. 	for i := 0; i < t.NumMethod(); i++ {
  28. 		method := t.Method(i)
  29. 		ret := reflect.ValueOf(xmlverify).MethodByName(method.Name).Call(nil)
  30. 		fmt.Printf("%s checks passed: %t\n", ret[0], ret[1])
  31. 	}
  32. }
  34. func main() {
  35. 	v := XmlVerify{"two"}
  36. 	verify(v)
  37. }

输出结果:

  1. cStartNum checks passed: false
  2. cSugPresDel checks passed: true
  3. cUTC checks passed: false
英文:

Here is an example of how you can do it with reflect. Only changed the value inside XmlVerify to make the example a bit easier. Also make sure the method names are exported (capitalize).

  1. package main
  3. import (
  4. 	&quot;fmt&quot;
  5. 	&quot;reflect&quot;
  6. )
  8. type XmlVerify struct {
  9. 	value string
  10. }
  12. func (xver XmlVerify) CheckUTC() (string, bool) {
  13. 	return &quot;cUTC&quot;, xver.value == &quot;one&quot;
  14. }
  16. func (xver XmlVerify) CheckSugPresDel() (string, bool) {
  17. 	return &quot;cSugPresDel&quot;, xver.value == &quot;two&quot;
  18. }
  20. func (xver XmlVerify) CheckStartNum() (string, bool) {
  21. 	return &quot;cStartNum&quot;, xver.value == &quot;three&quot;
  22. }
  24. func verify(xmlverify XmlVerify) {
  25. 	t := reflect.TypeOf(xmlverify)
  27. 	for i := 0; i &lt; t.NumMethod(); i++ {
  28. 		method := t.Method(i)
  29. 		ret := reflect.ValueOf(xmlverify).MethodByName(method.Name).Call(nil)
  30. 		fmt.Printf(&quot;%s checks passed: %t\n&quot;, ret[0], ret[1])
  31. 	}
  32. }
  34. func main() {
  35. 	v := XmlVerify{&quot;two&quot;}
  36. 	verify(v)
  37. }

output:

  1. cStartNum checks passed: false
  2. cSugPresDel checks passed: true
  3. cUTC checks passed: false

huangapple
  • 本文由 发表于 2021年10月27日 01:02:13
  • 转载请务必保留本文链接：https://go.coder-hub.com/69727223.html
  • go
  • interface
  • iterator
  • loops
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