Go – 验证的数据类型

huangapple
go评论117阅读模式
英文:

Go - Data types for validation

问题

如何为Go创建一个新的数据类型，在创建新变量（该类型的变量）时可以检查/验证其模式？

例如，要验证字符串是否有20个字符，我尝试了以下代码：

  1. // 格式：2006-01-12T06:06:06Z
  2. func date(str string) {
  3.   if len(str) != 20 {
  4.     fmt.Println("错误")
  5.   }
  6. }
  7. var Date = date()
  9. type Account struct {
  10.   domain   string
  11.   username string
  12.   created  Date
  13. }

但是它失败了，因为Date不是一个类型。

英文:

How to create a new data type for Go which to can check/validate its schema when is created a new variable (of that type)?

By example, to validate if a string has 20 characters, I tried:

  1. // Format: 2006-01-12T06:06:06Z
  2. func date(str string) {
  3.   if len(str) != 20 {
  4.     fmt.Println("error")
  5.   }
  6. }
  7. var Date = date()
  9. type Account struct {
  10.   domain  string
  11.   username string
  12.   created  Date
  13. }

but it fails because Date is not a type.

答案1

得分: 3

在你的示例中，你将Date定义为一个变量，然后尝试将其用作类型。

我猜你想做的是这样的。

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. 	"time"
  7. )
  9. type Date int64
  11. type Account struct {
  12. 	domain   string
  13. 	username string
  14. 	created  Date
  15. }
  17. func NewDate(date string) (Date, os.Error) {
  18. 	// 日期格式：2006-01-12T06:06:06Z
  19. 	if len(date) == 0 {
  20. 		// 默认为今天
  21. 		today := time.UTC()
  22. 		date = today.Format(time.ISO8601)
  23. 	}
  24. 	t, err := time.Parse(time.ISO8601, date)
  25. 	if err != nil {
  26. 		return 0, err
  27. 	}
  28. 	return Date(t.Seconds()), err
  29. }
  31. func (date Date) String() string {
  32. 	t := time.SecondsToUTC(int64(date))
  33. 	return t.Format(time.ISO8601)
  34. }
  36. func main() {
  37. 	var account Account
  38. 	date := "2006-01-12T06:06:06Z"
  39. 	created, err := NewDate(date)
  40. 	if err == nil {
  41. 		account.created = created
  42. 	} else {
  43. 		fmt.Println(err.String())
  44. 	}
  45. 	fmt.Println(account.created)
  46. }
英文:

In your example, you defined Date as a variable and then tried to use it as a type.

My guess is that you want to do something like this.

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. 	"time"
  7. )
  9. type Date int64
  11. type Account struct {
  12. 	domain   string
  13. 	username string
  14. 	created  Date
  15. }
  17. func NewDate(date string) (Date, os.Error) {
  18. 	// date format: 2006-01-12T06:06:06Z
  19. 	if len(date) == 0 {
  20. 		// default to today
  21. 		today := time.UTC()
  22. 		date = today.Format(time.ISO8601)
  23. 	}
  24. 	t, err := time.Parse(time.ISO8601, date)
  25. 	if err != nil {
  26. 		return 0, err
  27. 	}
  28. 	return Date(t.Seconds()), err
  29. }
  31. func (date Date) String() string {
  32. 	t := time.SecondsToUTC(int64(date))
  33. 	return t.Format(time.ISO8601)
  34. }
  36. func main() {
  37. 	var account Account
  38. 	date := "2006-01-12T06:06:06Z"
  39. 	created, err := NewDate(date)
  40. 	if err == nil {
  41. 		account.created = created
  42. 	} else {
  43. 		fmt.Println(err.String())
  44. 	}
  45. 	fmt.Println(account.created)
  46. }

答案2

得分: 1

您可能需要使用标准库中的Time类型。文档。

英文:

You probably want the Time type from the standard library. Documentation.

huangapple
  • 本文由 发表于 2010年4月14日 18:12:53
  • 转载请务必保留本文链接：https://go.coder-hub.com/2636485.html
  • go
  • validation
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