Go struct tag 生成

复制import json

# 模拟 Go struct tag 生成：根据字段名和类型推断常见 tag
fields = [
    ("UserID", "int"),
    ("UserName", "string"),
    ("Email", "string"),
    ("Age", "int"),
]

for name, typ in fields:
    # 驼峰转 snake_case 用于 json/yaml/db tag
    snake = "".join("_" + c.lower() if c.isupper() else c for c in name).lstrip("_")
    json_tag = f'json:"{snake}"'
    yaml_tag = f'yaml:"{snake}"'
    db_tag = f'db:"{snake}"'
    form_tag = f'form:"{snake}"'
    # validate tag 示例：非空 + 邮箱格式（仅 string 类型）
    if typ == "string":
        if "email" in name.lower():
            validate_tag = 'validate:"required,email"'
        else:
            validate_tag = 'validate:"required"'
    else:
        validate_tag = 'validate:"required"'
    print(f"{name} {typ} `{json_tag} {yaml_tag} {db_tag} {form_tag} {validate_tag}`")

# 输出示例：
# UserID int `json:"user_id" yaml:"user_id" db:"user_id" form:"user_id" validate:"required"`
# UserName string `json:"user_name" yaml:"user_name" db:"user_name" form:"user_name" validate:"required"`
# Email string `json:"email" yaml:"email" db:"email" form:"email" validate:"required,email"`
# Age int `json:"age" yaml:"age" db:"age" form:"age" validate:"required"`

复制package main

import (
	"fmt"
	"reflect"
	"strings"
)

// User 结构体，手动编写 tag 示例
// 实际工具自动生成这些 tag
type User struct {
	UserID   int    `json:"user_id" yaml:"user_id" db:"user_id" form:"user_id" validate:"required"`
	UserName string `json:"user_name" yaml:"user_name" db:"user_name" form:"user_name" validate:"required"`
	Email    string `json:"email" yaml:"email" db:"email" form:"email" validate:"required,email"`
	Age      int    `json:"age" yaml:"age" db:"age" form:"age" validate:"required"`
}

func main() {
	// 反射读取所有字段的 tag
	t := reflect.TypeOf(User{})
	for i := 0; i < t.NumField(); i++ {
		field := t.Field(i)
		// 获取 struct tag 中的 json 值
		jsonTag := field.Tag.Get("json")
		// 获取 validate 值
		validateTag := field.Tag.Get("validate")
		fmt.Printf("Field: %s, json: %s, validate: %s\n", field.Name, jsonTag, validateTag)
	}
	// 输出：
	// Field: UserID, json: user_id, validate: required
	// Field: UserName, json: user_name, validate: required
	// Field: Email, json: email, validate: required,email
	// Field: Age, json: age, validate: required

	// 模拟 JSON 序列化
	u := User{UserID: 1, UserName: "Alice", Email: "alice@example.com", Age: 30}
	// 实际使用 encoding/json 包
	_ = u
}

复制// 模拟 Go struct tag 生成：根据字段名和类型生成 tag 字符串
const fields = [
  { name: 'UserID', type: 'int' },
  { name: 'UserName', type: 'string' },
  { name: 'Email', type: 'string' },
  { name: 'Age', type: 'int' },
];

// 驼峰转 snake_case
function toSnakeCase(str) {
  return str.replace(/[A-Z]/g, (letter, idx) =>
    idx === 0 ? letter.toLowerCase() : '_' + letter.toLowerCase()
  );
}

fields.forEach(({ name, type }) => {
  const snake = toSnakeCase(name);
  const jsonTag = `json:"${snake}"`;
  const yamlTag = `yaml:"${snake}"`;
  const dbTag = `db:"${snake}"`;
  const formTag = `form:"${snake}"`;
  // 简单 validate 推断
  let validateTag = 'validate:"required"';
  if (type === 'string' && name.toLowerCase().includes('email')) {
    validateTag = 'validate:"required,email"';
  }
  console.log(`${name} ${type} \`${jsonTag} ${yamlTag} ${dbTag} ${formTag} ${validateTag}\``);
});

// 输出：
// UserID int `json:"user_id" yaml:"user_id" db:"user_id" form:"user_id" validate:"required"`
// UserName string `json:"user_name" yaml:"user_name" db:"user_name" form:"user_name" validate:"required"`
// Email string `json:"email" yaml:"email" db:"email" form:"email" validate:"required,email"`
// Age int `json:"age" yaml:"age" db:"age" form:"age" validate:"required"`