golang json使用10、-10、0表示，true、false、null

package main

import (
    "encoding/json"
    "errors"
    "fmt"
)

type A struct {
    Br Boolean `json:"br"`
}

func main() {
    var c A
    e := json.Unmarshal([]byte(`{"br":true}`), &c)
    fmt.Println(e)
    fmt.Println(c)

}

type Boolean int

func (b Boolean) MarshalJSON() ([]byte, error) {
    switch b {
    case 10:
        return []byte("true"), nil
    case -10:
        return []byte("false"), nil
    default:
        return []byte("null"), nil
    }
}

func (b *Boolean) UnmarshalJSON(data []byte) error {
    switch string(data) {
    case "true":
        *b = 10
    case "false":
        *b = -10
    case "null":
        *b = 0
    default:
        return errors.New("不是正确类型")
    }
    return nil
}

func (b Boolean) IsNil() bool {
    return b == 0
}

func (b Boolean) IsValue() bool {
    return b == 10
}