How to "override" struct fields in Golang?

Question

go

hello i have structure

DefaultResponse struct {
    Code  int    `json:"code"`
    Msg   string `json:"msg"`
          Datas []Data`json:"datas"` 
  }

and there are many separate packages where I want to override the Data structure while keeping the DefaultResponse.
For example, in one package I need:

Data struct {
    ID    int64
    Name  string
  }

and in another

Data struct {
    ID    int64
    Value  int64
  }

How to implement it?
UPD: The DefaultResponse common for all packages is needed so as not to drag the same functionality associated with it into all packages.

Answer 1

In Go this is done with composition
https://play.golang.org/p/9ThbqjKzytZ

The code

package main

import (
  "encoding/json"
  "fmt"
)

type Data1 struct {
  SomeField string `json:"some_field"`
}

type Data2 struct {
  SomeOtherField string `json:"some_other_field"`
}

type DefaultResponse struct {
  Code int    `json:"code"`
  Msg  string `json:"msg"`
}

type Response1 struct {
  DefaultResponse
  Datas []Data1 `json:"datas"`
}

type Response2 struct {
  DefaultResponse
  Datas []Data2 `json:"datas"`
}

func main() {
  json1 := `{"code":123,"msg":"test","datas":[{"some_field":"test field data"}]}`
  json2 := `{"code":456,"msg":"test2","datas":[{"some_other_field":"other test field data"}]}`

  var res1 Response1
  var res2 Response2

  json.Unmarshal([]byte(json1), &res1)
  json.Unmarshal([]byte(json2), &res2)

  fmt.Printf("%+v\n", res1)
  fmt.Printf("%+v\n", res2)
}