rustler2000

package main

import (
	"encoding/json"
	"fmt"
)

// Canonical types
type Aaa struct {
	Field1 string
	Field2 int
	Field3 map[int]*struct {
		Field4 int
		Field5 string
	}
}

func main() {
	// Data
	a := &Aaa{"string", -1, map[int]*struct {
		Field4 int
		Field5 string
	}{}}
	a.Field3[100] = &struct {
		Field4 int
		Field5 string
	}{100, "text"}
	a.Field3[200] = &struct {
		Field4 int
		Field5 string
	}{200, "text22222"}

	// Regular json marshal
	b1, _ := json.MarshalIndent(a, "", "  ")
	fmt.Printf("%s\n", string(b1))

	// Alternative types
	b2, _ := json.MarshalIndent(*(*struct {
		Field1 string `json:"Typ"`
		Field2 int    `json:"Prio,string"`
		Field3 map[int]*struct {
			Field4 int    `json:"-"`
			Field5 string `json:"Text"`
		} `json:"Map"`
	})(a), "", "  ")
	fmt.Printf("%s\n", string(b2))
}