json.Marshal — doesn't work

[RubaXa]

Hi,

I try convert OrderedMap to json, but receive empty object :/

package main

import (
	"fmt"
	"encoding/json"
	"github.com/elliotchance/orderedmap"
)

func main() {
	m := orderedmap.NewOrderedMap()

	m.Set("foo", "bar")
	m.Set("qux", 1.23)
	m.Set(123, true)

	b, err := json.Marshal(m)
	if err != nil {
		fmt.Println("error:", err)
	}
	
	fmt.Println("result:", string(b)) // "result: {}" ⚠️
}

https://play.golang.org/p/UFER3tR6uPA

[elliotchance]

This is because marshalling has not been implemented for orderedmap.

I'm not sure what this would actually look like because it must be reasonable that the order would also be retained in the data structure. So simply using a JSON object would not be sufficient.

Since there are multiple ways marshalling and unmarshalling could work so it's best to leave it up to the implementation. Here is one example that might suit your needs:

https://play.golang.org/p/LjOrp4k6lqf

[abusizhishen]

This is because marshalling has not been implemented for orderedmap.

I'm not sure what this would actually look like because it must be reasonable that the order would also be retained in the data structure. So simply using a JSON object would not be sufficient.

Since there are multiple ways marshalling and unmarshalling could work so it's best to leave it up to the implementation. Here is one example that might suit your needs:

https://play.golang.org/p/LjOrp4k6lqf

marshaling and unmarshaling may cause unexpected issue, like int type will be marshal into int64 type in your example
https://play.golang.org/p/IjP7E3lRMhT

[elliotchance]

If the order and specific data types must be retained in the serialized value then you will need a more complex marshaller to suit your specific needs.

[89trillion-feiyang]

This is because marshalling has not been implemented for orderedmap.

I'm not sure what this would actually look like because it must be reasonable that the order would also be retained in the data structure. So simply using a JSON object would not be sufficient.

Since there are multiple ways marshalling and unmarshalling could work so it's best to leave it up to the implementation. Here is one example that might suit your needs:

https://play.golang.org/p/LjOrp4k6lqf

The structure after serialization is not what I want.

According to your code result is

[
   [
     "2",
    {
      "a": "2",
      "b": "7"
    }
  ],
  [
    "3",
    {
      "a": "3",
      "b": "1"
    }
  ]
]

Expect:

{
  "2": {
        "a": 3,
        "b": 4
    }
}

[elliotchance]

@89trillion-feiyang - you can serialize it in any format you want. Here's some sample code to produce that: https://play.golang.org/p/tKGpbGCpFbC

Keep in mind some caveats with that:

1. The order will be lost when serializing (and unserializing). There's no way around that because Go sorts maps for JSON output.
2. All of your keys must be strings.

[89trillion-feiyang]

@89trillion-feiyang - you can serialize it in any format you want. Here's some sample code to produce that: https://play.golang.org/p/tKGpbGCpFbC

Keep in mind some caveats with that:

1. The order will be lost when serializing (and unserializing). There's no way around that because Go sorts maps for JSON output.
2. All of your keys must be strings.

OK. Thanks! I solved it.

[GitRowin]

Consider using my library, built on top of this library: https://github.com/GitRowin/orderedmapjson