orderedmapjson

orderedmapjson is a package that extends the orderedmap package by adding support for JSON marshalling and unmarshalling. Keys are required to be strings, as per the JSON specification.

Installation

go get github.com/GitRowin/orderedmapjson

Usage

The library provides two types: TypedOrderedMap and AnyOrderedMap. It also provides an UnmarshalArrayWithAnyOrderedMap function.

TypedOrderedMap

TypedOrderedMap allows you to specify the value type of the map.

m := orderedmapjson.NewTypedOrderedMap[int]()

m.Set("q", 1)
m.Set("w", 2)
m.Set("e", 3)
m.Set("r", 4)
m.Set("t", 5)
m.Set("y", 6)

b, err := json.Marshal(m)

if err != nil {
    panic(err)
}

fmt.Println(string(b)) // Output: {"q":1,"w":2,"e":3,"r":4,"t":5,"y":6}

AnyOrderedMap

AnyOrderedMap is similar to TypedOrderedMap[any], with one key difference: it unmarshals JSON objects at any level as AnyOrderedMap[any] rather than map[string]any. This ensures that the order of nested objects is preserved too.

const input = `{"foo":"bar","obj":{"2":2,"3":"3","1":1},"baz":[1, "2", 3, null]}`

var m *orderedmapjson.AnyOrderedMap
if err := json.Unmarshal([]byte(input), &m); err != nil {
    panic(err)
}

if obj, ok := m.Get("obj"); ok {
    fmt.Printf("%T %v\n", obj, obj) // Output: *orderedmapjson.AnyOrderedMap {2:2,3:3,1:1}
}

if baz, ok := m.Get("baz"); ok {
    fmt.Println(baz.([]any)[2]) // Output: 3
}

UnmarshalArrayWithAnyOrderedMap

UnmarshalArrayWithAnyOrderedMap unmarshals a JSON array. Like AnyOrderedMap, it unmarshals JSON objects at any level as AnyOrderedMap[any] rather than map[string]any.

const input = `["foo",1,{"3":"3","1":"1","2":"2"}]`

values, err := orderedmapjson.UnmarshalArrayWithAnyOrderedMap([]byte(input))

if err != nil {
    panic(err)
}

fmt.Println(values[2]) // Output: {3:3,1:1,2:2}