Use of Json.NET OptionTypeConverter and NullValueHandling in F#

Program.fs

open System
open Newtonsoft.Json
open OptionTypeConverter

let jsonSettings = JsonSerializerSettings()
jsonSettings.NullValueHandling <- NullValueHandling.Ignore
jsonSettings.Converters.Add(OptionTypeConverter())

let serialize obj = JsonConvert.SerializeObject obj
let serialize' obj = JsonConvert.SerializeObject(obj, jsonSettings)
let deserialize<'a> (json : string) = JsonConvert.DeserializeObject<'a>(json, OptionTypeConverter())

type Person =
  {
    id : int
    name : string
    age : option<int>
  }

let print (person : Person) =
  match person.age with
  | Some x -> printfn "%d. %s (%d)" person.id person.name person.age.Value
  | None -> printfn "%d. %s (no age given)" person.id person.name


[<EntryPoint>]
let main argv = 
  let people = [
    { id = 1; name = "[age Option.None]"; age = Option.None }
    { id = 2; name = "[age Some 10]"; age = Some 10 }
  ]

  printfn "%s" "Serialize with defaults:"
  people
  |> List.map (fun p -> serialize p)
  |> List.iter (fun j -> printfn "%s" j)

  printfn "\n%s" "Serialize with OptionTypeConverter and NullValueHandling.Ignore:"
  people
  |> List.map (fun p -> serialize' p)
  |> List.iter (fun j -> printfn "%s" j)



  let json = [
   """{"id": 3, "name": "[age provided]", age: 12}"""
   """{"id": 4, "name": "[age null]", age: null}"""
   """{"id": 5, "name": "[age missing]" }"""
   ]

  printfn "\n%s" "Deserialize with OptionTypeConverter:"
  json
  |> List.map (fun j -> deserialize<Person> j)
  |> List.iter (fun p -> print p)

  0