Why Option::from_json expected array?

[kkkiio]

I would like Int? to accept either Number(1) or Null when parsing from JSON.
For now I have to define Nullable[T] as a workaround:

///|
priv type Nullable[T] T? derive(Show)

///|
impl[T : @json.FromJson] @json.FromJson for Nullable[T] with from_json(
  json,
  path
) {
  if json is Null {
    None
  } else {
    Some(@json.from_json!(json, path~))
  }
}

[peter-jerry-ye]

Because otherwise you can't represent Some(None) for Option[Option[A]]