Rust JSON formats

rust-json.md

Be able to parse the following JSON format:

{
  "token": "ASDSD",
  "action": "Foo",
  "payload": {},
}

Where token maps to a uuid::Uuid (got this) and action maps to an ActionType enum (got this, but very verbose).

The tricky part is mapping payload to predefined structs (there's a lot of them). Some examples are:

#[derive(RustcDecodable, Debug)]
pub struct IncomingMessage<T> {
    pub token: Uuid,
    pub action: ActionType,
    pub payload: Option<T>,
}

pub struct AuthenticatePayload {
    pub id: u64,
    pub name: String,
}

pub struct MessageUserPayload {
    pub user: u64,
    pub message: String,
}

@hjr3 Yeah it's definitely a hard problem to solve when trying to avoid being super explicit. Was trying to make use of rustc-serialize's automatic decoding, but have had no luck targeting nested objects directly. Will look into your approach.