json.rs

// http://is.gd/gWewbP
extern mod extra;

use extra::treemap::TreeMap;
use extra::json::ToJson;
use extra::serialize::Decodable;
use json = extra::json;

// structs are required for decoding a JSON object into a Rust object
#[deriving(Decodable)]
struct Person {
    name: ~str,
    age: int
}

fn main() {
    // messing around with TreeMap
    println("Creating a TreeMap object");
    let mut person = ~TreeMap::new();
    person.insert(~"name", (~"Rudolf").to_json());
    person.insert(~"age", (26 as int).to_json());

    println("Finding data in the TreeMap object");
    let name = person.find(&~"name").unwrap();
    let age = person.find(&~"age").unwrap();

    println(format!("name: {:s}", name.to_str()));
    println(format!("age: {:s}", age.to_str()));

    let non_existent_attr = person.find(&~"HAHAHA");
    match non_existent_attr {
        None => println("HAHAHA doesn't exist"),
        _ => println(format!("HAHAHA: {:s}", non_existent_attr.unwrap().to_str()))
    }

    // serializing/deserializing
    let mut me = ~TreeMap::new();
    me.insert(~"name", (~"Awesome Man").to_json());
    me.insert(~"age", (26 as int).to_json());
    let serialized = json::Object(me).to_str();
    println(serialized);
    let mut decoder = json::Decoder::new(json::from_str(serialized).unwrap());
    let deserialized: Person = Decodable::decode(&mut decoder);
    println(format!("Hi I'm {:s} and I'm {:d} years old.", deserialized.name, deserialized.age));
}