derive Serialize Deserialize macros

[xlc]

Add derive macro to for auto serialization and deserialization implementation generation.

[jimmychu0807]

@xlc I want to try to tackle this issue.

Currently, I am using code here to get a certain value/object out from JsonValue. But this is kind of tedious. Will be nice if we can do something like what serde does.

use serde::{Serialize, Deserialize};

#[derive(Serialize, Deserialize, Debug)]
struct Point {
    x: i32,
    y: i32,
}

fn main() {
    let point = Point { x: 1, y: 2 };

    let serialized = serde_json::to_string(&point).unwrap();
    println!("serialized = {}", serialized);

    let deserialized: Point = serde_json::from_str(&serialized).unwrap();
    println!("deserialized = {:?}", deserialized);

     // So in lite-json
    let deserialized2: Point = lite_json::parse_json(&serialized).unwrap().deserialize().unwrap();
}

I am still not sure about the implementation yet. How hard would it be to do something like this in no_std env?

[xlc]

@jimmychu0807 I have started it at #13 and you are welcome to finish it. You can PR into derive branch.

Current status is it compiles, but I never ran it once so likely missing a lot of details.

The code is heavily inspired by parity-scale-codec.

[jimmychu0807]

Thanks. Let me take a look

[justinfrevert]

I would love to see this 🤞