base_token.rs

#![feature(proc_macro)]
extern crate mock_derive;
#[allow(dead_code)]
#[mock]
extern "C" {
    pub fn _read(x: Vec<u8>) -> Vec<u8>;
}
use mock_derive::mock;
extern crate rmp;
extern crate rmp_serialize;
extern crate rustc_serialize;
use rustc_serialize::{Encodable, Decodable};
use rmp_serialize::{Encoder, Decoder};

macro_rules! function {
    () => ();
    ($func_name:ident($buffer:ident: &[u8]) -> $t:ident $body:block) => (
        pub fn $func_name($buffer: &[u8]) -> [u8; 3]{
            unsafe {
                let run = || $body;
                let result = run();
                let mut buf2 = [0u8; 3];

                result.encode(&mut Encoder::new(&mut &mut buf2[..]));

                buf2
            }
        }
    );

    ($func_name:ident($buffer:ident: &[u8], $v1:ident: address)  -> $t:ident $body:block) => (
        function!($func_name($buffer: &[u8]) -> $t {
            let mut decoder = Decoder::new(&$buffer[..]);
            let $v1: [u8; 3] = Decodable::decode(&mut decoder).unwrap();
            $body
        });
    );
    ($func_name:ident($buffer:ident: &[u8], $($v1:ident: $t1:ident, $v2:ident: address),+)  -> $t:ident $body:block) => (
        function!($func_name($buffer: &[u8], $($v1: $t1)*) -> $t {
            let mut decoder = Decoder::new(&$buffer[..]);
            let $($v2)*: [u8; 3] = Decodable::decode(&mut decoder).unwrap();
            $body
        });
    );
    ($func_name:ident($($v1:ident: $t1:ident, $v2:ident: $t2:ident),+) -> $t:ident $body:block) => (
        function!($func_name(buf: &[u8], $($v1: $t1, $v2: $t2)*) -> $t {
            $body
        });
    );
}

fn read(key: [u8; 3]) -> u32 {
    unsafe {
        _read(key.to_vec());
    }
}

// Below here is the acutal contract

function![balance_of(address: address) -> u32 {
    read(address)
}];