#![feature(nll)]
#[derive(Debug)]
pub enum Command {
    Add(i32),
}

#[derive(Debug)]
pub struct Cpu {
    commands: Vec<Command>,
    pc: usize,
    acc: i32,
}

#[derive(Debug)]
pub struct Block {
    commands: Vec<Command>,
    pc: usize,
    acc: i32,
}

impl Block {
    pub fn new<T>(iter: T) -> Block
    where
        T: IntoIterator<Item = Command>,
    {
        Block {
            commands: iter.into_iter().collect(),
            pc: 0,
            acc: 0,
        }
    }

    pub fn step(&mut self) {
        match &self.commands[self.pc] {
            Command::Add(i) => self.add(i),
        };
    }

    fn add(&mut self, op: &i32) {
        self.acc += op;
    }
}

fn main() {
    let mut block = Block::new(vec![Command::Add(1)]);
    block.step();
    println!("{:#?}", block);
}