elm architecture in rust

test.rs

use ten::prelude::*;
use ten::prelude::time::{Time, Instant};


#[derive(Debug)]
pub enum Msg {
    Tick(Instant),
}

#[derive(Debug)]
pub struct Model {
    tick_count: u64,
}

fn init(_: Nothing) -> (Model, Cmd<Msg>) {
    (Model { tick_count: 0 }, Cmd::none())
}

fn update(msg: Msg, mut model: Model) -> (Model, Cmd<Msg>) {
    match msg {
        Msg::Tick(_) => {
            model.tick_count += 1;
            println!("ticks {}", model.tick_count);
            let cmd = if model.tick_count >= 20 {
                Cmd::batch([Process::exit(0)])
            } else {
                Cmd::none()
            };
            (model, cmd)
        }
    }
}

fn subscriptions(model: &Model) -> Sub<Msg> {
    // Do ten fast ticks and then slow ticks
    let interval = if model.tick_count < 10 { 100 } else { 1000 };
    Time::every_ms(interval, Msg::Tick)
}

fn main() {
    let app = Worker::application(init, update, subscriptions);
    Runtime::run_program(app, Nothing);
}