Trait SimState

Source

pub trait SimState {
    // Required methods
    fn get_effect(&self) -> Effect;
    fn set_effect(&mut self, effect: Effect);
    fn should_log(&self) -> bool;
}

Expand description

Data structures implementing this trait can be yielded from the coroutine associated with a Process. This allows attaching application-specific data to Effects. This data is then carried arround by the Simulation, passed into user callbacks for context or simply logged for later.

As a simple example, implementing SimState for a type (as shown for ItemState below) allows users to track item stages.

A process can then yield ItemState instead of Effect types:

#![feature (coroutines, coroutine_trait)]
use desim::{Effect, SimState, Simulation};

// enum used as part of state logged during simulation
#[derive(Clone)]
enum StageType {
    FirstPass,
    SecondPass,
}

// structure yielded from processes of the simulation
#[derive(Clone)]
struct ItemState {
    stage: StageType,
    effect: Effect,
    log: bool,
}

impl SimState for ItemState {
    fn get_effect(&self) -> Effect { self.effect }
    fn set_effect(&mut self, e: Effect) { self.effect = e; }
    fn should_log(&self) -> bool { self.log }
}

let mut sim = Simulation::new();
sim.create_process(Box::new(move |_| {
    yield ItemState { stage: StageType::FirstPass,
                      effect: Effect::TimeOut(10.0),
                      log: true,
                    };
}));