Struct Engine 

pub struct Engine {
    pub model: AppModel,
    /* private fields */
}

What one running yog is, minus its face. The model is public because a face renders it; the three threads are held only so they live as long as the engine and are stopped and joined when it drops (each owns that shape itself — §7.2).

Fields

model: AppModel

Implementations

impl Engine

pub fn serve(ambient: &Env, overrides: &[(String, String)])

Run the engine until a §8.5 stop is asked for. Converge the world’s tool shims (§8.4, bl-44a5 — the world PATH names that dir unconditionally, so every face that hands the world out seeds it), catch the signal before the engine exists so a stop during boot is not lost, then park. Returns when the engine has stopped and joined every thread it spawned; the caller’s only remaining act is to exit.

impl Engine

pub fn park_until_stopped(self)

The windowless face’s whole loop — park until a stop is asked for, then drop the engine. Takes self by value so that returning from it and stopping the engine are the same act: there is no way to park without the drop, which is exactly the defect this closes.

impl Engine

pub fn boot( world: &Env, overrides: &[(String, String)], clock: Arc<dyn Clock>, ) -> Self

Boot the engine into world (already composed, §16.2) with overrides standing on every child spawn.

The §5.2 startup sweep runs here rather than at either caller: dropping stale scratch is the engine’s housekeeping, and its wall clock is the injected Clock every other timestamp already comes from — so a test advances it like anything else. It is both of §5.2’s transient artifacts off one clock read: the scripted-editor staging dirs, and (bl-e47c) the I3 temps left in the destination directories yog writes through — the half the doc had promised since I3 and nobody had written.