Struct NearestCarDispatch 

pub struct NearestCarDispatch;

Scores (car, stop) by absolute distance between the car and the stop.

Paired with the Hungarian assignment in the dispatch system, this yields the globally minimum-total-distance matching across the group — no two cars can be sent to the same hall call.

Two guards are applied on top of the raw distance, both via the shared pair_is_useful predicate:

1. The (car, stop) pair must be serviceable — at least one aboard rider can exit, or at least one waiting rider can fit. A full car at a pickup stop it cannot serve otherwise self-assigns at zero cost (doors cycle open → reject → close forever).
2. A car carrying riders refuses pickups that would pull it backward (off the path to every aboard rider’s destination). Without this, a stream of closer-destination boarders can indefinitely preempt a farther aboard rider’s delivery — the reported “never reaches the passenger’s desired stop” loop.

Implementations

impl NearestCarDispatch

pub const fn new() -> Self

Create a new NearestCarDispatch.

Trait Implementations

impl Default for NearestCarDispatch

fn default() -> Self

Returns the “default value” for a type.

impl DispatchStrategy for NearestCarDispatch

fn rank(&mut self, ctx: &RankContext<'_>) -> Option<f64>

Score the cost of sending car to stop. Lower is better.

fn builtin_id(&self) -> Option<BuiltinStrategy>

If this strategy is a known built-in variant, return it so Simulation::new can stamp the correct BuiltinStrategy into the group’s snapshot identity.

fn pre_dispatch( &mut self, _group: &ElevatorGroup, _manifest: &DispatchManifest, _world: &mut World, )

Optional hook called once per group before the assignment pass.

fn prepare_car( &mut self, _car: EntityId, _car_position: f64, _group: &ElevatorGroup, _manifest: &DispatchManifest, _world: &World, )

Optional hook called once per candidate car, before any rank calls for that car in the current pass.

fn fallback( &mut self, _car: EntityId, _car_position: f64, _group: &ElevatorGroup, _manifest: &DispatchManifest, _world: &World, ) -> DispatchDecision

Decide what an idle car should do when no stop was assigned to it.

fn notify_removed(&mut self, _elevator: EntityId)

Notify the strategy that an elevator has been removed.

fn snapshot_config(&self) -> Option<String>

Serialize this strategy’s tunable configuration to a string that restore_config can apply to a freshly-instantiated instance.

fn restore_config(&mut self, _serialized: &str) -> Result<(), String>

Restore tunable configuration from a string previously produced by snapshot_config on the same strategy variant. Called by crate::snapshot::WorldSnapshot::restore immediately after BuiltinStrategy::instantiate builds the default instance, so the restore writes over the defaults.