Struct CommandQueue 

pub struct CommandQueue { /* private fields */ }

A deferred command queue for safe structural changes during system iteration.

Instead of mutating the world directly while iterating entities, systems can queue commands and apply them after iteration completes.

Example

use cougr_core::commands::CommandQueue;
use cougr_core::simple_world::SimpleWorld;
use soroban_sdk::{symbol_short, Bytes, Env};

let env = Env::default();
let mut world = SimpleWorld::new(&env);
let mut commands = CommandQueue::new();

commands.spawn();
let spawned = commands.apply(&mut world);
commands = CommandQueue::new();
commands.add_component(spawned[0], symbol_short!("bullet"), Bytes::new(&env));
commands.apply(&mut world);

assert!(world.has_component(spawned[0], &symbol_short!("bullet")));

Implementations

impl CommandQueue

pub fn new() -> Self

Create an empty command queue.

pub fn spawn(&mut self)

Queue a new entity spawn. The entity ID is assigned when apply() is called.

pub fn despawn(&mut self, entity_id: EntityId)

Queue an entity despawn.

pub fn add_component( &mut self, entity_id: EntityId, component_type: Symbol, data: Bytes, )

Queue adding a component (Table storage) to an entity.

pub fn add_sparse_component( &mut self, entity_id: EntityId, component_type: Symbol, data: Bytes, )

Queue adding a component with Sparse storage to an entity.

pub fn remove_component(&mut self, entity_id: EntityId, component_type: Symbol)

Queue removing a component from an entity.

pub fn apply(self, world: &mut SimpleWorld) -> Vec<EntityId>

Apply all queued commands to the world in order.

Returns the IDs of any spawned entities (in spawn order). Consumes the queue.

pub fn is_empty(&self) -> bool

Returns whether the queue is empty.

pub fn len(&self) -> usize

Returns the number of queued commands.

Trait Implementations

impl Default for CommandQueue

fn default() -> Self

Returns the “default value” for a type.