keyword
self
self()
self() yields the model instance currently being visited by the innermost enclosing query loop, as an entity handle. It is how a handler names "the instance this pass is about" — most often to despawn self(), to attach/detach a property on self(), or to pass the current instance to a function. Because it depends on the active query iteration, self() is only meaningful inside a for (…) in query […] loop (or a @Queries handler, which desugars to one). Outside any query it has no instance to refer to.
Example
program Reaper {
property Position { column: int = 0, row: int = 0 }
property Health { current: int = 100, maximum: int = 100 }
model Enemy { Position, Health }
handler Boot phase Start {
spawn Grunt { Position { column: 1, row: 1 }; Health { current: 0 } }
}
handler RemoveDefeated phase LateUpdate {
for (health) in query [Health, {Enemy}] {
if health.current <= 0 { despawn self() }
}
}
}