annotation

@Writes

@Writes(Property)

@Writes(Property) declares that a handler writes the named property. Like @Reads it is an analysis hint that documents a handler's data footprint so tooling and scheduling can reason about conflicts — two handlers that write the same property, or one that writes what another reads, cannot be reordered freely. It does not bind fields or grant access on its own; the handler still queries and mutates the property in its body as usual. Declaring reads and writes together makes a handler's effect on the world legible at a glance, which matters most in a large, modular codebase. Keep the named property accurate so the declared footprint matches the code.

Example

program WriteFootprint {
  property Health { current: int = 100 }
  model Enemy { Health }

  @Reads(Health) @Writes(Health)                     # full read/write footprint
  handler ApplyPoison phase Update {
    for (Health) in query [Health, {Enemy}] {
      Health.current = Health.current - 1
    }
  }

  handler SpawnEnemy phase Start {
    spawn Enemy { Health { current: 100 } }
  }
}

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