ludic/examples/lang/lifecycle.ludic

# lifecycle.ludic — a game's whole lifecycle as @-hooks. Each fires at one point
# on the timeline and reduces to ordinary code, so nothing is hidden and the
# data-oriented model is untouched. Running it prints: 1 700 50 950 2 — one line
# per hook, in the order the timeline reaches them.
#
#   boot ── @OnStart ──▶ spawn ── @OnAttach, @OnSpawn ──▶ … ── @OnDespawn ──▶ quit ── @OnQuit
program Life {
  property Health { hp: int = 0, max: int = 100 }
  property Sprite { id: int = 0 }
  model Enemy { Health, Sprite }

  # ---- program lifecycle -----------------------------------------------------
  @OnStart handler Boot { print(1) }               # once, at boot
  @OnQuit  handler Bye  { print(2) }               # once, at shutdown

  # ---- property / entity lifecycle -------------------------------------------
  @OnAttach(Sprite)  handler Load  { print(Sprite.id + 700) }   # when a Sprite is attached
  @OnSpawn(Enemy)    handler Init  { Health.hp = Health.max }        # constructor
  @OnDespawn(Enemy)  handler Clean { print(Health.hp + 900) }    # destructor (dispatched by kind)

  handler Seed phase Start { spawn Enemy { Health { max: 50 } } }

  handler Run phase Render {
    for (h) in query [Health] { print(h.hp) }      # 50 — Init set hp to max
    for (e) in query [Health] { despawn self() }        # Clean fires: 50 + 900 = 950
    quit()
  }
}