# reads.ludic - 0.R5: a reducer writes one state and may READ others, declared between its state and
# the action: what only becomes known inside the drain (a price another reducer set) need not ride in
# the action, and still no reducer changes a state it does not own.
program ReducerReads {
  state Shop { price: int = 3 }
  state Wallet { cash: int = 10 }
  state Pack { n: int = 0 }
  action Rise { by: int }
  action Buy { }

  reducer Shop on Rise(s: mut Shop, a: Rise) { s.price += a.by }
  reducer Wallet on Buy(w: mut Wallet, s: Shop, a: Buy) {
    if w.cash >= s.price { w.cash -= s.price }
  }
  reducer Pack on Buy(p: mut Pack, w: Wallet, a: Buy) { p.n += 1 }

  entry (s: Shop, w: Wallet, p: Pack) {
    dispatch Rise { by: 2 }
    dispatch Buy { }
    drain_actions()
    print(`{s.price} {w.cash} {p.n}`)
  }
}