Orkuncakilkaya
c64f8750e2
What only becomes known inside the drain - a value another reducer just set, the map in play - no longer has to be faked into the action, so a verb that reads several systems while it changes one is a reducer instead of an act handed its states. A second state to write is still refused, and the message says the way out. examples/actions/reads.ludic; reseeded. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
23 lines
827 B
Text
23 lines
827 B
Text
# 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}`)
|
|
}
|
|
}
|