ludic/examples/networking/net_rpc.ludic

# net_rpc.ludic — N4: remote events / RPCs (NETWORKING-DESIGN §6.4, §13 N4).
#
# An `event` marked @ToServer (client→server) or @ToClients (server→clients) is a
# directional remote event — the event bus with a direction flag, no new concept.
# At an `emit` site the POD payload is serialized as [event id][fields] and
# net_send in its direction; net_pump() drains inbound frames and re-emits each
# into the ordinary @On dispatch on the far side. So `emit Fire(...)` is a remote
# call — it does not run locally; the receiver's pump runs the handler.
#
# Here two Fire RPCs are emitted (dir 5, dir 3). Before net_pump the handler has
# not run (hits still 0); after, both are drained and re-emitted (5 + 3 = 8).
program NetRpc {
  property Log { hits: int = 0 }
  model Sink { Log }

  @ToServer event Fire { dir: int = 0 }
  @On(Fire) handler OnFire {
    for (Log) in query [Log] { Log.hits = Log.hits + dir }
  }

  entry {
    spawn Sink { Log { hits: 0 } }
    emit Fire(dir: 5)                     # serialized onto the wire (not run locally)
    emit Fire(dir: 3)
    for (Log) in query [Log] { print(Log.hits) }   # 0
    net_pump()                            # drain + re-emit both RPCs
    for (Log) in query [Log] { print(Log.hits) }   # 8
  }
}