ludic/docs/language/networking/fn-net_poll.md

id	name	category	kind	tokens	sig	tip	order
fn-net_poll	net_poll	networking	builtin	net_poll	net_poll(buf, cap) -> int	Receive queued bytes from the transport; returns the byte count.	1

net_poll copies up to cap waiting bytes into buf and returns how many actually arrived, or 0 when nothing is queued. It is the read half of the transport seam and the counterpart to net_send; each poll yields one datagram, so drain in a loop until it returns 0. Once you have the bytes you fold them back into a model instance with the generated apply — for a self-describing frame, write the entity id into the first word on send and read it back here before applying. Like net_send, this is the freedom layer beneath @Sync; most games never call it directly.

Parameters:

• buf — the destination buffer to copy received bytes into
• cap — the maximum number of bytes to accept this call

program ReceivePlayer {
  @Sync property Position { column: int = 0, row: int = 0 }
  @Owned model Player { @Sync Position }

  entry {
    spawn Player { Position { column: 0, row: 0 } }
    let incoming_bytes = words(512)
    var received_count = net_poll(incoming_bytes, 2048)
    while received_count > 0 {
      let target_id = incoming_bytes[0]                          # entity id led the frame
      apply(target_id, offset(incoming_bytes, 4), received_count - 4)
      received_count = net_poll(incoming_bytes, 2048)            # next datagram, if any
    }
  }
}