Extracting presences from message in authoritative multiplayer

Runtime Framework
1

Reading the docs on the go runtime, I came across this:

func (m *Match) MatchLoop(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, dispatcher runtime.MatchDispatcher, tick int64, state interface{}, messages []runtime.MatchData) interface{} {
    mState, _ := state.(*MatchState)

    for _, presence := range mState.presences {
        logger.Info("Presence %v named %v", presence.GetUserId(), presence.GetUsername())
    }

    for _, message := range messages {
        logger.Info("Received %v from %v", string(message.GetData()), message.GetUserId())
        reliable := true
        dispatcher.BroadcastMessage(1, message.GetData(), []runtime.Presence{message}, reliable)
    }

    return mState
}

I am not sure of what []runtime.Presence{message} means

I am not so hot on go yet, but I read this as “create a slice of presences from this message”

Does this mean that it creates a slice with a single element with the sender of the message?

(PS: unrelated but… doesn’t BroadcastMessage have an extra sender parameter before reliable?)

2

Does this mean that it creates a slice with a single element with the sender of the message?

Yes, but message implements the Presence interface so it works - duck-typing :slight_smile:

(PS: unrelated but… doesn’t BroadcastMessage have an extra sender parameter before reliable ?)

Yes, good catch - probably need docs update - cc @gabriel plz fix :).