Examples

Learning by example is one of the best ways to get familiar with Arbiter.

Ping, Pong!

The classic Actor model example: Ping Pong. We want an actor that acts as a Counter and responds to Ping messages.

#![allow(unused)]
fn main() {
use arbiter::prelude::*;

#[derive(Debug, Clone)]
pub struct Ping;

#[derive(Debug, Clone)]
pub struct Counter {
    pub count: usize,
}

impl LifeCycle for Counter {
    type Snapshot = usize;
    type StartMessage = ();
    type StopMessage = ();

    fn on_start(&mut self) -> Self::StartMessage {}
    fn on_stop(&mut self) -> Self::StopMessage {}
    fn snapshot(&self) -> Self::Snapshot { self.count }
}

impl Handler<Ping> for Counter {
    type Reply = (); // We aren't replying to the ping here

    fn handle(&mut self, _message: &Ping) -> Option<Self::Reply> {
        self.count += 1;
        println!("Received Ping! Count: {}", self.count);
        None
    }
}
}

The WASM Leader / Follower Example

Arbiter supports compiling to WebAssembly (wasm32-unknown-unknown). In the examples/leader/ directory, you’ll find a complete web application utilizing Arbiter actors to control UI components on an HTML canvas.

The example demonstrates:

• A Leader actor that moves autonomously.
• Follower actors that track and chase the leader.
• An overarching Canvas actor the manages rendering by interpreting the PositionUpdate messages emitted by agents.

Running the Leader Example

To run the example locally, navigate to examples/leader and follow the README.md instructions there, or run the build directly using your preferred WASM server.

The TCP Chat CLI Example

Arbiter’s TcpStream network allows actors to communicate over a local network. The examples/chat/ directory contains a decentralized chat application that demonstrates:

• Distributed Actors: Actors on different nodes connecting and exchanging messages.
• Mesh Networking: Automatic peer discovery and connection via a gossip protocol.
• Dynamic Registration: Automatic type registration for complex serializable types across nodes.
• Socket Injection: Using Runtime::socket() to bridge external input (keyboard/stdin) into the actor network.

Running the Chat Example

1. Open a terminal and start the first node (Alice):

   cargo run --example chat -- --name Alice
   

2. Alice will display her listening address (e.g., 192.168.1.10:51234).
3. Open another terminal and start the second node (Bob), connecting to Alice:

   cargo run --example chat -- --name Bob --connect <ALICE_IP>:<PORT>
   

4. Start a third node (Charlie) and connect it to either Alice or Bob. Thanks to the mesh gossip protocol, Charlie will automatically discover and connect to the other node, forming a complete three-way chat!
5. Type messages in any terminal to see them delivered in real-time across the entire mesh!