1. Run Unity, open scene in Assets/Scenes
2. Start the Unity server click the Play button, it's running at the following address: ws://localhost:1234.
3. Run stack repl in dimension-gate/scripting-api
4. Run runDGTest in the repl (Only works after you click Play because runDG connects to the Unity websocket engine on address ws://localhost:1234)

DimensionGate Websockets Server starts from the DimensionGateClient script which is placed on the Core object in the Scene hierarchy.

If you want to send something to the Haskell websocket client then use DimensionGateServer.inst.send("A string that will go to the Haskell client");

For example, in the DimensionGateClient there is the code bellow:

void Update () {
    if (Input.GetKeyDown(KeyCode.F)) {
        DimensionGateServer.inst.send("F");
    }
}

It means when we press Play, focus on the game window in the Unity editor and press the F button, then the "F" message is sent to the Haskell websockets client.

If you want to handle a message that Haskell websocket client sends, go to the DimensionGateServer class and and respond in the OnMessage function. BE CAREFUL, you can't just run Unity functions in the OnMessage callback because it's running not in the Unity thread, so to run something that uses MonoBehaviour or some another Unity API, use the next function:

UnityMainThreadDispatcher.Instance().Enqueue(() => {
    // Write some Unity code
})

For example, in the OnMessage function we have the following code:

if (e.Data == "Set camera to 0, 0") {
    UnityMainThreadDispatcher.Instance().Enqueue(() => {
        PlayerCamera.inst.setPosition(new Vector2(0, 0));
    });
}

It means that when Haskell websockets client sends to the Unity websockets server the message Set camera to 0, 0 the function PlayerCamera.inst.setPosition(new Vector2(0, 0)); is ran with the help of the UnityMainThreadDispatcher.Instance().Enqueue(() => { ... }) function.

Read the scripting-api/README.md file.