sS hInitWebSocket(O... _) {
  optPar S onOpen;
  optPar S onMessage;
  optPar S readyMsg = "WebSocket ready!";
  ret hreconnectingWebSockets()
    + hscript([[
      var wsReady = false;
      var ws = new ReconnectingWebSocket(((window.location.protocol === "https:") ? "wss://" : "ws://") + window.location.host + "/");
      ws.onopen = function(event) {
        console.log(]] + readyMsg + [[);
      ]] + unnull(onOpen) + [[ };
      ws.onmessage = function(event) {
        ]] + unnull(onMessage) + [[
      };
    ]]);
}