function CatEmitter() { }
CatEmitter.prototype._listeners = {};
CatEmitter.prototype.on = function(name, cb) {
  if (!this._listeners[name]) this._listeners[name] = [];
  for (let i = 0; i < this._listeners[name].length; i++) {
    if (this._listeners[name][i] === cb) return false; // already exists
  }
  this._listeners[name].push(cb);
  return true;
}
CatEmitter.prototype.removeListener = function(name, cb) {
  if (!this._listeners[name]) return;
  for (let i = 0; i < this._listeners[name].length; i++) {
    if (this._listeners[name][i] === cb) {
      this._listeners[name].splice(i, 1);
      return true;
    }
  }
  return false;
}
CatEmitter.prototype.emit = function(name, data) {
  if (!this._listeners[name]) return;
  for (let i = 0; i < this._listeners[name].length; i++) {
    if (this._listeners[name][i](data) === false) return false; // exit early if false is returned
  }
  return true;
}

module.exports = CatEmitter;