export function fireEvent<T> (event: Event<T>): Event<T> {
  return (listener: (e: T) => any, thisArgs?: any, disposables?: Disposable[]) => event(_ => (listener as any).call(thisArgs), null, disposables);
}

export function mapEvent<I, O> (event: Event<I>, map: (i: I) => O): Event<O> {
  return (listener: (e: O) => any, thisArgs?: any, disposables?: Disposable[]) => event(i => listener.call(thisArgs, map(i)), null, disposables);
}

/**
 * Create a new event that wraps an event and fires the first time the wrapped event
 * fires, then disposes of itself.
 * @param event The event to wrap.
 */