decisions

Implements.java

public static class Result<T> implements Future<T> {
  private Future<T> future;

  private Result(Future<T> future) {
    this.future = future;
  }

  /**
   * Block until done and {@code System.exit()} with an appropriate status code.
   */
  public void blockAndExit() {
    blockAndExit(System::exit);
  }

  void blockAndExit(Consumer<Integer> exiter) {
    try {
      future.get();
      exiter.accept(0);
    } catch (ExecutionException e) {
      final int status;
      if (e.getCause() instanceof NotReady) {
        status = 20;
      } else if (e.getCause() instanceof Persisted) {
        status = 0;
      } else {
        status = 1;
      }
      exiter.accept(status);
    } catch (RuntimeException | InterruptedException e) {
      exiter.accept(1);
    }
  }

  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    return future.cancel(mayInterruptIfRunning);
  }

  @Override
  public boolean isCancelled() {
    return future.isCancelled();
  }

  @Override
  public boolean isDone() {
    return future.isDone();
  }

  @Override
  public T get() throws InterruptedException, ExecutionException {
    return future.get();
  }

  @Override
  public T get(long timeout, TimeUnit unit)
      throws InterruptedException, ExecutionException, TimeoutException {
    return future.get(timeout, unit);
  }
}

NotImplements.java

public static class Result<T> implements Future<T> {
  private Future<T> future;

  private Result(Future<T> future) {
    this.future = future;
  }
  
  public Future<T> future() {
    return future;
  }

  /**
   * Block until done and {@code System.exit()} with an appropriate status code.
   */
  public void blockAndExit() {
    blockAndExit(System::exit);
  }

  void blockAndExit(Consumer<Integer> exiter) {
    try {
      future.get();
      exiter.accept(0);
    } catch (ExecutionException e) {
      final int status;
      if (e.getCause() instanceof NotReady) {
        status = 20;
      } else if (e.getCause() instanceof Persisted) {
        status = 0;
      } else {
        status = 1;
      }
      exiter.accept(status);
    } catch (RuntimeException | InterruptedException e) {
      exiter.accept(1);
    }
  }
}