Examples with Value javaslang.Value used on opensource projects

Example 1 with Value

use of javaslang.Value in project javaslang by javaslang.

the class Future method find.

/**
     * Returns a {@code Future} that eventually succeeds with the first result of the given {@code Future}s which
     * matches the given {@code predicate}. If no result matches, the {@code Future} will contain {@link Option.None}.
     * <p>
     * The returned {@code Future} is backed by the given {@link ExecutorService}.
     *
     * @param executorService An executor service.
     * @param futures         An iterable of futures.
     * @param predicate       A predicate that tests successful future results.
     * @param <T>             Result type of the futures.
     * @return A Future of an {@link Option} of the first result of the given {@code futures} that satisfies the given {@code predicate}.
     * @throws NullPointerException if one of the arguments is null
     */
static <T> Future<Option<T>> find(ExecutorService executorService, Iterable<? extends Future<? extends T>> futures, Predicate<? super T> predicate) {
    Objects.requireNonNull(executorService, "executorService is null");
    Objects.requireNonNull(futures, "futures is null");
    Objects.requireNonNull(predicate, "predicate is null");
    final Promise<Option<T>> promise = Promise.make(executorService);
    final List<Future<? extends T>> list = List.ofAll(futures);
    if (list.isEmpty()) {
        promise.success(Option.none());
    } else {
        final AtomicInteger count = new AtomicInteger(list.length());
        list.forEach(future -> future.onComplete(result -> {
            synchronized (count) {
                if (!promise.isCompleted()) {
                    final boolean wasLast = count.decrementAndGet() == 0;
                    result.filter(predicate).onSuccess(value -> promise.trySuccess(Option.some(value))).onFailure(ignored -> {
                        if (wasLast) {
                            promise.trySuccess(Option.none());
                        }
                    });
                }
            }
        }));
    }
    return promise.future();
}