Examples with Supplier java8.util.function.Supplier used on opensource projects

Example 6 with Supplier

use of java8.util.function.Supplier in project streamsupport by stefan-zobel.

the class Collection8Test method testRemoveAfterForEachRemaining.

/**
 * Calling Iterator#remove() after Iterator#forEachRemaining
 * should (maybe) remove last element
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
@Test(dataProvider = "Source")
public void testRemoveAfterForEachRemaining(String description, Supplier<CollectionImplementation> sci) {
    CollectionImplementation impl = sci.get();
    Collection c = impl.emptyCollection();
    ThreadLocalRandom rnd = ThreadLocalRandom.current();
    testCollection: {
        int n = 3 + rnd.nextInt(2);
        for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
        Iterator<?> it = c.iterator();
        assertTrue(it.hasNext());
        assertEquals(impl.makeElement(0), it.next());
        assertTrue(it.hasNext());
        assertEquals(impl.makeElement(1), it.next());
        Iterators.forEachRemaining(it, e -> assertTrue(c.contains(e)));
        if (testImplementationDetails) {
            if (c instanceof java.util.concurrent.ArrayBlockingQueue) {
                assertIteratorExhausted(it);
            } else {
                try {
                    it.remove();
                } catch (UnsupportedOperationException ok) {
                    break testCollection;
                }
                assertEquals(n - 1, c.size());
                for (int i = 0; i < n - 1; i++) assertTrue(c.contains(impl.makeElement(i)));
                assertFalse(c.contains(impl.makeElement(n - 1)));
            }
        }
    }
    if (c instanceof Deque) {
        Deque d = (Deque) impl.emptyCollection();
        int n = 3 + rnd.nextInt(2);
        for (int i = 0; i < n; i++) d.add(impl.makeElement(i));
        Iterator<?> it = d.descendingIterator();
        assertTrue(it.hasNext());
        assertEquals(impl.makeElement(n - 1), it.next());
        assertTrue(it.hasNext());
        assertEquals(impl.makeElement(n - 2), it.next());
        Iterators.forEachRemaining(it, e -> assertTrue(c.contains(e)));
        if (testImplementationDetails) {
            it.remove();
            assertEquals(n - 1, d.size());
            for (int i = 1; i < n; i++) assertTrue(d.contains(impl.makeElement(i)));
            assertFalse(d.contains(impl.makeElement(0)));
        }
    }
}

Example 7 with Supplier

use of java8.util.function.Supplier in project streamsupport by stefan-zobel.

the class Collection8Test method testForEach.

/**
 * collection.forEach returns elements in the collection
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
@Test(dataProvider = "Source")
public void testForEach(String description, Supplier<CollectionImplementation> sci) throws Throwable {
    CollectionImplementation impl = sci.get();
    final Collection c = impl.emptyCollection();
    // final AtomicLong count = new AtomicLong(0L);
    final Object x = impl.makeElement(1);
    final Object y = impl.makeElement(2);
    final ArrayList found = new ArrayList();
    Consumer<Object> spy = o -> found.add(o);
    Iterables.forEach(c, spy);
    assertTrue(found.isEmpty());
    assertTrue(c.add(x));
    Iterables.forEach(c, spy);
    assertEquals(Collections.singletonList(x), found);
    found.clear();
    assertTrue(c.add(y));
    Iterables.forEach(c, spy);
    assertEquals(2, found.size());
    assertTrue(found.contains(x));
    assertTrue(found.contains(y));
    found.clear();
    c.clear();
    Iterables.forEach(c, spy);
    assertTrue(found.isEmpty());
}

Example 8 with Supplier

use of java8.util.function.Supplier in project streamsupport by stefan-zobel.

the class CompletableFutureTest method testCompleteAsync3.

/**
 * completeAsync with given executor completes with value of given supplier
 */
public void testCompleteAsync3() {
    for (Integer v1 : new Integer[] { 1, null }) {
        CompletableFuture<Integer> f = new CompletableFuture<>();
        ThreadExecutor executor = new ThreadExecutor();
        f.completeAsync(() -> v1, executor);
        assertSame(v1, f.join());
        checkCompletedNormally(f, v1);
        assertEquals(1, executor.count.get());
    }
}

Example 9 with Supplier

use of java8.util.function.Supplier in project streamsupport by stefan-zobel.

the class CompletableFutureTest method testCompleteAsync.

/**
 * completeAsync completes with value of given supplier
 */
public void testCompleteAsync() {
    for (Integer v1 : new Integer[] { 1, null }) {
        CompletableFuture<Integer> f = new CompletableFuture<>();
        f.completeAsync(() -> v1);
        f.join();
        checkCompletedNormally(f, v1);
    }
}

Example 10 with Supplier

use of java8.util.function.Supplier in project streamsupport by stefan-zobel.

the class TestDoubleSumAverage method testForCompensation.

/**
 * Compute the sum and average of a sequence of double values in
 * various ways and report an error if naive summation is used.
 */
private static int testForCompensation() {
    int failures = 0;
    /*
         * The exact sum of the test stream is 1 + 1e6*ulp(1.0) but a
         * naive summation algorithm will return 1.0 since (1.0 +
         * ulp(1.0)/2) will round to 1.0 again.
         */
    final double base = 1.0;
    final double increment = Math.ulp(base) / 2.0;
    final int count = 1000001;
    double expectedSum = base + (increment * (count - 1));
    double expectedAvg = expectedSum / count;
    // Factory for double a stream of [base, increment, ..., increment] limited to a size of count
    Supplier<DoubleStream> ds = new Supplier<DoubleStream>() {

        @Override
        public DoubleStream get() {
            return DoubleStreams.iterate(base, new DoubleUnaryOperator() {

                @Override
                public double applyAsDouble(double e) {
                    return increment;
                }
            }).limit(count);
        }
    };
    DoubleSummaryStatistics stats = ds.get().collect(new Supplier<DoubleSummaryStatistics>() {

        @Override
        public DoubleSummaryStatistics get() {
            return new DoubleSummaryStatistics();
        }
    }, (ObjDoubleConsumer<DoubleSummaryStatistics>) new ObjDoubleConsumer<DoubleSummaryStatistics>() {

        @Override
        public void accept(DoubleSummaryStatistics doubleSummaryStatistics, double v) {
            doubleSummaryStatistics.accept(v);
        }
    }, (BiConsumer<DoubleSummaryStatistics, DoubleSummaryStatistics>) new BiConsumer<DoubleSummaryStatistics, DoubleSummaryStatistics>() {

        @Override
        public void accept(DoubleSummaryStatistics doubleSummaryStatistics, DoubleSummaryStatistics doubleSummaryStatistics2) {
            doubleSummaryStatistics.combine(doubleSummaryStatistics2);
        }
    });
    failures += compareUlpDifference(expectedSum, stats.getSum(), 3);
    failures += compareUlpDifference(expectedAvg, stats.getAverage(), 3);
    failures += compareUlpDifference(expectedSum, ds.get().sum(), 3);
    failures += compareUlpDifference(expectedAvg, ds.get().average().getAsDouble(), 3);
    failures += compareUlpDifference(expectedSum, ds.get().boxed().collect(Collectors.summingDouble(new ToDoubleFunction<Double>() {

        @Override
        public double applyAsDouble(Double d) {
            return d;
        }
    })), 3);
    failures += compareUlpDifference(expectedAvg, ds.get().boxed().collect(Collectors.averagingDouble(new ToDoubleFunction<Double>() {

        @Override
        public double applyAsDouble(Double d) {
            return d;
        }
    })), 3);
    return failures;
}