Java Code Examples for java.util.PrimitiveIterator#OfInt

@Test(dataProvider = "cases")
public void testBitsetStream(String name, IntStream data) {
    BitSet bs = new BitSet();
    long setBits = data.distinct()
                       .peek(i -> bs.set(i))
                       .count();

    assertEquals(bs.cardinality(), setBits);
    assertEquals(bs.cardinality(), bs.stream().reduce(0, (s, i) -> s+1));

    PrimitiveIterator.OfInt it = bs.stream().iterator();
    for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
        assertTrue(it.hasNext());
        assertEquals(it.nextInt(), i);
    }
    assertFalse(it.hasNext());
}
 

/**
 * Returns an infinite sequential ordered {@code IntStream} produced by iterative
 * application of a function {@code f} to an initial element {@code seed},
 * producing a {@code Stream} consisting of {@code seed}, {@code f(seed)},
 * {@code f(f(seed))}, etc.
 *
 * <p>The first element (position {@code 0}) in the {@code IntStream} will be
 * the provided {@code seed}.  For {@code n > 0}, the element at position
 * {@code n}, will be the result of applying the function {@code f} to the
 * element at position {@code n - 1}.
 *
 * @param seed the initial element
 * @param f a function to be applied to to the previous element to produce
 *          a new element
 * @return A new sequential {@code IntStream}
 */
public static IntStream iterate(final int seed, final IntUnaryOperator f) {
    Objects.requireNonNull(f);
    final PrimitiveIterator.OfInt iterator = new PrimitiveIterator.OfInt() {
        int t = seed;

        @Override
        public boolean hasNext() {
            return true;
        }

        @Override
        public int nextInt() {
            int v = t;
            t = f.applyAsInt(t);
            return v;
        }
    };
    return StreamSupport.intStream(Spliterators.spliteratorUnknownSize(
            iterator,
            Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL), false);
}
 

@Test(dataProvider = "cases")
public void testBitsetStream(String name, IntStream data) {
    BitSet bs = new BitSet();
    long setBits = data.distinct()
                       .peek(i -> bs.set(i))
                       .count();

    assertEquals(bs.cardinality(), setBits);
    assertEquals(bs.cardinality(), bs.stream().reduce(0, (s, i) -> s+1));

    PrimitiveIterator.OfInt it = bs.stream().iterator();
    for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
        assertTrue(it.hasNext());
        assertEquals(it.nextInt(), i);
    }
    assertFalse(it.hasNext());
}
 

/**
 * Returns an infinite sequential ordered {@code IntStream} produced by iterative
 * application of a function {@code f} to an initial element {@code seed},
 * producing a {@code Stream} consisting of {@code seed}, {@code f(seed)},
 * {@code f(f(seed))}, etc.
 *
 * <p>The first element (position {@code 0}) in the {@code IntStream} will be
 * the provided {@code seed}.  For {@code n > 0}, the element at position
 * {@code n}, will be the result of applying the function {@code f} to the
 * element at position {@code n - 1}.
 *
 * @param seed the initial element
 * @param f a function to be applied to to the previous element to produce
 *          a new element
 * @return A new sequential {@code IntStream}
 */
public static IntStream iterate(final int seed, final IntUnaryOperator f) {
    Objects.requireNonNull(f);
    final PrimitiveIterator.OfInt iterator = new PrimitiveIterator.OfInt() {
        int t = seed;

        @Override
        public boolean hasNext() {
            return true;
        }

        @Override
        public int nextInt() {
            int v = t;
            t = f.applyAsInt(t);
            return v;
        }
    };
    return StreamSupport.intStream(Spliterators.spliteratorUnknownSize(
            iterator,
            Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL), false);
}
 

/**
 * Returns an infinite sequential ordered {@code IntStream} produced by iterative
 * application of a function {@code f} to an initial element {@code seed},
 * producing a {@code Stream} consisting of {@code seed}, {@code f(seed)},
 * {@code f(f(seed))}, etc.
 *
 * <p>The first element (position {@code 0}) in the {@code IntStream} will be
 * the provided {@code seed}.  For {@code n > 0}, the element at position
 * {@code n}, will be the result of applying the function {@code f} to the
 * element at position {@code n - 1}.
 *
 * @param seed the initial element
 * @param f a function to be applied to to the previous element to produce
 *          a new element
 * @return A new sequential {@code IntStream}
 */
public static IntStream iterate(final int seed, final IntUnaryOperator f) {
    Objects.requireNonNull(f);
    final PrimitiveIterator.OfInt iterator = new PrimitiveIterator.OfInt() {
        int t = seed;

        @Override
        public boolean hasNext() {
            return true;
        }

        @Override
        public int nextInt() {
            int v = t;
            t = f.applyAsInt(t);
            return v;
        }
    };
    return StreamSupport.intStream(Spliterators.spliteratorUnknownSize(
            iterator,
            Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL), false);
}
 

public Stream<int[]> internalRandomWalk(@Name(value = "steps", defaultValue = "80") int steps, org.neo4j.graphalgo.impl.walking.NodeWalker.NextNodeStrategy strategy, TerminationFlag terminationFlag,
                                        int concurrency, int limit, PrimitiveIterator.OfInt idStream) {
    int timeout = 100;
    int queueSize = 1000;
    int batchSize = ParallelUtil.adjustBatchSize(limit, concurrency, 100);
    Collection<Runnable> tasks = new ArrayList<>((limit / batchSize) + 1);

    ArrayBlockingQueue<int[]> queue = new ArrayBlockingQueue<>(queueSize);
    int[] TOMB = new int[0];

    while (idStream.hasNext()) {
        int[] ids = new int[batchSize];
        int i = 0;
        while (i < batchSize && idStream.hasNext()) {
            ids[i++] = idStream.nextInt();
        }
        int size = i;
        tasks.add(() -> {
            for (int j = 0; j < size; j++) {
                put(queue, doInternalWalk(ids[j], steps, strategy, terminationFlag));
            }
        });
    }
    new Thread(() -> {
        ParallelUtil.runWithConcurrency(concurrency, tasks, terminationFlag, Pools.DEFAULT);
        put(queue, TOMB);
    }).start();

    QueueBasedSpliterator<int[]> spliterator = new QueueBasedSpliterator<>(queue, TOMB, terminationFlag, timeout);
    return StreamSupport.stream(spliterator, false);
}
 

private Node.OfInt degenerateTree(PrimitiveIterator.OfInt it) {
    if (!it.hasNext()) {
        return Nodes.node(new int[0]);
    }

    int i = it.nextInt();
    if (it.hasNext()) {
        return new Nodes.ConcNode.OfInt(Nodes.node(new int[] {i}), degenerateTree(it));
    }
    else {
        return Nodes.node(new int[] {i});
    }
}
 

/**
 * Returns a stream of {@code int} zero-extending the {@code char} values
 * from this sequence.  Any char which maps to a <a
 * href="{@docRoot}/java/lang/Character.html#unicode">surrogate code
 * point</a> is passed through uninterpreted.
 *
 * <p>If the sequence is mutated while the stream is being read, the
 * result is undefined.
 *
 * @return an IntStream of char values from this sequence
 * @since 1.8
 */
public default IntStream chars() {
    class CharIterator implements PrimitiveIterator.OfInt {
        int cur = 0;

        public boolean hasNext() {
            return cur < length();
        }

        public int nextInt() {
            if (hasNext()) {
                return charAt(cur++);
            } else {
                throw new NoSuchElementException();
            }
        }

        @Override
        public void forEachRemaining(IntConsumer block) {
            for (; cur < length(); cur++) {
                block.accept(charAt(cur));
            }
        }
    }

    return StreamSupport.intStream(() ->
            Spliterators.spliterator(
                    new CharIterator(),
                    length(),
                    Spliterator.ORDERED),
            Spliterator.SUBSIZED | Spliterator.SIZED | Spliterator.ORDERED,
            false);
}
 

/**
 * Returns a stream of {@code int} zero-extending the {@code char} values
 * from this sequence.  Any char which maps to a <a
 * href="{@docRoot}/java/lang/Character.html#unicode">surrogate code
 * point</a> is passed through uninterpreted.
 *
 * <p>If the sequence is mutated while the stream is being read, the
 * result is undefined.
 *
 * @return an IntStream of char values from this sequence
 * @since 1.8
 */
public default IntStream chars() {
    class CharIterator implements PrimitiveIterator.OfInt {
        int cur = 0;

        public boolean hasNext() {
            return cur < length();
        }

        public int nextInt() {
            if (hasNext()) {
                return charAt(cur++);
            } else {
                throw new NoSuchElementException();
            }
        }

        @Override
        public void forEachRemaining(IntConsumer block) {
            for (; cur < length(); cur++) {
                block.accept(charAt(cur));
            }
        }
    }

    return StreamSupport.intStream(() ->
            Spliterators.spliterator(
                    new CharIterator(),
                    length(),
                    Spliterator.ORDERED),
            Spliterator.SUBSIZED | Spliterator.SIZED | Spliterator.ORDERED,
            false);
}
 

static String formatStringLiteral(String s)
    {
        s = s.replace("'", "''");
//        if (CharMatcher.inRange((char) 0x20, (char) 0x7E).matchesAllOf(s)) {
//            return "'" + s + "'";
//        }
        if (charMatches((char) 0x20, (char) 0x7E, s)) {
            return "'" + s + "'";
        }

        StringBuilder builder = new StringBuilder();
        builder.append("U&'");
        PrimitiveIterator.OfInt iterator = s.codePoints().iterator();
        while (iterator.hasNext()) {
            int codePoint = iterator.nextInt();
            checkArgument(codePoint >= 0, "Invalid UTF-8 encoding in characters: %s", s);
            if (isAsciiPrintable(codePoint)) {
                char ch = (char) codePoint;
                if (ch == '\\') {
                    builder.append(ch);
                }
                builder.append(ch);
            }
            else if (codePoint <= 0xFFFF) {
                builder.append('\\');
                builder.append(String.format("%04X", codePoint));
            }
            else {
                builder.append("\\+");
                builder.append(String.format("%06X", codePoint));
            }
        }
        builder.append("'");
        return builder.toString();
    }
 

@Override
public final PrimitiveIterator.OfInt iterator() {
    return Spliterators.iterator(spliterator());
}
 

@Override
public PrimitiveIterator.OfInt iterator() {
    return Spliterators.iterator(spliterator());
}
 

@Override
public PrimitiveIterator.OfInt iterator() {
    return Spliterators.iterator(spliterator());
}
 

@Test(expectedExceptions = NoSuchElementException.class)
public void testEmptyCodePoints() {
    PrimitiveIterator.OfInt s = "".codePoints().iterator();
    assertFalse(s.hasNext());
    int cp = s.nextInt();
}
 

@Override
PrimitiveIterator.OfInt iterator();
 

@Override
public final PrimitiveIterator.OfInt iterator() {
    return Spliterators.iterator(spliterator());
}
 

@Test(expectedExceptions = NoSuchElementException.class)
public void testEmptyCodePoints() {
    PrimitiveIterator.OfInt s = "".codePoints().iterator();
    assertFalse(s.hasNext());
    int cp = s.nextInt();
}
 

@Override
PrimitiveIterator.OfInt iterator();
 

@Override
PrimitiveIterator.OfInt iterator();
 

@Test(expectedExceptions = NoSuchElementException.class)
public void testEmptyChars() {
    PrimitiveIterator.OfInt s = "".chars().iterator();
    assertFalse(s.hasNext());
    int ch = s.nextInt();
}