/*
* Copyright 2015, 2016 Tagir Valeev
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package one.util.streamex;
import org.junit.FixMethodOrder;
import org.junit.Test;
import org.junit.runners.MethodSorters;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.IntBuffer;
import java.util.*;
import java.util.PrimitiveIterator.OfInt;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.*;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.IntStream.Builder;
import java.util.stream.StreamSupport;
import static one.util.streamex.TestHelpers.*;
import static org.junit.Assert.*;
/**
* @author Tagir Valeev
*/
@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class IntStreamExTest {
private static final byte[] EVEN_BYTES = new byte[] { 2, 4, 6, 8, 10 };
@Test
public void testCreate() {
assertArrayEquals(new int[] {}, IntStreamEx.empty().toArray());
// double test is intended
assertArrayEquals(new int[] {}, IntStreamEx.empty().toArray());
assertArrayEquals(new int[] { 1 }, IntStreamEx.of(1).toArray());
assertArrayEquals(new int[] { 1 }, IntStreamEx.of(OptionalInt.of(1)).toArray());
assertArrayEquals(new int[] {}, IntStreamEx.of(OptionalInt.empty()).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(1, 2, 3).toArray());
assertArrayEquals(new int[] { 4, 6 }, IntStreamEx.of(new int[] { 2, 4, 6, 8, 10 }, 1, 3).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(new byte[] { 1, 2, 3 }).toArray());
assertArrayEquals(new int[] { 4, 6 }, IntStreamEx.of(EVEN_BYTES, 1, 3).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(new short[] { 1, 2, 3 }).toArray());
assertArrayEquals(new int[] { 4, 6 }, IntStreamEx.of(new short[] { 2, 4, 6, 8, 10 }, 1, 3).toArray());
assertArrayEquals(new int[] { 'a', 'b', 'c' }, IntStreamEx.of('a', 'b', 'c').toArray());
assertArrayEquals(new int[] { '1', 'b' }, IntStreamEx.of(new char[] { 'a', '1', 'b', '2', 'c', '3' }, 1, 3)
.toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(IntStream.of(1, 2, 3)).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(Arrays.asList(1, 2, 3)).toArray());
assertArrayEquals(new int[] { 0, 1, 2 }, IntStreamEx.range(3).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.range(1, 4).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.rangeClosed(1, 3).toArray());
assertArrayEquals(new int[] { 1, 1, 1, 1 }, IntStreamEx.generate(() -> 1).limit(4).toArray());
assertArrayEquals(new int[] { 1, 1, 1, 1 }, IntStreamEx.constant(1, 4).toArray());
assertArrayEquals(new int[] { 'a', 'b', 'c' }, IntStreamEx.ofChars("abc").toArray());
assertEquals(10, IntStreamEx.of(new Random(), 10).count());
assertTrue(IntStreamEx.of(new Random(), 100, 1, 10).allMatch(x -> x >= 1 && x < 10));
assertArrayEquals(IntStreamEx.of(new Random(1), 100, 1, 10).toArray(), IntStreamEx.of(new Random(1), 1, 10)
.limit(100).toArray());
IntStream stream = IntStreamEx.of(1, 2, 3);
assertSame(stream, IntStreamEx.of(stream));
assertArrayEquals(new int[] { 4, 2, 0, -2, -4 }, IntStreamEx.zip(new int[] { 5, 4, 3, 2, 1 },
new int[] { 1, 2, 3, 4, 5 }, (a, b) -> a - b).toArray());
assertArrayEquals(new int[] { 1, 5, 3 }, IntStreamEx.of(Spliterators.spliterator(new int[] { 1, 5, 3 }, 0))
.toArray());
assertArrayEquals(new int[] { 1, 5, 3 }, IntStreamEx.of(
Spliterators.iterator(Spliterators.spliterator(new int[] { 1, 5, 3 }, 0))).toArray());
assertArrayEquals(new int[0], IntStreamEx.of(Spliterators.iterator(Spliterators.emptyIntSpliterator()))
.parallel().toArray());
BitSet bs = new BitSet();
bs.set(1);
bs.set(3);
bs.set(5);
assertArrayEquals(new int[] { 1, 3, 5 }, IntStreamEx.of(bs).toArray());
assertArrayEquals(new int[] { 2, 4, 6 }, IntStreamEx.of(new Integer[] { 2, 4, 6 }).toArray());
}
@Test
public void testOfIntBuffer() {
int[] data = IntStreamEx.range(100).toArray();
assertArrayEquals(data, IntStreamEx.of(IntBuffer.wrap(data)).toArray());
assertArrayEquals(IntStreamEx.range(50, 70).toArray(), IntStreamEx.of(IntBuffer.wrap(data, 50, 20)).toArray());
assertArrayEquals(data, IntStreamEx.of(IntBuffer.wrap(data)).parallel().toArray());
assertArrayEquals(IntStreamEx.range(50, 70).toArray(), IntStreamEx.of(IntBuffer.wrap(data, 50, 20)).parallel()
.toArray());
}
@Test
public void testIterate() {
assertArrayEquals(new int[] { 1, 2, 4, 8, 16 }, IntStreamEx.iterate(1, x -> x * 2).limit(5).toArray());
assertArrayEquals(new int[] { 1, 2, 4, 8, 16, 32, 64 }, IntStreamEx.iterate(1, x -> x < 100, x -> x * 2).toArray());
assertEquals(0, IntStreamEx.iterate(0, x -> x < 0, x -> 1 / x).count());
assertFalse(IntStreamEx.iterate(1, x -> x < 100, x -> x * 2).has(10));
checkSpliterator("iterate", () -> IntStreamEx.iterate(1, x -> x < 100, x -> x * 2).spliterator());
}
@Test
public void testInts() {
assertEquals(Integer.MAX_VALUE, IntStreamEx.ints().spliterator().getExactSizeIfKnown());
assertArrayEquals(new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }, IntStreamEx.ints().limit(10).toArray());
}
@Test
public void testRangeStep() {
assertArrayEquals(new int[] { 0 }, IntStreamEx.range(0, 1000, 100000).toArray());
assertArrayEquals(new int[] { 0 }, IntStreamEx.range(0, 1000, 1000).toArray());
assertArrayEquals(new int[] { 0, Integer.MAX_VALUE - 1 }, IntStreamEx.range(0, Integer.MAX_VALUE,
Integer.MAX_VALUE - 1).toArray());
assertArrayEquals(new int[] { Integer.MIN_VALUE, -1, Integer.MAX_VALUE - 1 }, IntStreamEx.range(
Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MIN_VALUE, -1 }, IntStreamEx.range(Integer.MIN_VALUE,
Integer.MAX_VALUE - 1, Integer.MAX_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MAX_VALUE, -1 }, IntStreamEx.range(Integer.MAX_VALUE, Integer.MIN_VALUE,
Integer.MIN_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MAX_VALUE }, IntStreamEx.range(Integer.MAX_VALUE, 0, Integer.MIN_VALUE)
.toArray());
assertArrayEquals(new int[] { 1, Integer.MIN_VALUE + 1 }, IntStreamEx.range(1, Integer.MIN_VALUE,
Integer.MIN_VALUE).toArray());
assertArrayEquals(new int[] { 0 }, IntStreamEx.range(0, Integer.MIN_VALUE, Integer.MIN_VALUE).toArray());
assertArrayEquals(new int[] { 0, 2, 4, 6, 8 }, IntStreamEx.range(0, 9, 2).toArray());
assertArrayEquals(new int[] { 0, 2, 4, 6 }, IntStreamEx.range(0, 8, 2).toArray());
assertArrayEquals(new int[] { 0, -2, -4, -6, -8 }, IntStreamEx.range(0, -9, -2).toArray());
assertArrayEquals(new int[] { 0, -2, -4, -6 }, IntStreamEx.range(0, -8, -2).toArray());
assertArrayEquals(new int[] { 5, 4, 3, 2, 1, 0 }, IntStreamEx.range(5, -1, -1).toArray());
assertEquals(Integer.MAX_VALUE + 1L, IntStreamEx.range(Integer.MIN_VALUE, Integer.MAX_VALUE, 2).spliterator()
.getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE, IntStreamEx.range(Integer.MIN_VALUE, Integer.MAX_VALUE - 1, 2).spliterator()
.getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE + 1L, IntStreamEx.range(Integer.MAX_VALUE, Integer.MIN_VALUE, -2).spliterator()
.getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE, IntStreamEx.range(Integer.MAX_VALUE, Integer.MIN_VALUE + 1, -2).spliterator()
.getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE * 2L + 1L, IntStreamEx.range(Integer.MIN_VALUE, Integer.MAX_VALUE, 1)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE * 2L + 1L, IntStreamEx.range(Integer.MAX_VALUE, Integer.MIN_VALUE, -1)
.spliterator().getExactSizeIfKnown());
assertEquals(0, IntStreamEx.range(0, -1000, 1).count());
assertEquals(0, IntStreamEx.range(0, 1000, -1).count());
assertEquals(0, IntStreamEx.range(0, 0, -1).count());
assertEquals(0, IntStreamEx.range(0, 0, 1).count());
assertEquals(0, IntStreamEx.range(0, -1000, 2).count());
assertEquals(0, IntStreamEx.range(0, 1000, -2).count());
assertEquals(0, IntStreamEx.range(0, 0, -2).count());
assertEquals(0, IntStreamEx.range(0, 0, 2).count());
assertEquals(0, IntStreamEx.range(0, Integer.MIN_VALUE, 2).spliterator().getExactSizeIfKnown());
assertEquals(0, IntStreamEx.range(0, Integer.MAX_VALUE, -2).spliterator().getExactSizeIfKnown());
}
@Test(expected = IllegalArgumentException.class)
public void testRangeIllegalStep() {
IntStreamEx.range(0, 1000, 0);
}
@Test
public void testRangeClosedStep() {
assertArrayEquals(new int[] { 0 }, IntStreamEx.rangeClosed(0, 1000, 100000).toArray());
assertArrayEquals(new int[] { 0, 1000 }, IntStreamEx.rangeClosed(0, 1000, 1000).toArray());
assertArrayEquals(new int[] { 0, Integer.MAX_VALUE - 1 }, IntStreamEx.rangeClosed(0, Integer.MAX_VALUE,
Integer.MAX_VALUE - 1).toArray());
assertArrayEquals(new int[] { 0, Integer.MAX_VALUE }, IntStreamEx.rangeClosed(0, Integer.MAX_VALUE,
Integer.MAX_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MIN_VALUE, -1, Integer.MAX_VALUE - 1 }, IntStreamEx.rangeClosed(
Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MIN_VALUE, -1, Integer.MAX_VALUE - 1 }, IntStreamEx.rangeClosed(
Integer.MIN_VALUE, Integer.MAX_VALUE - 1, Integer.MAX_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MAX_VALUE, -1 }, IntStreamEx.rangeClosed(Integer.MAX_VALUE,
Integer.MIN_VALUE, Integer.MIN_VALUE).toArray());
assertArrayEquals(new int[] { Integer.MAX_VALUE }, IntStreamEx.rangeClosed(Integer.MAX_VALUE, 0,
Integer.MIN_VALUE).toArray());
assertArrayEquals(new int[] { 0, Integer.MIN_VALUE }, IntStreamEx.rangeClosed(0, Integer.MIN_VALUE,
Integer.MIN_VALUE).toArray());
assertArrayEquals(new int[] { 0, 2, 4, 6, 8 }, IntStreamEx.rangeClosed(0, 9, 2).toArray());
assertArrayEquals(new int[] { 0, 2, 4, 6, 8 }, IntStreamEx.rangeClosed(0, 8, 2).toArray());
assertArrayEquals(new int[] { 0, 2, 4, 6 }, IntStreamEx.rangeClosed(0, 7, 2).toArray());
assertArrayEquals(new int[] { 0, -2, -4, -6, -8 }, IntStreamEx.rangeClosed(0, -9, -2).toArray());
assertArrayEquals(new int[] { 0, -2, -4, -6, -8 }, IntStreamEx.rangeClosed(0, -8, -2).toArray());
assertArrayEquals(new int[] { 0, -2, -4, -6 }, IntStreamEx.rangeClosed(0, -7, -2).toArray());
assertArrayEquals(new int[] { 5, 4, 3, 2, 1, 0 }, IntStreamEx.rangeClosed(5, 0, -1).toArray());
assertEquals(Integer.MAX_VALUE + 1L, IntStreamEx.rangeClosed(Integer.MIN_VALUE, Integer.MAX_VALUE, 2)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE + 1L, IntStreamEx.rangeClosed(Integer.MIN_VALUE, Integer.MAX_VALUE - 1, 2)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE, IntStreamEx.rangeClosed(Integer.MIN_VALUE, Integer.MAX_VALUE - 2, 2)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE + 1L, IntStreamEx.rangeClosed(Integer.MAX_VALUE, Integer.MIN_VALUE, -2)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE + 1L, IntStreamEx.rangeClosed(Integer.MAX_VALUE, Integer.MIN_VALUE + 1, -2)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE * 2L + 2L, IntStreamEx.rangeClosed(Integer.MIN_VALUE, Integer.MAX_VALUE, 1)
.spliterator().getExactSizeIfKnown());
assertEquals(Integer.MAX_VALUE * 2L + 2L, IntStreamEx.rangeClosed(Integer.MAX_VALUE, Integer.MIN_VALUE, -1)
.spliterator().getExactSizeIfKnown());
assertEquals(0, IntStreamEx.rangeClosed(0, -1000, 1).count());
assertEquals(0, IntStreamEx.rangeClosed(0, 1000, -1).count());
assertEquals(0, IntStreamEx.rangeClosed(0, 1, -1).count());
assertEquals(0, IntStreamEx.rangeClosed(0, -1, 1).count());
assertEquals(0, IntStreamEx.rangeClosed(0, -1000, 2).count());
assertEquals(0, IntStreamEx.rangeClosed(0, 1000, -2).count());
assertEquals(0, IntStreamEx.rangeClosed(0, 1, -2).count());
assertEquals(0, IntStreamEx.rangeClosed(0, -1, 2).count());
}
@Test(expected = ArrayIndexOutOfBoundsException.class)
public void testArrayOffsetUnderflow() {
IntStreamEx.of(EVEN_BYTES, -1, 3).findAny();
}
@Test(expected = ArrayIndexOutOfBoundsException.class)
public void testArrayOffsetWrong() {
IntStreamEx.of(EVEN_BYTES, 3, 1).findAny();
}
@Test(expected = ArrayIndexOutOfBoundsException.class)
public void testArrayLengthOverflow() {
IntStreamEx.of(EVEN_BYTES, 3, 6).findAny();
}
@Test
public void testArrayLengthOk() {
assertEquals(10, IntStreamEx.of(EVEN_BYTES, 3, 5).skip(1).findFirst().getAsInt());
}
@Test
public void testOfIndices() {
assertArrayEquals(new int[] {}, IntStreamEx.ofIndices(new int[0]).toArray());
assertArrayEquals(new int[] { 0, 1, 2 }, IntStreamEx.ofIndices(new int[] { 5, -100, 1 }).toArray());
assertArrayEquals(new int[] { 0, 2 }, IntStreamEx.ofIndices(new int[] { 5, -100, 1 }, i -> i > 0).toArray());
assertArrayEquals(new int[] { 0, 1, 2 }, IntStreamEx.ofIndices(new long[] { 5, -100, 1 }).toArray());
assertArrayEquals(new int[] { 0, 2 }, IntStreamEx.ofIndices(new long[] { 5, -100, 1 }, i -> i > 0).toArray());
assertArrayEquals(new int[] { 0, 1, 2 }, IntStreamEx.ofIndices(new double[] { 5, -100, 1 }).toArray());
assertArrayEquals(new int[] { 0, 2 }, IntStreamEx.ofIndices(new double[] { 5, -100, 1 }, i -> i > 0).toArray());
assertArrayEquals(new int[] { 0, 1, 2 }, IntStreamEx.ofIndices(new String[] { "a", "b", "c" }).toArray());
assertArrayEquals(new int[] { 1 }, IntStreamEx.ofIndices(new String[] { "a", "", "c" }, String::isEmpty)
.toArray());
assertArrayEquals(new int[] { 0, 1, 2 }, IntStreamEx.ofIndices(Arrays.asList("a", "b", "c")).toArray());
assertArrayEquals(new int[] { 1 }, IntStreamEx.ofIndices(Arrays.asList("a", "", "c"), String::isEmpty)
.toArray());
}
@Test
public void testBasics() {
assertFalse(IntStreamEx.of(1).isParallel());
assertTrue(IntStreamEx.of(1).parallel().isParallel());
assertFalse(IntStreamEx.of(1).parallel().sequential().isParallel());
AtomicInteger i = new AtomicInteger();
try (IntStreamEx s = IntStreamEx.of(1).onClose(i::incrementAndGet)) {
assertEquals(1, s.count());
}
assertEquals(1, i.get());
assertEquals(6, IntStreamEx.range(0, 4).sum());
assertEquals(3, IntStreamEx.range(0, 4).max().getAsInt());
assertEquals(0, IntStreamEx.range(0, 4).min().getAsInt());
assertEquals(1.5, IntStreamEx.range(0, 4).average().getAsDouble(), 0.000001);
assertEquals(4, IntStreamEx.range(0, 4).summaryStatistics().getCount());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.range(0, 5).skip(1).limit(3).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(3, 1, 2).sorted().toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(1, 2, 1, 3, 2).distinct().toArray());
assertArrayEquals(new int[] { 2, 4, 6 }, IntStreamEx.range(1, 4).map(x -> x * 2).toArray());
assertArrayEquals(new long[] { 2, 4, 6 }, IntStreamEx.range(1, 4).mapToLong(x -> x * 2).toArray());
assertArrayEquals(new double[] { 2, 4, 6 }, IntStreamEx.range(1, 4).mapToDouble(x -> x * 2).toArray(), 0.0);
assertArrayEquals(new int[] { 1, 3 }, IntStreamEx.range(0, 5).filter(x -> x % 2 == 1).toArray());
assertEquals(6, IntStreamEx.of(1, 2, 3).reduce(Integer::sum).getAsInt());
assertEquals(Integer.MAX_VALUE, IntStreamEx.rangeClosed(1, Integer.MAX_VALUE).spliterator()
.getExactSizeIfKnown());
assertTrue(IntStreamEx.of(1, 2, 3).spliterator().hasCharacteristics(Spliterator.ORDERED));
assertFalse(IntStreamEx.of(1, 2, 3).unordered().spliterator().hasCharacteristics(Spliterator.ORDERED));
OfInt iterator = IntStreamEx.of(1, 2, 3).iterator();
assertEquals(1, iterator.nextInt());
assertEquals(2, iterator.nextInt());
assertEquals(3, iterator.nextInt());
assertFalse(iterator.hasNext());
List<Integer> list = new ArrayList<>();
IntStreamEx.range(10).parallel().forEachOrdered(list::add);
assertEquals(Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9), list);
assertTrue(IntStreamEx.empty().noneMatch(x -> true));
assertFalse(IntStreamEx.of(1).noneMatch(x -> true));
assertTrue(IntStreamEx.of(1).noneMatch(x -> false));
}
@Test
public void testFlatMap() {
long[][] vals = { { 1, 2, 3 }, { 2, 3, 4 }, { 5, 4, Long.MAX_VALUE, Long.MIN_VALUE } };
assertArrayEquals(new long[] { 1, 2, 3, 2, 3, 4, 5, 4, Long.MAX_VALUE, Long.MIN_VALUE }, IntStreamEx.ofIndices(
vals).flatMapToLong(idx -> Arrays.stream(vals[idx])).toArray());
String expected = IntStream.range(0, 200).boxed().flatMap(
i -> IntStream.range(0, i).<String> mapToObj(j -> i + ":" + j)).collect(Collectors.joining("/"));
String res = IntStreamEx.range(200).flatMapToObj(i -> IntStreamEx.range(i).mapToObj(j -> i + ":" + j)).joining(
"/");
String parallel = IntStreamEx.range(200).parallel().flatMapToObj(
i -> IntStreamEx.range(i).mapToObj(j -> i + ":" + j)).joining("/");
assertEquals(expected, res);
assertEquals(expected, parallel);
double[] fractions = IntStreamEx.range(1, 5).flatMapToDouble(
i -> IntStreamEx.range(1, i).mapToDouble(j -> ((double) j) / i)).toArray();
assertArrayEquals(new double[] { 1 / 2.0, 1 / 3.0, 2 / 3.0, 1 / 4.0, 2 / 4.0, 3 / 4.0 }, fractions, 0.000001);
assertArrayEquals(new int[] { 0, 0, 1, 0, 1, 2 }, IntStreamEx.of(1, 2, 3).flatMap(IntStreamEx::range).toArray());
}
@Test
public void testElements() {
assertEquals(Arrays.asList("f", "d", "b"), IntStreamEx.of(5, 3, 1).elements("abcdef".split("")).toList());
assertEquals(Arrays.asList("f", "d", "b"), IntStreamEx.of(5, 3, 1).elements(
Arrays.asList("a", "b", "c", "d", "e", "f")).toList());
assertArrayEquals(new int[] { 10, 6, 2 }, IntStreamEx.of(5, 3, 1).elements(new int[] { 0, 2, 4, 6, 8, 10 })
.toArray());
assertArrayEquals(new long[] { 10, 6, 2 }, IntStreamEx.of(5, 3, 1).elements(new long[] { 0, 2, 4, 6, 8, 10 })
.toArray());
assertArrayEquals(new double[] { 10, 6, 2 }, IntStreamEx.of(5, 3, 1).elements(
new double[] { 0, 2, 4, 6, 8, 10 }).toArray(), 0.0);
}
@Test
public void testPrepend() {
assertArrayEquals(new int[] { -1, 0, 1, 2, 3 }, IntStreamEx.of(1, 2, 3).prepend(-1, 0).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(1, 2, 3).prepend().toArray());
assertArrayEquals(new int[] { 10, 11, 0, 1, 2, 3 }, IntStreamEx.range(0, 4).prepend(IntStreamEx.range(10, 12))
.toArray());
}
@Test
public void testAppend() {
assertArrayEquals(new int[] { 1, 2, 3, 4, 5 }, IntStreamEx.of(1, 2, 3).append(4, 5).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.of(1, 2, 3).append().toArray());
assertArrayEquals(new int[] { 0, 1, 2, 3, 10, 11 }, IntStreamEx.range(0, 4).append(IntStreamEx.range(10, 12))
.toArray());
}
@Test
public void testHas() {
assertTrue(IntStreamEx.range(1, 4).has(3));
assertFalse(IntStreamEx.range(1, 4).has(4));
}
@Test
public void testWithout() {
assertArrayEquals(new int[] { 1, 2 }, IntStreamEx.range(1, 4).without(3).toArray());
assertArrayEquals(new int[] { 1, 2, 3 }, IntStreamEx.range(1, 4).without(5).toArray());
IntStreamEx ise = IntStreamEx.range(5);
assertSame(ise, ise.without());
assertArrayEquals(new int[] { 0, 1, 3, 4 }, IntStreamEx.range(5).without(new int[] { 2 }).toArray());
assertArrayEquals(new int[] { 0 }, IntStreamEx.range(5).without(1, 2, 3, 4, 5, 6).toArray());
}
@Test
public void testRanges() {
assertArrayEquals(new int[] { 5, 4, Integer.MAX_VALUE }, IntStreamEx.of(1, 5, 3, 4, -1, Integer.MAX_VALUE)
.greater(3).toArray());
assertArrayEquals(new int[] { 5, 3, 4, Integer.MAX_VALUE }, IntStreamEx.of(1, 5, 3, 4, -1, Integer.MAX_VALUE)
.atLeast(3).toArray());
assertArrayEquals(new int[] { 1, -1 }, IntStreamEx.of(1, 5, 3, 4, -1, Integer.MAX_VALUE).less(3).toArray());
assertArrayEquals(new int[] { 1, 3, -1 }, IntStreamEx.of(1, 5, 3, 4, -1, Integer.MAX_VALUE).atMost(3).toArray());
assertArrayEquals(new int[] { 1, 3, 4, -1 }, IntStreamEx.of(1, 5, 3, 4, -1, Integer.MAX_VALUE).atMost(4).toArray());
}
@Test
public void testToBitSet() {
assertEquals("{0, 1, 2, 3, 4}", IntStreamEx.range(5).toBitSet().toString());
assertEquals("{0, 2, 3, 4, 10}", IntStreamEx.of(0, 2, 0, 3, 0, 4, 0, 10).parallel().toBitSet().toString());
}
@Test
public void testAs() {
assertEquals(4, IntStreamEx.range(0, 5).asLongStream().findAny(x -> x > 3).getAsLong());
assertEquals(4.0, IntStreamEx.range(0, 5).asDoubleStream().findAny(x -> x > 3).getAsDouble(), 0.0);
}
@Test
public void testFind() {
assertEquals(6, IntStreamEx.range(1, 10).findFirst(i -> i > 5).getAsInt());
assertFalse(IntStreamEx.range(1, 10).findAny(i -> i > 10).isPresent());
}
@Test
public void testRemove() {
assertArrayEquals(new int[] { 1, 2 }, IntStreamEx.of(1, 2, 3).remove(x -> x > 2).toArray());
}
@Test
public void testSort() {
assertArrayEquals(new int[] { 0, 3, 6, 1, 4, 7, 2, 5, 8 }, IntStreamEx.range(0, 9).sortedByInt(
i -> i % 3 * 3 + i / 3).toArray());
assertArrayEquals(new int[] { 0, 3, 6, 1, 4, 7, 2, 5, 8 }, IntStreamEx.range(0, 9).sortedByLong(
i -> (long) i % 3 * Integer.MAX_VALUE + i / 3).toArray());
assertArrayEquals(new int[] { 8, 7, 6, 5, 4, 3, 2, 1 }, IntStreamEx.range(1, 9).sortedByDouble(i -> 1.0 / i)
.toArray());
assertArrayEquals(new int[] { 10, 11, 5, 6, 7, 8, 9 }, IntStreamEx.range(5, 12).sortedBy(String::valueOf)
.toArray());
assertArrayEquals(new int[] { Integer.MAX_VALUE, 1000, 1, 0, -10, Integer.MIN_VALUE }, IntStreamEx.of(0, 1,
1000, -10, Integer.MIN_VALUE, Integer.MAX_VALUE).reverseSorted().toArray());
}
@Test
public void testToString() {
assertEquals("LOWERCASE", IntStreamEx.ofChars("lowercase").map(c -> Character.toUpperCase((char) c))
.charsToString());
assertEquals("LOWERCASE", IntStreamEx.ofCodePoints("lowercase").map(Character::toUpperCase)
.codePointsToString());
}
@SafeVarargs
private final void checkEmpty(Function<IntStreamEx, OptionalInt>... fns) {
int i = 0;
for (Function<IntStreamEx, OptionalInt> fn : fns) {
assertFalse("#" + i, fn.apply(IntStreamEx.empty()).isPresent());
assertFalse("#" + i, fn.apply(IntStreamEx.of(1, 2, 3, 4).greater(5).parallel()).isPresent());
assertEquals("#" + i, 10, fn.apply(IntStreamEx.of(1, 1, 1, 1, 10, 10, 10, 10).greater(5).parallel())
.getAsInt());
i++;
}
}
@Test
public void testMinMax() {
checkEmpty(s -> s.maxBy(Integer::valueOf), s -> s.maxByInt(x -> x), s -> s.maxByLong(x -> x), s -> s
.maxByDouble(x -> x), s -> s.minBy(Integer::valueOf), s -> s.minByInt(x -> x),
s -> s.minByLong(x -> x), s -> s.minByDouble(x -> x));
assertEquals(9, IntStreamEx.range(5, 12).max(Comparator.comparing(String::valueOf)).getAsInt());
assertEquals(10, IntStreamEx.range(5, 12).min(Comparator.comparing(String::valueOf)).getAsInt());
assertEquals(9, IntStreamEx.range(5, 12).maxBy(String::valueOf).getAsInt());
assertEquals(10, IntStreamEx.range(5, 12).minBy(String::valueOf).getAsInt());
assertEquals(5, IntStreamEx.range(5, 12).maxByDouble(x -> 1.0 / x).getAsInt());
assertEquals(11, IntStreamEx.range(5, 12).minByDouble(x -> 1.0 / x).getAsInt());
assertEquals(29, IntStreamEx.of(15, 8, 31, 47, 19, 29).maxByInt(x -> x % 10 * 10 + x / 10).getAsInt());
assertEquals(31, IntStreamEx.of(15, 8, 31, 47, 19, 29).minByInt(x -> x % 10 * 10 + x / 10).getAsInt());
assertEquals(29, IntStreamEx.of(15, 8, 31, 47, 19, 29).maxByLong(x -> Long.MIN_VALUE + x % 10 * 10 + x / 10)
.getAsInt());
assertEquals(31, IntStreamEx.of(15, 8, 31, 47, 19, 29).minByLong(x -> Long.MIN_VALUE + x % 10 * 10 + x / 10)
.getAsInt());
Supplier<IntStreamEx> s = () -> IntStreamEx.of(1, 50, 120, 35, 130, 12, 0);
IntUnaryOperator intKey = x -> String.valueOf(x).length();
IntToLongFunction longKey = x -> String.valueOf(x).length();
IntToDoubleFunction doubleKey = x -> String.valueOf(x).length();
IntFunction<Integer> objKey = x -> String.valueOf(x).length();
List<Function<IntStreamEx, OptionalInt>> minFns = Arrays.asList(is -> is.minByInt(intKey), is -> is
.minByLong(longKey), is -> is.minByDouble(doubleKey), is -> is.minBy(objKey));
List<Function<IntStreamEx, OptionalInt>> maxFns = Arrays.asList(is -> is.maxByInt(intKey), is -> is
.maxByLong(longKey), is -> is.maxByDouble(doubleKey), is -> is.maxBy(objKey));
minFns.forEach(fn -> assertEquals(1, fn.apply(s.get()).getAsInt()));
minFns.forEach(fn -> assertEquals(1, fn.apply(s.get().parallel()).getAsInt()));
maxFns.forEach(fn -> assertEquals(120, fn.apply(s.get()).getAsInt()));
maxFns.forEach(fn -> assertEquals(120, fn.apply(s.get().parallel()).getAsInt()));
}
private IntStreamEx dropLast(IntStreamEx s) {
return s.pairMap((a, b) -> a);
}
@Test
public void testPairMap() {
assertEquals(0, IntStreamEx.range(0).pairMap(Integer::sum).count());
assertEquals(0, IntStreamEx.range(1).pairMap(Integer::sum).count());
assertEquals(Collections.singletonMap(1, 9999L), IntStreamEx.range(10000).pairMap((a, b) -> b - a).boxed()
.groupingBy(Function.identity(), Collectors.counting()));
assertEquals(Collections.singletonMap(1, 9999L), IntStreamEx.range(10000).parallel().pairMap((a, b) -> b - a)
.boxed().groupingBy(Function.identity(), Collectors.counting()));
assertEquals("Test Capitalization Stream", IntStreamEx.ofChars("test caPiTaliZation streaM").parallel()
.prepend(0).pairMap(
(c1, c2) -> !Character.isLetter(c1) && Character.isLetter(c2) ? Character.toTitleCase(c2)
: Character.toLowerCase(c2)).charsToString());
assertArrayEquals(IntStreamEx.range(9999).toArray(), dropLast(IntStreamEx.range(10000)).toArray());
withRandom(r -> {
int data[] = r.ints(1000, 1, 1000).toArray();
int[] expected = new int[data.length - 1];
int lastSquare = data[0] * data[0];
for (int i = 0; i < expected.length; i++) {
int newSquare = data[i + 1] * data[i + 1];
expected[i] = newSquare - lastSquare;
lastSquare = newSquare;
}
int[] result = IntStreamEx.of(data).map(x -> x * x).pairMap((a, b) -> b - a).toArray();
assertArrayEquals(expected, result);
});
assertEquals(1, IntStreamEx.range(1000).map(x -> x * x).pairMap((a, b) -> b - a).pairMap((a, b) -> b - a)
.distinct().count());
assertArrayEquals(IntStreamEx.constant(1, 100).toArray(), IntStreamEx.iterate(0, i -> i + 1).parallel()
.pairMap((a, b) -> b - a).limit(100).toArray());
assertFalse(IntStreamEx.range(1000).greater(2000).parallel().pairMap((a, b) -> a).findFirst().isPresent());
}
@Test
public void testToByteArray() {
byte[] expected = new byte[10000];
for (int i = 0; i < expected.length; i++)
expected[i] = (byte) i;
assertArrayEquals(expected, IntStreamEx.range(0, 10000).toByteArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).parallel().toByteArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).greater(-1).toByteArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).parallel().greater(-1).toByteArray());
}
@Test
public void testToCharArray() {
char[] expected = new char[10000];
for (int i = 0; i < expected.length; i++)
expected[i] = (char) i;
assertArrayEquals(expected, IntStreamEx.range(0, 10000).toCharArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).parallel().toCharArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).greater(-1).toCharArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).parallel().greater(-1).toCharArray());
}
@Test
public void testToShortArray() {
short[] expected = new short[10000];
for (int i = 0; i < expected.length; i++)
expected[i] = (short) i;
assertArrayEquals(expected, IntStreamEx.range(0, 10000).toShortArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).parallel().toShortArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).greater(-1).toShortArray());
assertArrayEquals(expected, IntStreamEx.range(0, 10000).parallel().greater(-1).toShortArray());
}
@Test
public void testJoining() {
assertEquals("0,1,2,3,4,5,6,7,8,9", IntStreamEx.range(10).joining(","));
assertEquals("0,1,2,3,4,5,6,7,8,9", IntStreamEx.range(10).parallel().joining(","));
assertEquals("[0,1,2,3,4,5,6,7,8,9]", IntStreamEx.range(10).joining(",", "[", "]"));
assertEquals("[0,1,2,3,4,5,6,7,8,9]", IntStreamEx.range(10).parallel().joining(",", "[", "]"));
}
@Test
public void testMapToEntry() {
Map<Integer, List<Integer>> result = IntStreamEx.range(10).mapToEntry(x -> x % 2, x -> x).grouping();
assertEquals(Arrays.asList(0, 2, 4, 6, 8), result.get(0));
assertEquals(Arrays.asList(1, 3, 5, 7, 9), result.get(1));
}
static final class HundredIterator implements PrimitiveIterator.OfInt {
int i = 0;
@Override
public boolean hasNext() {
return i < 100;
}
@Override
public int nextInt() {
return i++;
}
}
@Test
public void testRecreate() {
Set<Integer> expected = IntStreamEx.range(1, 100).boxed().toSet();
assertEquals(expected, IntStreamEx.of(
StreamSupport.intStream(Spliterators.spliteratorUnknownSize(new HundredIterator(), Spliterator.ORDERED),
false)).skip(1).boxed().toSet());
assertEquals(expected, IntStreamEx.of(
StreamSupport.intStream(Spliterators.spliteratorUnknownSize(new HundredIterator(), Spliterator.ORDERED),
true)).skip(1).boxed().toCollection(HashSet<Integer>::new));
assertEquals(expected, IntStreamEx.of(
StreamSupport.intStream(Spliterators.spliteratorUnknownSize(new HundredIterator(), Spliterator.ORDERED),
true)).skipOrdered(1).boxed().toSet());
assertEquals(expected, IntStreamEx.of(
StreamSupport.intStream(Spliterators.spliterator(new HundredIterator(), 100, Spliterator.ORDERED
| Spliterator.CONCURRENT), true)).skipOrdered(1).boxed().toSet());
assertEquals(expected, IntStreamEx.of(
StreamSupport.intStream(Spliterators.spliteratorUnknownSize(new HundredIterator(), Spliterator.ORDERED),
true)).unordered().skipOrdered(1).boxed().toCollection(HashSet<Integer>::new));
assertEquals(expected, IntStreamEx.iterate(0, i -> i + 1).skip(1).greater(0).limit(99).boxed().toSet());
assertEquals(500, (int) IntStreamEx.iterate(0, i -> i + 1).skipOrdered(1).greater(0).boxed().parallel()
.findAny(i -> i == 500).get());
assertEquals(expected, IntStreamEx.iterate(0, i -> i + 1).skipOrdered(1).greater(0).limit(99).boxed()
.parallel().toSet());
}
@Test
public void testTakeWhile() {
assertArrayEquals(IntStreamEx.range(100).toArray(), IntStreamEx.iterate(0, i -> i + 1).takeWhile(i -> i < 100)
.toArray());
assertEquals(0, IntStreamEx.empty().takeWhile(i -> true).count());
assertEquals(0, IntStreamEx.iterate(0, i -> i + 1).takeWhile(i -> i < 0).count());
assertEquals(1, IntStreamEx.of(1, 3, 2).takeWhile(i -> i < 3).count());
assertEquals(3, IntStreamEx.of(1, 2, 3).takeWhile(i -> i < 100).count());
}
@Test
public void testTakeWhileInclusive() {
assertArrayEquals(IntStreamEx.range(101).toArray(), IntStreamEx.iterate(0, i -> i + 1).takeWhileInclusive(
i -> i < 100).toArray());
assertEquals(0, IntStreamEx.empty().takeWhileInclusive(i -> true).count());
assertEquals(1, IntStreamEx.iterate(0, i -> i + 1).takeWhileInclusive(i -> i < 0).count());
assertEquals(2, IntStreamEx.of(1, 3, 2).takeWhileInclusive(i -> i < 3).count());
assertEquals(3, IntStreamEx.of(1, 2, 3).takeWhileInclusive(i -> i < 100).count());
}
@Test
public void testDropWhile() {
assertArrayEquals(new int[] { 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 }, IntStreamEx.range(100).dropWhile(
i -> i % 10 < 5).limit(10).toArray());
assertEquals(100, IntStreamEx.range(100).dropWhile(i -> i % 10 < 0).count());
assertEquals(0, IntStreamEx.range(100).dropWhile(i -> i % 10 < 10).count());
assertEquals(OptionalInt.of(0), IntStreamEx.range(100).dropWhile(i -> i % 10 < 0).findFirst());
assertEquals(OptionalInt.empty(), IntStreamEx.range(100).dropWhile(i -> i % 10 < 10).findFirst());
java.util.Spliterator.OfInt spltr = IntStreamEx.range(100).dropWhile(i -> i % 10 < 1).spliterator();
assertTrue(spltr.tryAdvance((int x) -> assertEquals(1, x)));
Builder builder = IntStream.builder();
spltr.forEachRemaining(builder);
assertArrayEquals(IntStreamEx.range(2, 100).toArray(), builder.build().toArray());
}
@Test
public void testIndexOf() {
assertEquals(5, IntStreamEx.range(50, 100).indexOf(55).getAsLong());
assertFalse(IntStreamEx.range(50, 100).indexOf(200).isPresent());
assertEquals(5, IntStreamEx.range(50, 100).parallel().indexOf(55).getAsLong());
assertFalse(IntStreamEx.range(50, 100).parallel().indexOf(200).isPresent());
assertEquals(11, IntStreamEx.range(50, 100).indexOf(x -> x > 60).getAsLong());
assertFalse(IntStreamEx.range(50, 100).indexOf(x -> x < 0).isPresent());
assertEquals(11, IntStreamEx.range(50, 100).parallel().indexOf(x -> x > 60).getAsLong());
assertFalse(IntStreamEx.range(50, 100).parallel().indexOf(x -> x < 0).isPresent());
}
@Test
public void testFoldLeft() {
// non-associative
IntBinaryOperator accumulator = (x, y) -> (x + y) * (x + y);
assertEquals(2322576, IntStreamEx.constant(3, 4).foldLeft(accumulator).orElse(-1));
assertEquals(2322576, IntStreamEx.constant(3, 4).parallel().foldLeft(accumulator).orElse(-1));
assertFalse(IntStreamEx.empty().foldLeft(accumulator).isPresent());
assertEquals(144, IntStreamEx.rangeClosed(1, 3).foldLeft(0, accumulator));
assertEquals(144, IntStreamEx.rangeClosed(1, 3).parallel().foldLeft(0, accumulator));
}
@Test
public void testMapFirstLast() {
// capitalize
String str = "testString";
assertEquals("TestString", IntStreamEx.ofCodePoints(str).mapFirst(Character::toUpperCase).codePointsToString());
streamEx(() -> StreamEx.of(1, 2, 3, 4, 5), s ->
assertArrayEquals(new int[] { -3, 2, 3, 4, 9 }, s.get().mapToInt(Integer::intValue)
.mapFirst(x -> x - 2).mapLast(x -> x + 2)
.mapFirst(x -> x - 2).mapLast(x -> x + 2).toArray()));
}
@Test
public void testPeekFirst() {
int[] input = {1, 10, 100, 1000};
AtomicInteger firstElement = new AtomicInteger();
assertArrayEquals(new int[] {10, 100, 1000}, IntStreamEx.of(input).peekFirst(firstElement::set).skip(1).toArray());
assertEquals(1, firstElement.get());
assertArrayEquals(new int[] {10, 100, 1000}, IntStreamEx.of(input).skip(1).peekFirst(firstElement::set).toArray());
assertEquals(10, firstElement.get());
firstElement.set(-1);
assertArrayEquals(new int[] {}, IntStreamEx.of(input).skip(4).peekFirst(firstElement::set).toArray());
assertEquals(-1, firstElement.get());
}
@Test
public void testPeekLast() {
int[] input = {1, 10, 100, 1000};
AtomicInteger lastElement = new AtomicInteger(-1);
assertArrayEquals(new int[] {1, 10, 100}, IntStreamEx.of(input).peekLast(lastElement::set).limit(3).toArray());
assertEquals(-1, lastElement.get());
assertArrayEquals(new int[] { 1, 10, 100 }, IntStreamEx.of(input).less(1000).peekLast(lastElement::set)
.limit(3).toArray());
assertEquals(100, lastElement.get());
assertArrayEquals(input, IntStreamEx.of(input).peekLast(lastElement::set).limit(4).toArray());
assertEquals(1000, lastElement.get());
assertArrayEquals(new int[] {1, 10, 100}, IntStreamEx.of(input).limit(3).peekLast(lastElement::set).toArray());
assertEquals(100, lastElement.get());
}
@Test
public void testScanLeft() {
assertArrayEquals(new int[] { 0, 1, 3, 6, 10, 15, 21, 28, 36, 45 }, IntStreamEx.range(10)
.scanLeft(Integer::sum));
assertArrayEquals(new int[] { 0, 1, 3, 6, 10, 15, 21, 28, 36, 45 }, IntStreamEx.range(10).parallel().scanLeft(
Integer::sum));
assertArrayEquals(new int[] { 0, 1, 3, 6, 10, 15, 21, 28, 36, 45 }, IntStreamEx.range(10).filter(x -> true)
.scanLeft(Integer::sum));
assertArrayEquals(new int[] { 0, 1, 3, 6, 10, 15, 21, 28, 36, 45 }, IntStreamEx.range(10).filter(x -> true)
.parallel().scanLeft(Integer::sum));
assertArrayEquals(new int[] { 1, 1, 2, 6, 24, 120 }, IntStreamEx.rangeClosed(1, 5).scanLeft(1, (a, b) -> a * b));
assertArrayEquals(new int[] { 1, 1, 2, 6, 24, 120 }, IntStreamEx.rangeClosed(1, 5).parallel().scanLeft(1,
(a, b) -> a * b));
}
// Reads numbers from scanner stopping when non-number is encountered
// leaving scanner in known state
public static IntStreamEx scannerInts(Scanner sc) {
return IntStreamEx.produce(action -> {
if(sc.hasNextInt())
action.accept(sc.nextInt());
return sc.hasNextInt();
});
}
@Test
public void testProduce() {
Scanner sc = new Scanner("1 2 3 4 20000000000 test");
assertArrayEquals(new int[] {1, 2, 3, 4}, scannerInts(sc).stream().toArray());
assertEquals("20000000000", sc.next());
}
@Test
public void testOfInputStream() {
byte[] data = new byte[] { 5, 3, 10, 1, 4, -1 };
try(IntStream s = IntStreamEx.of(new ByteArrayInputStream(data))) {
assertEquals(22, s.map(b -> (byte)b).sum());
}
try(IntStream s = IntStreamEx.of(new ByteArrayInputStream(data))) {
assertEquals(278, s.sum());
}
}
@Test
public void testAsInputStream() throws IOException {
AtomicBoolean flag = new AtomicBoolean(false);
InputStream is = IntStreamEx.range(256).onClose(() -> flag.set(true)).asByteInputStream();
byte[] data = new byte[256];
assertEquals(2, is.skip(2));
assertEquals(254, is.read(data));
assertEquals(-1, is.read());
for(int i=0; i<254; i++) {
assertEquals((byte)(i+2), data[i]);
}
assertEquals(0, data[254]);
assertEquals(0, data[255]);
assertFalse(flag.get());
is.close();
assertTrue(flag.get());
}
@Test
public void testPrefix() {
assertArrayEquals(new int[] { 1, 3, 6, 10, 20 }, IntStreamEx.of(1, 2, 3, 4, 10).prefix(Integer::sum).toArray());
assertEquals(OptionalInt.of(10), IntStreamEx.of(1, 2, 3, 4, 10).prefix(Integer::sum).findFirst(x -> x > 7));
assertEquals(OptionalInt.empty(), IntStreamEx.of(1, 2, 3, 4, 10).prefix(Integer::sum).findFirst(x -> x > 20));
}
@Test
public void testIntersperse() {
assertArrayEquals(new int[] { 1, 0, 10, 0, 100, 0, 1000 }, IntStreamEx.of(1, 10, 100, 1000).intersperse(0)
.toArray());
assertEquals(0L, IntStreamEx.empty().intersperse(1).count());
}
}