Ilya Gorbunov
55 lines
1.9 KiB
Kotlin
55 lines
1.9 KiB
Kotlin
package kotlin.jdk8.streams.test
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import kotlin.streams.*
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import org.junit.Test
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import java.util.stream.*
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import kotlin.test.*
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class StreamsTest {
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@Test fun toList() {
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val data = arrayOf(1, 2L, 1.23, null)
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val streamBuilder = { Stream.of(*data) }
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assertEquals(data.asList(), streamBuilder().toList())
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assertEquals(listOf(1), streamBuilder().filter { it is Int }.mapToInt { it as Int }.toList())
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assertEquals(listOf(2L), streamBuilder().filter { it is Long }.mapToLong { it as Long }.toList())
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assertEquals(listOf(1.23), streamBuilder().filter { it is Double }.mapToDouble { it as Double }.toList())
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}
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@Test fun asSequence() {
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val data = arrayOf(1, 2L, 1.23, null)
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fun<T> assertSequenceContent(expected: List<T>, actual: Sequence<T>) {
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assertEquals(expected, actual.toList())
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assertFailsWith<IllegalStateException> ("Second iteration fails") { actual.toList() }
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}
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assertSequenceContent(data.asList(), Stream.of(*data).asSequence())
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assertSequenceContent(listOf(1, 2), IntStream.of(1, 2).asSequence())
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assertSequenceContent(listOf(1L, 2L), LongStream.of(1L, 2L).asSequence())
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assertSequenceContent(listOf(1.0, 2.0), DoubleStream.of(1.0, 2.0).asSequence())
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}
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@Test fun asStream() {
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val sequence = generateSequence(0) { it -> it * it + 1 }
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val stream = sequence.asStream()
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val expected = Stream.iterate(0) { it -> it * it + 1 }
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assertEquals(expected.limit(7).toList(), stream.limit(7).toList())
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}
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@Test fun asParallelStream() {
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val sequence = generateSequence(0) { it + 2 } // even numbers
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val stream = sequence.asStream().parallel().map { it / 2 }
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val n = 100000
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val expected = (0 until n).toList()
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assertEquals(expected, stream.limit(n.toLong()).toList())
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}
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}
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