Ilya Ryzhenkov
34 lines
1.0 KiB
Kotlin
34 lines
1.0 KiB
Kotlin
package iterators
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import kotlin.test.assertEquals
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import org.junit.Test as test
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import kotlin.test.failsWith
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class IteratorsJVMTest {
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test fun flatMapAndTakeExtractTheTransformedElements() {
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fun intToBinaryDigits() = { (i: Int) ->
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val binary = Integer.toBinaryString(i)!!
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var index = 0
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stream<Char> { if (index < binary.length()) binary.get(index++) else null }
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}
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val expected = arrayListOf(
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'0', // fibonacci(0) = 0
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'1', // fibonacci(1) = 1
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'1', // fibonacci(2) = 1
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'1', '0', // fibonacci(3) = 2
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'1', '1', // fibonacci(4) = 3
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'1', '0', '1' // fibonacci(5) = 5
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)
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assertEquals(expected, fibonacci().flatMap<Int, Char>(intToBinaryDigits()).take(10).toList())
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}
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test fun flatMapOnIterator() {
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val result = streamOf(1, 2).flatMap { i -> (0..i).stream()}
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assertEquals(listOf(0, 1, 0, 1, 2), result.toList())
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}
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}
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