while (j < n && hasNext) {

next()

import scala.tools.testing.AssertUtil._

import Seq.empty

@Test def groupedIteratorShouldNotAskForUnneededElement(): Unit = {

@Test def dropDoesNotGrowStack(): Unit = {

def it = new Iterator[Throwable] { def hasNext = true ; def next = new Throwable }

assertEquals(it.drop(1).next.getStackTrace.length, it.drop(1).drop(1).next.getStackTrace.length)

}

@Test def dropIsChainable(): Unit = {

assertSameElements(1 to 4, Iterator from 0 take 5 drop 1)

assertSameElements(3 to 4, Iterator from 0 take 5 drop 3)

assertSameElements(empty, Iterator from 0 take 5 drop 5)

assertSameElements(empty, Iterator from 0 take 5 drop 10)

assertSameElements(0 to 4, Iterator from 0 take 5 drop 0)

assertSameElements(0 to 4, Iterator from 0 take 5 drop -1)

assertSameElements(2 to 8 by 2, Iterator from 0 take 5 drop 1 map (2 * _))

assertSameElements(2 to 8 by 2, Iterator from 0 take 5 map (2 * _) drop 1)

assertSameElements(3 to 4, Iterator from 0 take 5 drop 1 drop 2)

assertSameElements(3 to 4, Iterator from 0 take 5 drop 2 drop 1)

}

@Test def sliceIsChainable(): Unit = {

assertSameElements(3 to 6, Iterator from 0 slice (3, 7))

assertSameElements(empty, Iterator from 0 slice (3, 3))

assertSameElements(0 to 2, Iterator from 0 slice (-1, 3))

assertSameElements(empty, Iterator from 0 slice (3, -1))

assertSameElements(6 to 12 by 2, Iterator from 0 slice (3, 7) map (2 * _))

assertSameElements(6 to 12 by 2, Iterator from 0 map (2 * _) slice (3, 7))

assertSameElements(4 to 6, Iterator from 0 slice (3, 7) drop 1)

assertSameElements(4 to 7, Iterator from 0 drop 1 slice (3, 7))

assertSameElements(4 to 5, Iterator from 0 slice (3, 7) slice (1, 3))

assertSameElements(4 to 6, Iterator from 0 slice (3, 7) slice (1, 10))

}

// test/files/run/iterator-concat.scala

@Test def concatIsStackFriendly(): Unit = {

// Create `size` Function0s, each of which evaluates to an Iterator

// which produces 1. Then fold them over ++ to get a single iterator,

// which should sum to "size".

def mk(size: Int): Iterator[Int] = {

//val closures = (1 to size).toList.map(x => (() => Iterator(1)))

//closures.foldLeft(Iterator.empty: Iterator[Int])((res, f) => res ++ f())

List.fill(size)(() => Iterator(1)).foldLeft(Iterator.empty: Iterator[Int])((res, f) => res ++ f())

}

assertEquals(100, mk(100).sum)

assertEquals(1000, mk(1000).sum)

assertEquals(10000, mk(10000).sum)

assertEquals(100000, mk(100000).sum)

}

@Test def from(): Unit = {

val it1 = Iterator.from(-1)

val it2 = Iterator.from(0, -1)

assertEquals(-1, it1.next())

assertEquals(0, it2.next())

}

@Test def range(): Unit = {

assertEquals(5, Iterator.range(0, 10, 2).size)

assertEquals(0, Iterator.range(0, 10, -2).size)

assertEquals(5, Iterator.range(10, 0, -2).size)

assertEquals(0, Iterator.range(10, 0, 2).size)

assertEquals(1, Iterator.range(0, 10, 11).size)

assertEquals(10, Iterator.range(0, 10, 1).size)

assertEquals(10, Iterator.range(10, 0, -1).size)

}

@Test def range3(): Unit = {

val r1 = Iterator.range(0, 10)

assertTrue(r1 contains 5)

assertTrue(r1 contains 6)

assertFalse(r1 contains 4)

val r2a = Iterator.range(0, 10, 2)

assertFalse(r2a contains 5)

val r2b = Iterator.range(0, 10, 2)

assertTrue(r2b contains 6)

val r3 = Iterator.range(0, 10, 11)

assertFalse(r3 contains 5)

assertTrue(r3.isEmpty)

}

@Test def take(): Unit = {

assertEquals(10, (Iterator from 0 take 10).size)

}

@Test def foreach(): Unit = {

val it1 = Iterator.from(0) take 20

var n = 0

it1 foreach { n += _ }

assertEquals(190, n)

}

// ticket #429

@Test def fromArray(): Unit = {

val a = List(1, 2, 3, 4).toArray

var xs0 = a.iterator.toList;

var xs1 = a.slice(0, 1).iterator

var xs2 = a.slice(0, 2).iterator

var xs3 = a.slice(0, 3).iterator

var xs4 = a.slice(0, 4).iterator

assertEquals(14, xs0.size + xs1.size + xs2.size + xs3.size + xs4.size)

}

@Test def toSeq(): Unit = {

assertEquals("1x2x3x4x5", List(1, 2, 3, 4, 5).iterator.mkString("x"))

}

@Test def indexOf(): Unit = {

assertEquals(3, List(1, 2, 3, 4, 5).iterator.indexOf(4))

assertEquals(-1, List(1, 2, 3, 4, 5).iterator.indexOf(16))

}

@Test def indexWhere(): Unit = {

assertEquals(3, List(1, 2, 3, 4, 5).iterator.indexWhere { x: Int => x >= 4 })

assertEquals(-1, List(1, 2, 3, 4, 5).iterator.indexWhere { x: Int => x >= 16 })

}

// iterator-iterate-lazy.scala

// was java.lang.UnsupportedOperationException: tail of empty list

@Test def iterateIsSufficientlyLazy(): Unit = {

//Iterator.iterate((1 to 5).toList)(_.tail).takeWhile(_.nonEmpty).toList // suffices

Iterator.iterate((1 to 5).toList)(_.tail).takeWhile(_.nonEmpty).map(_.head).toList

}

// SI-3516

@Test def toStreamIsSufficientlyLazy(): Unit = {

val results = collection.mutable.ListBuffer.empty[Int]

def mkIterator = (1 to 5).iterator map (x => { results += x ; x })

def mkInfinite = Iterator continually { results += 1 ; 1 }

// Stream is strict in its head so we should see 1 from each of them.

val s1 = mkIterator.toStream

val s2 = mkInfinite.toStream

// back and forth without slipping into nontermination.

results += (Stream from 1).toIterator.drop(10).toStream.drop(10).toIterator.next()

assertSameElements(List(1,1,21), results)

}