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author | Seth Tisue <seth@tisue.net> | 2016-02-11 15:06:26 -0800 |
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committer | Seth Tisue <seth@tisue.net> | 2016-02-11 15:06:26 -0800 |
commit | 6d09a1ba5fffadd1d886afb66ab4496291fda3dd (patch) | |
tree | 802da9f49dab8905e94b033f21b3484c1bce35c8 /src/library | |
parent | b19e2535624de0907264a3c7710bf02b2fd0f952 (diff) | |
parent | 645506250208eb3fd75ce6ab925692adb068e553 (diff) | |
download | scala-6d09a1ba5fffadd1d886afb66ab4496291fda3dd.tar.gz scala-6d09a1ba5fffadd1d886afb66ab4496291fda3dd.tar.bz2 scala-6d09a1ba5fffadd1d886afb66ab4496291fda3dd.zip |
Merge pull request #4957 from retronym/topic/merge-2.11.x-to-2.12.x-20160210
Merge 2.11.x to 2.12.x [ci:last-only]
Diffstat (limited to 'src/library')
-rw-r--r-- | src/library/scala/collection/Iterator.scala | 51 | ||||
-rw-r--r-- | src/library/scala/util/Properties.scala | 2 |
2 files changed, 46 insertions, 7 deletions
diff --git a/src/library/scala/collection/Iterator.scala b/src/library/scala/collection/Iterator.scala index 17bb83e52e..518bba6b6d 100644 --- a/src/library/scala/collection/Iterator.scala +++ b/src/library/scala/collection/Iterator.scala @@ -10,7 +10,7 @@ package scala package collection import mutable.ArrayBuffer -import scala.annotation.migration +import scala.annotation.{tailrec, migration} import immutable.Stream /** The `Iterator` object provides various functions for creating specialized iterators. @@ -166,8 +166,10 @@ object Iterator { private[scala] final class ConcatIterator[+A](private[this] var current: Iterator[A], initial: Vector[() => Iterator[A]]) extends Iterator[A] { @deprecated def this(initial: Vector[() => Iterator[A]]) = this(Iterator.empty, initial) // for binary compatibility private[this] var queue: Vector[() => Iterator[A]] = initial + private[this] var currentHasNextChecked = false // Advance current to the next non-empty iterator // current is set to null when all iterators are exhausted + @tailrec private[this] def advance(): Boolean = { if (queue.isEmpty) { current = null @@ -176,20 +178,57 @@ object Iterator { else { current = queue.head() queue = queue.tail - current.hasNext || advance() + if (current.hasNext) { + currentHasNextChecked = true + true + } else advance() } } - def hasNext = (current ne null) && (current.hasNext || advance()) - def next() = if (hasNext) current.next() else Iterator.empty.next() + def hasNext = + if (currentHasNextChecked) true + else if (current eq null) false + else if (current.hasNext) { + currentHasNextChecked = true + true + } else advance() + def next() = + if (hasNext) { + currentHasNextChecked = false + current.next() + } else Iterator.empty.next() override def ++[B >: A](that: => GenTraversableOnce[B]): Iterator[B] = new ConcatIterator(current, queue :+ (() => that.toIterator)) } private[scala] final class JoinIterator[+A](lhs: Iterator[A], that: => GenTraversableOnce[A]) extends Iterator[A] { + private[this] var state = 0 // 0: lhs not checked, 1: lhs has next, 2: switched to rhs private[this] lazy val rhs: Iterator[A] = that.toIterator - def hasNext = lhs.hasNext || rhs.hasNext - def next() = if (lhs.hasNext) lhs.next() else rhs.next() + def hasNext = state match { + case 0 => + if (lhs.hasNext) { + state = 1 + true + } else { + state = 2 + rhs.hasNext + } + case 1 => true + case _ => rhs.hasNext + } + def next() = state match { + case 0 => + if (lhs.hasNext) lhs.next() + else { + state = 2 + rhs.next() + } + case 1 => + state = 0 + lhs.next() + case _ => + rhs.next() + } override def ++[B >: A](that: => GenTraversableOnce[B]) = new ConcatIterator(this, Vector(() => that.toIterator)) diff --git a/src/library/scala/util/Properties.scala b/src/library/scala/util/Properties.scala index d4a5e2f0e8..7ea597eac9 100644 --- a/src/library/scala/util/Properties.scala +++ b/src/library/scala/util/Properties.scala @@ -105,7 +105,7 @@ private[scala] trait PropertiesTrait { * or "version (unknown)" if it cannot be determined. */ val versionString = "version " + scalaPropOrElse("version.number", "(unknown)") - val copyrightString = scalaPropOrElse("copyright.string", "Copyright 2002-2015, LAMP/EPFL") + val copyrightString = scalaPropOrElse("copyright.string", "Copyright 2002-2016, LAMP/EPFL") /** This is the encoding to use reading in source files, overridden with -encoding. * Note that it uses "prop" i.e. looks in the scala jar, not the system properties. |