diff options
-rw-r--r-- | src/library/scala/collection/immutable/Queue.scala | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/src/library/scala/collection/immutable/Queue.scala b/src/library/scala/collection/immutable/Queue.scala index 2d5b05778b..079c3f3a3d 100644 --- a/src/library/scala/collection/immutable/Queue.scala +++ b/src/library/scala/collection/immutable/Queue.scala @@ -40,17 +40,13 @@ class Queue[+A] protected( * @throws Predef.NoSuchElementException if the queue is too short. */ def apply(n: Int): A = { - @tailrec - def walk(i: Int, inlist: List[A], outlist: List[A]): A = - (i == 0, inlist.isEmpty, outlist.isEmpty) match { - case (_, true, true) => throw new NoSuchElementException("index out of range") - case (true, _, false) => outlist.head - case (true, _, true) => inlist.last - case (false, _, false) => walk(i - 1, inlist, outlist.tail) - case (false, false, true) => walk(i - 1, Nil, inlist.reverse.tail) - } - - walk(n, in, out) + val len = out.length + if (n < len) out.apply(n) + else { + val m = n - len + if (m < in.length) in.reverse.apply(m) + else throw new NoSuchElementException("index out of range") + } } /** Returns the elements in the list as an iterator |