From ad6983518dd6860564d16f5b6e99178db3cff7a2 Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Tue, 5 Mar 2013 10:27:41 +0100 Subject: SI-7215 Fix transpose of an empty Array[Array[T]]. --- .../scala/collection/mutable/ArrayOps.scala | 23 ++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'src/library') diff --git a/src/library/scala/collection/mutable/ArrayOps.scala b/src/library/scala/collection/mutable/ArrayOps.scala index bb938a7aeb..25ba7e4ce6 100644 --- a/src/library/scala/collection/mutable/ArrayOps.scala +++ b/src/library/scala/collection/mutable/ArrayOps.scala @@ -76,18 +76,21 @@ trait ArrayOps[T] extends Any with ArrayLike[T, Array[T]] with CustomParalleliza * @return An array obtained by replacing elements of this arrays with rows the represent. */ def transpose[U](implicit asArray: T => Array[U]): Array[Array[U]] = { - def mkRowBuilder() = Array.newBuilder(ClassTag[U](arrayElementClass(elementClass))) - val bs = asArray(head) map (_ => mkRowBuilder()) - for (xs <- this) { - var i = 0 - for (x <- asArray(xs)) { - bs(i) += x - i += 1 + val bb: Builder[Array[U], Array[Array[U]]] = Array.newBuilder(ClassTag[Array[U]](elementClass)) + if (isEmpty) bb.result() + else { + def mkRowBuilder() = Array.newBuilder(ClassTag[U](arrayElementClass(elementClass))) + val bs = asArray(head) map (_ => mkRowBuilder()) + for (xs <- this) { + var i = 0 + for (x <- asArray(xs)) { + bs(i) += x + i += 1 + } } + for (b <- bs) bb += b.result() + bb.result() } - val bb: Builder[Array[U], Array[Array[U]]] = Array.newBuilder(ClassTag[Array[U]](elementClass)) - for (b <- bs) bb += b.result - bb.result } def seq = thisCollection -- cgit v1.2.3