matching on arrays via unapplySeq

3 files changed, 17 insertions, 5 deletions

diff --git a/src/library/scala/Array.scala b/src/library/scala/Array.scala
index 82745709ba..dd253ab658 100644
--- a/src/library/scala/Array.scala
+++ b/src/library/scala/Array.scala
@@ -157,6 +157,14 @@ object Array {
     array
   }
 
+  /** This method is called in a pattern match { case Array(...) => }.
+   *
+   *  @param x the selector value
+   *  @return  array wrapped in an option, if this is a Seq, otherwise none
+   */
+  def unapplySeq[A](x: Any): Option[Seq[A]] =
+    if (x.isInstanceOf[Array[A]]) Some(x.asInstanceOf[Array[A]]) else None
+
 }
 
 /** This class represents polymorphic arrays. It is never instantiated.
diff --git a/src/library/scala/Seq.scala b/src/library/scala/Seq.scala
index 83deeef39e..1a488b82b2 100644
--- a/src/library/scala/Seq.scala
+++ b/src/library/scala/Seq.scala
@@ -23,13 +23,16 @@ object Seq {
     def elements = Iterator.empty
   }
 
-  /** ...
+  /** This method is called in a pattern match { case Seq(...) => }.
    *
-   *  @param x ...
-   *  @return  ...
+   *  @param x the selector value
+   *  @return  sequence wrapped in an option, if this is a Seq, otherwise none
    */
-  def unapplySeq[A](x: Any): Option[Seq[A]] =
-    if (x.isInstanceOf[Seq[A]]) Some(x.asInstanceOf[Seq[A]]) else None
+  def unapplySeq[A](x: Any): Option[Seq[A]] = x match {
+    case z: Seq[_] => Some(z.asInstanceOf[Seq[A]])
+    case z: AnyRef if runtime.ScalaRunTime.isArray(z) => Some(runtime.ScalaRunTime.boxArray(z).asInstanceOf[Seq[A]])
+    case _ =>  None
+  }
 
   /** Builds a singleton sequence.
    *
diff --git a/src/library/scala/runtime/ScalaRunTime.scala b/src/library/scala/runtime/ScalaRunTime.scala
index f29ca6d1e7..248904c0e1 100644
--- a/src/library/scala/runtime/ScalaRunTime.scala
+++ b/src/library/scala/runtime/ScalaRunTime.scala
@@ -39,6 +39,7 @@ object ScalaRunTime {
   val BooleanTYPE = java.lang.Boolean.TYPE
   val UnitTYPE = java.lang.Void.TYPE
 
+  def isArray(x:AnyRef): Boolean = x.getClass.isArray
   def isValueTag(tag: String) = tag.charAt(0) == '.'
   def isValueClass(clazz: Class) = clazz.isPrimitive()