Added infrastructure to enable easy enrichment of GenTraversables.

1 files changed, 30 insertions, 0 deletions

diff --git a/test/files/run/enrich-gentraversable.scala b/test/files/run/enrich-gentraversable.scala
new file mode 100644
index 0000000000..c9320ff985
--- /dev/null
+++ b/test/files/run/enrich-gentraversable.scala
@@ -0,0 +1,30 @@
+object Test extends App {
+  import scala.collection.generic.{ CanBuildFrom, FromRepr, HasElem }
+
+  def typed[T](t : => T) {}
+
+  class FilterMapImpl[A, Repr](val r : Repr)(implicit hasElem : HasElem[Repr, A]) {
+    def filterMap[B, That](f : A => Option[B])(implicit cbf : CanBuildFrom[Repr, B, That]) : That = r.flatMap(f(_).toSeq)
+  }
+  
+  implicit def filterMap[Repr : FromRepr](r : Repr) = new FilterMapImpl(r)
+
+  val l = List(1, 2, 3, 4, 5)
+  val fml = l.filterMap(i => if(i % 2 == 0) Some(i) else None)
+  typed[List[Int]](fml)
+  println(fml)
+
+  val a = Array(1, 2, 3, 4, 5)
+  val fma = a.filterMap(i => if(i % 2 == 0) Some(i) else None)
+  typed[Array[Int]](fma)
+  println(fma.deep)
+  
+  val s = "Hello World"
+  val fms1 = s.filterMap(c => if(c >= 'A' && c <= 'Z') Some(c) else None)
+  typed[String](fms1)
+  println(fms1)
+  
+  val fms2 = s.filterMap(c =>if(c % 2 == 0) Some(c.toInt) else None)
+  typed[IndexedSeq[Int]](fms2)
+  println(fms2)
+}