Gave Stream a lazy withFilter implementation.

can have a collection containing all the even numbers in the universe
and still be home in time for tea. Threw in some Stream cleanups for
free. Closes #3265, review by community.

1 files changed, 11 insertions, 0 deletions

diff --git a/test/files/run/streamWithFilter.scala b/test/files/run/streamWithFilter.scala
new file mode 100644
index 0000000000..cb919d4f55
--- /dev/null
+++ b/test/files/run/streamWithFilter.scala
@@ -0,0 +1,11 @@
+object Test {
+  val nums = Stream.from(1)
+  def isFizz(x: Int) = x % 3 == 0
+  def isBuzz(x: Int) = x % 5 == 0
+  // next line will run forever if withFilter isn't doing its thing.
+  val fizzbuzzes = for (n <- nums ; if isFizz(n) ; if isBuzz(n)) yield n
+
+  def main(args: Array[String]): Unit = {
+    fizzbuzzes take 5 foreach println
+  }
+}