Changed Stream implementation to use tail recur...

Changed Stream implementation to use tail recursive calls directly,
instead of tail-recursive local functions. This has better GC behavior,
see ticket #692.

2 files changed, 20 insertions, 0 deletions

diff --git a/test/files/run/streams.check b/test/files/run/streams.check
index 5346c73d12..7f894052d9 100644
--- a/test/files/run/streams.check
+++ b/test/files/run/streams.check
@@ -17,3 +17,9 @@ Stream()
 
 999
 512
+100000
+Stream(100001, ?)
+Stream(100001, ?)
+true
+true
+705082704
diff --git a/test/files/run/streams.scala b/test/files/run/streams.scala
index 1e781a6171..970f3cef16 100644
--- a/test/files/run/streams.scala
+++ b/test/files/run/streams.scala
@@ -29,4 +29,18 @@ object Test extends Application {
   def powers(x: Int) = if ((x&(x-1)) == 0) Some(x) else None
   println(s3.flatMap(powers).reverse.head)
 
+  // large enough to generate StackOverflows (on most systems)
+  // unless the following methods are tail call optimized.
+  val size = 100000
+
+  // test tail recursive methods
+  println(Stream.from(1).take(size).last)
+  println(Stream.from(1).drop(size))
+  println(Stream.from(1).filter(_ > size).take(5))
+  println(Stream.from(1).take(size).forall(_ >= 0))
+  println(Stream.from(1).exists(_ > size))
+  Stream.from(1).take(size).foreach( x => () )
+  println(Stream.from(1).take(size).foldLeft(0)(_ + _))
+  val arr = new Array[Int](size)
+  Stream.from(1).take(size).copyToArray(arr, 0)
 }