Merge pull request #1535 from paulp/stream-distinct

Fix SI-6584, Stream#distinct uses too much memory.

4 files changed, 29 insertions, 1 deletions

diff --git a/test/files/run/streams.check b/test/files/run/streams.check
index 7f894052d9..032057d4a1 100644
--- a/test/files/run/streams.check
+++ b/test/files/run/streams.check
@@ -23,3 +23,4 @@ Stream(100001, ?)
 true
 true
 705082704
+6
diff --git a/test/files/run/streams.scala b/test/files/run/streams.scala
index 51b4e5d76c..dc5d0204ac 100644
--- a/test/files/run/streams.scala
+++ b/test/files/run/streams.scala
@@ -29,7 +29,7 @@ object Test extends App {
   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) 
+  // large enough to generate StackOverflows (on most systems)
   // unless the following methods are tail call optimized.
   val size = 100000
 
@@ -43,4 +43,7 @@ object Test extends App {
   println(Stream.from(1).take(size).foldLeft(0)(_ + _))
   val arr = new Array[Int](size)
   Stream.from(1).take(size).copyToArray(arr, 0)
+
+  // dropRight terminates
+  println(Stream from 1 dropRight 1000 take 3 sum)
 }
diff --git a/test/files/run/t6584.check b/test/files/run/t6584.check
new file mode 100644
index 0000000000..35c8688751
--- /dev/null
+++ b/test/files/run/t6584.check
@@ -0,0 +1,8 @@
+Array: 102400
+Vector: 102400
+List: 102400
+Stream: 102400
+Array: 102400
+Vector: 102400
+List: 102400
+Stream: 102400
diff --git a/test/files/run/t6584.scala b/test/files/run/t6584.scala
new file mode 100644
index 0000000000..24c236ef35
--- /dev/null
+++ b/test/files/run/t6584.scala
@@ -0,0 +1,16 @@
+object Test {
+  def main(args: Array[String]): Unit = {
+    val size = 100 * 1024
+    val doubled = (1 to size) ++ (1 to size)
+
+    println("Array: " + Array.tabulate(size)(x => x).distinct.size)
+    println("Vector: " + Vector.tabulate(size)(x => x).distinct.size)
+    println("List: " + List.tabulate(size)(x => x).distinct.size)
+    println("Stream: " + Stream.tabulate(size)(x => x).distinct.size)
+
+    println("Array: " + doubled.toArray.distinct.size)
+    println("Vector: " + doubled.toVector.distinct.size)
+    println("List: " + doubled.toList.distinct.size)
+    println("Stream: " + doubled.toStream.distinct.size)
+  }
+}