unify mutable and immutable stacks behavior (#957)

2 files changed, 52 insertions, 0 deletions

diff --git a/test/files/run/collection-stacks.check b/test/files/run/collection-stacks.check
new file mode 100644
index 0000000000..fcb39c460c
--- /dev/null
+++ b/test/files/run/collection-stacks.check
@@ -0,0 +1,14 @@
+1-2-3: true
+1-2-3: true
+apply
+1: true
+1: true
+3: true
+3: true
+top
+3: true
+3: true
+pop
+1-2: true
+3: true
+1-2: true
diff --git a/test/files/run/collection-stacks.scala b/test/files/run/collection-stacks.scala
new file mode 100644
index 0000000000..ec557cb91d
--- /dev/null
+++ b/test/files/run/collection-stacks.scala
@@ -0,0 +1,38 @@
+import scala.collection._
+
+object Test extends Application {
+  def mutableStack[T](xs: T*): mutable.Stack[T] = {
+    val s = new mutable.Stack[T]
+    s.push(xs: _*)
+    s
+  }
+
+  def immutableStack[T](xs: T*): immutable.Stack[T] = {
+    immutable.Stack.Empty push xs
+  }
+
+  def check[T](expected: T, got: T) {
+    println(got + ": " + (expected == got))
+  }
+
+  // check #957
+  check("1-2-3", immutableStack(1, 2, 3).elements.mkString("-"))
+  check("1-2-3", mutableStack(1, 2, 3).elements.mkString("-"))
+
+  println("apply")
+  check(1, immutableStack(1, 2, 3).apply(0))
+  check(1, mutableStack(1, 2, 3).apply(0))
+  check(3, immutableStack(1, 2, 3).apply(2))
+  check(3, mutableStack(1, 2, 3).apply(2))
+
+  println("top")
+  check(3, immutableStack(1, 2, 3).top)
+  check(3, mutableStack(1, 2, 3).top)
+
+  println("pop")
+  check("1-2", immutableStack(1, 2, 3).pop.mkString("-"))
+  check(3, mutableStack(1, 2, 3).pop())
+  check("1-2", { val s = mutableStack(1, 2, 3); s.pop(); s.toList.mkString("-") })
+}
+
+// vim: set ts=2 sw=2 et: