New test case

Author: odersky

tests/pos/enum-List-control.scala

@@ -0,0 +1,14 @@
+abstract sealed class List[T] extends Enum
+object List {
+  final case class Cons[T](x: T, xs: List[T]) extends List[T] {
+    def enumTag = 0
+  }
+  final case class Nil[T]() extends List[T] {
+    def enumTag = 1
+  }
+}
+object Test {
+  import List._
+  val xs = Cons(1, Cons(2, Cons(3, Nil())))
+  def main(args: Array[String]) = println(xs)
+}

tests/run/enum-Tree.check

@@ -0,0 +1 @@
+If(IsZero(Pred(Succ(Zero))),Succ(Succ(Zero)),Pred(Pred(Zero))) --> 2

tests/run/enum-Tree.scala

@@ -0,0 +1,29 @@
+enum Tree[T] {
+  case True extends Tree[Boolean]
+  case False extends Tree[Boolean]
+  case Zero extends Tree[Int]
+  case Succ(n: Tree[Int]) extends Tree[Int]
+  case Pred(n: Tree[Int]) extends Tree[Int]
+  case IsZero(n: Tree[Int]) extends Tree[Boolean]
+  case If(cond: Tree[Boolean], thenp: Tree[T], elsep: Tree[T])
+}
+
+object Test {
+  import Tree._
+
+  def eval[T](e: Tree[T]): T = e match {
+    case True => true
+    case False => false
+    case Zero => 0
+    case Succ(f) => eval(f) + 1
+    case Pred(f) => eval(f) - 1
+    case IsZero(f) => eval(f) == 0
+    case If(cond, thenp, elsep) => if (eval(cond)) eval(thenp) else eval(elsep)
+  }
+
+  val data = If(IsZero(Pred(Succ(Zero))), Succ(Succ(Zero)), Pred(Pred(Zero)))
+
+  def main(args: Array[String]) = {
+    println(s"$data --> ${eval(data)}")
+  }
+}