1 files changed, 55 insertions, 0 deletions
diff --git a/tests/untried/pos/t267.scala b/tests/untried/pos/t267.scala
new file mode 100644
index 000000000..7e5876eae
--- /dev/null
+++ b/tests/untried/pos/t267.scala
@@ -0,0 +1,55 @@
+package expAbstractData
+
+/** A base class consisting of
+ *   - a root trait (i.e. abstract class) `Exp' with an `eval' function
+ *   - an abstract type `exp' bounded by `Exp'
+ *   - a concrete instance class `Num' of `Exp' for numeric literals
+ */
+trait Base {
+  type exp <: Exp
+
+  trait Exp {
+    def eval: Int
+  }
+  class Num(v: Int) extends Exp { self: exp =>
+    val value = v
+    def eval = value
+  }
+}
+
+object testBase extends App with Base {
+  type exp = Exp
+  val term = new Num(2);
+  Console.println(term.eval)
+}
+
+/** Data extension: An extension of `Base' with `Plus' expressions
+ */
+trait BasePlus extends Base {
+  class Plus(l: exp, r: exp) extends Exp { self: exp =>
+    val left = l
+    val right = r
+    def eval = left.eval + right.eval
+  }
+}
+
+/** Operation extension: An extension of `Base' with 'show' methods.
+ */
+trait Show extends Base {
+  type exp <: Exp1
+
+  trait Exp1 extends Exp {
+    def show: String
+  }
+  class Num1(v: Int) extends Num(v) with Exp1 { self: exp with Num1 =>
+    def show = value.toString()
+  }
+}
+
+/** Operation extension: An extension of `BasePlus' with 'show' methods.
+ */
+trait ShowPlus extends BasePlus with Show {
+  class Plus1(l: exp, r: exp) extends Plus(l, r) with Exp1 { self: exp with Plus1 =>
+    def show = left.show + " + " + right.show
+  }
+}