Merge pull request #1881 from dotty-staging/add-structural-select

Implement structural type member access

3 files changed, 49 insertions, 0 deletions

diff --git a/tests/run/structural.scala b/tests/run/structural.scala
new file mode 100644
index 000000000..0f18f4579
--- /dev/null
+++ b/tests/run/structural.scala
@@ -0,0 +1,25 @@
+case class Record(elems: (String, Any)*) extends Selectable {
+  def selectDynamic(name: String): Any = elems.find(_._1 == name).get._2
+}
+
+object Test {
+  import scala.reflect.Selectable.reflectiveSelectable
+
+  def f(closeable: { def close(): Unit }) =
+    closeable.close()
+
+  type RN = Record { val name: String; val age: Int }
+
+  def g(r: RN) = r.name
+
+  val rr: RN = Record("name" -> "Bob", "age" -> 42).asInstanceOf[RN]
+
+  def main(args: Array[String]): Unit = {
+    f(new java.io.PrintStream("foo"))
+    assert(g(rr) == "Bob")
+
+    val s: { def concat(s: String): String } = "abc"
+    assert(s.concat("def") == "abcdef")
+  }
+}
+
diff --git a/tests/run/structuralNoSuchMethod.check b/tests/run/structuralNoSuchMethod.check
new file mode 100644
index 000000000..20576fc9c
--- /dev/null
+++ b/tests/run/structuralNoSuchMethod.check
@@ -0,0 +1 @@
+no such method
diff --git a/tests/run/structuralNoSuchMethod.scala b/tests/run/structuralNoSuchMethod.scala
new file mode 100644
index 000000000..476d7ed82
--- /dev/null
+++ b/tests/run/structuralNoSuchMethod.scala
@@ -0,0 +1,23 @@
+import scala.reflect.Selectable.reflectiveSelectable
+
+/** Demonstrates limitation of structural method dispatch (in Scala 2.x and dotty).
+ *  The method must be defined at exactly the argument types given in the structural type;
+ *  Generic instantiation is not possible.
+ */
+object Test {
+  type T = { def f(x: String, y: String): String }
+
+  class C[X] {
+    def f(x: X, y: String): String = "f1"
+  }
+
+  val x: T = new C[String]
+
+  def main(args: Array[String]) =
+    try println(x.f("", ""))  // throws NoSuchMethodException
+    catch {
+      case ex: NoSuchMethodException =>
+        println("no such method")
+    }
+
+}