Data commit

Task/Delegates/Objeck/delegates.objeck

@@ -0,0 +1,54 @@
+interface Thingable {
+  method : virtual : public : Thing() ~ String;
+}
+
+class Delegator {
+  @delegate : Thingable;
+
+  New() {
+  }
+
+  method : public : SetDelegate(delegate : Thingable) ~ Nil {
+    @delegate := delegate;
+  }
+
+  method : public : Operation() ~ String {
+    if(@delegate = Nil) {
+      return "default implementation";
+    }
+    else {
+      return @delegate->Thing();
+    };
+  }
+}
+
+class Delegate implements Thingable {
+  New() {
+  }
+
+  method : public : Thing() ~ String {
+    return "delegate implementation";
+  }
+}
+
+class Example {
+  function : Main(args : String[]) ~ Nil {
+    # Without a delegate:
+    a := Delegator->New();
+    Runtime->Assert(a->Operation()->Equals("default implementation"));
+
+    # With a delegate:
+    d := Delegate->New();
+    a->SetDelegate(d);
+    Runtime->Assert(a->Operation()->Equals("delegate implementation"));
+
+    # Same as the above, but with an anonymous class:
+    a->SetDelegate(Base->New() implements Thingable {
+      method : public : Thing() ~ String {
+        return "anonymous delegate implementation";
+      }
+    });
+
+    Runtime->Assert(a->Operation()->Equals("anonymous delegate implementation"));
+  }
+}