Data commit

Task/Respond-to-an-unknown-method-call/Fantom/respond-to-an-unknown-method-call.fantom

@@ -0,0 +1,32 @@
+class A
+{
+  public Void doit (Int n)
+  {
+    echo ("known function called on $n")
+  }
+
+  // override the 'trap' method, which catches dynamic invocations of methods
+  override Obj? trap(Str name, Obj?[]? args := null)
+  {
+    try
+    {
+      return super.trap(name, args)
+    }
+    catch (UnknownSlotErr err)
+    {
+      echo ("In trap, you called: " + name + " with args " + args.join(","))
+      return null
+    }
+  }
+}
+
+class Main
+{
+  public static Void main ()
+  {
+    a := A()
+    // note the dynamic dispatch
+    a->doit (1)
+    a->methodName (1, 2, 3)
+  }
+}