Java usually lets you do something like this:
Code:

Foo f = new Foo() {
  public int method(int input) {
    return input + 5;
  }
}; 

Which will extend a previously defined class named Foo, adding or overriding the methods that are defined in the declaration. Processing seems to choke on this. Is this a bug or a feature? (I understand it's a bit confusing for beginners to understand what's going on with that syntax. Perhaps enable it in full-on Java programming mode?)

Sorry, my bad. Java apparently only lets you override methods defined in the class that is being implicitly extended; it doesn't let you add new methods. Works fine in both normal mode and regular Java mode.