I have updated the Iterator API to include a generic CollectionIterator which can be used to iterate over concrete IList implementations such as ListCollectionView, ArrayCollection and XMLListCollection.

I have also removed the abstract base implementation for all concrete Iterators in favor of the IIterator interface.

In case you are not familiar with the Iterator API, it allows developers to traverse an aggregate without the need to expose it’s underlying implementation. Developers can utilize the Iterator API to easily and intuitively iterate over Arrays, Collections and objects with the same Iterator instance. You can also implement the IIterator interface to provide additional concrete iterators in addition to the ones which I have provided; Array Iterator, Object Iterator and Collection Iterator.

A concrete Iterator can be instantiated directly or dynamically at runtime via the IteratorFactory. Typically, developers would type an iterator instance as an IIterator so as to utilize the IteratorFactory to retrieve the concrete iterator types as needed.

I have provided a simple example which contains the compiled source as well as the ASDoc and UML diagram.

source / example
ASDoc
UML