Iterator in modern Java: traversing an aggregate without exposing it, and choosing between Iterator, Stream and Spliterator — external pull versus internal lazy pipeline versus the parallel decomposition primitive. Covers when a Spliterator can adapt to both, what fail-fast really promises and how weakly consistent iterators differ, streams that hold a resource and must be closed, remote pagination as iteration with page drift, and the characteristics that decide whether a stream can be sized or split. Use when exposing a collection from a type, when a custom traversal is being written, when ConcurrentModificationException appears, when a stream over a file or a result se…
