> It's being replaced by transducers to avoid having to implement the same functionality whenever there's a new paradigm/idea. I.e this week we're doing lazy se

> It's being replaced by transducers to avoid having to implement the same functionality whenever there's a new paradigm/idea. I.e this week we're doing lazy seqs, the next CSP or streams - the transducer logic stays the same. AFAICT, iterator adapters don't require you to reimplement the "transducer logic" any more than transducers do. You implement a transformation into an iterator (eg. IntoIterator) and from an iterator (eg. FromIterator) and use the standard transformations on the iterators. Since a transducer is like an iterator adapter, one is comparing these to functions Iterator<A> → Iterator<B>, which can be passed around and reused as first class citizens with no more difficulty than any other object. I'm not sure, but one difference might be that you can't give a chunk of stuff to an iterator adaptor and say "run as much of this as possible, and then suspend". Iterators are inherently pull-based, so instead you say "I want X values". I can imagine the former being more useful in some cases where the producer is deciding when computation should be performed.