Major Description
I would like to introduce a new Iterator to the iterator library: ExtendedIterator
This Iterator is an Iterator that extends the functionality of other iterators and makes using some iterators in the library more idiomatic. It is based on the ExtendedIterator found in the new Apache Rat core package that was inspired by the Apache Jena ExtendedIterator interface.
I propose a class ExtendedIterator<T> that extends Iterator<T> and has the following additional methods.
Static methods (all methods return an ExtendedIterator<T>) * createNoRemove(final Iterator<T> it) – prohibits removal on an iterator that otherwise would allow removal.
- create(final Stream<T> stream) – convenience method to create ExtendedIterator from stream.
- create(final Iterator<T> it)-- creates an ExtendedIterator from a plain iterator. If the Iterator is already "extended" just return it.
- emptyIterator() – convenience method to creat an empty ExtendedIterator.
- flatten(final Iterator<Iterator<T>> iteratorIterator) – creates an Iterator<T> by iterating through each of the iterators in "iteratorIterator"
Instance methods (Unless otherwise noted all methods return an ExtendedIterator<T>) * T removeNext() – extracts the next item from the iterator and calls remove() to remove it.
- andThen(final Iterator<X> other)-- <X extends T> uses an IteratorChain to create a chain of iterators.
- filter(final Predicate<T> predicate) – uses a FilterIterator to exclude the items from the iterator.
- ExtendedIterator<U> map(final Function<T, U> function) – uses a TransformerIterator to transform the items to a new type.
- <U extends Collection<T>> U addTo(final U collection) – Adds the remaining items in the iterator to the collection.
The advantage of the iterator is the idiomatic nature.
Iterator<Thing> iter;
List<OtherThing> lst = ExtendedIteratot.create(iter).filter(Thing::isValid).map(thing -> new OtherThing(thing)).addTo(new ArrayList<>());
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