package org.psjava.util;

import java.util.Iterator;

public class MergedIterator {

public static <T> Iterator<T> create(final Iterable<? extends Iterable<? extends T>> iterables) {

return new ReadOnlyIterator<T>() {

Iterator<? extends Iterable<? extends T>> topIterator = iterables.iterator();

Iterator<? extends T> currentSubIterator = null;

@Override

public boolean hasNext() {

while (currentSubIterator == null || !currentSubIterator.hasNext()) {

if (topIterator.hasNext())

currentSubIterator = topIterator.next().iterator();

else

return false;

}

return true;

}

@Override

public T next() {

hasNext();

return currentSubIterator.next();

}

};

}

private MergedIterator() {

}

}