public class MyIterator implements Iterator<Tree<String>> {
private Iterator<File> fileIt;
private Iterator<Tree<String>> treeIt = Iterators.emptyIterator();
public MyIterator(Iterator<File> fileIt) {
this.fileIt = fileIt;
}
private Iterator<Tree<String>> getTreeIterator() {
String nextPath = fileIt.next().getAbsolutePath();
Iterator<Tree<String>> treeIt = new Trees.PennTreeReader(IOUtils.openInHard(nextPath));
Method<Tree<String>, Tree<String>> transformMethod =
new Method<Tree<String>, Tree<String>>() {
public Tree<String> call(Tree<String> obj) {
return treeTransformer.transformTree(obj);
}
};
Filter<Tree<String>> treeFilter =
new Filter<Tree<String>>() {
public boolean accept(Tree<String> t) {
int length = t.getYield().size();
return (length >= minLength && length <= maxLength);
}
};
treeIt =
new Iterators.TransformingIterator<Tree<String>, Tree<String>>(treeIt, transformMethod);
treeIt = new Iterators.FilteredIterator<Tree<String>>(treeFilter, treeIt);
return treeIt;
}
private boolean queueNext() {
if (treeIt.hasNext()) {
return true;
}
if (!fileIt.hasNext()) {
return false;
}
treeIt = getTreeIterator();
return queueNext();
}
public boolean hasNext() {
return queueNext();
}
public Tree<String> next() {
queueNext();
return treeTransformer.transformTree(treeIt.next());
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public Iterator<Tree<String>> iterator() {
List<File> files = IOUtils.getFilesUnder(dataRoot, IOUtil.getFileFilter(prefix, extension));
initializeTreeTransformer();
Iterator<Tree<String>> treeIt = new MyIterator(files.iterator());
return Iterators.maxLengthIterator(treeIt, maxNumTrees);
}