package edu.stanford.nlp.trees.international.tuebadz;
import java.util.ArrayList;
import java.util.List;
import edu.stanford.nlp.trees.Tree;
import edu.stanford.nlp.trees.TreeFactory;
import edu.stanford.nlp.trees.TreeNormalizer;
import edu.stanford.nlp.trees.TreebankLanguagePack;
/**
* Tree normalizer for the TueBaDZ treebank.
*
* (An adaptation of Roger Levy's NegraPennTreeNormalizer.)
*
* @author Wolfgang Maier (wmaier@sfs.uni-tuebingen.de)
*/
public class TueBaDZPennTreeNormalizer extends TreeNormalizer {
/** How to clean up node labels: 0 = do nothing, 1 = keep category and
* function, 2 = just category.
*/
private final int nodeCleanup;
private final String root;
protected final TreebankLanguagePack tlp;
private List<TreeNormalizer> tns = new ArrayList<TreeNormalizer>();
public String rootSymbol() {
return root;
}
// public TueBaDZPennTreeNormalizer() {
// this(new TueBaDZLanguagePack(), 0);
// }
public TueBaDZPennTreeNormalizer(TreebankLanguagePack tlp, int nodeCleanup) {
this.tlp = tlp;
this.nodeCleanup = nodeCleanup;
root = tlp.startSymbol();
}
public TueBaDZPennTreeNormalizer(TreebankLanguagePack tlp, int nodeCleanup, List<TreeNormalizer> tns) {
this.tlp = tlp;
this.nodeCleanup = nodeCleanup;
root = tlp.startSymbol();
this.tns.addAll(tns);
}
/**
* Normalizes a leaf contents.
* This implementation interns the leaf.
*/
@Override
public String normalizeTerminal(String leaf) {
// We could unquote * and / with backslash \ in front of them
return leaf.intern();
}
/**
* Normalizes a nonterminal contents.
* This implementation strips functional tags, etc. and interns the
* nonterminal.
*/
@Override
public String normalizeNonterminal(String category) {
return cleanUpLabel(category).intern();
}
/**
* Remove things like hyphened functional tags and equals from the
* end of a node label.
*/
protected String cleanUpLabel(String label) {
if (label == null) {
return root;
} else if (nodeCleanup == 1) {
return tlp.categoryAndFunction(label);
} else if (nodeCleanup == 2) {
return tlp.basicCategory(label);
} else {
return label;
}
}
/**
* Normalize a whole tree.
* TueBa-D/Z adaptation. Fixes trees with non-unary roots, does nothing else.
*/
@Override
public Tree normalizeWholeTree(Tree tree, TreeFactory tf) {
if (tree.label().value().equals(root) && tree.children().length > 1) {
Tree underRoot = tree.treeFactory().newTreeNode(root, tree.getChildrenAsList());
tree.setChildren(new Tree[1]);
tree.setChild(0, underRoot);
}
// we just want the non-unary root fixed.
return tree;
}
private static final long serialVersionUID = 8009544230321390490L;
}