private static <L> List<Tree<L>> spliceNodesHelper(Tree<L> tree, Filter<L> filter) {
List<Tree<L>> splicedChildren = new ArrayList<Tree<L>>();
for (Tree<L> child : tree.getChildren()) {
List<Tree<L>> splicedChildList = spliceNodesHelper(child, filter);
splicedChildren.addAll(splicedChildList);
}
if (filter.accept(tree.getLabel())) return splicedChildren;
return Collections.singletonList(new Tree<L>(tree.getLabel(), splicedChildren));
}
private static <L> Tree<L> pruneNodesHelper(Tree<L> tree, Filter<L> filter) {
if (filter.accept(tree.getLabel())) return null;
List<Tree<L>> prunedChildren = new ArrayList<Tree<L>>();
for (Tree<L> child : tree.getChildren()) {
Tree<L> prunedChild = pruneNodesHelper(child, filter);
if (prunedChild != null) prunedChildren.add(prunedChild);
}
if (prunedChildren.isEmpty() && !tree.isLeaf()) return null;
return new Tree<L>(tree.getLabel(), prunedChildren);
}
private static <L> void renderFlat(Tree<L> tree, StringBuilder sb) {
if (tree.isLeaf()) {
sb.append(tree.getLabel().toString());
return;
}
sb.append('(');
sb.append(tree.getLabel().toString());
sb.append(' ');
sb.append(tree.getChildren().get(0).getLabel().toString());
sb.append(')');
}
private static <L> void renderChildren(
List<Tree<L>> children, int indent, boolean parentLabelNull, StringBuilder sb) {
boolean firstSibling = true;
boolean leftSibIsPreTerm = true; // counts as true at beginning
for (Tree<L> child : children) {
renderTree(child, indent, parentLabelNull, firstSibling, leftSibIsPreTerm, false, sb);
leftSibIsPreTerm = child.isPreTerminal();
// CC is a special case
if (child.getLabel() != null && child.getLabel().toString().startsWith("CC")) {
leftSibIsPreTerm = false;
}
firstSibling = false;
}
}
private static <L> Tree<L> deepCopy(Tree<L> tree) {
List<Tree<L>> childrenCopies = new ArrayList<Tree<L>>();
for (Tree<L> child : tree.getChildren()) {
childrenCopies.add(deepCopy(child));
}
return new Tree<L>(tree.getLabel(), childrenCopies);
}
private static <L> void appendPreTerminalYield(Tree<L> tree, List<L> yield) {
if (tree.isPreTerminal()) {
yield.add(tree.getLabel());
return;
}
for (Tree<L> child : tree.getChildren()) {
appendPreTerminalYield(child, yield);
}
}
public static String transformLabel(Tree<String> tree) {
String transformedLabel = tree.getLabel();
int cutIndex = transformedLabel.indexOf('-');
int cutIndex2 = transformedLabel.indexOf('=');
if (cutIndex2 > 0 && (cutIndex2 < cutIndex || cutIndex == -1)) cutIndex = cutIndex2;
if (cutIndex > 0 && !tree.isLeaf()) {
transformedLabel = transformedLabel.substring(0, cutIndex);
}
return transformedLabel;
}
private static <L> int toConstituentCollectionHelper(
Tree<L> tree, int start, List<Constituent<L>> constituents) {
if (tree.isLeaf() || tree.isPreTerminal()) return 1;
int span = 0;
for (Tree<L> child : tree.getChildren()) {
span += toConstituentCollectionHelper(child, start + span, constituents);
}
constituents.add(new Constituent<L>(tree.getLabel(), start, start + span));
return span;
}
/** Display a node, implementing Penn Treebank style layout */
private static <L> void renderTree(
Tree<L> tree,
int indent,
boolean parentLabelNull,
boolean firstSibling,
boolean leftSiblingPreTerminal,
boolean topLevel,
StringBuilder sb) {
// the condition for staying on the same line in Penn Treebank
boolean suppressIndent =
(parentLabelNull
|| (firstSibling && tree.isPreTerminal())
|| (leftSiblingPreTerminal
&& tree.isPreTerminal()
&& (tree.getLabel() == null || !tree.getLabel().toString().startsWith("CC"))));
if (suppressIndent) {
sb.append(' ');
} else {
if (!topLevel) {
sb.append('\n');
}
for (int i = 0; i < indent; i++) {
sb.append(" ");
}
}
if (tree.isLeaf() || tree.isPreTerminal()) {
renderFlat(tree, sb);
return;
}
sb.append('(');
sb.append(tree.getLabel());
renderChildren(
tree.getChildren(),
indent + 1,
tree.getLabel() == null || tree.getLabel().toString() == null,
sb);
sb.append(')');
}
public Tree<E> transformTree(Tree<E> tree) {
E label = tree.getLabel();
List<Tree<E>> children = tree.getChildren();
while (children.size() == 1
&& !children.get(0).isLeaf()
&& label.equals(children.get(0).getLabel())) {
children = children.get(0).getChildren();
}
List<Tree<E>> transformedChildren = new ArrayList<Tree<E>>();
for (Tree<E> child : children) {
transformedChildren.add(transformTree(child));
}
return new Tree<E>(label, transformedChildren);
}
public Tree<String> transformTree(Tree<String> tree) {
String label = tree.getLabel();
if (label.equals("-NONE-")) {
return null;
}
if (tree.isLeaf()) {
return new Tree<String>(label);
}
List<Tree<String>> children = tree.getChildren();
List<Tree<String>> transformedChildren = new ArrayList<Tree<String>>();
for (Tree<String> child : children) {
Tree<String> transformedChild = transformTree(child);
if (transformedChild != null) transformedChildren.add(transformedChild);
}
if (transformedChildren.size() == 0) return null;
return new Tree<String>(label, transformedChildren);
}
public Tree<String> transformTree(Tree<String> tree) {
String label = tree.getLabel();
Matcher matcher = punctuationPattern.matcher(label);
if (matcher.matches()) {
return null;
}
if (tree.isLeaf()) {
return new Tree<String>(label);
}
List<Tree<String>> children = tree.getChildren();
List<Tree<String>> transformedChildren = new ArrayList<Tree<String>>();
for (Tree<String> child : children) {
Tree<String> transformedChild = transformTree(child);
if (transformedChild != null) transformedChildren.add(transformedChild);
}
if (transformedChildren.size() == 0) return null;
return new Tree<String>(label, transformedChildren);
}