private void tallyTree(
Tree<String> tree,
Counter<String> symbolCounter,
Counter<UnaryRule> unaryRuleCounter,
Counter<BinaryRule> binaryRuleCounter) {
if (tree.isLeaf()) return;
if (tree.isPreTerminal()) return;
if (tree.getChildren().size() == 1) {
UnaryRule unaryRule = makeUnaryRule(tree);
symbolCounter.incrementCount(tree.getLabel(), 1.0);
unaryRuleCounter.incrementCount(unaryRule, 1.0);
}
if (tree.getChildren().size() == 2) {
BinaryRule binaryRule = makeBinaryRule(tree);
symbolCounter.incrementCount(tree.getLabel(), 1.0);
binaryRuleCounter.incrementCount(binaryRule, 1.0);
}
if (tree.getChildren().size() < 1 || tree.getChildren().size() > 2) {
throw new RuntimeException(
"Attempted to construct a Grammar with an illegal tree: " + tree);
}
for (Tree<String> child : tree.getChildren()) {
tallyTree(child, symbolCounter, unaryRuleCounter, binaryRuleCounter);
}
}
private int tallySpans(Tree<String> tree, int start) {
if (tree.isLeaf() || tree.isPreTerminal()) return 1;
int end = start;
for (Tree<String> child : tree.getChildren()) {
int childSpan = tallySpans(child, end);
end += childSpan;
}
String category = tree.getLabel();
if (!category.equals("ROOT")) spanToCategories.incrementCount(end - start, category, 1.0);
return end - start;
}
private static Tree<String> binarizeTree(Tree<String> tree) {
String label = tree.getLabel();
if (tree.isLeaf()) return new Tree<String>(label);
if (tree.getChildren().size() == 1) {
return new Tree<String>(
label, Collections.singletonList(binarizeTree(tree.getChildren().get(0))));
}
// I think it tries to binarize a binary tree. This is silly. Just binarize the subtrees.
if (tree.getChildren().size() == 2) {
List<Tree<String>> children = new ArrayList<Tree<String>>();
children.add(binarizeTree(tree.getChildren().get(0)));
children.add(binarizeTree(tree.getChildren().get(1)));
return new Tree<String>(label, children);
}
// otherwise, it's a TERNARY-or-more local tree,
// so decompose it into a sequence of binary and unary trees.
String intermediateLabel = "@" + label + "->";
Tree<String> intermediateTree = binarizeTreeHelper(tree, 0, intermediateLabel);
return new Tree<String>(label, intermediateTree.getChildren());
}