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);
}
}
/* Returns a list of the preterminals gotten by traversing from left
* to right. This is effectively an POS tagging for the words that
* tree represents. */
public List<L> getPreTerminalYield() {
List<L> yield = new ArrayList<L>();
appendPreTerminalYield(this, yield);
return yield;
}
