/// <summary>
/// Checks the node's ancestors to find the highest ancestor with the
/// same
/// <c>headWordNode</c>
/// as this node.
/// </summary>
public virtual Edu.Stanford.Nlp.Trees.TreeGraphNode HighestNodeWithSameHead()
{
Edu.Stanford.Nlp.Trees.TreeGraphNode node = this;
while (true)
{
Edu.Stanford.Nlp.Trees.TreeGraphNode parent = SafeCast(((Edu.Stanford.Nlp.Trees.TreeGraphNode)node.Parent()));
if (parent == null || parent.HeadWordNode() != node.HeadWordNode())
{
return(node);
}
node = parent;
}
}
/// <summary>
/// Uses the specified
/// <see cref="IHeadFinder"/>
///
/// <c>HeadFinder</c>
/// }
/// to determine the heads for this node and all its descendants,
/// and to store references to the head word node and head tag node
/// in this node's
/// <see cref="Edu.Stanford.Nlp.Ling.CoreLabel"/>
///
/// <c>CoreLabel</c>
/// } and the
/// <c>CoreLabel</c>
/// s of all its descendants.<p>
/// <p/>
/// Note that, in contrast to
/// <see cref="Tree.PercolateHeads(IHeadFinder)"/>
/// {
/// <c>Tree.percolateHeads()</c>
/// }, which assumes
/// <see cref="Edu.Stanford.Nlp.Ling.CategoryWordTag"/>
/// {
/// <c>CategoryWordTag</c>
/// } labels and therefore stores head
/// words and head tags merely as
/// <c>String</c>
/// s, this
/// method stores references to the actual nodes. This mitigates
/// potential problems in sentences which contain the same word
/// more than once.
/// </summary>
/// <param name="hf">The headfinding algorithm to use</param>
public override void PercolateHeads(IHeadFinder hf)
{
if (IsLeaf())
{
Edu.Stanford.Nlp.Trees.TreeGraphNode hwn = HeadWordNode();
if (hwn == null)
{
SetHeadWordNode(this);
}
}
else
{
foreach (Tree child in ((Edu.Stanford.Nlp.Trees.TreeGraphNode[])Children()))
{
child.PercolateHeads(hf);
}
Edu.Stanford.Nlp.Trees.TreeGraphNode head = SafeCast(hf.DetermineHead(this, parent));
if (head != null)
{
Edu.Stanford.Nlp.Trees.TreeGraphNode hwn = head.HeadWordNode();
if (hwn == null && head.IsLeaf())
{
// below us is a leaf
SetHeadWordNode(head);
}
else
{
SetHeadWordNode(hwn);
}
}
else
{
log.Info("Head is null: " + this);
}
}
}