edu.stanford.nlp.trees.HeadFinder Maven / Gradle / Ivy
package edu.stanford.nlp.trees;
import java.io.Serializable;
/**
* An interface for finding the "head" daughter of a phrase structure tree.
* This could potentially be any sense of "head", but has mainly been used
* to find the lexical head for lexicalized PCFG parsing.
*
* @author Christopher Manning
*/
public interface HeadFinder extends Serializable {
/**
* Determine which daughter of the current parse tree is the head.
* It assumes that the daughters already have had their heads
* determined. Another method has to do the tree walking.
*
* @param t The parse tree to examine the daughters of
* @return The parse tree that is the head. The convention has been
* that this returns null
if no head is found.
* But maybe it should throw an exception?
*/
public Tree determineHead(Tree t);
/**
* Determine which daughter of the current parse tree is the head given the parent of
* the tree.
* It assumes that the daughters already have had their heads
* determined. Another method has to do the tree walking.
*
* @param t The parse tree to examine the daughters of
* @param parent The parent of tree t
* @return The parse tree that is the head. The convention has been
* that this returns null
if no head is found.
* But maybe it should throw an exception?
*/
public Tree determineHead(Tree t, Tree parent);
}