edu.stanford.nlp.trees
Interface HeadFinder

All Superinterfaces:

java.io.Serializable

All Known Implementing Classes:

AbstractCollinsHeadFinder, ArabicHeadFinder, BikelChineseHeadFinder, ChineseHeadFinder, ChineseSemanticHeadFinder, CollinsHeadFinder, DybroFrenchHeadFinder, FrenchHeadFinder, LeftHeadFinder, ModCollinsHeadFinder, NegraHeadFinder, SemanticHeadFinder, SunJurafskyChineseHeadFinder, TueBaDZHeadFinder

public interface HeadFinder
extends 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

Method Summary

Tree	determineHead(Tree t) Determine which daughter of the current parse tree is the head.
Tree	determineHead(Tree t, Tree parent) Determine which daughter of the current parse tree is the head given the parent of the tree.

Method Detail

determineHead

Tree determineHead(Tree t)

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.

Parameters:

t - The parse tree to examine the daughters of

Returns:

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?

determineHead

Tree determineHead(Tree t,
                   Tree parent)

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.

Parameters:

t - The parse tree to examine the daughters of

parent - The parent of tree t

Returns:

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?