edu.illinois.cs.cogcomp.nlp.utilities

Class HeadFinderBase

java.lang.Object

edu.illinois.cs.cogcomp.nlp.utilities.HeadFinderBase

Direct Known Subclasses:

CollinsHeadFinder

public abstract class HeadFinderBase
extends Object

This is mainly an abstract class for the Collins' head finder. It allows for head information to be found in other ways, though.

This file is based on the similar file from the Stanford NLP code, rewritten to talk nicely to the other parts of this package.

Author:

Vivek Srikumar

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HeadFinderBase.HeadSearchDirection

Field Summary

Fields

Modifier and Type	Field and Description
protected Pair<HeadFinderBase.HeadSearchDirection,String[]>	defaultRule

Constructor Summary

Constructors

Constructor and Description
HeadFinderBase()

Method Summary

Modifier and Type	Method and Description
protected Constituent	findHead(Constituent parseNode)
protected int	fixHeadChildHacks(int headChildId, Constituent node)
protected static String	getChildLabel(Constituent tree, int headCandidate)
Constituent	getHeadChild(Constituent parseNode) Get the head node of a constituent belonging to a parse tree.
Constituent	getHeadWord(Constituent tree)
int	getHeadWordPosition(Constituent subTree)
abstract List<Pair<HeadFinderBase.HeadSearchDirection,String[]>>	getNonterminalHeadInformation(String nonTerminal) Return information about how the head is to be computed, given the non-terminal.
protected Constituent	getPredefinedHead(Constituent treeNode)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

defaultRule

protected Pair<HeadFinderBase.HeadSearchDirection,String[]> defaultRule

Constructor Detail

HeadFinderBase

public HeadFinderBase()

Method Detail

getChildLabel

protected static String getChildLabel(Constituent tree,
                                      int headCandidate)

getHeadChild

public Constituent getHeadChild(Constituent parseNode)

Get the head node of a constituent belonging to a parse tree. The input constituent *must* be from a parse tree view.

Parameters:

parseNode - A node from the parse tree view

Returns:

The head child of the input node from the parse tree

getHeadWord

public Constituent getHeadWord(Constituent tree)

getHeadWordPosition

public int getHeadWordPosition(Constituent subTree)

getPredefinedHead

protected Constituent getPredefinedHead(Constituent treeNode)

findHead

protected Constituent findHead(Constituent parseNode)

fixHeadChildHacks

protected int fixHeadChildHacks(int headChildId,
                                Constituent node)

getNonterminalHeadInformation

public abstract List<Pair<HeadFinderBase.HeadSearchDirection,String[]>> getNonterminalHeadInformation(String nonTerminal)

Return information about how the head is to be computed, given the non-terminal.

NOTE: If no rule is specified, return null.