edu.umn.cs.nlp.old
Class ChartCell

java.lang.Object
  edu.umn.cs.nlp.old.ChartCell

All Implemented Interfaces:

Iterable<ParseSpan>

public class ChartCell
extends Object
implements Iterable<ParseSpan>

Parse chart cell for a Chiang-style CKY+ parser

Version:

$LastChangedDate: 2007-11-14 09:28:40 -0600 (Wed, 14 Nov 2007) $

Author:

Lane Schwartz

Constructor Summary

ChartCell(int X_node_b, double X_node_beta, int S_node_b, double S_node_beta, LanguageModel languageModel)
Construct a new ChartCell; use the specified parameters for pruning.

Method Summary

boolean	add(int i, int j, TranslationRule rule) Attempt to store a new terminal parse span in this chart cell.
boolean	add(int i, int j, TranslationRule rule, ParseSpan... children) Attempt to store a new parse span in this chart cell.
void	addTerminal(int i, String token) Set the specified token to be the terminal token for this chart cell
Iterable<ParseSpan>	getNBest(int n)
boolean	isEmpty() Is this chart cell empty?
Iterator<ParseSpan>	iterator()
int	size() Get the total number of parse spans stored in this chart cell.
int	ssize() Get the number of S parse spans stored in this chart cell.
int	xsize() Get the number of X parse spans stored in this chart cell.

Methods inherited from class java.lang.Object

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

Constructor Detail

ChartCell

public ChartCell(int X_node_b,
                 double X_node_beta,
                 int S_node_b,
                 double S_node_beta,
                 LanguageModel languageModel)

Construct a new ChartCell; use the specified parameters for pruning.

Parameters:

X_node_b -

X_node_beta -

S_node_b -

S_node_beta -

Method Detail

xsize

public int xsize()

Get the number of X parse spans stored in this chart cell.

Returns:

the number of X parse spans stored in this chart cell

ssize

public int ssize()

Get the number of S parse spans stored in this chart cell.

Returns:

the number of S parse spans stored in this chart cell

size

public int size()

Get the total number of parse spans stored in this chart cell.

Returns:

the total number of parse spans stored in this chart cell

isEmpty

public boolean isEmpty()

Is this chart cell empty?

Returns:

true if there are no ParseSpan objects stored in this chart cell; false otherwise

addTerminal

public void addTerminal(int i,
                        String token)

Set the specified token to be the terminal token for this chart cell

Parameters:

i - the start index in the chart for this token

token - the token to store as a terminal parse span

add

public boolean add(int i,
                   int j,
                   TranslationRule rule)

Attempt to store a new terminal parse span in this chart cell.

If appropriate, this method will also attempt to add a new parse span for the rule S => X to this chart cell.

If the rule to be added has a left-hand side of "X", and the rule is successfully added as a new parse span, but the corresponding S => X rule is not sucessfully added, this method will still return true.

Returns:

true if a new parse span was successfully added to the chart cell, false otherwise

add

public boolean add(int i,
                   int j,
                   TranslationRule rule,
                   ParseSpan... children)

Attempt to store a new parse span in this chart cell.

If appropriate, this method will also attempt to add a new parse span for the rule S => X to this chart cell.

If the rule to be added has a left-hand side of "X", and the rule is successfully added as a new parse span, but the corresponding S => X rule is not sucessfully added, this method will still return true.

Returns:

true if a new parse span was successfully added to the chart cell, false otherwise

getNBest

public Iterable<ParseSpan> getNBest(int n)

iterator

public Iterator<ParseSpan> iterator()

Specified by:

iterator in interface Iterable<ParseSpan>