edu.cmu.sphinx.linguist.language.grammar

Class GrammarNode

java.lang.Object

edu.cmu.sphinx.linguist.language.grammar.GrammarNode

public class GrammarNode
extends java.lang.Object

Represents a grammar node in a grammar. A grammar is represented as a graph of grammar nodes and arcs. A grammar node usually represents a word or words, but it can also be a transition point or simply silence.

Note that all probabilities are maintained in the LogMath log base

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GrammarNode(int id, boolean isFinal) Creates a GrammarNode with the given ID and silence or final attributes.
	GrammarNode(int id, Word[][] alternatives) Creates a GrammarNode with the given ID, Words.

Method Summary

Modifier and Type	Method and Description
void	add(GrammarNode node, float logProbability) Adds an arc to the given node
void	dump() Dumps the grammar
void	dumpDot(java.lang.String path)
void	dumpGDL(java.lang.String path) Dumps the grammar in GDL form
Word[][]	getAlternatives() Retrieves the words associated with this grammar node
int	getID() Returns the ID of this GrammarNode.
int	getNumAlternatives() Gets the number of alternatives
GrammarArc[]	getSuccessors() Retrieves the set of transitions out of this node
Word	getWord() Retrieve the single word associated with this grammar
Word[]	getWords(int alternative) Retrieves the words associated with a specific alternative
boolean	isEmpty() Determines if this grammar node is empty (that is, has no words).
boolean	isFinalNode() Determines if this grammar node is a final node in the grammar
void	setFinalNode(boolean isFinal) Sets the 'final' state of the grammar node.
java.lang.String	toString() Returns the string representation of this object

Methods inherited from class java.lang.Object

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

Constructor Detail

GrammarNode

public GrammarNode(int id,
                   Word[][] alternatives)

Creates a GrammarNode with the given ID, Words. A GrammarNode with words is, by default, neither a silence nor a final node.

Parameters:

id - the identity of this GrammarNode

alternatives - the set of Words in this GrammarNode. This is a two dimensional array, the first index corresponds to the set of alternative choices, the second index corresponds to a particular word for the alternative

GrammarNode

protected GrammarNode(int id,
                      boolean isFinal)

Creates a GrammarNode with the given ID and silence or final attributes. A silence or final node does not have any words by default.

Parameters:

id - the identity of this GrammarNode

isFinal - if true this is a final node

Method Detail

getID

public int getID()

Returns the ID of this GrammarNode.

Returns:

the ID of this GrammarNode

getAlternatives

public Word[][] getAlternatives()

Retrieves the words associated with this grammar node

Returns:

the words associated with this grammar node

getWords

public Word[] getWords(int alternative)

Retrieves the words associated with a specific alternative

Parameters:

alternative - the index of the alternative

Returns:

the words associated with this grammar node

getWord

public Word getWord()

Retrieve the single word associated with this grammar

Returns:

the word associated with this grammar node

getNumAlternatives

public int getNumAlternatives()

Gets the number of alternatives

Returns:

the number of alternatives

isEmpty

public boolean isEmpty()

Determines if this grammar node is empty (that is, has no words).

Returns:

true if the node is empty, otherwise false.

getSuccessors

public GrammarArc[] getSuccessors()

Retrieves the set of transitions out of this node

Returns:

the transitions to the successors for this node.

isFinalNode

public boolean isFinalNode()

Determines if this grammar node is a final node in the grammar

Returns:

true if the node is a final node in the grammar

setFinalNode

public void setFinalNode(boolean isFinal)

Sets the 'final' state of the grammar node. A 'final' state grammar marks the end of a grammar

Parameters:

isFinal - if true the grammar node is a final node.

add

public void add(GrammarNode node,
                float logProbability)

Adds an arc to the given node

Parameters:

node - the node that this new arc goes to

logProbability - the log probability of the transition occuring

toString

public java.lang.String toString()

Returns the string representation of this object

Overrides:

toString in class java.lang.Object

dumpGDL

public void dumpGDL(java.lang.String path)

Dumps the grammar in GDL form

Parameters:

path - the path to write the gdl file to

dump

public void dump()

Dumps the grammar

dumpDot

public void dumpDot(java.lang.String path)