edu.umass.cs.mallet.base.util.search

Class SearchNode

java.lang.Object

edu.umass.cs.mallet.base.util.search.SearchNode

All Implemented Interfaces:

QueueElement

Direct Known Subclasses:

AStarNode

public class SearchNode
extends Object
implements QueueElement

Created by IntelliJ IDEA. User: pereira Date: Jun 20, 2005 Time: 4:46:56 PM Search tree node. A search tree node pertains to some search graph state. Multiple nodes may refer to the same state, representing different ways of reaching the state. Search nodes have a priority, which determines when they will be expanded, and cost of reaching the node from the start of the search.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	SearchNode.NextNodeIterator This iterator generates search nodes that refer to the states reachable from the state pertaining to a this search node.

Constructor Summary

Constructors

Constructor and Description
SearchNode(SearchState state, SearchNode parent, double cost) Create a search node with given state, parent, and cost.

Method Summary

Modifier and Type	Method and Description
double	getCost() Get the cost for this node.
SearchNode.NextNodeIterator	getNextNodes() Get an iterator over the new search nodes reachable from this node by state transitions.
SearchNode	getParent() The node that generated this node.
int	getPosition() Get the queue position of this element.
double	getPriority() Get this element's priority.
SearchState	getState() The state for this search node.
boolean	isFinal() Is the node's state final?
void	setPosition(int position) Set the current queue position for this element.
void	setPriority(double priority) Set the priority of this element.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

SearchNode

public SearchNode(SearchState state,
                  SearchNode parent,
                  double cost)

Create a search node with given state, parent, and cost.

Parameters:

state - the state

parent - the parent

cost - the cost

Method Detail

getPriority

public double getPriority()

Description copied from interface: QueueElement

Get this element's priority.

Specified by:

getPriority in interface QueueElement

Returns:

the priority

setPriority

public void setPriority(double priority)

Description copied from interface: QueueElement

Set the priority of this element.

Specified by:

setPriority in interface QueueElement

Parameters:

priority - the element's new priority

getPosition

public int getPosition()

Description copied from interface: QueueElement

Get the queue position of this element. If the element is not in a queue, the returned value is meaningless.

Specified by:

getPosition in interface QueueElement

Returns:

the current position

setPosition

public void setPosition(int position)

Description copied from interface: QueueElement

Set the current queue position for this element. This should only be called by a queue implementation.

Specified by:

setPosition in interface QueueElement

Parameters:

position - the new position for the element

getParent

public SearchNode getParent()

The node that generated this node.

Returns:

the parent

getCost

public double getCost()

Get the cost for this node.

Returns:

the cost

getState

public SearchState getState()

The state for this search node.

Returns:

the state

isFinal

public boolean isFinal()

Is the node's state final?

Returns:

whether this state's node is final

getNextNodes

public SearchNode.NextNodeIterator getNextNodes()

Get an iterator over the new search nodes reachable from this node by state transitions.

Returns:

the iterator

toString

public String toString()

Overrides:

toString in class Object