burlap.behavior.singleagent.planning.deterministic

Class SearchNode

java.lang.Object

burlap.behavior.singleagent.planning.deterministic.SearchNode

Direct Known Subclasses:

PrioritizedSearchNode

public class SearchNode
extends java.lang.Object

The SearchNode class is used for classic deterministic forward search planners. It represents a current state, a back pointer to the search node from which this node's state was generated, and the action that was taken in the generating node's state to produce this node's state. Once a goal state is found by the forward search valueFunction, the back pointers can be traced to find the plan that got to the goal.

Author:

James MacGlashan

Field Summary

Fields

Modifier and Type	Field and Description
SearchNode	backPointer The search node for the previous state that generated this node's state.
Action	generatingAction The action that generated this state in the previous state.
HashableState	s The (hashed) state of this node

Constructor Summary

Constructors

Constructor and Description
SearchNode(HashableState s) Constructs a SearchNode for the input state.
SearchNode(HashableState s, Action ga, SearchNode bp) Constructs a SearchNode for the input state and sets the generating action and back pointer to the provided elements.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
int	hashCode()

Methods inherited from class java.lang.Object

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

Field Detail

s

public HashableState s

The (hashed) state of this node

generatingAction

public Action generatingAction

The action that generated this state in the previous state. Null if this node is for the initial state.

backPointer

public SearchNode backPointer

The search node for the previous state that generated this node's state. Null if this node is for the initial state.

Constructor Detail

SearchNode

public SearchNode(HashableState s)

Constructs a SearchNode for the input state. The generating action and back pointer are set to null, which is valid if this is the search node for an initial state. Otherwise, these fields should be filled in.

Parameters:

s - the hashed input state this node will represent.

SearchNode

public SearchNode(HashableState s,
                  Action ga,
                  SearchNode bp)

Constructs a SearchNode for the input state and sets the generating action and back pointer to the provided elements.

Parameters:

s - the hashed input state this node will represent.

ga - the action that was used to generate s

bp - the search node that contains the previous state from which s was generated.

Method Detail

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object