planner.aStarPlan

Class WorldState

java.lang.Object

planner.aStarPlan.WorldState

Direct Known Subclasses:

SearchWorldState

public abstract class WorldState
extends Object

Abstract class representing the world state at some point of the A* search

Version:

$Revision: 1.7 $

Author:

dtdavis

Contact: Don Brutzman (web.nps.navy.mil/~brutzman) brutzman@nps.navy.mil

Constructor Summary

Constructors

Constructor and Description
WorldState() Creates a new instance of WorldState

Method Summary

Modifier and Type	Method and Description
void	addCondition(Condition newCondition) Adds a condition to the end of the set of conditions defining the world state
void	addCondition(Condition newCondition, int index) Adds a condition to an index-specified location in the condition set
abstract WorldState	computeStepEffect(PlanStep step) Computes the effect of a plan step on the world state conditions
Condition	getCondition(int index) Returns the condition specified by the index If index is outside the range (i.e. < 0 or >= size(), null is returned
boolean	hasCondition(Condition testCondition) Returns true this WorldState object has a condition that matches the parameter
boolean	match(WorldState testState) Compares this state with another and returns true if they match.
int	numberOfConditions() Returns the number of conditions that make up the world state
abstract List<SearchPlanStep>	possibleSteps() Returns an ArrayList containing all steps that are possible from the current state
String	toString() Converts the WorldState object to a user-readable String
abstract double	worldStateDistance(WorldState candidate) Compares this state with another to measure how different they are

Methods inherited from class java.lang.Object

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

Constructor Detail

WorldState

public WorldState()

Creates a new instance of WorldState

Method Detail

possibleSteps

public abstract List<SearchPlanStep> possibleSteps()

Returns an ArrayList containing all steps that are possible from the current state

Returns:

an ArrayList containing all steps.

computeStepEffect

public abstract WorldState computeStepEffect(PlanStep step)

Computes the effect of a plan step on the world state conditions

Parameters:

step - PlanStep object.

Returns:

the effect of a plan step on the world state conditions.

worldStateDistance

public abstract double worldStateDistance(WorldState candidate)

Compares this state with another to measure how different they are

Parameters:

candidate - WorldState object.

Returns:

the value of double of comparison this state with another.

match

public boolean match(WorldState testState)

Compares this state with another and returns true if they match. This state matches a test state if this state contains all of the conditions of the test state

Parameters:

testState - another world state to which this one is being compared

Returns:

whether WorldState matches the testState

numberOfConditions

public int numberOfConditions()

Returns the number of conditions that make up the world state

Returns:

the number of conditions.

hasCondition

public boolean hasCondition(Condition testCondition)

Returns true this WorldState object has a condition that matches the parameter

Parameters:

testCondition -

Returns:

whether this WorldState contains Condition testCondition

getCondition

public Condition getCondition(int index)

Returns the condition specified by the index If index is outside the range (i.e. < 0 or >= size(), null is returned

Parameters:

index - the position number.

Returns:

If index is outside the range (i.e. < 0 or >= size(), null is returned.

addCondition

public void addCondition(Condition newCondition)

Adds a condition to the end of the set of conditions defining the world state

Parameters:

newCondition - Condition object.

addCondition

public void addCondition(Condition newCondition,
                         int index)

Adds a condition to an index-specified location in the condition set

Parameters:

newCondition - Condition object.

index - the position number.

toString

public String toString()

Converts the WorldState object to a user-readable String

Overrides:

toString in class Object