Package FAtiMA.Core.conditions

Class Condition

java.lang.Object

FAtiMA.Core.conditions.Condition

All Implemented Interfaces:

IGroundable, java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

MoodCondition, PredicateCondition, PropertyCondition

public abstract class Condition
extends java.lang.Object
implements IGroundable, java.lang.Cloneable, java.io.Serializable

Abstract condition test, used to represent preconditions, success conditions, etc. Conditions can be either Predicate conditions or Property conditions. Provides methods to search the value of such conditions in the KnowledgeBase.

Author:

Joao Dias

See Also:

PredicateCondition, PropertyCondition, KnowledgeBase, Serialized Form

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Condition()
protected	Condition(Condition c)	Creates a new Condition - not used directly because its an abstract class
	Condition(Name name)	Creates a new Condition - not used directly because its an abstract class
	Condition(Name name, Symbol ToM)

Method Summary

Modifier and Type	Method	Description
static java.util.ArrayList<SubstitutionSet>	CheckActivation(AgentModel am, java.util.ArrayList<Condition> preconditions)	Checks if a list of conditions (usually preconditions) to see if all of them are verified.
abstract boolean	CheckCondition(AgentModel am)	Checks if the condition is verified in the agent's memory (KB + AM)
abstract java.lang.Object	clone()	Clones this Condition, returning an equal copy.
Name	getName()
Symbol	getToM()
java.util.ArrayList<SubstitutionSet>	GetValidBindings(AgentModel am)	This method finds all the possible sets of Substitutions that applied to the condition will make it valid (true) according to the agent's memory (KB + AM)
abstract Name	GetValue()	Gets the condition's value - the object compared against the condition's name
protected abstract java.util.ArrayList<Substitution>	GetValueBindings(AgentModel am)	Find a set of Substitutions for the second part of the condition, which will make it become true.
boolean	hasChangedVerifiability()
boolean	isGrounded()	Indicates if the Predicate is grounded (no unbound variables in it's WFN) Example: Stronger(Luke,John) is grounded while Stronger(John,[X]) is not.
boolean	isVerifiable()
void	MakeGround(Substitution subst)	Applies a set of substitutions to the object, grounding it.
void	MakeGround(java.util.ArrayList<Substitution> bindings)	Applies a set of substitutions to the object, grounding it.
void	ReplaceUnboundVariables(int variableID)	Replaces all unbound variables in the object by applying a numeric identifier to each one.
protected void	setName(Name name)
protected void	setToM(Symbol ToM)
void	setVerifiable(boolean verifiableStatus)

Methods inherited from class java.lang.Object

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

Constructor Detail

Condition

protected Condition(Condition c)

Creates a new Condition - not used directly because its an abstract class

Condition

protected Condition()

Condition

public Condition(Name name)

Creates a new Condition - not used directly because its an abstract class

Parameters:

name - - the condition's name

Condition

public Condition(Name name,
                 Symbol ToM)

Method Detail

getName

public Name getName()

getToM

public Symbol getToM()

isVerifiable

public boolean isVerifiable()

setName

protected void setName(Name name)

setToM

protected void setToM(Symbol ToM)

CheckActivation

public static java.util.ArrayList<SubstitutionSet> CheckActivation(AgentModel am,
                                                                   java.util.ArrayList<Condition> preconditions)

Checks if a list of conditions (usually preconditions) to see if all of them are verified. The method returns a list of possible SubstitutionSets. Each of the returned SustitutionSet applied to the entire set of conditions will make them all true. As example, if we have the generic goal of bullying someone Bully([Victim]), and we have a precondition list consisting of seing someone weaker than us, So if we see John (a weak victim) and Frances (another weak victim) we can activate the preconditions and subsequently the specific goal Bully(John) and Bully(Frances), by applying the substitutionset {[Victim]/John} and the substitutionset {[Victim]/Frances}

Parameters:

preconditions - - the list of preconditions that we want to test for activation

Returns:

a list of SubstitutionSets that if applied to all the preconditions will make them true, returns null if no such SubstitutionSet exists

See Also:

SubstitutionSet

setVerifiable

public void setVerifiable(boolean verifiableStatus)

hasChangedVerifiability

public boolean hasChangedVerifiability()

clone

public abstract java.lang.Object clone()

Clones this Condition, returning an equal copy. If this clone is changed afterwards, the original object remains the same.

Overrides:

clone in class java.lang.Object

Returns:

The Conditions's copy.

CheckCondition

public abstract boolean CheckCondition(AgentModel am)

Checks if the condition is verified in the agent's memory (KB + AM)

Returns:

true if the condition is verified, false otherwise

See Also:

KnowledgeBase

GetValidBindings

public java.util.ArrayList<SubstitutionSet> GetValidBindings(AgentModel am)

This method finds all the possible sets of Substitutions that applied to the condition will make it valid (true) according to the agent's memory (KB + AM)

Returns:

A list with all SubstitutionsSets that make the condition valid, if there are no such substitutions, the method returns null

See Also:

KnowledgeBase

GetValue

public abstract Name GetValue()

Gets the condition's value - the object compared against the condition's name

Returns:

the condition's value

GetValueBindings

protected abstract java.util.ArrayList<Substitution> GetValueBindings(AgentModel am)

Find a set of Substitutions for the second part of the condition, which will make it become true. With this method it is possible to test conditions that have unbound variables in the second part such as: "Owner(Ball) = [x]" this condition will be true if there is anyone in the world that owns a Ball. If John owns the ball, the method returns [x]/John

Returns:

returns all set of Substitutions that make the condition valid.

ReplaceUnboundVariables

public void ReplaceUnboundVariables(int variableID)

Replaces all unbound variables in the object by applying a numeric identifier to each one. For example, the variable [x] becomes [x4] if the received ID is 4. Attention, this method modifies the original object.

Specified by:

ReplaceUnboundVariables in interface IGroundable

Parameters:

variableID - - the identifier to be applied

MakeGround

public void MakeGround(java.util.ArrayList<Substitution> bindings)

Applies a set of substitutions to the object, grounding it. Example: Applying the substitution "[X]/John" in the name "Weak([X])" returns "Weak(John)". Attention, this method modifies the original object.

Specified by:

MakeGround in interface IGroundable

Parameters:

bindings - - A list of substitutions of the type "[Variable]/value"

See Also:

Substitution

MakeGround

public void MakeGround(Substitution subst)

Applies a set of substitutions to the object, grounding it. Example: Applying the substitution "[X]/John" in the name "Weak([X])" returns "Weak(John)". Attention, this method modifies the original object.

Specified by:

MakeGround in interface IGroundable

Parameters:

subst - - a substitution of the type "[Variable]/value"

See Also:

Substitution

isGrounded

public boolean isGrounded()

Indicates if the Predicate is grounded (no unbound variables in it's WFN) Example: Stronger(Luke,John) is grounded while Stronger(John,[X]) is not.

Specified by:

isGrounded in interface IGroundable

Returns:

true if the Predicate is grounded, false otherwise