org.jacop.constraints

Class IfThen

java.lang.Object

org.jacop.constraints.DecomposedConstraint

org.jacop.constraints.Constraint

org.jacop.constraints.PrimitiveConstraint

org.jacop.constraints.IfThen

public class IfThen
extends PrimitiveConstraint

Constraint if constraint1 then constraint2

Version:

4.2

Author:

Krzysztof Kuchcinski and Radoslaw Szymanek

Field Summary

Fields

Modifier and Type	Field and Description
PrimitiveConstraint	condC It specifies constraint condC in the IfThen constraint.
PrimitiveConstraint	thenC It specifies constraint condC in the IfThen constraint.
static String[]	xmlAttributes It specifies the arguments required to be saved by an XML format as well as the constructor being called to recreate an object from an XML format.

Fields inherited from class org.jacop.constraints.PrimitiveConstraint

notConsistencyPruningEvents

Fields inherited from class org.jacop.constraints.Constraint

atomicExecution, consistencyPruningEvents, earlyTerminationOK, id, increaseWeight, numberArgs, numberId, trace

Fields inherited from class org.jacop.constraints.DecomposedConstraint

queueIndex

Constructor Summary

Constructors

Constructor and Description
IfThen(PrimitiveConstraint condC, PrimitiveConstraint thenC) It constructs ifthen constraint.

Method Summary

Modifier and Type	Method and Description
ArrayList<Var>	arguments() It returns the variables in a scope of the constraint.
void	consistency(Store store) It is a (most probably incomplete) consistency function which removes the values from variables domains.
int	getConsistencyPruningEvent(Var var) It retrieves the pruning event which causes reevaluation of the constraint.
int	getNestedPruningEvent(Var var, boolean mode) It retrieves the pruning event for which any composed constraint which uses this constraint should be evaluated.
int	getNotConsistencyPruningEvent(Var var) It retrieves the pruning event which causes reevaluation of the constraint notConsistency() function.
void	impose(Store store) It imposes the constraint in a given store.
void	include(Store store) It provide store for constraints that are not imposed but called from ather constraints.
void	increaseWeight() It increases the weight of the variables in the constraint scope.
void	notConsistency(Store store) It makes pruning in such a way that constraint is notConsistent.
boolean	notSatisfied() It checks if constraint would be always not satisfied.
void	removeConstraint() It removes the constraint by removing this constraint from all variables.
boolean	satisfied() It checks if the constraint is satisfied.
String	toString() It produces a string representation of a constraint state.

Methods inherited from class org.jacop.constraints.PrimitiveConstraint

setNotConsistencyPruningEvent

Methods inherited from class org.jacop.constraints.Constraint

cleanAfterFailure, decompose, getGuideConstraint, getGuideValue, getGuideVariable, id, impose, imposeDecomposition, numberArgs, queueVariable, removeLevel, removeLevelLate, requiresMonotonicity, setConsistencyPruningEvent, supplyGuideFeedback

Methods inherited from class org.jacop.constraints.DecomposedConstraint

auxiliaryVariables, derivative, imposeDecomposition

Methods inherited from class java.lang.Object

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

Field Detail

condC

public PrimitiveConstraint condC

It specifies constraint condC in the IfThen constraint.

thenC

public PrimitiveConstraint thenC

It specifies constraint condC in the IfThen constraint.

xmlAttributes

public static String[] xmlAttributes

It specifies the arguments required to be saved by an XML format as well as the constructor being called to recreate an object from an XML format.

Constructor Detail

IfThen

public IfThen(PrimitiveConstraint condC,
              PrimitiveConstraint thenC)

It constructs ifthen constraint.

Parameters:

condC - the condition of the ifthen constraint.

thenC - the constraint which must hold if the condition holds.

Method Detail

arguments

public ArrayList<Var> arguments()

Description copied from class: Constraint

It returns the variables in a scope of the constraint.

Specified by:

arguments in class Constraint

Returns:

variables in a scope of the constraint.

consistency

public void consistency(Store store)

Description copied from class: Constraint

It is a (most probably incomplete) consistency function which removes the values from variables domains. Only values which do not have any support in a solution space are removed.

Specified by:

consistency in class Constraint

Parameters:

store - constraint store within which the constraint consistency is being checked.

notSatisfied

public boolean notSatisfied()

Description copied from class: PrimitiveConstraint

It checks if constraint would be always not satisfied.

Specified by:

notSatisfied in class PrimitiveConstraint

Returns:

true if constraint must be notSatisfied, false otherwise.

notConsistency

public void notConsistency(Store store)

Description copied from class: PrimitiveConstraint

It makes pruning in such a way that constraint is notConsistent. It removes values which always belong to a solution.

Specified by:

notConsistency in class PrimitiveConstraint

Parameters:

store - the constraint store in which context the notConsistency technique is evaluated.

getConsistencyPruningEvent

public int getConsistencyPruningEvent(Var var)

Description copied from class: Constraint

It retrieves the pruning event which causes reevaluation of the constraint.

Specified by:

getConsistencyPruningEvent in class Constraint

Parameters:

var - variable for which pruning event is retrieved

Returns:

it returns the int code of the pruning event (GROUND, BOUND, ANY, NONE)

getNotConsistencyPruningEvent

public int getNotConsistencyPruningEvent(Var var)

Description copied from class: PrimitiveConstraint

It retrieves the pruning event which causes reevaluation of the constraint notConsistency() function.

Specified by:

getNotConsistencyPruningEvent in class PrimitiveConstraint

Parameters:

var - for which pruning event is retrieved

Returns:

the int denoting the pruning event associated with given variable.

getNestedPruningEvent

public int getNestedPruningEvent(Var var,
                                 boolean mode)

Description copied from class: PrimitiveConstraint

It retrieves the pruning event for which any composed constraint which uses this constraint should be evaluated. This events are the ones which can change satisfied status?

Specified by:

getNestedPruningEvent in class PrimitiveConstraint

Parameters:

var - for which pruning event is retrieved

mode - decides if pruning event for consistency or nonconsistency is required.

Returns:

pruning event associated with the given variable for a given consistency mode.

impose

public void impose(Store store)

Description copied from class: Constraint

It imposes the constraint in a given store.

Specified by:

impose in class Constraint

Parameters:

store - the constraint store to which the constraint is imposed to.

include

public void include(Store store)

Description copied from class: PrimitiveConstraint

It provide store for constraints that are not imposed but called from ather constraints.

Overrides:

include in class PrimitiveConstraint

Parameters:

store - the constraint store in which context the constraint is executed.

removeConstraint

public void removeConstraint()

Description copied from class: Constraint

It removes the constraint by removing this constraint from all variables.

Specified by:

removeConstraint in class Constraint

satisfied

public boolean satisfied()

Description copied from class: Constraint

It checks if the constraint is satisfied. If this function is incorrectly implemented a constraint may not be satisfied in a solution.

Specified by:

satisfied in class Constraint

Returns:

true if the constraint is for certain satisfied, false otherwise.

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Specified by:

toString in class Constraint

increaseWeight

public void increaseWeight()

Description copied from class: Constraint

It increases the weight of the variables in the constraint scope.

Specified by:

increaseWeight in class Constraint