JaCoP.set.constraints
Class ElementSet

java.lang.Object
  JaCoP.constraints.DecomposedConstraint
      JaCoP.constraints.Constraint
          JaCoP.set.constraints.ElementSet

public class ElementSet
extends Constraint

It is an element constraint that make sure that set variable value has a domain equal to the index-th element of the supplied list of sets. By default, indexing starts from 1, if it is required to be different for example starting from 0, then indexOffset must be specified to be equal to -1.

Author:

Radoslaw Szymanek, Krzysztof Kuchcinski and Robert Åkemalm

Field Summary

IntVar	index It specifies what element from the list of sets is equal to set variable value.
int	indexOffset It allows to offset the indexing.
IntDomain[]	list It specifies a list of sets from which one element will be made equal to set variable value.
SetVar	value It specifies the set variable which is equal to one of the sets from the list as indicated by int variable index.
static java.lang.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 JaCoP.constraints.Constraint

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

Fields inherited from class JaCoP.constraints.DecomposedConstraint

queueIndex

Constructor Summary

ElementSet(IntVar index, IntDomain[] list, SetVar value)
It constructs an elementSet constraint to restrict the domains of the variables index and value.

ElementSet(IntVar index, IntDomain[] list, SetVar value, int indexOffset)
It constructs a constraint to restrict the domains of the variables index and value.

Method Summary

java.util.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.
java.lang.String	id() It gives the id string of a constraint.
void	impose(Store store) It imposes the constraint in a given store.
void	increaseWeight() It increases the weight of the variables in the constraint scope.
void	removeConstraint() It removes the constraint by removing this constraint from all variables.
boolean	satisfied() It checks if the constraint is satisfied.
java.lang.String	toString() It produces a string representation of a constraint state.

Methods inherited from class JaCoP.constraints.Constraint

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

Methods inherited from class JaCoP.constraints.DecomposedConstraint

auxiliaryVariables, imposeDecomposition

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

index

public IntVar index

It specifies what element from the list of sets is equal to set variable value.

list

public IntDomain[] list

It specifies a list of sets from which one element will be made equal to set variable value.

value

public SetVar value

It specifies the set variable which is equal to one of the sets from the list as indicated by int variable index.

indexOffset

public int indexOffset

It allows to offset the indexing. By default the indexing starts from 1, if index variable starts from 0, and 0 denotes the first element then indexOffset should be set to -1.

xmlAttributes

public static java.lang.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

ElementSet

public ElementSet(IntVar index,
                  IntDomain[] list,
                  SetVar value,
                  int indexOffset)

It constructs a constraint to restrict the domains of the variables index and value.

Parameters:

value - variable that is restricted to have the same elements as list[index].

list - array of sets that contains possible values for variable value.

index - variable that is restricted to be the index of sets for which list[index] == value.

indexOffset - the shift applied to the index variable.

ElementSet

public ElementSet(IntVar index,
                  IntDomain[] list,
                  SetVar value)

It constructs an elementSet constraint to restrict the domains of the variables index and value.

Parameters:

value - variable that is restricted to have the same elements as list[index].

list - array of sets that contains possible values for variable value.

index - variable that is restricted to be the index of sets for which list[index] == value.

Method Detail

arguments

public java.util.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.

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)

id

public java.lang.String id()

Description copied from class: Constraint

It gives the id string of a constraint.

Specified by:

id in class Constraint

Returns:

string id of the constraint.

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.

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 java.lang.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