Class XeqA

  • All Implemented Interfaces:
    SatisfiedPresent, StoreAware

    public class XeqA
    extends PrimitiveConstraint
    It creates a constraint that makes sure that the value assigned to the integer variable x is the only element of the set assigned to a set variable a.
    Version:
    4.8
    • Field Detail

      • idNumber

        static java.util.concurrent.atomic.AtomicInteger idNumber
      • x

        public IntVar x
        It specifies variable a.
      • a

        public SetVar a
        It specifies variable b.
    • Constructor Detail

      • XeqA

        public XeqA​(IntVar x,
                    SetVar a)
        It constructs an XeqA constraint to restrict the domain of the integer variables x and set variable a.
        Parameters:
        x - variable x that is restricted to be the only element of a set assigned to set variable a.
        a - set variable that must be equal to a set containing only one element as specified by integer variable x.
    • Method Detail

      • 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.
        Overrides:
        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.
        Overrides:
        getNotConsistencyPruningEvent in class PrimitiveConstraint
        Parameters:
        var - for which pruning event is retrieved
        Returns:
        the int denoting the pruning event associated with given variable.
      • 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.
      • 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.
      • satisfied

        public boolean satisfied()
        Description copied from interface: SatisfiedPresent
        It checks if the constraint is satisfied. It can return false even if constraint is satisfied but not all variables in its scope are grounded. It needs to return true if all variables in its scope are grounded and constraint is satisfied.

        Implementations of this interface for constraints that are not PrimitiveConstraint may require constraint imposition and consistency check as a requirement to work correctly.

        Returns:
        true if constraint is possible to verify that it is satisfied.
      • 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?
        Overrides:
        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.
      • toString

        public java.lang.String toString()
        Description copied from class: Constraint
        It produces a string representation of a constraint state.
        Overrides:
        toString in class Constraint