Package org.jacop.constraints

Class ElementVariableFast

java.lang.Object
org.jacop.constraints.DecomposedConstraint<Constraint>
org.jacop.constraints.Constraint
org.jacop.constraints.ElementVariableFast
All Implemented Interfaces:
SatisfiedPresent, Stateful
public class ElementVariableFast extends Constraint implements Stateful, SatisfiedPresent

  • Field Details

    • idNumber

      static final AtomicInteger idNumber

    • firstConsistencyCheck

      boolean firstConsistencyCheck

    • firstConsistencyLevel

      int firstConsistencyLevel

    • index

      public final IntVar index
      It specifies variable index within an element constraint list[index - indexOffset] = value.

    • value

      public final IntVar value
      It specifies variable value within an element constraint list[index - indexOffset] = value.

    • indexOffset

      protected final int indexOffset
      It specifies indexOffset within an element constraint list[index - indexOffset] = value.

    • list

      public final IntVar[] list
      It specifies list of variables within an element constraint list[index - indexOffset] = value. The list is addressed by positive integers (>=1) if indexOffset is equal to 0.

  • Constructor Details

    • ElementVariableFast

      public ElementVariableFast(IntVar index, IntVar[] list, IntVar value, int indexOffset)
      It constructs an element constraint.
      Parameters:
      index - variable index
      list - list of variables from which an index-th element is taken
      value - a value of the index-th element from list
      indexOffset - shift applied to index variable.

    • ElementVariableFast

      public ElementVariableFast(IntVar index, List<? extends IntVar> list, IntVar value)
      It constructs an element constraint.
      Parameters:
      index - variable index
      list - list of variables from which an index-th element is taken
      value - a value of the index-th element from list

    • ElementVariableFast

      public ElementVariableFast(IntVar index, List<? extends IntVar> list, IntVar value, int indexOffset)
      It constructs an element constraint.
      Parameters:
      index - variable index
      list - list of variables from which an index-th element is taken
      value - a value of the index-th element from list
      indexOffset - shift applied to index variable.

    • ElementVariableFast

      public ElementVariableFast(IntVar index, IntVar[] list, IntVar value)
      It constructs an element constraint.
      Parameters:
      index - variable index
      list - list of variables from which an index-th element is taken
      value - a value of the index-th element from list

  • Method Details

    • isStateful

      public boolean isStateful()
      Description copied from interface: Stateful
      This function can be overriden by any constraint to specify dynamic conditions (based on the domain of variables at imposition level to decide if it is a stateful constraint.
      Specified by:
      isStateful in interface Stateful
      Returns:
      true if constraint is stateful.

    • impose

      public void impose(Store store)
      It imposes the constraint in a given store.
      Overrides:
      impose in class Constraint
      Parameters:
      store - the constraint store to which the constraint is imposed to.

    • 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.

    • disjoint

      private boolean disjoint(IntVar v1, IntVar v2)

    • getDefaultConsistencyPruningEvent

      public int getDefaultConsistencyPruningEvent()
      Specified by:
      getDefaultConsistencyPruningEvent in class Constraint

    • removeLevel

      public void removeLevel(int level)
      Description copied from interface: Stateful
      This function is called in case of the backtrack, so a constraint can clear the queue of changed variables which is no longer valid. This function is called *before* all timestamps, variables, mutablevariables have reverted to their previous value.
      Specified by:
      removeLevel in interface Stateful
      Parameters:
      level - the level which is being removed.

    • 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.

      Specified by:
      satisfied in interface SatisfiedPresent
      Returns:
      true if constraint is possible to verify that it is satisfied.

    • toString

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