choco.palm.integer.constraints
Class PalmElt

java.lang.Object
  choco.AbstractEntity
      choco.AbstractConstraint
          choco.integer.constraints.AbstractIntConstraint
              choco.integer.constraints.AbstractBinIntConstraint
                  choco.palm.integer.AbstractPalmBinIntConstraint
                      choco.palm.integer.constraints.PalmElt

All Implemented Interfaces:

Constraint, Entity, IntConstraint, IntVarEventListener, PalmIntVarListener, PalmConstraint, PalmVarListener, VarEventListener, Propagator, java.lang.Cloneable, java.util.EventListener

public class PalmElt
extends AbstractPalmBinIntConstraint

Created by IntelliJ IDEA. User: Hadrien Date: 18 janv. 2004 Time: 19:22:28 To change this template use Options | File Templates.

Field Summary

protected int	cste Uses the cste slot: l[i + cste] = x.
protected int[]	lvals Values the variable should be equal to.

Fields inherited from class choco.integer.constraints.AbstractBinIntConstraint

cIdx0, cIdx1, v0, v1

Fields inherited from class choco.integer.constraints.AbstractIntConstraint

logger

Fields inherited from class choco.AbstractConstraint

active, constAwakeEvent, hook, priority

Fields inherited from class choco.AbstractEntity

problem

Constructor Summary

PalmElt(IntDomainVar v0, IntDomainVar v1, int cste, int[] lvals)
Element constraint accessing the ith element in a list of values, where i is a variable.

Method Summary

void	awakeOnInf(int idx) Propagation when a lower bound is increased.
void	awakeOnRem(int idx, int val) Propagation when a value is removed from a domain.
void	awakeOnRestore(int idx) Propagation when a value is restored to a domain (for repairing a contradiction for instance).
void	awakeOnRestoreInf(int idx) Propagation when values are restored to a domain (for repairing a contradiction for instance).
void	awakeOnRestoreSup(int idx) Propagation when values are restored to a domain (for repairing a contradiction for instance).
void	awakeOnRestoreVal(int idx, int val) Propagation when a value is restored to a domain (for repairing a contradiction for instance).
void	awakeOnSup(int idx) Propagation when an upper bound is decreased.
java.lang.Boolean	isEntailed() Checks if the constraint is entailed (it can be proven that the constraint will be satisfied).
boolean	isSatisfied() When variables are instantiated, checks that the constraint is satisfied.
void	propagate() Generic propagation algorithm.
java.util.Set	whyIsFalse() Determines why the constraints is not satified.
java.util.Set	whyIsTrue() Determines why the constraints is satified.

Methods inherited from class choco.palm.integer.AbstractPalmBinIntConstraint

awakeOnInst, awakeOnRestoreVal, getIntVar, takeIntoAccountStatusChange, updateDataStructuresOnConstraint, updateDataStructuresOnRestoreConstraint

Methods inherited from class choco.integer.constraints.AbstractBinIntConstraint

assignIndices, getConstraintIdx, getNbVars, getVar, isCompletelyInstantiated, setConstraintIndex, setVar

Methods inherited from class choco.integer.constraints.AbstractIntConstraint

awakeOnBounds, awakeOnRemovals, getSelfIndex, isConsistent

Methods inherited from class choco.AbstractConstraint

addListener, awake, awakeOnVar, clone, connectVar, constAwake, delete, fail, getEvent, getPlugIn, getPriority, getProblem, getVarIdxInOpposite, isActive, isEquivalentTo, opposite, setActive, setEntailed, setPassive, setPlugIn, substituteVar

Methods inherited from class choco.AbstractEntity

pretty

Methods inherited from class java.lang.Object

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

Methods inherited from interface choco.palm.PalmVarListener

getConstraintIdx, setConstraintIndex

Methods inherited from interface choco.prop.VarEventListener

addListener, isActive, setActive, setPassive

Methods inherited from interface choco.integer.var.IntVarEventListener

getConstraintIdx, setConstraintIndex

Methods inherited from interface choco.prop.VarEventListener

addListener, isActive, setActive, setPassive

Methods inherited from interface choco.Propagator

assignIndices, awake, awakeOnVar, constAwake, delete, getEvent, getPlugIn, getPriority, isCompletelyInstantiated, isConsistent

Methods inherited from interface choco.prop.VarEventListener

addListener, isActive, setActive, setPassive

Methods inherited from interface choco.Constraint

clone, getConstraintIdx, getNbVars, getVar, getVarIdxInOpposite, isEquivalentTo, opposite, setConstraintIndex, setVar

Methods inherited from interface choco.Entity

getProblem, pretty

Methods inherited from interface choco.palm.PalmVarListener

getConstraintIdx, setConstraintIndex

Methods inherited from interface choco.prop.VarEventListener

addListener, isActive, setActive, setPassive

Field Detail

cste

protected final int cste

Uses the cste slot: l[i + cste] = x. (ex: cste = 1 allows to use and index from 0 to length(l) - 1.

lvals

protected int[] lvals

Values the variable should be equal to.

Constructor Detail

PalmElt

public PalmElt(IntDomainVar v0,
               IntDomainVar v1,
               int cste,
               int[] lvals)

Element constraint accessing the ith element in a list of values, where i is a variable. The slot v0 represents the index and the slot v1 represents the value. Propagation with complete arc consistency from values to indices (v1 to v0). Propagation with interval approximation from indices to values (v0 to v1).

Parameters:

v0 - The index variable.

v1 - The value variable.

cste - The offset for the index in the values array.

lvals - Values among which the variable should be affected to.

Method Detail

propagate

public void propagate()
               throws ContradictionException

Generic propagation algorithm. It propagates from index variable to value variable and then from value to index.

Specified by:

propagate in interface Propagator

Overrides:

propagate in class AbstractBinIntConstraint

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnInf

public void awakeOnInf(int idx)
                throws ContradictionException

Propagation when a lower bound is increased. The other variable is updated accordingly.

Specified by:

awakeOnInf in interface IntVarEventListener

Overrides:

awakeOnInf in class AbstractIntConstraint

Parameters:

idx - the index of the modified variable

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnSup

public void awakeOnSup(int idx)
                throws ContradictionException

Propagation when an upper bound is decreased. The other variable is updated accordingly.

Specified by:

awakeOnSup in interface IntVarEventListener

Overrides:

awakeOnSup in class AbstractIntConstraint

Parameters:

idx - the index of the modified variable

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnRem

public void awakeOnRem(int idx,
                       int val)
                throws ContradictionException

Propagation when a value is removed from a domain.

Specified by:

awakeOnRem in interface IntVarEventListener

Overrides:

awakeOnRem in class AbstractIntConstraint

Parameters:

idx - the index of the modified variable

val - the removed value

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnRestore

public void awakeOnRestore(int idx)
                    throws ContradictionException

Propagation when a value is restored to a domain (for repairing a contradiction for instance).

Parameters:

idx - the index of the modified variable

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnRestoreInf

public void awakeOnRestoreInf(int idx)
                       throws ContradictionException

Propagation when values are restored to a domain (for repairing a contradiction for instance).

Specified by:

awakeOnRestoreInf in interface PalmIntVarListener

Overrides:

awakeOnRestoreInf in class AbstractPalmBinIntConstraint

Parameters:

idx - the index of the modified variable

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnRestoreSup

public void awakeOnRestoreSup(int idx)
                       throws ContradictionException

Propagation when values are restored to a domain (for repairing a contradiction for instance).

Specified by:

awakeOnRestoreSup in interface PalmIntVarListener

Overrides:

awakeOnRestoreSup in class AbstractPalmBinIntConstraint

Parameters:

idx - the index of the modified variable

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

awakeOnRestoreVal

public void awakeOnRestoreVal(int idx,
                              int val)
                       throws ContradictionException

Propagation when a value is restored to a domain (for repairing a contradiction for instance).

Parameters:

idx - the index of the modified variable

val - the restored value

Throws:

ContradictionException - if a contradiction occurs or a domain becomes empty.

isEntailed

public java.lang.Boolean isEntailed()

Checks if the constraint is entailed (it can be proven that the constraint will be satisfied).

Specified by:

isEntailed in interface Propagator

Overrides:

isEntailed in class AbstractConstraint

Returns:

Boolean.TRUE if the constraint will be satisfied, Boolean.FALSE if it will not, null if we do not know yet.

isSatisfied

public boolean isSatisfied()

When variables are instantiated, checks that the constraint is satisfied.

Returns:

true if the constraint is satified by the current instantiation.

whyIsTrue

public java.util.Set whyIsTrue()

Determines why the constraints is satified.

Returns:

an explanation justifying that the constraint is satified.

whyIsFalse

public java.util.Set whyIsFalse()

Determines why the constraints is not satified.

Returns:

an explanation justifying that the constraint is not satified.