Package org.jacop.constraints
Class ElementVariable
java.lang.Object
org.jacop.constraints.DecomposedConstraint<Constraint>
org.jacop.constraints.Constraint
org.jacop.constraints.ElementVariable
- All Implemented Interfaces:
SatisfiedPresent
,Stateful
,UsesQueueVariable
public class ElementVariable
extends Constraint
implements UsesQueueVariable, Stateful, SatisfiedPresent
ElementVariable constraint defines a relation
list[index - indexOffset] = value.
The first element of the list corresponds to index - indexOffset = 1. By default indexOffset is equal 0 so first value within a list corresponds to index equal 1.
If index has a domain from 0 to list.length-1 then indexOffset has to be equal -1 to make addressing of list array starting from 1.
- Version:
- 4.9
-
Field Summary
FieldsModifier and TypeFieldDescription(package private) boolean
(package private) int
(package private) Random
(package private) static AtomicInteger
It specifies variable index within an element constraint list[index - indexOffset] = value.(package private) boolean
final int
It specifies indexOffset within an element constraint list[index - indexOffset] = value.(package private) IntDomain
IntVar[]
It specifies list of variables within an element constraint list[index - indexOffset] = value.(package private) IntDomain[]
It specifies variable value within an element constraint list[index - indexOffset] = value.private boolean
(package private) LinkedHashSet
<IntVar> Fields inherited from class org.jacop.constraints.Constraint
afcWeight, atomicExecution, consistencyPruningEvents, constraintScope, earlyTerminationOK, increaseWeight, numberId, scope, trace, watchedVariableGrounded
Fields inherited from class org.jacop.constraints.DecomposedConstraint
queueIndex
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Constructor Summary
ConstructorsConstructorDescriptionElementVariable
(IntVar index, List<? extends IntVar> list, IntVar value) It constructs an element constraint.ElementVariable
(IntVar index, List<? extends IntVar> list, IntVar value, int indexOffset) It constructs an element constraint.ElementVariable
(IntVar index, IntVar[] list, IntVar value) It constructs an element constraint.ElementVariable
(IntVar index, IntVar[] list, IntVar value, int indexOffset) It constructs an element constraint. -
Method Summary
Modifier and TypeMethodDescriptionvoid
consistency
(Store store) It is a (most probably incomplete) consistency function which removes the values from variables domains.int
void
It imposes the constraint in a given store.void
queueVariable
(int level, Var var) This is a function called to indicate which variable in a scope of constraint has changed.void
removeLevel
(int level) This function is called in case of the backtrack, so a constraint can clear the queue of changed variables which is no longer valid.boolean
It checks if the constraint is satisfied.toString()
It produces a string representation of a constraint state.Methods inherited from class org.jacop.constraints.Constraint
afc, arguments, cleanAfterFailure, decompose, getConsistencyPruningEvent, getGuideConstraint, getGuideValue, getGuideVariable, grounded, grounded, id, impose, imposeDecomposition, increaseWeight, intArrayToString, long2int, numberArgs, removeConstraint, requiresMonotonicity, setConsistencyPruningEvent, setConstraintScope, setScope, setScope, setScope, setScope, setScope, setWatchedVariableGrounded, supplyGuideFeedback, toInt, toInt, updateAFC, watchedVariableGrounded
Methods inherited from class org.jacop.constraints.DecomposedConstraint
auxiliaryVariables, checkInput, checkInput, checkInputForDuplication, checkInputForDuplicationSkipSingletons, checkInputForNullness, checkInputForNullness, checkInputForNullness, derivative, getDubletonsSkipSingletons, imposeDecomposition
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.jacop.api.Stateful
isStateful
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Field Details
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idNumber
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firstConsistencyCheck
boolean firstConsistencyCheck -
firstConsistencyLevel
int firstConsistencyLevel -
index
It specifies variable index within an element constraint list[index - indexOffset] = value. -
value
It specifies variable value within an element constraint list[index - indexOffset] = value. -
indexOffset
public final int indexOffsetIt specifies indexOffset within an element constraint list[index - indexOffset] = value. -
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. -
indexHasChanged
boolean indexHasChanged -
indexRange
IntDomain indexRange -
variableQueue
LinkedHashSet<IntVar> variableQueue -
mapping
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duplicates
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supports
IntDomain[] supports -
valueHasChanged
private boolean valueHasChanged -
generator
Random generator
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Constructor Details
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ElementVariable
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from listindexOffset
- shift applied to index variable.
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ElementVariable
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from list
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ElementVariable
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from listindexOffset
- shift applied to index variable.
-
ElementVariable
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from list
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Method Details
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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 interfaceStateful
- Parameters:
level
- the level which is being removed.
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consistency
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 classConstraint
- Parameters:
store
- constraint store within which the constraint consistency is being checked.
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getDefaultConsistencyPruningEvent
public int getDefaultConsistencyPruningEvent()- Specified by:
getDefaultConsistencyPruningEvent
in classConstraint
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impose
Description copied from class:Constraint
It imposes the constraint in a given store.- Overrides:
impose
in classConstraint
- Parameters:
store
- the constraint store to which the constraint is imposed to.
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queueVariable
Description copied from class:Constraint
This is a function called to indicate which variable in a scope of constraint has changed. It also indicates a store level at which the change has occurred.- Overrides:
queueVariable
in classConstraint
- Parameters:
level
- the level of the store at which the change has occurred.var
- variable which has changed.
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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 interfaceSatisfiedPresent
- Returns:
- true if constraint is possible to verify that it is satisfied.
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toString
Description copied from class:Constraint
It produces a string representation of a constraint state.- Overrides:
toString
in classConstraint
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