ElementInteger (JaCoP 4.9.0 API)

java.lang.Object
- org.jacop.constraints.DecomposedConstraint<Constraint>
- - org.jacop.constraints.Constraint
  - - org.jacop.constraints.ElementInteger

All Implemented Interfaces:

SatisfiedPresent, Stateful, UsesQueueVariable
```
public class ElementInteger
extends Constraint
implements UsesQueueVariable, Stateful, SatisfiedPresent
```
ElementInteger 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

Author:

Radoslaw Szymanek and Krzysztof Kuchcinski

Field Summary

Fields
Modifier and Type	Field and Description
`boolean`	`checkDuplicates` It specifies whether duplicate values should be treated specially (combined to a single check).
`IntVar`	`index` It specifies variable index within an element constraint list[index-indexOffset] = value.
`int`	`indexOffset` It specifies indexOffset within an element constraint list[index-indexOffset] = value.
`int[]`	`list` It specifies list of variables within an element constraint list[index-indexOffset] = value.
`IntVar`	`value` It specifies variable value within an element constraint list[index-indexOffset] = value.

Fields inherited from class org.jacop.constraints.Constraint
atomicExecution, consistencyPruningEvents, constraintScope, earlyTerminationOK, increaseWeight, numberId, scope, trace

Fields inherited from class org.jacop.constraints.DecomposedConstraint
queueIndex

Constructor Summary

Constructors
Constructor and Description
`ElementInteger(IntVar index, int[] list, IntVar value, int indexOffset)` It constructs an element constraint.
`ElementInteger(IntVar index, int[] list, IntVar value, int indexOffset, boolean checkDuplicates)` It constructs an element constraint.
`ElementInteger(IntVar index, List<Integer> list, IntVar value)` It constructs an element constraint with default indexOffset equal 0.
`ElementInteger(IntVar index, List<Integer> list, IntVar value, int indexOffset)` It constructs an element constraint.
`ElementInteger(IntVar index, List<Integer> list, IntVar value, int indexOffset, boolean checkDuplicates)` It constructs an element constraint.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`consistency(Store store)` It is a (most probably incomplete) consistency function which removes the values from variables domains.
`int`	`getDefaultConsistencyPruningEvent()`
`void`	`impose(Store store)` It imposes the constraint in a given store.
`boolean`	`isStateful()` 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.
`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`	`satisfied()` It checks if the constraint is satisfied.
`String`	`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, 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

- Field Detail
  - index
```
public IntVar index
```
    It specifies variable index within an element constraint list[index-indexOffset] = value.
  - value
```
public IntVar value
```
    It specifies variable value within an element constraint list[index-indexOffset] = value.
  - indexOffset
```
public final int indexOffset
```
    It specifies indexOffset within an element constraint list[index-indexOffset] = value.
  - checkDuplicates
```
public final boolean checkDuplicates
```
    It specifies whether duplicate values should be treated specially (combined to a single check). In general a good idea but when lists are long it makes the process slower instead of faster.
  - list
```
public int[] 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 Detail
  - ElementInteger
```
public ElementInteger(IntVar index,
                      int[] list,
                      IntVar value,
                      int indexOffset)
```
    It constructs an element constraint.
    
    Parameters:
    
    index - variable index
    
    list - list of integers from which an index-th element is taken
    
    value - a value of the index-th element from list
    
    indexOffset - shift applied to index variable.
  - ElementInteger
```
public ElementInteger(IntVar index,
                      int[] list,
                      IntVar value,
                      int indexOffset,
                      boolean checkDuplicates)
```
    It constructs an element constraint.
    
    Parameters:
    
    index - variable index
    
    list - list of integers from which an index-th element is taken
    
    value - a value of the index-th element from list
    
    indexOffset - shift applied to index variable.
    
    checkDuplicates - informs whether to create duplicates list for values from list (default = true).
  - ElementInteger
```
public ElementInteger(IntVar index,
                      List<Integer> list,
                      IntVar value)
```
    It constructs an element constraint with default indexOffset equal 0.
    
    Parameters:
    
    index - index variable.
    
    list - list containing variables which one pointed out by index variable is made equal to value variable.
    
    value - a value variable equal to the specified element from the list.
  - ElementInteger
```
public ElementInteger(IntVar index,
                      List<Integer> list,
                      IntVar value,
                      int indexOffset)
```
    It constructs an element constraint.
    
    Parameters:
    
    index - variable index
    
    list - list of integers from which an index-th element is taken
    
    value - a value of the index-th element from list
    
    indexOffset - shift applied to index variable.
  - ElementInteger
```
public ElementInteger(IntVar index,
                      List<Integer> list,
                      IntVar value,
                      int indexOffset,
                      boolean checkDuplicates)
```
    It constructs an element constraint.
    
    Parameters:
    
    index - variable index
    
    list - list of integers from which an index-th element is taken
    
    value - a value of the index-th element from list
    
    indexOffset - shift applied to index variable.
    
    checkDuplicates - informs whether to create duplicates list for values from list (default = true).
- Method Detail
  - 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.
  - 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.
  - getDefaultConsistencyPruningEvent
```
public int getDefaultConsistencyPruningEvent()
```
    Specified by:
    
    getDefaultConsistencyPruningEvent in class Constraint
  - 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.
  - queueVariable
```
public void queueVariable(int level,
                          Var var)
```
    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 class Constraint
    
    Parameters:
    
    level - the level of the store at which the change has occurred.
    
    var - variable which has changed.
  - 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

Class ElementInteger

Field Summary

Fields inherited from class org.jacop.constraints.Constraint

Fields inherited from class org.jacop.constraints.DecomposedConstraint

Constructor Summary

Method Summary

Methods inherited from class org.jacop.constraints.Constraint

Methods inherited from class org.jacop.constraints.DecomposedConstraint

Methods inherited from class java.lang.Object

Field Detail

index

value

indexOffset

checkDuplicates

list

Constructor Detail

ElementInteger

ElementInteger

ElementInteger

ElementInteger

ElementInteger

Method Detail

removeLevel

consistency

getDefaultConsistencyPruningEvent

isStateful

impose

queueVariable

satisfied

toString