Package ai.timefold.solver.core.impl.heuristic.selector.list

Class ElementDestinationSelector<Solution_>

java.lang.Object

ai.timefold.solver.core.impl.heuristic.selector.AbstractSelector<Solution_>

ai.timefold.solver.core.impl.heuristic.selector.list.ElementDestinationSelector<Solution_>

Type Parameters:

Solution_ - the solution type, the class with the PlanningSolution annotation

All Implemented Interfaces:

IterableSelector<Solution_,ElementPosition>, DestinationSelector<Solution_>, Selector<Solution_>, PhaseLifecycleListener<Solution_>, SolverLifecycleListener<Solution_>, Iterable<ElementPosition>, EventListener

public class ElementDestinationSelector<Solution_>
extends AbstractSelector<Solution_>
implements DestinationSelector<Solution_>

Selects destinations for list variable change moves. The destination specifies a future position in a list variable, expressed as an PositionInList, where a moved element or subList can be inserted.

Destination completeness is achieved by using both entity and value child selectors. When an entity A is selected, the destination becomes A[0]. When a value x is selected, its current position A[i] is determined using inverse and index supplies and the destination becomes A[i + 1].

Fairness in random selection is achieved by first deciding between entity and value selector with a probability that is proportional to the entity/value ratio. The child entity and value selectors are assumed to be fair.

Field Summary

Fields inherited from class ai.timefold.solver.core.impl.heuristic.selector.AbstractSelector

logger, phaseLifecycleSupport, workingRandom

Constructor Summary

Constructors

Constructor	Description
ElementDestinationSelector(EntitySelector<Solution_> entitySelector, EntityIndependentValueSelector<Solution_> valueSelector, boolean randomSelection)

Method Summary

Modifier and Type	Method	Description
Iterator<Object>	endingIterator()
boolean	equals(Object o)
EntityDescriptor<Solution_>	getEntityDescriptor()
long	getSize()	A random JIT Selector with Selector.isNeverEnding() true should return a size as if it would be able to return each distinct element only once, because the size can be used in SelectionProbabilityWeightFactory.
ListVariableDescriptor<Solution_>	getVariableDescriptor()
int	hashCode()
boolean	isCountable()	If false, then Selector.isNeverEnding() is true.
boolean	isNeverEnding()	Is true if Selector.isCountable() is false or if this selector is in random order (for most cases).
Iterator<ElementPosition>	iterator()
void	solvingEnded(SolverScope<Solution_> solverScope)
void	solvingStarted(SolverScope<Solution_> solverScope)
String	toString()

Methods inherited from class ai.timefold.solver.core.impl.heuristic.selector.AbstractSelector

getCacheType, phaseEnded, phaseStarted, stepEnded, stepStarted

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface ai.timefold.solver.core.impl.heuristic.selector.IterableSelector

spliterator

Methods inherited from interface ai.timefold.solver.core.impl.phase.event.PhaseLifecycleListener

phaseEnded, phaseStarted, stepEnded, stepStarted

Methods inherited from interface ai.timefold.solver.core.impl.heuristic.selector.Selector

getCacheType

Methods inherited from interface ai.timefold.solver.core.impl.solver.event.SolverLifecycleListener

solvingError

Constructor Details

ElementDestinationSelector

public ElementDestinationSelector(EntitySelector<Solution_> entitySelector,
 EntityIndependentValueSelector<Solution_> valueSelector,
 boolean randomSelection)

Method Details

solvingStarted

public void solvingStarted(SolverScope<Solution_> solverScope)

Specified by:

solvingStarted in interface SolverLifecycleListener<Solution_>

Overrides:

solvingStarted in class AbstractSelector<Solution_>

solvingEnded

public void solvingEnded(SolverScope<Solution_> solverScope)

Specified by:

solvingEnded in interface SolverLifecycleListener<Solution_>

Overrides:

solvingEnded in class AbstractSelector<Solution_>

getSize

public long getSize()

Description copied from interface: IterableSelector

A random JIT Selector with Selector.isNeverEnding() true should return a size as if it would be able to return each distinct element only once, because the size can be used in SelectionProbabilityWeightFactory.

Specified by:

getSize in interface IterableSelector<Solution_,ElementPosition>

Returns:

the approximate number of elements generated by this Selector, always >= 0

iterator

public Iterator<ElementPosition> iterator()

Specified by:

iterator in interface Iterable<Solution_>

isCountable

public boolean isCountable()

Description copied from interface: Selector

If false, then Selector.isNeverEnding() is true.

Specified by:

isCountable in interface Selector<Solution_>

Returns:

true if all the ValueRanges are countable (for example a double value range between 1.2 and 1.4 is not countable)

isNeverEnding

public boolean isNeverEnding()

Description copied from interface: Selector

Is true if Selector.isCountable() is false or if this selector is in random order (for most cases). Is never true when this selector is in shuffled order (which is less scalable but more exact).

Specified by:

isNeverEnding in interface Selector<Solution_>

Returns:

true if the Iterator.hasNext() of the Iterator created by Iterable.iterator() never returns false (except when it's empty).

getVariableDescriptor

public ListVariableDescriptor<Solution_> getVariableDescriptor()

getEntityDescriptor

public EntityDescriptor<Solution_> getEntityDescriptor()

endingIterator

public Iterator<Object> endingIterator()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object