Package ai.timefold.solver.core.preview.api.move.builtin

Class ChangeMove<Solution_,Entity_,Value_>

java.lang.Object

ai.timefold.solver.core.impl.move.AbstractMove<Solution_>

ai.timefold.solver.core.preview.api.move.builtin.ChangeMove<Solution_,Entity_,Value_>

Type Parameters:

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

Entity_ - the entity type, the class with the PlanningEntity annotation

Value_ - the variable type, the type of the property with the PlanningVariable annotation

All Implemented Interfaces:

Move<Solution_>

@NullMarked
public class ChangeMove<Solution_,Entity_,Value_>
extends AbstractMove<Solution_>

Field Summary

Fields

Modifier and Type	Field	Description
protected final Entity_	entity
protected final @Nullable Value_	toPlanningValue
protected final PlanningVariableMetaModel<Solution_,Entity_,Value_>	variableMetaModel

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ChangeMove(PlanningVariableMetaModel<Solution_,Entity_,Value_> variableMetaModel, Entity_ entity, @Nullable Value_ toPlanningValue)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
void	execute(MutableSolutionView<Solution_> solutionView)	Runs the move and optionally records the changes done, so that they can be undone later.
Collection<Entity_>	getPlanningEntities()	Returns all planning entities that this move is changing.
Collection<Value_>	getPlanningValues()	Returns all planning values that this move is assigning to entity variables.
protected @Nullable Value_	getValue()
int	hashCode()
ChangeMove<Solution_,Entity_,Value_>	rebase(Rebaser rebaser)	Rebases a move from an origin ScoreDirector to another destination ScoreDirector which is usually on another Thread.
String	toString()
List<PlanningVariableMetaModel<Solution_,Entity_,Value_>>	variableMetaModels()

Methods inherited from class ai.timefold.solver.core.impl.move.AbstractMove

describe, getVariableDescriptor, getVariableDescriptor, getVariableDescriptor

Methods inherited from class java.lang.Object

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

Field Details

variableMetaModel

protected final PlanningVariableMetaModel<Solution_,Entity_,Value_> variableMetaModel

entity

protected final Entity_ entity

toPlanningValue

protected final @Nullable Value_ toPlanningValue

Constructor Details

ChangeMove

protected ChangeMove(PlanningVariableMetaModel<Solution_,Entity_,Value_> variableMetaModel,
 Entity_ entity,
 @Nullable Value_ toPlanningValue)

Method Details

getValue

protected @Nullable Value_ getValue()

execute

public void execute(MutableSolutionView<Solution_> solutionView)

Description copied from interface: Move

Runs the move and optionally records the changes done, so that they can be undone later.

Parameters:

solutionView - Exposes all possible mutative operations on the variables. Remembers those mutative operations and can replay them in reverse order when the solver needs to undo the move. Do not store this parameter in a field.

rebase

public ChangeMove<Solution_,Entity_,Value_> rebase(Rebaser rebaser)

Description copied from interface: Move

Rebases a move from an origin ScoreDirector to another destination ScoreDirector which is usually on another Thread. It is necessary for multithreaded solving to function.

The new move returned by this method translates the entities and problem facts to the destination PlanningSolution of the destination ScoreDirector, That destination PlanningSolution is a deep planning clone (or an even deeper clone) of the origin PlanningSolution that this move has been generated from.

That new move does the exact same change as this move, resulting in the same PlanningSolution state, presuming that destination PlanningSolution was in the same state as the original PlanningSolution to begin with.

An implementation of this method typically iterates through every entity and fact instance in this move, translates each one to the destination ScoreDirector with Rebaser.rebase(Object) and creates a new move instance of the same move type, using those translated instances.

The destination PlanningSolution can be in a different state than the original PlanningSolution. So, rebasing can only depend on the identity of planning entities and problem facts, which are usually declared by a PlanningId on those classes. It must not depend on the state of the planning variables. One thread might rebase a move before, amid or after another thread does that same move instance.

The default implementation throws an UnsupportedOperationException, making multithreaded solving impossible unless the move class implements this method.

Parameters:

rebaser - Do not store this parameter in a field

Returns:

New move that does the same change as this move on another solution instance

getPlanningEntities

public Collection<Entity_> getPlanningEntities()

Description copied from interface: Move

Returns all planning entities that this move is changing. Required for entity tabu.

This method is only called after Move.execute(MutableSolutionView), which might affect the return values.

Duplicate entries in the returned Collection are best avoided. The returned Collection is recommended to be in a stable order. For example, use List or LinkedHashSet, but not HashSet.

The default implementation throws an UnsupportedOperationException, making tabu search impossible unless the move class implements this method.

Returns:

Each entity only once.

getPlanningValues

public Collection<Value_> getPlanningValues()

Description copied from interface: Move

Returns all planning values that this move is assigning to entity variables. Required for value tabu.

This method is only called after Move.execute(MutableSolutionView), which might affect the return values.

Duplicate entries in the returned Collection are best avoided. The returned Collection is recommended to be in a stable order. For example, use List or LinkedHashSet, but not HashSet.

The default implementation throws an UnsupportedOperationException, making tabu search impossible unless the move class implements this method.

Returns:

Each value only once. May contain null.

variableMetaModels

public List<PlanningVariableMetaModel<Solution_,Entity_,Value_>> variableMetaModels()

Specified by:

variableMetaModels in class AbstractMove<Solution_>

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Specified by:

toString in class AbstractMove<Solution_>