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

Class CompositeMove<Solution_>

java.lang.Object
ai.timefold.solver.core.preview.api.move.builtin.CompositeMove<Solution_>
Type Parameters:
Solution_ - the solution type, the class with the PlanningSolution annotation
All Implemented Interfaces:
Move<Solution_>
@NullMarked public final class CompositeMove<Solution_> extends Object implements Move<Solution_>
A CompositeMove is composed out of multiple other moves.

Warning: each of moves in the moveList must not rely on the effect of a previous move in the moveList to create its undoMove correctly.

See Also:

  • Method Details

    • 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.
      Specified by:
      execute in interface Move<Solution_>
      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 Move<Solution_> 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.

      Specified by:
      rebase in interface Move<Solution_>
      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<?> 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.

      Specified by:
      getPlanningEntities in interface Move<Solution_>
      Returns:
      Each entity only once.

    • getPlanningValues

      public Collection<?> 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.

      Specified by:
      getPlanningValues in interface Move<Solution_>
      Returns:
      Each value only once. May contain null.

    • describe

      public String describe()
      Description copied from interface: Move
      Describes the move type for statistical purposes. For example, a move which changes a variable "computer" on a class "Process" could be described as "ChangeMove(Process.computer)".

      The format is not formalized, but it is recommended to stick to ASCII, avoiding whitespace and special characters. Never parse the String returned by this method, it is only intended to be used by the solver.

      Specified by:
      describe in interface Move<Solution_>
      Returns:
      Non-empty String that describes the move type.

    • 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