org.optaplanner.core.api.domain.variable

Enum PlanningVariableGraphType

java.lang.Object

java.lang.Enum<PlanningVariableGraphType>

org.optaplanner.core.api.domain.variable.PlanningVariableGraphType

All Implemented Interfaces:

Serializable, Comparable<PlanningVariableGraphType>

public enum PlanningVariableGraphType
extends Enum<PlanningVariableGraphType>

Enum Constant Summary

Enum Constants

Enum Constant and Description
CHAINED Changes to this variable need to trigger chain correction.
NONE This is the default.

Method Summary

Modifier and Type	Method and Description
static PlanningVariableGraphType	valueOf(String name) Returns the enum constant of this type with the specified name.
static PlanningVariableGraphType[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

NONE

public static final PlanningVariableGraphType NONE

This is the default.

CHAINED

public static final PlanningVariableGraphType CHAINED

Changes to this variable need to trigger chain correction.

In some use cases, such as Vehicle Routing, planning entities are chained. A chained variable recursively points to a problem fact, which is called the anchor. So either it points directly to the anchor (that problem fact) or it points to another planning entity which recursively points to the anchor. Chains always have exactly 1 anchor, thus they never loop and the tail is always open. Chains never split into a tree: a anchor or planning entity has at most 1 trailing planning entity.

When a chained planning entity changes position, then chain correction must happen:

• divert the chain link at the new position to go through the modified planning entity
• close the missing chain link at the old position

For example: Given A <- B <- C <- D <- X <- Y, when B moves between X and Y, pointing to X, then Y is also changed to point to B and C is also changed to point to A, giving the result A <- C <- D <- X <- B <- Y.

PlanningVariable.nullable() true is not compatible with this.

Method Detail

values

public static PlanningVariableGraphType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (PlanningVariableGraphType c : PlanningVariableGraphType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static PlanningVariableGraphType valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null