Constraint

```
public interface Constraint
```
The interface Constraint defines a generic interface for all constraints that could be created and posted within the Problem. Concrete constraints can be defined in two ways:
- explicitly in the interface Problem such as "allDifferent"
- implicitly inside constrained expressions such as var1.eq(var2).
The interface Problem includes only commonly used and de-facto standardized global constraints in their most popular forms. This API assumes that there will be a library of global constraints that implements the interface Constraint and follows the guidelines of the Global Constraint Catalog.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`Constraint`	`and(Constraint c)` Returns an "AND" Constraint.
`VarBool`	`asBool()` This method returns a Var variable that is equal 1 if the constraint is satisfied and equals 0 if it is violated.
`java.lang.Object`	`getImpl()` This method should be defined by a concrete solver implementation.
`java.lang.String`	`getName()` Returns the name of this object.
`java.lang.Object`	`getObject()` This method may be used to get an attached Business Object for this object.
`Problem`	`getProblem()` Return a problem to which this object belongs
`Constraint`	`implies(Constraint c)` Returns a Constraint that states the implication: if this then c.
`Constraint`	`negation()` Returns a Constraint that is satisfied if and only if this constraint is not satisfied.
`Constraint`	`or(Constraint c)` Returns an "OR" Constraint.
`void`	`post()` This method is used to post the constraint.
`void`	`post(ConsistencyLevel consistencyLevel)` This method is used to post the constraint.
`void`	`post(java.lang.String name, Probability probability)` This method is used to post the constraint assuming that it can be violated.
`void`	`setImpl(java.lang.Object impl)` This method defines an Object that represents an actual implementation of this object inside a concrete solver.
`void`	`setName(java.lang.String name)` Sets the name of this object.
`void`	`setObject(java.lang.Object obj)` This method may be used to attach a business object to this object.

- Method Detail
  - and
```
Constraint and(Constraint c)
```
    Returns an "AND" Constraint. The Constraint "AND" is satisfied if both of the Constraints "this" and "c" are satisfied. The Constraint "AND" is not satisfied if at least one of the Constraints "this" or "c" is not satisfied.
    
    Parameters:
    
    c - the Constraint which is part of the new "AND" Constraint
    
    Returns:
    
    a Constraint "AND" between the Constraints "this" and "c2".
  - asBool
```
VarBool asBool()
```
    This method returns a Var variable that is equal 1 if the constraint is satisfied and equals 0 if it is violated.
    
    Returns:
    
    Var with a domain [0;1]: a 1 value indicates the constraint is satisfied, a 0 value indicates the constraint is violated.
  - getImpl
```
java.lang.Object getImpl()
```
    This method should be defined by a concrete solver implementation. This method returns an Object that represents an actual implementation of this object inside an underlying solver.
    
    Returns:
    
    an Object that represents an actual implementation of this Constrained Object inside an underlying solver.
  - getName
```
java.lang.String getName()
```
    Returns the name of this object.
    
    Returns:
    
    the name of this object.
  - getObject
```
java.lang.Object getObject()
```
    This method may be used to get an attached Business Object for this object.
    
    Returns:
    
    the Business Object attached to this object.
  - getProblem
```
Problem getProblem()
```
    Return a problem to which this object belongs
    
    Returns:
    
    a problem to which this object belongs
  - implies
```
Constraint implies(Constraint c)
```
    Returns a Constraint that states the implication: if this then c. In other words, if this constraint is satisfied, then constraint "c" should also be satisfied.
    
    Parameters:
    
    c - the Constraint in the implication.
    
    Returns:
    
    a Constraint that means 'if this then c'.
  - negation
```
Constraint negation()
```
    Returns a Constraint that is satisfied if and only if this constraint is not satisfied.
    
    Returns:
    
    a Constraint that is satisfied if and only if this constraint is not satisfied.
  - or
```
Constraint or(Constraint c)
```
    Returns an "OR" Constraint. The Constraint "OR" is satisfied if either of the Constraints "this" and "c" is satisfied. The Constraint "OR" is not satisfied if both of the Constraints "this" and "c" are not satisfied.
    
    Parameters:
    
    c - the Constraint which is part of the new "OR" Constraint
    
    Returns:
    
    a Constraint "OR" between the Constraints "this" and "c".
  - post
```
void post()
```
    This method is used to post the constraint. The constraint posting may do two things: 1) initial constraint propagation will be executed; 2) the constraint will be memorized and wait for notification events when the variables it controls are changed. The actual posting logic depends on an underlying CP solver. If the posting was unsuccessful, this method throws a runtime exception. A user may put constraint posting in a try-catch block to react to posting failures.
    
    Throws:
    
    java.lang.RuntimeException - if a failure happened during the posting
  - post
```
void post(ConsistencyLevel consistencyLevel)
```
    This method is used to post the constraint. Additionally to post() this methods specifies a particular level of consistency that will be selected by an implementation to control the propagation strength of this constraint.
    
    Parameters:
    
    consistencyLevel -
    
    Throws:
    
    java.lang.RuntimeException - if a failure happened during the posting
  - post
```
void post(java.lang.String name,
          Probability probability)
```
    This method is used to post the constraint assuming that it can be violated. The parameter probability defines a probability that this constraint will not be violated. If it's ALWAYS this is the same as a regular constraint posting. If it's NEVER, the posting of this constraint will fail producing a RuntimeException. All other values allow the constraint to be violated with certain penalties. For instance, probability LOW invokes higher penalty to compare with probability HIGH, but a lower penalty to compare with VERY_LOW. The Problem' method getTotalConstraintViolation() returns a variable that could be minimized to find a solution that may all synchronize all relative constraint violations. Thus, posting related constraints with different probabilities may resolve their conflicts.
    
    Parameters:
    
    name - of the constraint
    
    probability -
    
    Throws:
    
    java.lang.RuntimeException - if a failure happened during the posting
  - setImpl
```
void setImpl(java.lang.Object impl)
```
    This method defines an Object that represents an actual implementation of this object inside a concrete solver.
    
    Parameters:
    
    impl - the Object that represents an actual implementation of this object inside a implementation solver.
  - setName
```
void setName(java.lang.String name)
```
    Sets the name of this object.
    
    Parameters:
    
    name - the name for this object.
  - setObject
```
void setObject(java.lang.Object obj)
```
    This method may be used to attach a business object to this object.
    
    Parameters:
    
    obj - the business object being attached.

Interface Constraint

Method Summary

Method Detail

and

asBool

getImpl

getName

getObject

getProblem

implies

negation

or

post

post

post

setImpl

setName

setObject