ConstraintSolver (   The Meta-CSP FrameworkA Java API for Meta-CSP based reasoning)

java.lang.Object
- org.metacsp.framework.ConstraintSolver

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

APSPSolver, BooleanSatisfiabilitySolver, DE9IMRelationSolver, FuzzyAllenIntervalNetworkSolver, FuzzySymbolicVariableConstraintSolver, MultiConstraintSolver, QualitativeAllenSolver, RCC2ConstraintSolver, RCCConstraintSolver, ReachabilityContraintSolver
```
public abstract class ConstraintSolver
extends java.lang.Object
implements java.io.Serializable
```
This class provides common infrastructure and functionality for all constraint solvers. All constraint solvers should implement either this class or the MultiConstraint class. The latter is in fact an extension of this class, as it implements the, addConstraintsSub() and removeConstraintsSub() methods. This abstract class also maintains a ConstraintNetwork, which is represented internally as a graph. Any specific solver must implement this abstract class to provide methods to create/remove variables, add/remove constraints, and perform propagation.

Author:

Federico Pecora

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ConstraintSolver.OPTIONS
General class options.

Nested Classes
Modifier and Type	Class and Description
`static class`	`ConstraintSolver.OPTIONS` General class options.

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`autoprop`
`protected java.util.HashMap<java.lang.String,java.util.ArrayList<Variable>>`	`components`
`protected java.lang.Class<?>[]`	`constraintTypes`
`protected int`	`IDs`
`protected java.util.logging.Logger`	`logger`
`protected java.lang.String`	`name`
`protected static int`	`nesting`
`protected boolean`	`noPropOnVarCreation`
`static int`	`numcalls`
`protected boolean`	`skipPropagation`
`protected static java.lang.String`	`spacing`
`protected ConstraintNetwork`	`theNetwork` Access to the underlying constraint network.
`protected java.lang.Class<?>`	`variableType`

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`ConstraintSolver(java.lang.Class<?>[] constraintTypes, java.lang.Class<?> variableType)` Default constructor for this class.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`addConstraint(Constraint c)` Add a constraint between `Variable`s.
`boolean`	`addConstraintNoPropagation(Constraint c)` Add a constraint between `Variable`s, without propagation.
`boolean`	`addConstraints(Constraint... c)` Add a batch of constraints between `Variable`s.
`Constraint`	`addConstraintsDebug(Constraint... c)` Add a batch of constraints between `Variable`s.
`boolean`	`addConstraintsNoPropagation(Constraint... c)` Add a batch of constraints between `Variable`s, but do not propagate.
`protected abstract boolean`	`addConstraintsSub(Constraint[] c)` This method must be implemented by the developer of the specific `ConstraintSolver` class.
`boolean`	`containsVariable(Variable v)` Return if the network of this `ConstraintSolver` contains a `Variable`.
`Variable`	`createVariable()` Factory method for creating a new `Variable` for this `ConstraintSolver`.
`Variable`	`createVariable(java.lang.String component)` Create a new `Variable` for this `ConstraintSolver`, and assign it to the given component label.
`Variable[]`	`createVariables(int num)` Create a batch of new `Variable`s for this `ConstraintSolver`.
`Variable[]`	`createVariables(int num, java.lang.String component)` Create a batch of new `Variable`s for this `ConstraintSolver`.
`protected abstract Variable[]`	`createVariablesSub(int num)` This method must be implemented by the developer of the specific `ConstraintSolver` class.
`protected Variable[]`	`createVariablesSub(int num, java.lang.String component)` This method must be implemented by the developer of the specific `ConstraintSolver` class.
`void`	`deplenish()` Deplenish the network associated to the `ConstraintSolver` (remove all constraints and variables).
`java.lang.String`	`getComponent(Variable v)` Get the component of a given `Variable`.
`java.util.HashMap<java.lang.String,java.util.ArrayList<Variable>>`	`getComponents()` Get a `HashMap` of all component tags with associated variables.
`ConstraintNetwork`	`getConstraintNetwork()` Get the `ConstraintNetwork` of this `ConstraintSolver`.
`Constraint[]`	`getConstraints()` Get all the `Constraint`s contained in this `ConstraintSolver`'s `ConstraintNetwork`.
`Constraint[]`	`getConstraints(Variable from, Variable to)` Get all `Constraint`s contained in this `ConstraintSolver`'s `ConstraintNetwork` with given source and destination `Variable`s.
`java.lang.String`	`getDescription()` Gets a description of this `ConstraintSolver` stating which variable and constraint types it supports.
`int`	`getID(Variable var)` Get the ID of a `Variable`.
`boolean`	`getOption(ConstraintSolver.OPTIONS op)` Get option value for this `ConstraintSolver`.
`Variable`	`getVariable(int id)` Get a `Variable` given its ID.
`Variable[]`	`getVariables()` Get all the `Variable`s contained in this `ConstraintSolver`'s `ConstraintNetwork`.
`Variable[]`	`getVariables(java.lang.String component)` Get all the `Variable`s contained in this `ConstraintSolver`'s `ConstraintNetwork`.
`Variable[]`	`getVariables(java.lang.String component, java.lang.Object... markingsToExclude)` Get all the `Variable`s contained in this `ConstraintSolver`'s `ConstraintNetwork`.
`boolean`	`isCompatible(Constraint c)` Assess whether a `Constraint` is compatible with this `ConstraintSolver`.
`void`	`maskConstraints(Constraint[] constraints)` Method to mask constraints; does nothing, must be overridden; always called before propagation.
`abstract boolean`	`propagate()` Propagate the constraint network.
`abstract void`	`registerValueChoiceFunctions()`
`void`	`removeConstraint(Constraint c)` Retract a constraint between `Variable`s.
`void`	`removeConstraints(Constraint[] c)` Retract a batch of constraints between `Variable`s.
`protected abstract void`	`removeConstraintsSub(Constraint[] c)` This method must be implemented by the developer of the specific `ConstraintSolver` class.
`void`	`removeVariable(Variable v)` Remove a `Variable` from this `ConstraintSolver`.
`void`	`removeVariables(Variable[] v)` Remove a batch of `Variable`s from this `ConstraintSolver`.
`protected abstract void`	`removeVariablesSub(Variable[] v)` This method must be implemented by the developer of the specific `ConstraintSolver` class.
`void`	`setComponent(java.lang.String component, Variable... vars)` Used to set the component of a variable.
`void`	`setComponents(java.util.HashMap<java.lang.String,java.util.ArrayList<Variable>> components)` Set the component tags of all variables.
`void`	`setConstraintNetwork(ConstraintNetwork newCS)`
`void`	`setName(java.lang.String name)`
`void`	`setOptions(ConstraintSolver.OPTIONS... ops)` Set options for this `ConstraintSolver`.
`java.lang.String`	`toString()`
`void`	`unmaskConstraints(Constraint[] constraints)` Method to unmask constraints (reverse making done in maskConstraints() method); does nothing, must be overridden; always called after propagation.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - numcalls
```
public static int numcalls
```
  - constraintTypes
```
protected java.lang.Class<?>[] constraintTypes
```
  - variableType
```
protected java.lang.Class<?> variableType
```
  - nesting
```
protected static int nesting
```
  - spacing
```
protected static java.lang.String spacing
```
  - IDs
```
protected int IDs
```
  - name
```
protected java.lang.String name
```
  - theNetwork
```
protected ConstraintNetwork theNetwork
```
    Access to the underlying constraint network.
  - autoprop
```
protected boolean autoprop
```
  - noPropOnVarCreation
```
protected boolean noPropOnVarCreation
```
  - skipPropagation
```
protected boolean skipPropagation
```
  - components
```
protected java.util.HashMap<java.lang.String,java.util.ArrayList<Variable>> components
```
  - logger
```
protected transient java.util.logging.Logger logger
```
- Constructor Detail
  - ConstraintSolver
```
protected ConstraintSolver(java.lang.Class<?>[] constraintTypes,
                           java.lang.Class<?> variableType)
```
    Default constructor for this class. Calls to subclass constructors will call this by default.
- Method Detail
  - setName
```
public void setName(java.lang.String name)
```
  - setOptions
```
public void setOptions(ConstraintSolver.OPTIONS... ops)
```
    Set options for this ConstraintSolver.
    
    Parameters:
    
    ops - Options to set (see ConstraintSolver.OPTIONS).
  - getOption
```
public boolean getOption(ConstraintSolver.OPTIONS op)
```
    Get option value for this ConstraintSolver.
    
    Parameters:
    
    op - The option to get (see ConstraintSolver.OPTIONS).
    
    Returns:
    
    true iff the given option is set.
  - isCompatible
```
public boolean isCompatible(Constraint c)
```
    Assess whether a Constraint is compatible with this ConstraintSolver. This is used internally to ignore processing of incompatible constraints by ConstraintSolvers that are aggregated into MultiConstraintSolvers.
    
    Parameters:
    
    c - The Constraint to check.
    
    Returns:
    
    true iff the given Constraint is compatible with this ConstraintSolver.
  - propagate
```
public abstract boolean propagate()
```
    Propagate the constraint network.
    
    Returns:
    
    A boolean value indicating whether propagation was successful.
  - addConstraint
```
public final boolean addConstraint(Constraint c)
```
    Add a constraint between Variables.
    
    Parameters:
    
    c - The constraint to add.
    
    Returns:
    
    true iff the constraint was added successfully.
  - addConstraintNoPropagation
```
public final boolean addConstraintNoPropagation(Constraint c)
```
    Add a constraint between Variables, without propagation.
    
    Parameters:
    
    c - The constraint to add.
    
    Returns:
    
    true.
  - addConstraintsDebug
```
public final Constraint addConstraintsDebug(Constraint... c)
```
    Add a batch of constraints between Variables. This method is NOT implemented so as to perform only one propagation, rather it adds all constraints sequentially, and returns the first constraint that fails, null if no constraint fails.
    
    Parameters:
    
    c - The constraints to add.
    
    Returns:
    
    The first constraint that fails, null if no constraint fails.
  - addConstraintsNoPropagation
```
public final boolean addConstraintsNoPropagation(Constraint... c)
```
    Add a batch of constraints between Variables, but do not propagate. This method always returns true, hence if the constraint(s) to add are inconsistent, this will result in propagation failure the next time a constraint is added and propagation occurs.
    
    Parameters:
    
    c - The constraints to add.
    
    Returns:
    
    true
  - addConstraints
```
public final boolean addConstraints(Constraint... c)
```
    Add a batch of constraints between Variables. This method is implemented so as to perform only one propagation, thus being more convenient than performing c.length invocations of addConstraint(Constraint c). In addition, all constraints are either accepted or rejected together.
    
    Parameters:
    
    c - The constraints to add.
    
    Returns:
    
    Whether the resulting ConstraintNetwork is consistent. If false, the Constraint are not added.
  - addConstraintsSub
```
protected abstract boolean addConstraintsSub(Constraint[] c)
```
    This method must be implemented by the developer of the specific ConstraintSolver class. It should implement all operations necessary to add multiple constraints, and should return true upon success, false otherwise.
    
    Parameters:
    
    c - The constraints to add.
    
    Returns:
    
    true iff the constraints were added to the ConstraintNetwork.
  - removeConstraint
```
public final void removeConstraint(Constraint c)
                            throws ConstraintNotFound
```
    Retract a constraint between Variables.
    
    Parameters:
    
    c - The constraint to retract.
    
    Throws:
    
    ConstraintNotFound
  - removeConstraints
```
public final void removeConstraints(Constraint[] c)
                             throws ConstraintNotFound
```
    Retract a batch of constraints between Variables. This method should be implemented so as to perform only one propagation, thus being more convenient than performing c.length invocations of removeConstraint(Constraint c). In addition, all constraints should be either accepted or rejected together.
    
    Parameters:
    
    c - The constraints to add.
    
    Throws:
    
    ConstraintNotFound
  - removeConstraintsSub
```
protected abstract void removeConstraintsSub(Constraint[] c)
```
    This method must be implemented by the developer of the specific ConstraintSolver class. Should implement all operations necessary to remove a batch of constraints.
    
    Parameters:
    
    c - The constraints to remove.
  - createVariable
```
public final Variable createVariable(java.lang.String component)
```
    Create a new Variable for this ConstraintSolver, and assign it to the given component label.
    
    Parameters:
    
    component - The component label to which assign the new variable.
    
    Returns:
    
    A new Variable.
  - createVariable
```
public final Variable createVariable()
```
    Factory method for creating a new Variable for this ConstraintSolver.
    
    Returns:
    
    A new Variable.
  - setComponent
```
public void setComponent(java.lang.String component,
                         Variable... vars)
```
    Used to set the component of a variable. Components are "tags" that are used, e.g., in timeline plotting.
    
    Parameters:
    
    component - The component to set.
    
    vars - The variables that should be tagged under this component.
  - createVariables
```
public final Variable[] createVariables(int num)
```
    Create a batch of new Variables for this ConstraintSolver.
    
    Parameters:
    
    num - The number of variables to create.
    
    Returns:
    
    A batch of new Variables.
  - createVariables
```
public final Variable[] createVariables(int num,
                                        java.lang.String component)
```
    Create a batch of new Variables for this ConstraintSolver.
    
    Parameters:
    
    num - The number of variables to create.
    
    component - The component tag to associate to these new variables.
    
    Returns:
    
    A batch of new Variables.
  - createVariablesSub
```
protected abstract Variable[] createVariablesSub(int num)
```
    This method must be implemented by the developer of the specific ConstraintSolver class. It should implement all operations necessary to create a batch of variable for the specific type of ConstraintSolver.
    
    Parameters:
    
    num - The number of variables to create.
    
    Returns:
    
    A batch of new Variable for this ConstraintSolver.
  - createVariablesSub
```
protected Variable[] createVariablesSub(int num,
                                        java.lang.String component)
```
    This method must be implemented by the developer of the specific ConstraintSolver class. It should implement all operations necessary to create a batch of variable for the specific type of ConstraintSolver.
    
    Parameters:
    
    component - The component label to associate to the new Variables.
    
    num - The number of Variables to create.
    
    Returns:
    
    A batch of new Variable for this ConstraintSolver.
  - removeVariable
```
public final void removeVariable(Variable v)
                          throws VariableNotFound,
                                 IllegalVariableRemoval
```
    Remove a Variable from this ConstraintSolver.
    
    Parameters:
    
    v - The Variable to remove.
    
    Throws:
    
    VariableNotFound
    
    IllegalVariableRemoval
  - removeVariables
```
public final void removeVariables(Variable[] v)
                           throws VariableNotFound,
                                  IllegalVariableRemoval
```
    Remove a batch of Variables from this ConstraintSolver.
    
    Parameters:
    
    v - The batch of Variables to remove.
    
    Throws:
    
    VariableNotFound
    
    IllegalVariableRemoval
  - removeVariablesSub
```
protected abstract void removeVariablesSub(Variable[] v)
```
    This method must be implemented by the developer of the specific ConstraintSolver class. It should implement all operations necessary to remove a batch of variables for the specific type of ConstraintSolver.
    
    Parameters:
    
    v - The Variables to remove.
  - getConstraintNetwork
```
public ConstraintNetwork getConstraintNetwork()
```
    Get the ConstraintNetwork of this ConstraintSolver.
    
    Returns:
    
    the ConstraintNetwork of this ConstraintSolver.
  - getVariable
```
public Variable getVariable(int id)
```
    Get a Variable given its ID.
    
    Parameters:
    
    id - The ID of the Variable to get.
    
    Returns:
    
    The Variable whose ID is id.
  - getID
```
public int getID(Variable var)
```
    Get the ID of a Variable.
    
    Parameters:
    
    var - The Variable of which to get the ID.
    
    Returns:
    
    The ID of the given variable.
  - getVariables
```
public Variable[] getVariables()
```
    Get all the Variables contained in this ConstraintSolver's ConstraintNetwork.
    
    Returns:
    
    all the Variables contained in this ConstraintSolver's ConstraintNetwork.
  - getVariables
```
public Variable[] getVariables(java.lang.String component,
                               java.lang.Object... markingsToExclude)
```
    Get all the Variables contained in this ConstraintSolver's ConstraintNetwork.
    
    Parameters:
    
    component - Only Variables associated with the given label (component) should be returned.
    
    Returns:
    
    all the Variables contained in this ConstraintSolver's ConstraintNetwork.
  - getVariables
```
public Variable[] getVariables(java.lang.String component)
```
    Get all the Variables contained in this ConstraintSolver's ConstraintNetwork.
    
    Parameters:
    
    component - Only Variables associated with the given label (component) should be returned.
    
    Returns:
    
    all the Variables contained in this ConstraintSolver's ConstraintNetwork.
  - getConstraints
```
public Constraint[] getConstraints()
```
    Get all the Constraints contained in this ConstraintSolver's ConstraintNetwork.
    
    Returns:
    
    all the Constraints contained in this ConstraintSolver's ConstraintNetwork.
  - getConstraints
```
public Constraint[] getConstraints(Variable from,
                                   Variable to)
```
    Get all Constraints contained in this ConstraintSolver's ConstraintNetwork with given source and destination Variables.
    
    Parameters:
    
    from - The source Variable of the Constraints to be obtained.
    
    to - The destination Variable of the Constraints to be obtained.
    
    Returns:
    
    The Constraints contained in this ConstraintSolver's ConstraintNetwork with given source and destination Variables.
  - getComponent
```
public java.lang.String getComponent(Variable v)
```
    Get the component of a given Variable. A component is a String labeling of Variables.
    
    Parameters:
    
    v - The Variable of which to get the component.
    
    Returns:
    
    A String representing the component of the given Variable.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - getDescription
```
public java.lang.String getDescription()
```
    Gets a description of this ConstraintSolver stating which variable and constraint types it supports.
    
    Returns:
    
    A description of this ConstraintSolver stating which variable and constraint types it supports.
  - deplenish
```
public void deplenish()
```
    Deplenish the network associated to the ConstraintSolver (remove all constraints and variables).
  - getComponents
```
public java.util.HashMap<java.lang.String,java.util.ArrayList<Variable>> getComponents()
```
    Get a HashMap of all component tags with associated variables.
    
    Returns:
    
    A HashMap whose entries are component tags and the associated variables.
  - setComponents
```
public void setComponents(java.util.HashMap<java.lang.String,java.util.ArrayList<Variable>> components)
```
    Set the component tags of all variables.
    
    Parameters:
    
    components - A HashMap whose entries are the component tags and the associated variables.
  - containsVariable
```
public boolean containsVariable(Variable v)
```
    Return if the network of this ConstraintSolver contains a Variable.
    
    Parameters:
    
    v - The Variable variable to check.
    
    Returns:
    
    true iff the variable is present in the network.
  - registerValueChoiceFunctions
```
public abstract void registerValueChoiceFunctions()
```
  - setConstraintNetwork
```
public void setConstraintNetwork(ConstraintNetwork newCS)
```
  - maskConstraints
```
public void maskConstraints(Constraint[] constraints)
```
    Method to mask constraints; does nothing, must be overridden; always called before propagation.
    
    Parameters:
    
    constraints - The constraints that are being added by this call to propagate.
  - unmaskConstraints
```
public void unmaskConstraints(Constraint[] constraints)
```
    Method to unmask constraints (reverse making done in maskConstraints() method); does nothing, must be overridden; always called after propagation.
    
    Parameters:
    
    constraints - The constraints that were added by this call to propagate.

Class ConstraintSolver

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

numcalls

constraintTypes

variableType

nesting

spacing

IDs

name

theNetwork

autoprop

noPropOnVarCreation

skipPropagation

components

logger

Constructor Detail

ConstraintSolver

Method Detail

setName

setOptions

getOption

isCompatible

propagate

addConstraint

addConstraintNoPropagation

addConstraintsDebug

addConstraintsNoPropagation

addConstraints

addConstraintsSub

removeConstraint

removeConstraints

removeConstraintsSub

createVariable

createVariable

setComponent

createVariables

createVariables

createVariablesSub

createVariablesSub

removeVariable

removeVariables

removeVariablesSub

getConstraintNetwork

getVariable

getID

getVariables

getVariables

getVariables

getConstraints

getConstraints

getComponent

toString

getDescription

deplenish

getComponents

setComponents

containsVariable

registerValueChoiceFunctions

setConstraintNetwork

maskConstraints

unmaskConstraints