Package net.ssehub.easy.varModel.cstEvaluation

Class EvaluationVisitor.EvaluationContextImpl

java.lang.Object

net.ssehub.easy.varModel.cstEvaluation.EvaluationContext

net.ssehub.easy.varModel.cstEvaluation.EvaluationVisitor.EvaluationContextImpl

All Implemented Interfaces:

IConfiguration

Enclosing class:

EvaluationVisitor

private class EvaluationVisitor.EvaluationContextImpl
extends EvaluationContext

Implements the evaluation context. The context may contain nested local configurations in order to represent the nested (recursive) execution of operations defining parameters or local variables (let). Decision variables are searched along this stack starting at the top.

Author:

Holger Eichelberger

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	allowPropagation
private java.util.Stack<IConfiguration>	configStack

Constructor Summary

Constructors

Constructor	Description
EvaluationContextImpl(IConfiguration config)	Creates the context.

Method Summary

Modifier and Type	Method	Description
void	addMessage(EvaluationVisitor.Message message)	Adds an evaluation message.
boolean	allowAssignValues()	Returns whether values shall be assigned, i.e., the configuration may be changed.
boolean	allowPropagation()	Returns whether the expression to be evaluated is a propagation.
(package private) Value	bind(IDatatype type)	Binds the type to the first/closest definition of type.
(package private) void	clear()	Clears this instance for reuse.
Value	getAllInstances(IDatatype type)	Returns all instances of type.
IAssignmentState	getAssignmentState()	Returns the global (target) assignment state for the actual evaluation.
IDecisionVariable	getDecision(AbstractVariable variable)	Returns the specified IDecisionVariable.
IAssignmentState	getTargetState(IDecisionVariable var)	Returns the target state of the evaluation for variable.
void	issueWarning()	Indicates that the evaluation of this constraint shall lead to a warning.
void	notifyChangeListener(IDecisionVariable variable, Value value, IAssignmentState oldState, IValueChangeListener.ChangeKind kind)	Notifies the change listener, i.e., the value of variable has changed.
(package private) void	popLevel()	Pops the top-most configuration level.
(package private) void	pushLevel(IConfiguration config)	Pushes a level.
(package private) EvaluationVisitor.EvaluationContextImpl	reset(IConfiguration config)	Resets this instance for reuse.
(package private) boolean	setAllowPropagation(Operation op, boolean inPropagation)	Changes the propagation state of this context.

Methods inherited from class net.ssehub.easy.varModel.cstEvaluation.EvaluationContext

addErrorMessage, addErrorMessage, addErrorMessage, getCollator, getDereferencedValue, getLocale, setLocale

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

configStack

private java.util.Stack<IConfiguration> configStack

allowPropagation

private boolean allowPropagation

Constructor Detail

EvaluationContextImpl

EvaluationContextImpl(IConfiguration config)

Creates the context.

Parameters:

config - the variability model configuration (outermost stack level)

Method Detail

reset

EvaluationVisitor.EvaluationContextImpl reset(IConfiguration config)

Resets this instance for reuse.

Parameters:

config - the variability model configuration (outermost stack level)

Returns:

this

clear

void clear()

Clears this instance for reuse.

Overrides:

clear in class EvaluationContext

pushLevel

void pushLevel(IConfiguration config)

Pushes a level.

Parameters:

config - the configuration to be pushed

popLevel

void popLevel()

Pops the top-most configuration level.

allowAssignValues

public boolean allowAssignValues()

Description copied from class: EvaluationContext

Returns whether values shall be assigned, i.e., the configuration may be changed.

Specified by:

allowAssignValues in class EvaluationContext

Returns:

true if values shall be assigned, false else

notifyChangeListener

public void notifyChangeListener(IDecisionVariable variable,
                                 Value value,
                                 IAssignmentState oldState,
                                 IValueChangeListener.ChangeKind kind)

Description copied from class: EvaluationContext

Notifies the change listener, i.e., the value of variable has changed.

Specified by:

notifyChangeListener in class EvaluationContext

Parameters:

variable - the changed variable

value - the value of variable before the change (may be null)

oldState - the old state of variable before the change

kind - the change kind

addMessage

public void addMessage(EvaluationVisitor.Message message)

Description copied from class: EvaluationContext

Adds an evaluation message.

Specified by:

addMessage in class EvaluationContext

Parameters:

message - the message to be added

getTargetState

public IAssignmentState getTargetState(IDecisionVariable var)

Description copied from class: EvaluationContext

Returns the target state of the evaluation for variable.

Specified by:

getTargetState in class EvaluationContext

Parameters:

var - the variable to return the target state for (do not modify!!!)

Returns:

the target state (may be null if the actual value cannot be assigned do to a state conflict)

getDecision

public IDecisionVariable getDecision(AbstractVariable variable)

Description copied from interface: IConfiguration

Returns the specified IDecisionVariable.

Parameters:

variable - The declaration for which the configuration entity should be returned.

Returns:

The IDecisionVariable for the given declaration

getAllInstances

public Value getAllInstances(IDatatype type)

Description copied from interface: IConfiguration

Returns all instances of type.

Parameters:

type - the type to return the instances for

Returns:

all instances of type in terms of a container value consisting of references (may be null if this is not possible, e.g., in case of Integer)

bind

Value bind(IDatatype type)

Binds the type to the first/closest definition of type.

Parameters:

type - the type to search for

Returns:

the value (may be null if there is none)

issueWarning

public void issueWarning()

Description copied from class: EvaluationContext

Indicates that the evaluation of this constraint shall lead to a warning.

Specified by:

issueWarning in class EvaluationContext

allowPropagation

public boolean allowPropagation()

Description copied from class: EvaluationContext

Returns whether the expression to be evaluated is a propagation.

Specified by:

allowPropagation in class EvaluationContext

Returns:

true if it is a propagation, i.e. propagation shall be allowed, false else

setAllowPropagation

boolean setAllowPropagation(Operation op,
                            boolean inPropagation)

Changes the propagation state of this context.

Parameters:

inPropagation - whether we are currently in a propagation

op - a filter for allowing propagation, basically implies is allow to change or null (no operation as filter)

Returns:

the propagation state before

getAssignmentState

public IAssignmentState getAssignmentState()

Description copied from class: EvaluationContext

Returns the global (target) assignment state for the actual evaluation. This may differ from EvaluationContext.getTargetState(IDecisionVariable).

Specified by:

getAssignmentState in class EvaluationContext

Returns:

the assignment state