org.eclipse.ocl.examples.impactanalyzer.instanceScope

Class NavigationStepSequence

java.lang.Object

org.eclipse.ocl.examples.impactanalyzer.instanceScope.AbstractNavigationStep

org.eclipse.ocl.examples.impactanalyzer.instanceScope.CompositeNavigationStep

org.eclipse.ocl.examples.impactanalyzer.instanceScope.NavigationStepSequence

All Implemented Interfaces:

HashCodeChangeListener, NavigationStep, SemanticComparable

public class NavigationStepSequence
extends CompositeNavigationStep

Performs a sequence of navigation steps where the subsequent step uses as its input the output of the previous step. When this navigation reaches an empty set, the result of the entire navigation step sequence is defined to be empty, even if further navigation steps follow. The rationale behind this is this: the navigation steps each compute the set of objects that, when used as context for the root OCL expression, let the subexpression for which the navigation step is responsible evaluate to a given element. This means that when a navigation step produces an empty result, then for no element does the subexpression produce the result sought. Therefore, the further ascend towards the root expression's context can be aborted at that point.

Constructor Summary

Constructors

Constructor and Description
NavigationStepSequence(OCLExpression debugInfo, NavigationStep... steps) Because some NavigationSteps such as IndirectingStep may change their source/target type as they get lazily initialized, this constructor passes on null as source/target type.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.String	contentToString(java.util.Map<NavigationStep,java.lang.Integer> visited, int indent)
boolean	isAbsolute() The sequence is considered absolute if its last step is always empty.
protected java.util.Set<AnnotatedEObject>	navigate(AnnotatedEObject fromObject, TracebackCache cache, org.eclipse.emf.common.notify.Notification changeEvent)

Methods inherited from class org.eclipse.ocl.examples.impactanalyzer.instanceScope.CompositeNavigationStep

afterHashCodeChange, beforeHashCodeChange, distinctSize, getInstanceScopeAnalysis, getSemanticIdentity, getSemanticIdentityOfAbstractNavigationStep, getSteps, size

Methods inherited from class org.eclipse.ocl.examples.impactanalyzer.instanceScope.AbstractNavigationStep

addAlwaysEmptyChangeListener, addEnteringScopes, addExpressionForWhichThisIsNavigationStep, addHashCodeChangeListener, addLeavingScopes, addSourceTypeChangeListener, addTargetTypeChangeListener, annotateEObject, distinctSize, doesSourceTypeMatch, fireAfterHashCodeChange, fireBeforeHashCodeChange, getDebugInfo, getEnteringScopes, getId, getLeavingScopes, getNavigateCounter, getResultObjectsCounter, getSourceType, getTargetType, haveIntersectingSubclassTree, incrementNavigateCounter, isAlwaysEmpty, navigate, newTokenForFiringHashCodeChangeEvent, setAlwaysEmpty, size, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

NavigationStepSequence

public NavigationStepSequence(OCLExpression debugInfo,
                      NavigationStep... steps)

Because some NavigationSteps such as IndirectingStep may change their source/target type as they get lazily initialized, this constructor passes on null as source/target type. Instead, this class redefined AbstractNavigationStep.getSourceType() and AbstractNavigationStep.getTargetType() and dynamically fetches them from the underlying step sequence.

Method Detail

isAbsolute

public boolean isAbsolute()

The sequence is considered absolute if its last step is always empty. This is equivalent to AbstractNavigationStep.isAlwaysEmpty().

Specified by:

isAbsolute in interface NavigationStep

Overrides:

isAbsolute in class AbstractNavigationStep

Returns:

always false

navigate

protected java.util.Set<AnnotatedEObject> navigate(AnnotatedEObject fromObject,
                                       TracebackCache cache,
                                       org.eclipse.emf.common.notify.Notification changeEvent)

Specified by:

navigate in class AbstractNavigationStep

contentToString

public java.lang.String contentToString(java.util.Map<NavigationStep,java.lang.Integer> visited,
                               int indent)

Overrides:

contentToString in class AbstractNavigationStep