// Copyright 2012 Georg-August-Universität Göttingen, Germany
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package de.ugoe.cs.autoquest.tasktrees.taskequality;
import de.ugoe.cs.autoquest.tasktrees.treeifc.IIteration;
import de.ugoe.cs.autoquest.tasktrees.treeifc.IIterationInstance;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ISelection;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITask;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstance;
/**
*
* This class is capable of comparing Iterations. Iterations equal at distinct levels
* in distinct situations. The following table shows the results of the comparison for the
* specific situations (the parameters are commutative). In any other situation, the comparison
* returns NodeEquality.UNEQUAL
:
*
*
*
*
* iteration 1 |
* iteration 2 |
* comparison result |
*
*
* any iteration |
* any iteration with a child that is lexically equal to the child of iteration 1 |
* NodeEquality.LEXICALLY_EQUAL |
*
*
* any iteration |
* any iteration with a child that is syntactically equal to the child of iteration 1 |
* NodeEquality.SYNTACTICALLY_EQUAL |
*
*
* any iteration |
* any iteration with a child that is semantically equal to the child of iteration 1 |
* NodeEquality.SEMANTICALLY_EQUAL |
*
*
* an iteration with a selection of syntactically equal children |
* an iteration with a child that is syntactically equal to the children of the child
* selection of iteration 1 |
* NodeEquality.SYNTACTICALLY_EQUAL |
*
*
* an iteration with a selection of syntactically equal children |
* an iteration with a selection of syntactically equal children that are all syntactically
* equal to the selection of children of iteration 1 |
* NodeEquality.SYNTACTICALLY_EQUAL |
*
*
* an iteration with a selection of semantically equal children |
* an iteration with a child that is semantically equal to the children of the child
* selection of iteration 1 |
* NodeEquality.SEMANTICALLY_EQUAL |
*
*
* an iteration with a selection of semantically equal children |
* an iteration with a selection of semantically equal children that are all semantically
* equal to the selection of children of iteration 1 |
* NodeEquality.SEMANTICALLY_EQUAL |
*
*
*
* @version $Revision: $ $Date: 19.02.2012$
* @author 2012, last modified by $Author: patrick$
*/
public class IterationComparisonRule implements TaskComparisonRule {
/* (non-Javadoc)
* @see TaskComparisonRule#isApplicable(ITask, ITask)
*/
@Override
public boolean isApplicable(ITask task1, ITask task2) {
return (task1 instanceof IIteration) && (task2 instanceof IIteration);
}
/* (non-Javadoc)
* @see TaskComparisonRule#areLexicallyEqual(ITask, ITask)
*/
@Override
public boolean areLexicallyEqual(ITask task1, ITask task2) {
ITask child1 = ((IIteration) task1).getMarkedTask();
ITask child2 = ((IIteration) task2).getMarkedTask();
if (child1 != null) {
if (child2 == null) {
return false;
}
else {
// iterations may have 3 different structures.
// 1. they have one child, which is the iterated one
// 2. they have a sequence of children, which is iterated
// 3. they have a selection of different iterated variants (usually the variants
// are semantically equal)
// ignore the type of the children but check them for equality.
return getNodeEquality(child1, child2).isAtLeast(TaskEquality.LEXICALLY_EQUAL);
}
}
else if (child2 == null) {
return true;
}
return false;
}
/* (non-Javadoc)
* @see TaskComparisonRule#areSyntacticallyEqual(ITask, ITask)
*/
@Override
public boolean areSyntacticallyEqual(ITask task1, ITask task2) {
return areLexicallyEqual(task1, task2);
}
/* (non-Javadoc)
* @see TaskComparisonRule#areSemanticallyEqual(ITask, ITask)
*/
@Override
public boolean areSemanticallyEqual(ITask task1, ITask task2) {
return compare(task1, task2).isAtLeast(TaskEquality.SEMANTICALLY_EQUAL);
}
/* (non-Javadoc)
* @see TaskComparisonRule#compare(ITask, ITask)
*/
@Override
public TaskEquality compare(ITask task1, ITask task2) {
ITask child1 = ((IIteration) task1).getMarkedTask();
ITask child2 = ((IIteration) task2).getMarkedTask();
// if both iterations do not have children, they are equal although this doesn't make sense
if ((child1 == null) && (child2 == null)) {
return TaskEquality.LEXICALLY_EQUAL;
}
else if ((child1 == null) || (child2 == null)) {
return TaskEquality.UNEQUAL;
}
// iterations may have 3 different structures.
// 1. they have one child, which is the iterated one
// 2. they have a sequence of children, which is iterated
// 3. they have a selection of different iterated variants (usually the variants are
// semantically equal)
//
// the permutations of the three variants in combination must be checked
// check if both tasks are the same variants of iterations and if their children are equal.
// This condition matches, if both iterations are the same variants of iteration. I.e. three
// combinations of the permutation are handled herewith.
TaskEquality taskEquality = getNodeEquality(child1, child2);
if (taskEquality != null) {
return taskEquality;
}
// compare one iteration with a single task as a child and another one with a selection of
// semantically equal tasks
return selectionChildrenSemanticallyEqualNode(child1, child2);
// all other combinations (i.e. sequence with single child and sequence with selection)
// can not match
}
/* (non-Javadoc)
* @see TaskComparisonRule#isApplicable(ITaskInstance, ITaskInstance)
*/
@Override
public boolean isApplicable(ITaskInstance instance1, ITaskInstance instance2) {
return isApplicable(instance1.getTask(), instance2.getTask());
}
/* (non-Javadoc)
* @see TaskComparisonRule#areLexicallyEqual(ITaskInstance, ITaskInstance)
*/
@Override
public boolean areLexicallyEqual(ITaskInstance instance1, ITaskInstance instance2) {
IIterationInstance iteration1 = (IIterationInstance) instance1;
IIterationInstance iteration2 = (IIterationInstance) instance2;
// if both iterations do not have children, they are equal although this doesn't make sense
if ((iteration1.size() == 0) && (iteration2.size() == 0)) {
return true;
}
if (iteration1.size() != iteration2.size()) {
return false;
}
for (int i = 0; i < iteration1.size(); i++) {
ITaskInstance child1 = iteration1.get(i);
ITaskInstance child2 = iteration2.get(i);
TaskEquality taskEquality =
callRuleManager(child1, child2, TaskEquality.LEXICALLY_EQUAL);
if ((taskEquality == null) || (taskEquality == TaskEquality.UNEQUAL)) {
return false;
}
}
return true;
}
/* (non-Javadoc)
* @see TaskComparisonRule#areSyntacticallyEqual(ITaskInstance, ITaskInstance)
*/
@Override
public boolean areSyntacticallyEqual(ITaskInstance instance1, ITaskInstance instance2) {
return areLexicallyEqual(instance1, instance2);
}
/* (non-Javadoc)
* @see TaskComparisonRule#areSemanticallyEqual(ITaskInstance, ITaskInstance)
*/
@Override
public boolean areSemanticallyEqual(ITaskInstance instance1, ITaskInstance instance2) {
return areLexicallyEqual(instance1, instance2);
}
/* (non-Javadoc)
* @see TaskComparisonRule#compare(ITaskInstance, ITaskInstance)
*/
@Override
public TaskEquality compare(ITaskInstance instance1, ITaskInstance instance2) {
if (areLexicallyEqual(instance1, instance2)) {
return TaskEquality.LEXICALLY_EQUAL;
}
else {
return TaskEquality.UNEQUAL;
}
}
/**
*
* compares two tasks with each other by calling the rule manager. If the rule manager returns
* identity, then the returned equality is set to lexically equal. The reason is, that
* the children of the iterations are compared and that therefore the distinct iterations
* can be at most lexically equal.
*
*
* @param child1 the first task to be compared
* @param child2 the second task to be compared
*
* @return the determined equality being at most lexical equality.
*/
private TaskEquality getNodeEquality(ITask child1, ITask child2) {
TaskEquality taskEquality = callRuleManager(child1, child2, null);
if (taskEquality.isAtLeast(TaskEquality.SEMANTICALLY_EQUAL)) {
// prevent, that identical is returned, because the iterations itself are not identical
// although the iterated tasks are
if (taskEquality == TaskEquality.IDENTICAL) {
return TaskEquality.LEXICALLY_EQUAL;
}
else {
return taskEquality;
}
}
return TaskEquality.UNEQUAL;
}
/**
*
* compares two tasks. One of them must be a selection, the other one can be any task.
* The method returns a task equality that is not NodeEquality.UNEQUAL
* if the other task is at least semantically equal to the children of the selection. It
* returns more concrete equalities, if the equality between the other task and the children
* of the selection is more concrete.
*
*
* @param task1 the first task to compare
* @param task2 the second task to compare
*
* @return as described
*/
private TaskEquality selectionChildrenSemanticallyEqualNode(ITask task1, ITask task2) {
ISelection selection = null;
ITask task = null;
if (task1 instanceof ISelection) {
selection = (ISelection) task1;
task = task2;
}
else if (task2 instanceof ISelection) {
selection = (ISelection) task2;
task = task1;
}
else {
return TaskEquality.UNEQUAL;
}
// Iterations, where one has a selection and the other one not can at most be syntactically
// equal but not identical
TaskEquality commonDenominatorForAllComparisons = TaskEquality.SYNTACTICALLY_EQUAL;
for (ITask child : selection.getChildren()) {
TaskEquality taskEquality =
callRuleManager(task, child, commonDenominatorForAllComparisons);
if ((taskEquality == null) || (taskEquality == TaskEquality.UNEQUAL)) {
return TaskEquality.UNEQUAL;
}
commonDenominatorForAllComparisons =
commonDenominatorForAllComparisons.getCommonDenominator(taskEquality);
}
return commonDenominatorForAllComparisons;
}
/**
*
* used to to call the task equality rule manager for the comparison of the two provided
* children. If no required equality level is provided, than the most concrete equality is
* returned. Otherwise, the required equality is returned as long as the children are equal
* on that level.
*
*
* @param child1 the first task to be compared
* @param child2 the second task to be compared
* @param requiredEqualityLevel the equality level to be checked for
*
* @return the determined equality
*/
private TaskEquality callRuleManager(ITask child1,
ITask child2,
TaskEquality requiredEqualityLevel)
{
if (requiredEqualityLevel == null) {
return TaskEqualityRuleManager.getInstance().compare(child1, child2);
}
else if (TaskEqualityRuleManager.getInstance().areAtLeastEqual
(child1, child2, requiredEqualityLevel))
{
return requiredEqualityLevel;
}
else {
return TaskEquality.UNEQUAL;
}
}
/**
*
* used to to call the task equality rule manager for the comparison of the two provided
* children. If no required equality level is provided, than the most concrete equality is
* returned. Otherwise, the required equality is returned as long as the children are equal
* on that level.
*
*
* @param taskInstance1 the first task instance to be compared
* @param taskInstance2 the second task instance to be compared
* @param requiredEqualityLevel the equality level to be checked for
*
* @return the determined equality
*/
private TaskEquality callRuleManager(ITaskInstance taskInstance1,
ITaskInstance taskInstance2,
TaskEquality requiredEqualityLevel)
{
if (requiredEqualityLevel == null) {
return TaskEqualityRuleManager.getInstance().compare(taskInstance1, taskInstance2);
}
else if (TaskEqualityRuleManager.getInstance().areAtLeastEqual
(taskInstance1, taskInstance2, requiredEqualityLevel))
{
return requiredEqualityLevel;
}
else {
return TaskEquality.UNEQUAL;
}
}
}