craterdog.collections.abstractions.OpenCollection Maven / Gradle / Ivy
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* Copyright (c) Crater Dog Technologies(TM). All Rights Reserved. *
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. *
* *
* This code is free software; you can redistribute it and/or modify it *
* under the terms of The MIT License (MIT), as published by the Open *
* Source Initiative. (See http://opensource.org/licenses/MIT) *
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package craterdog.collections.abstractions;
import craterdog.core.Iterator;
import org.slf4j.ext.XLogger;
import org.slf4j.ext.XLoggerFactory;
/**
* This abstract class implements a collection that allows its internal structure to be
* directly manipulated.
*
* @author Derk Norton
* @param The type of element managed by the collection.
*/
public abstract class OpenCollection extends Collection {
static private final XLogger logger = XLoggerFactory.getXLogger(OpenCollection.class);
@Override
public Collection getElements(int firstIndex, int lastIndex) {
logger.entry(firstIndex, lastIndex);
firstIndex = normalizedIndex(firstIndex);
lastIndex = normalizedIndex(lastIndex);
OpenCollection result = emptyCopy();
Iterator iterator = createIterator();
iterator.toIndex(firstIndex);
int numberOfElements = lastIndex - firstIndex + 1;
while (numberOfElements-- > 0) {
E element = iterator.getNext();
logger.debug("Including element: {}", element);
result.addElement(element);
}
logger.exit(result);
return result;
}
/**
* This method adds a new element to the collection. If the collection
* is empty then the new element will be the first element in the collection.
*
* @param element The new element to be added.
* @return Whether or not the element was actually added to the collection.
*/
public abstract boolean addElement(E element);
/**
* This method adds an array of new elements to the collection. The new
* elements will be added in the order they appear in the specified array.
*
* @param elements The array of new elements to be added.
* @return The number of elements that were actually added to the collection.
*/
public int addElements(E[] elements) {
logger.entry(elements);
int count = 0;
for (E element : elements) {
if (addElement(element)) count++;
}
logger.exit(count);
return count;
}
/**
* This method adds a list of new elements to the collection. The new
* elements will be added in the order they appear in the specified collection.
*
* @param elements The list of new elements to be added.
* @return The number of elements that were actually added to the collection.
*/
public int addElements(Iterable elements) {
logger.entry(elements);
int count = 0;
for (E element : elements) {
if (addElement(element)) count++;
}
logger.exit(count);
return count;
}
/**
* This method removes the specified element from the collection. If the element
* is not found in the collection, no changes are made.
*
* @param element The element to be removed.
* @return Whether or not the element was found.
*/
public abstract boolean removeElement(E element);
/**
* This method removes the elements in the specified array from the collection.
* The number of matching elements is returned.
*
* @param elements The array of elements to be removed from the collection.
* @return The number of elements that were actually removed.
*/
public int removeElements(E[] elements) {
logger.entry(elements);
int count = 0;
for (E element : elements) {
if (removeElement(element)) {
count++;
}
}
logger.exit(count);
return count;
}
/**
* This method removes the specified elements from the collection. The number of
* matching elements is returned.
*
* @param elements The list of elements to be removed from the collection.
* @return The number of elements that were actually removed.
*/
public int removeElements(Iterable elements) {
logger.entry(elements);
int count = 0;
for (E element : elements) {
if (removeElement(element)) {
count++;
}
}
logger.exit(count);
return count;
}
/**
* This protected method must be implemented by all concrete open collections
* and pass back an empty concrete collection.
*
* @param The concrete type of open collection.
* @return An empty concrete open collection.
*/
protected abstract > T emptyCopy();
}