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/*
* Copyright (c) 2013, SRI International
* All rights reserved.
* Licensed under the The BSD 3-Clause License;
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://opensource.org/licenses/BSD-3-Clause
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of the aic-util nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.sri.ai.util.collect;
import static com.sri.ai.util.Util.forAll;
import static com.sri.ai.util.Util.join;
import static com.sri.ai.util.Util.thereExists;
import static com.sri.ai.util.collect.NestedIterator.nestedIterator;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import com.google.common.annotations.Beta;
import com.sri.ai.util.Util;
/**
* An implementation of {@link List}
* sharing elements with a pre-existing given list.
*
* This works by receiving the base list at construction time and keeping a linked list of additional elements.
*
* Modification of the base list is not allowed and
* will throw a {@link UnsupportedOperationException}.
*
* An immutable, more efficient version is offered at {@link ImmutableStackedLinkedList}.
*
* @author braz
*/
@Beta
public class StackedLinkedList implements List {
private List base;
private List extension;
public StackedLinkedList(List base) {
this.base = base;
this.extension = new LinkedList();
}
public StackedLinkedList(E top, List base) {
this(base);
this.extension.add(top);
}
public StackedLinkedList(List top, List base) {
this.base = base;
this.extension = top;
}
public List getBase() {
return base;
}
@Override
public int size() {
return base.size() + extension.size();
}
@Override
public boolean isEmpty() {
boolean result = base.isEmpty() && extension.isEmpty();
return result;
}
@Override
public boolean contains(Object o) {
boolean result = extension.contains(o) || base.contains(o);
return result;
}
@Override
public Iterator iterator() {
return new NestedIterator(base, extension);
}
@Override
public Object[] toArray() {
@SuppressWarnings("unchecked")
E[] result = (E[]) new Object[size()];
base.toArray(result);
int i = base.size();
for (E element : extension) {
result[i++] = element;
}
return result;
}
@SuppressWarnings("unchecked")
@Override
public T[] toArray(T[] a) {
T[] result;
if (a.length < size()) {
result = (T[]) new Object[size()];
}
else {
result = a;
}
base.toArray(result);
int i = base.size();
for (E element : extension) {
result[i++] = (T) element;
}
for (; i != result.length; i++) {
result[i] = null;
}
return result;
}
@Override
public boolean add(E e) {
boolean result = extension.add(e);
return result;
}
@Override
public boolean remove(Object o) {
if (base.contains(o)) {
throw new UnsupportedOperationException("Cannot remove objects in base list of " + getClass());
}
boolean result = extension.remove(o);
return result;
}
@Override
public boolean containsAll(Collection c) {
boolean result = forAll(c, this::contains);
return result;
}
@Override
public boolean addAll(Collection c) {
boolean result = extension.addAll(c);
return result;
}
@Override
public boolean addAll(int index, Collection c) {
if (index < base.size()) {
throw new UnsupportedOperationException("Cannot add objects to base list of " + getClass() + ". Base size is " + base.size() + " and given index is " + index);
}
boolean result = extension.addAll(index - base.size(), c);
return result;
}
@Override
public boolean removeAll(Collection c) {
boolean result = thereExists(c, this::remove);
return result;
}
@Override
public boolean retainAll(Collection c) {
throw new UnsupportedOperationException("retainAll not supported for " + getClass());
}
@Override
public void clear() {
if (base.isEmpty()) {
extension.clear();
}
else {
throw new UnsupportedOperationException("Cannot clear a " + getClass() + " if base list is not empty.");
}
}
@Override
public E get(int index) {
E result;
if (index < base.size()) {
result = base.get(index);
}
else {
result = extension.get(index - base.size());
}
return result;
}
@Override
public E set(int index, E element) {
E result;
if (index < base.size()) {
throw new UnsupportedOperationException("Cannot set elements to base list of " + getClass() + ". Base size is " + base.size() + " and given index is " + index);
}
else {
result = extension.set(index - base.size(), element);
}
return result;
}
@Override
public void add(int index, E element) {
if (index < base.size()) {
throw new UnsupportedOperationException("Cannot add elements to base list of " + getClass() + ". Base size is " + base.size() + " and given index is " + index);
}
else {
extension.add(index - base.size(), element);
}
}
@Override
public E remove(int index) {
E result;
if (index < base.size()) {
throw new UnsupportedOperationException("Cannot remove elements from base list of " + getClass() + ". Base size is " + base.size() + " and given index is " + index);
}
else {
result = extension.remove(index - base.size());
return result;
}
}
@Override
public int indexOf(Object o) {
int result = base.indexOf(o);
if (result == -1) {
result = extension.indexOf(o) + base.size();
}
return result;
}
@Override
public int lastIndexOf(Object o) {
int result = extension.indexOf(o);
if (result == -1) {
result = base.indexOf(o);
}
else {
result = result + base.size();
}
return result;
}
@Override
public ListIterator listIterator() {
throw new UnsupportedOperationException("List iterators not supported for " + getClass());
}
@Override
public ListIterator listIterator(int index) {
throw new UnsupportedOperationException("List iterators not supported for " + getClass());
}
@Override
public List subList(int fromIndex, int toIndex) {
throw new UnsupportedOperationException("subList not supported for " + getClass());
}
@Override
public String toString() {
return "[" + join(", ", nestedIterator(base, extension)) + "]";
}
@Override
public boolean equals(Object o) {
if (o == this) {
return true;
}
if ( !(o instanceof List)) {
return false;
}
@SuppressWarnings("unchecked")
List oList = (List) o;
if (oList.size() != size()) {
return false;
}
Iterator i1 = iterator();
Iterator i2 = oList.iterator();
while (i1.hasNext()) {
if ( ! Util.equals(i1.next(), i2.next())) {
return false;
}
}
return true;
}
@Override
public int hashCode() {
int hashCode = 1;
for (E e : this) {
hashCode = 31*hashCode + (e == null ? 0 : e.hashCode());
}
return hashCode;
}
}