org.javimmutable.collections.list.JImmutableArrayList Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of javimmutable-collections Show documentation
Show all versions of javimmutable-collections Show documentation
Library providing immutable/persistent collection classes for
Java. While collections are immutable they provide methods for
adding and removing values by creating new modified copies of
themselves. Each copy shares almost all of its structure with
other copies to minimize memory consumption.
///###////////////////////////////////////////////////////////////////////////
//
// Burton Computer Corporation
// http://www.burton-computer.com
//
// Copyright (c) 2013, Burton Computer Corporation
// All rights reserved.
//
// 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 Burton Computer Corporation 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 org.javimmutable.collections.list;
import org.javimmutable.collections.Cursor;
import org.javimmutable.collections.Indexed;
import org.javimmutable.collections.JImmutableList;
import org.javimmutable.collections.array.trie.EmptyTrieNode;
import org.javimmutable.collections.array.trie.StandardTrieNode;
import org.javimmutable.collections.array.trie.TrieNode;
import org.javimmutable.collections.common.ListAdaptor;
import org.javimmutable.collections.cursors.Cursors;
import org.javimmutable.collections.cursors.StandardCursor;
import java.util.Iterator;
import java.util.List;
/**
* Implementation of PersistentIndexedList that uses a sparse array for its implementation.
* Values are stored and traversed in the same order as they are added using insert().
* Performance is slower than PersistentLinkedList so if forward order and/or random
* access are not required using that class may be a better option.
*
* @param
*/
public class JImmutableArrayList
implements JImmutableList
{
private static final JImmutableArrayList EMPTY = new JImmutableArrayList();
public static final int MAX_INDEXED_CONSTRUCTOR_SIZE = 32 * 32;
private final TrieNode values;
private final int first;
private final int next;
public JImmutableArrayList()
{
this(EmptyTrieNode.of(), 0, 0);
}
private JImmutableArrayList(TrieNode values,
int first,
int next)
{
this.values = values;
this.first = first;
this.next = next;
}
@SuppressWarnings("unchecked")
public static JImmutableArrayList of()
{
return (JImmutableArrayList)EMPTY;
}
public static JImmutableArrayList of(Indexed source,
int offset,
int limit)
{
final int size = limit - offset;
if (size == 0) {
return of();
}
if (size <= JImmutableArrayList.MAX_INDEXED_CONSTRUCTOR_SIZE) {
return new JImmutableArrayList(new StandardTrieNode(source, offset, limit), 0, size);
}
JImmutableArrayList list = new JImmutableArrayList(new StandardTrieNode(source, offset, offset + JImmutableArrayList.MAX_INDEXED_CONSTRUCTOR_SIZE), 0, JImmutableArrayList.MAX_INDEXED_CONSTRUCTOR_SIZE);
offset += JImmutableArrayList.MAX_INDEXED_CONSTRUCTOR_SIZE;
while (offset < limit) {
list = list.insert(source.get(offset));
offset += 1;
}
return list;
}
public static JImmutableArrayList of(Indexed source)
{
return of(source, 0, source.size());
}
@Override
public boolean isEmpty()
{
return first == next;
}
@Override
public JImmutableList assign(int index,
T value)
{
final int realIndex = calcRealIndex(index);
return new JImmutableArrayList(values.assign(realIndex >>> 5, realIndex & 0x1f, value), first, next);
}
@Override
public JImmutableArrayList insert(T value)
{
final int index = next;
return new JImmutableArrayList(values.assign(index >>> 5, index & 0x1f, value), first, index + 1);
}
@Override
public JImmutableArrayList insertFirst(T value)
{
final int index = first - 1;
return new JImmutableArrayList(values.assign(index >>> 5, index & 0x1f, value), index, next);
}
@Override
public JImmutableArrayList insertLast(T value)
{
return insert(value);
}
@Override
public JImmutableArrayList deleteFirst()
{
if (first == next) {
throw new IndexOutOfBoundsException();
}
final int index = first;
return new JImmutableArrayList(values.delete(index >>> 5, index & 0x1f), first + 1, next);
}
@Override
public JImmutableArrayList deleteLast()
{
if (first == next) {
throw new IndexOutOfBoundsException();
}
final int index = next - 1;
return new JImmutableArrayList(values.delete(index >>> 5, index & 0x1f), first, index);
}
@Override
public int size()
{
return next - first;
}
@Override
public JImmutableList deleteAll()
{
return of();
}
@Override
public T get(int index)
{
final int realIndex = calcRealIndex(index);
return values.get(realIndex >>> 5, realIndex & 0x1f).getValue();
}
@Override
public List getList()
{
return ListAdaptor.of(this);
}
@Override
public Cursor cursor()
{
return StandardCursor.of(new CursorSource());
}
@Override
public Iterator iterator()
{
return StandardCursor.iterator(new CursorSource());
}
@Override
public boolean equals(Object o)
{
return (o == this) || (o instanceof JImmutableList && Cursors.areEqual(cursor(), ((JImmutableList)o).cursor()));
}
@Override
public int hashCode()
{
return Cursors.computeHashCode(cursor());
}
@Override
public String toString()
{
return Cursors.makeString(cursor());
}
private int calcRealIndex(int index)
{
final int realIndex = first + index;
if (realIndex < first || realIndex >= next) {
throw new IndexOutOfBoundsException();
}
return realIndex;
}
private class CursorSource
implements StandardCursor.Source
{
private final int realIndex;
private CursorSource()
{
this(first);
}
private CursorSource(int realIndex)
{
this.realIndex = realIndex;
}
@Override
public boolean atEnd()
{
return realIndex >= next;
}
@Override
public T currentValue()
{
return values.get(realIndex >>> 5, realIndex & 0x1f).getValue();
}
@Override
public StandardCursor.Source advance()
{
return new CursorSource(realIndex + 1);
}
}
}