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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) 2018, 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
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package org.javimmutable.collections.array;
import org.javimmutable.collections.Cursor;
import org.javimmutable.collections.Holder;
import org.javimmutable.collections.Holders;
import org.javimmutable.collections.JImmutableMap;
import org.javimmutable.collections.MapEntry;
import org.javimmutable.collections.SplitableIterator;
import org.javimmutable.collections.common.MutableDelta;
import org.javimmutable.collections.cursors.SingleValueCursor;
import org.javimmutable.collections.iterators.SingleValueIterator;
import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;
@Immutable
public class LeafTrieNode
extends TrieNode
implements JImmutableMap.Entry,
Holders.Filled
{
private final int index;
private final T value;
private final int shift;
private LeafTrieNode(int index,
T value,
int shift)
{
this.index = index;
this.value = value;
this.shift = shift;
}
static LeafTrieNode of(int index,
@Nonnull T value)
{
return new LeafTrieNode<>(index, value, shiftForIndex(index));
}
@Override
public boolean isEmpty()
{
return false;
}
@Nonnull
@Override
public Integer getKey()
{
return index;
}
@Override
public T getValue()
{
return value;
}
@Override
public T getValueOr(int shift,
int index,
T defaultValue)
{
assert shift >= -5;
return (this.index == index) ? value : defaultValue;
}
@Override
public Holder find(int shift,
int index)
{
assert shift >= -5;
return (this.index == index) ? this : Holders.of();
}
@Override
public TrieNode assign(int shift,
int index,
T value,
MutableDelta sizeDelta)
{
assert shift >= -5;
if (this.index == index) {
if (this.value == value) {
return this;
} else {
return withValue(value);
}
} else {
assert shift >= 0;
return SingleBranchTrieNode.forIndex(shift, this.index, this).assign(shift, index, value, sizeDelta);
}
}
@Override
public TrieNode delete(int shift,
int index,
MutableDelta sizeDelta)
{
assert shift >= -5;
if (this.index == index) {
sizeDelta.subtract(1);
return of();
} else {
return this;
}
}
@Override
public int getShift()
{
return shift;
}
@Override
public boolean isLeaf()
{
return true;
}
@Override
public TrieNode paddedToMinimumDepthForShift(int shift)
{
if (this.shift >= shift) {
return this;
} else {
return SingleBranchTrieNode.forIndex(shift, index, this);
}
}
@Nonnull
@Override
public SplitableIterator> iterator()
{
return SingleValueIterator.of(this);
}
@Nonnull
@Override
public Cursor> cursor()
{
return SingleValueCursor.of(this);
}
@Override
public void checkInvariants()
{
if (shift < -5 || shift > ROOT_SHIFT) {
throw new IllegalStateException("illegal shift value: " + shift);
}
}
@Override
public boolean equals(Object o)
{
if (this == o) {
return true;
}
if ((o == null) || (getClass() != o.getClass())) {
return false;
}
LeafTrieNode that = (LeafTrieNode)o;
if (index != that.index) {
return false;
}
if (shift != that.shift) {
return false;
}
//noinspection RedundantIfStatement
if (!value.equals(that.value)) {
return false;
}
return true;
}
@Override
public int hashCode()
{
int result = index;
result = 31 * result + value.hashCode();
result = 31 * result + shift;
return result;
}
@Override
public String toString()
{
return MapEntry.makeToString(this);
}
private TrieNode withValue(T newValue)
{
return new LeafTrieNode<>(index, newValue, shift);
}
}