Java example source code file (EmptyContiguousSet.java)

This example Java source code file (EmptyContiguousSet.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

annotation, comparable, contiguousset, emptycontiguousset, gwtincompatible, immutablelist, immutablesortedset, navigableset, nosuchelementexception, object, override, range, serializedform, unmodifiableiterator, util

The EmptyContiguousSet.java Java example source code

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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 com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

import java.io.Serializable;
import java.util.NoSuchElementException;
import java.util.Set;

import javax.annotation.Nullable;

/**
 * An empty contiguous set.
 *
 * @author Gregory Kick
 */
@GwtCompatible(emulated = true)
@SuppressWarnings("unchecked") // allow ungenerified Comparable types
final class EmptyContiguousSet<C extends Comparable> extends ContiguousSet {
  EmptyContiguousSet(DiscreteDomain<C> domain) {
    super(domain);
  }

  @Override
  public C first() {
    throw new NoSuchElementException();
  }

  @Override
  public C last() {
    throw new NoSuchElementException();
  }

  @Override
  public int size() {
    return 0;
  }

  @Override
  public ContiguousSet<C> intersection(ContiguousSet other) {
    return this;
  }

  @Override
  public Range<C> range() {
    throw new NoSuchElementException();
  }

  @Override
  public Range<C> range(BoundType lowerBoundType, BoundType upperBoundType) {
    throw new NoSuchElementException();
  }

  @Override
  ContiguousSet<C> headSetImpl(C toElement, boolean inclusive) {
    return this;
  }

  @Override
  ContiguousSet<C> subSetImpl(
      C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
    return this;
  }

  @Override
  ContiguousSet<C> tailSetImpl(C fromElement, boolean fromInclusive) {
    return this;
  }

  @Override
  public boolean contains(Object object) {
    return false;
  }

  @GwtIncompatible // not used by GWT emulation
  @Override
  int indexOf(Object target) {
    return -1;
  }

  @Override
  public UnmodifiableIterator<C> iterator() {
    return Iterators.emptyIterator();
  }

  @GwtIncompatible // NavigableSet
  @Override
  public UnmodifiableIterator<C> descendingIterator() {
    return Iterators.emptyIterator();
  }

  @Override
  boolean isPartialView() {
    return false;
  }

  @Override
  public boolean isEmpty() {
    return true;
  }

  @Override
  public ImmutableList<C> asList() {
    return ImmutableList.of();
  }

  @Override
  public String toString() {
    return "[]";
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object instanceof Set) {
      Set<?> that = (Set) object;
      return that.isEmpty();
    }
    return false;
  }

  @GwtIncompatible // not used in GWT
  @Override
  boolean isHashCodeFast() {
    return true;
  }

  @Override
  public int hashCode() {
    return 0;
  }

  @GwtIncompatible // serialization
  private static final class SerializedForm<C extends Comparable> implements Serializable {
    private final DiscreteDomain<C> domain;

    private SerializedForm(DiscreteDomain<C> domain) {
      this.domain = domain;
    }

    private Object readResolve() {
      return new EmptyContiguousSet<C>(domain);
    }

    private static final long serialVersionUID = 0;
  }

  @GwtIncompatible // serialization
  @Override
  Object writeReplace() {
    return new SerializedForm<C>(domain);
  }

  @GwtIncompatible // NavigableSet
  ImmutableSortedSet<C> createDescendingSet() {
    return ImmutableSortedSet.emptySet(Ordering.natural().reverse());
  }
}