/*
 * Copyright (C) 2009 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.VisibleForTesting;
import java.util.Spliterator;
import java.util.Spliterators;

Implementation of ImmutableList backed by a simple array.
Author:Kevin Bourrillion
/** * Implementation of {@link ImmutableList} backed by a simple array. * * @author Kevin Bourrillion */
@GwtCompatible(serializable = true, emulated = true) @SuppressWarnings("serial") // uses writeReplace(), not default serialization class RegularImmutableList<E> extends ImmutableList<E> { static final ImmutableList<Object> EMPTY = new RegularImmutableList<>(new Object[0]); @VisibleForTesting final transient Object[] array; RegularImmutableList(Object[] array) { this.array = array; } @Override public int size() { return array.length; } @Override boolean isPartialView() { return false; } @Override int copyIntoArray(Object[] dst, int dstOff) { System.arraycopy(array, 0, dst, dstOff, array.length); return dstOff + array.length; } // The fake cast to E is safe because the creation methods only allow E's @Override @SuppressWarnings("unchecked") public E get(int index) { return (E) array[index]; } @SuppressWarnings("unchecked") @Override public UnmodifiableListIterator<E> listIterator(int index) { // for performance // The fake cast to E is safe because the creation methods only allow E's return (UnmodifiableListIterator<E>) Iterators.forArray(array, 0, array.length, index); } @Override public Spliterator<E> spliterator() { return Spliterators.spliterator(array, SPLITERATOR_CHARACTERISTICS); } // TODO(lowasser): benchmark optimizations for equals() and see if they're worthwhile }