| /* |
| * Copyright (C) 2012 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 static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import java.util.Iterator; |
| |
| /** |
| * An iterator that transforms a backing iterator; for internal use. This avoids the object overhead |
| * of constructing a {@link com.google.common.base.Function Function} for internal methods. |
| * |
| * @author Louis Wasserman |
| */ |
| @GwtCompatible |
| abstract class TransformedIterator<F, T> implements Iterator<T> { |
| final Iterator<? extends F> backingIterator; |
| |
| TransformedIterator(Iterator<? extends F> backingIterator) { |
| this.backingIterator = checkNotNull(backingIterator); |
| } |
| |
| abstract T transform(F from); |
| |
| @Override |
| public final boolean hasNext() { |
| return backingIterator.hasNext(); |
| } |
| |
| @Override |
| public final T next() { |
| return transform(backingIterator.next()); |
| } |
| |
| @Override |
| public final void remove() { |
| backingIterator.remove(); |
| } |
| } |