Coverage Summary for Class: TransformedIterator (com.google.common.collect)

1 /*
2  * Copyright (C) 2012 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.common.collect;
18 
19 import static com.google.common.base.Preconditions.checkNotNull;
20 
21 import com.google.common.annotations.GwtCompatible;
22 import java.util.Iterator;
23 
24 /**
25  * An iterator that transforms a backing iterator; for internal use. This avoids the object overhead
26  * of constructing a {@link com.google.common.base.Function Function} for internal methods.
27  *
28  * @author Louis Wasserman
29  */
30 @GwtCompatible
31 abstract class TransformedIterator<F, T> implements Iterator<T> {
32   final Iterator<? extends F> backingIterator;
33 
34   TransformedIterator(Iterator<? extends F> backingIterator) {
35     this.backingIterator = checkNotNull(backingIterator);
36   }
37 
38   abstract T transform(F from);
39 
40   @Override
41   public final boolean hasNext() {
42     return backingIterator.hasNext();
43   }
44 
45   @Override
46   public final T next() {
47     return transform(backingIterator.next());
48   }
49 
50   @Override
51   public final void remove() {
52     backingIterator.remove();
53   }
54 }