1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.functor.generator.loop;
18
19 import org.apache.commons.functor.Predicate;
20 import org.apache.commons.functor.Procedure;
21 import org.apache.commons.functor.generator.Generator;
22 import org.apache.commons.lang3.Validate;
23
24 /**
25 * Wrap another {@link Generator} such that {@link #run(Procedure)} terminates once
26 * a condition has been satisfied.
27 *
28 * @param <E> the type of elements held in this generator.
29 * @version $Revision: 1508677 $ $Date: 2013-07-30 19:48:02 -0300 (Tue, 30 Jul 2013) $
30 */
31 public class UntilGenerate<E> extends LoopGenerator<E> {
32
33 /**
34 * The condition has to verified in order to execute the generation.
35 */
36 private final Predicate<? super E> test;
37
38 /**
39 * Create a new UntilGenerate.
40 * @param wrapped {@link Generator}
41 * @param test {@link Predicate}
42 */
43 public UntilGenerate(Predicate<? super E> test, Generator<? extends E> wrapped) {
44 super(Validate.notNull(wrapped, "Generator argument was null"));
45 this.test = Validate.notNull(test, "Predicate argument was null");
46 }
47
48 /**
49 * {@inheritDoc}
50 */
51 public void run(final Procedure<? super E> proc) {
52 getWrappedGenerator().run(new Procedure<E>() {
53 public void run(E obj) {
54 if (test.test(obj)) {
55 UntilGenerate.this.stop();
56 } else {
57 proc.run(obj);
58 }
59 }
60 });
61 }
62
63 /**
64 * {@inheritDoc}
65 */
66 @Override
67 public boolean equals(Object obj) {
68 if (obj == this) {
69 return true;
70 }
71 if (!(obj instanceof UntilGenerate<?>)) {
72 return false;
73 }
74 UntilGenerate<?> other = (UntilGenerate<?>) obj;
75 return other.getWrappedGenerator().equals(getWrappedGenerator()) && other.test.equals(test);
76 }
77
78 /**
79 * {@inheritDoc}
80 */
81 @Override
82 public int hashCode() {
83 int result = "UntilGenerate".hashCode();
84 result <<= 2;
85 Generator<?> gen = getWrappedGenerator();
86 result ^= gen.hashCode();
87 result <<= 2;
88 result ^= test.hashCode();
89 return result;
90 }
91 }