Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
CompositeUnaryPredicate |
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| 1.625;1.625 |
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.core.composite; | |
18 | ||
19 | import java.io.Serializable; | |
20 | ||
21 | import org.apache.commons.functor.UnaryFunction; | |
22 | import org.apache.commons.functor.UnaryPredicate; | |
23 | import org.apache.commons.functor.adapter.UnaryPredicateUnaryFunction; | |
24 | ||
25 | /** | |
26 | * A {@link UnaryPredicate UnaryPredicate} | |
27 | * representing the composition of | |
28 | * {@link UnaryFunction UnaryFunctions}, | |
29 | * "chaining" the output of one to the input | |
30 | * of another. For example, | |
31 | * <pre>new CompositeUnaryPredicate(p).of(f)</pre> | |
32 | * {@link #test tests} to | |
33 | * <code>p.test(f.evaluate(obj))</code>, and | |
34 | * <pre>new CompositeUnaryPredicate(p).of(f).of(g)</pre> | |
35 | * {@link #test tests} to | |
36 | * <code>p.test(f.evaluate(g.evaluate(obj)))</code>. | |
37 | * <p> | |
38 | * Note that although this class implements | |
39 | * {@link Serializable}, a given instance will | |
40 | * only be truly <code>Serializable</code> if all the | |
41 | * underlying functors are. Attempts to serialize | |
42 | * an instance whose delegates are not all | |
43 | * <code>Serializable</code> will result in an exception. | |
44 | * </p> | |
45 | * @version $Revision: 1166375 $ $Date: 2011-09-07 22:13:25 +0200 (Wed, 07 Sep 2011) $ | |
46 | * @author Rodney Waldhoff | |
47 | */ | |
48 | public final class CompositeUnaryPredicate<A> implements UnaryPredicate<A>, Serializable { | |
49 | /** | |
50 | * serialVersionUID declaration. | |
51 | */ | |
52 | private static final long serialVersionUID = 4880363949059265252L; | |
53 | // attributes | |
54 | // ------------------------------------------------------------------------ | |
55 | private final CompositeUnaryFunction<? super A, Boolean> function; | |
56 | ||
57 | // constructor | |
58 | // ------------------------------------------------------------------------ | |
59 | /** | |
60 | * Create a new CompositeUnaryPredicate. | |
61 | * @param predicate UnaryPredicate against which the composite functions' output will be tested | |
62 | */ | |
63 | 28 | public CompositeUnaryPredicate(UnaryPredicate<? super A> predicate) { |
64 | 28 | if (null == predicate) { |
65 | 2 | throw new IllegalArgumentException("predicate must not be null"); |
66 | } | |
67 | 26 | this.function = new CompositeUnaryFunction<A, Boolean>(new UnaryPredicateUnaryFunction<A>(predicate)); |
68 | 26 | } |
69 | ||
70 | /** | |
71 | * Create a new CompositeUnaryPredicate. | |
72 | * @param function delegate | |
73 | */ | |
74 | 66 | private CompositeUnaryPredicate(CompositeUnaryFunction<? super A, Boolean> function) { |
75 | 66 | this.function = function; |
76 | 66 | } |
77 | ||
78 | // modifiers | |
79 | // ------------------------------------------------------------------------ | |
80 | /** | |
81 | * Fluently obtain a CompositeUnaryPredicate that applies our predicate to the result of the preceding function. | |
82 | * @param preceding UnaryFunction | |
83 | * @return CompositeUnaryPredicate<P> | |
84 | */ | |
85 | public <P> CompositeUnaryPredicate<P> of(UnaryFunction<? super P, ? extends A> preceding) { | |
86 | 66 | return new CompositeUnaryPredicate<P>(function.of(preceding)); |
87 | } | |
88 | ||
89 | // predicate interface | |
90 | // ------------------------------------------------------------------------ | |
91 | /** | |
92 | * {@inheritDoc} | |
93 | */ | |
94 | public boolean test(A obj) { | |
95 | 158 | return function.evaluate(obj); |
96 | } | |
97 | ||
98 | /** | |
99 | * {@inheritDoc} | |
100 | */ | |
101 | public boolean equals(Object that) { | |
102 | 66 | return that == this || (that instanceof CompositeUnaryPredicate<?> |
103 | && equals((CompositeUnaryPredicate<?>) that)); | |
104 | } | |
105 | ||
106 | /** | |
107 | * Learn whether another CompositeUnaryPredicate is equal to this. | |
108 | * @param that CompositeUnaryPredicate to test | |
109 | * @return boolean | |
110 | */ | |
111 | public boolean equals(CompositeUnaryPredicate<?> that) { | |
112 | 58 | return null != that && function.equals(that.function); |
113 | } | |
114 | ||
115 | /** | |
116 | * {@inheritDoc} | |
117 | */ | |
118 | public int hashCode() { | |
119 | 68 | int hash = "CompositeUnaryPredicate".hashCode(); |
120 | 68 | hash <<= 2; |
121 | 68 | hash ^= function.hashCode(); |
122 | 68 | return hash; |
123 | } | |
124 | ||
125 | /** | |
126 | * {@inheritDoc} | |
127 | */ | |
128 | public String toString() { | |
129 | 60 | return "CompositeUnaryFunction<" + function + ">"; |
130 | } | |
131 | ||
132 | } |