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.math4.legacy.genetics;
18
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.Collections;
22 import java.util.List;
23
24 /**
25 * Chromosome represented by an immutable list of a fixed length.
26 *
27 * @param <T> type of the representation list
28 * @since 2.0
29 */
30 public abstract class AbstractListChromosome<T> extends Chromosome {
31
32 /** List representing the chromosome. */
33 private final List<T> representation;
34
35 /**
36 * Constructor, copying the input representation.
37 * @param representation inner representation of the chromosome
38 * @throws InvalidRepresentationException iff the <code>representation</code> can not represent a valid chromosome
39 */
40 public AbstractListChromosome(final List<T> representation) throws InvalidRepresentationException {
41 this(representation, true);
42 }
43
44 /**
45 * Constructor, copying the input representation.
46 * @param representation inner representation of the chromosome
47 * @throws InvalidRepresentationException iff the <code>representation</code> can not represent a valid chromosome
48 */
49 public AbstractListChromosome(final T[] representation) throws InvalidRepresentationException {
50 this(Arrays.asList(representation));
51 }
52
53 /**
54 * Constructor.
55 * @param representation inner representation of the chromosome
56 * @param copyList if {@code true}, the representation will be copied, otherwise it will be referenced.
57 * @since 3.3
58 */
59 public AbstractListChromosome(final List<T> representation, final boolean copyList) {
60 checkValidity(representation);
61 this.representation =
62 Collections.unmodifiableList(copyList ? new ArrayList<>(representation) : representation);
63 }
64
65 /**
66 * Asserts that <code>representation</code> can represent a valid chromosome.
67 *
68 * @param chromosomeRepresentation representation of the chromosome
69 * @throws InvalidRepresentationException iff the <code>representation</code> can not represent a valid chromosome
70 */
71 protected abstract void checkValidity(List<T> chromosomeRepresentation) throws InvalidRepresentationException;
72
73 /**
74 * Returns the (immutable) inner representation of the chromosome.
75 * @return the representation of the chromosome
76 */
77 protected List<T> getRepresentation() {
78 return representation;
79 }
80
81 /**
82 * Returns the length of the chromosome.
83 * @return the length of the chromosome
84 */
85 public int getLength() {
86 return getRepresentation().size();
87 }
88
89 /**
90 * Creates a new instance of the same class as <code>this</code> is, with a given <code>arrayRepresentation</code>.
91 * This is needed in crossover and mutation operators, where we need a new instance of the same class, but with
92 * different array representation.
93 * <p>
94 * Usually, this method just calls a constructor of the class.
95 *
96 * @param chromosomeRepresentation the inner array representation of the new chromosome.
97 * @return new instance extended from FixedLengthChromosome with the given arrayRepresentation
98 */
99 public abstract AbstractListChromosome<T> newFixedLengthChromosome(List<T> chromosomeRepresentation);
100
101 /** {@inheritDoc} */
102 @Override
103 public String toString() {
104 return String.format("(f=%s %s)", getFitness(), getRepresentation());
105 }
106 }