1 package net.bmahe.genetics4j.gp.mutation;
2
3 import java.util.ArrayList;
4 import java.util.List;
5 import java.util.Optional;
6
7 import org.apache.commons.lang3.Validate;
8 import org.apache.logging.log4j.LogManager;
9 import org.apache.logging.log4j.Logger;
10
11 import net.bmahe.genetics4j.core.Genotype;
12 import net.bmahe.genetics4j.core.chromosomes.Chromosome;
13 import net.bmahe.genetics4j.core.chromosomes.TreeChromosome;
14 import net.bmahe.genetics4j.core.chromosomes.TreeNode;
15 import net.bmahe.genetics4j.core.mutation.Mutator;
16 import net.bmahe.genetics4j.core.spec.AbstractEAConfiguration;
17 import net.bmahe.genetics4j.core.spec.chromosome.ChromosomeSpec;
18 import net.bmahe.genetics4j.gp.Operation;
19 import net.bmahe.genetics4j.gp.program.Program;
20 import net.bmahe.genetics4j.gp.spec.chromosome.ProgramTreeChromosomeSpec;
21 import net.bmahe.genetics4j.gp.spec.mutation.Rule;
22 import net.bmahe.genetics4j.gp.utils.TreeNodeUtils;
23
24 public class ProgramRulesApplicatorMutator implements Mutator {
25 final static public Logger logger = LogManager.getLogger(ProgramRulesApplicatorMutator.class);
26
27 private final List<Rule> rules;
28 private final AbstractEAConfiguration eaConfiguration;
29
30 public ProgramRulesApplicatorMutator(final List<Rule> _rules, final AbstractEAConfiguration _eaConfiguration) {
31 Validate.notNull(_rules);
32 Validate.isTrue(_rules.isEmpty() == false);
33 Validate.notNull(_eaConfiguration);
34
35 this.rules = _rules;
36 this.eaConfiguration = _eaConfiguration;
37 }
38
39 protected TreeNode<Operation<?>> duplicateAndApplyRule(final Program program, final TreeNode<Operation<?>> root) {
40 Validate.notNull(root);
41
42 logger.trace("A - {}", TreeNodeUtils.toStringTreeNode(root));
43
44 final Operation<?> rootOperation = root.getData();
45 final List<TreeNode<Operation<?>>> children = root.getChildren();
46
47 TreeNode<Operation<?>> currentRoot = new TreeNode<Operation<?>>(rootOperation);
48
49 if (children.size() > 0) {
50 final List<TreeNode<Operation<?>>> newChildren = new ArrayList<>();
51 for (int i = 0; i < children.size(); i++) {
52 final TreeNode<Operation<?>> childNode = children.get(i);
53
54 final TreeNode<Operation<?>> childCopy = duplicateAndApplyRule(program, childNode);
55 newChildren.add(childCopy);
56
57 }
58 currentRoot.addChildren(newChildren);
59 }
60
61 boolean done = false;
62 while (done == false) {
63 final TreeNode<Operation<?>> localRoot = currentRoot;
64
65 logger.trace("B - {}", TreeNodeUtils.toStringTreeNode(localRoot));
66
67 final Optional<Rule> applicableRule = rules.stream().filter((rule) -> rule.test(localRoot)).findFirst();
68 final Optional<TreeNode<Operation<?>>> newRootOpt = applicableRule.map(x -> x.apply(program, localRoot));
69
70 done = newRootOpt.map(newRoot -> TreeNodeUtils.areSame(newRoot, localRoot)).orElse(true);
71
72 if (newRootOpt.isPresent()) {
73 currentRoot = newRootOpt.get();
74 }
75 }
76
77 return currentRoot;
78 }
79
80 @Override
81 public Genotype mutate(final Genotype original) {
82 Validate.notNull(original);
83
84 logger.trace("Mutating genotype: {}", original);
85
86 final Chromosome[] newChromosomes = new Chromosome[original.getSize()];
87 final Chromosome[] chromosomes = original.getChromosomes();
88 for (int chromosomeIndex = 0; chromosomeIndex < chromosomes.length; chromosomeIndex++) {
89 final ChromosomeSpec chromosomeSpec = eaConfiguration.getChromosomeSpec(chromosomeIndex);
90 final Chromosome chromosome = chromosomes[chromosomeIndex];
91
92 if (chromosomeSpec instanceof ProgramTreeChromosomeSpec == false) {
93 throw new IllegalArgumentException("This mutator does not support chromosome specs " + chromosomeSpec);
94 }
95
96 if (chromosome instanceof TreeChromosome<?> == false) {
97 throw new IllegalArgumentException(
98 "This mutator does not support chromosome of type " + chromosome.getClass().getSimpleName());
99 }
100
101 final ProgramTreeChromosomeSpec programTreeChromosomeSpec = (ProgramTreeChromosomeSpec) chromosomeSpec;
102
103 final TreeChromosome<Operation<?>> treeChromosome = (TreeChromosome<Operation<?>>) chromosome;
104 final TreeNode<Operation<?>> root = treeChromosome.getRoot();
105
106 if (logger.isTraceEnabled()) {
107 logger.trace("Original chromosome {} - {}", chromosomeIndex, TreeNodeUtils.toStringTreeNode(root));
108 }
109
110 final TreeNode<Operation<?>> newRoot = duplicateAndApplyRule(programTreeChromosomeSpec.program(), root);
111 final TreeChromosome<Operation<?>> newTreeChromosome = new TreeChromosome<>(newRoot);
112 newChromosomes[chromosomeIndex] = newTreeChromosome;
113
114 }
115
116 return new Genotype(newChromosomes);
117 }
118 }