AbstractChromosome.java
/*
* Java Genetic Algorithm Library (@__identifier__@).
* Copyright (c) @__year__@ Franz Wilhelmstötter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Author:
* Franz Wilhelmstötter (franz.wilhelmstoetter@gmx.at)
*/
package org.jenetics;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
import static org.jenetics.internal.util.object.Verify;
import static org.jenetics.internal.util.object.eq;
import static org.jenetics.util.functions.Null;
import java.util.Iterator;
import java.util.RandomAccess;
import org.jenetics.internal.util.HashBuilder;
import org.jenetics.internal.util.cast;
import org.jenetics.util.Function;
import org.jenetics.util.ISeq;
/**
* The abstract base implementation of the Chromosome interface. The implementors
* of this class must assure that the protected member {@code _genes} is not
* {@code null} and the length of the {@code genes} > 0.
*
* @param <G> the gene type.
*
* @author <a href="mailto:franz.wilhelmstoetter@gmx.at">Franz Wilhelmstötter</a>
* @since 1.0
* @version 1.5 — <em>$Date: 2014-03-01 $</em>
*/
public abstract class AbstractChromosome<G extends Gene<?, G>>
implements
Chromosome<G>,
RandomAccess
{
private static final long serialVersionUID = 1;
/**
* Array of genes which forms the chromosome. This array must
* be initialized by the derived classes.
*/
protected transient ISeq<G> _genes = null;
/**
* Indicates whether this chromosome is valid or not. If the variable is
* {@code null} the validation state hasn't been calculated yet.
*/
protected transient Boolean _valid = null;
/**
* Create a new {@code AbstractChromosome} from the given {@code genes}
* array. The genes array is not copied, but sealed, so changes to the given
* genes array doesn't effect the genes of this chromosome.
*
* @param genes the genes that form the chromosome.
* @throws NullPointerException if the given gene array is {@code null}.
* @throws IllegalArgumentException if the length of the gene array is
* smaller than one.
*/
protected AbstractChromosome(final ISeq<? extends G> genes) {
requireNonNull(genes, "Gene array");
assert (genes.indexWhere(Null) == -1) : "Found at least on null gene.";
if (genes.length() < 1) {
throw new IllegalArgumentException(format(
"Chromosome length < 1: %d", genes.length()
));
}
_genes = cast.apply(genes);
}
@Override
public G getGene(final int index) {
return _genes.get(index);
}
@Override
public G getGene() {
return _genes.get(0);
}
@Override
public ISeq<G> toSeq() {
return _genes;
}
@Override
public boolean isValid() {
if (_valid == null) {
_valid = _genes.forAll(Verify);
}
return _valid;
}
@Override
public Iterator<G> iterator() {
return _genes.iterator();
}
@Override
public int length() {
return _genes.length();
}
/**
* Return the index of the first occurrence of the given {@code gene}.
*
* @param gene the {@link Gene} to search for.
* @return the index of the searched gene, or -1 if the given gene was not
* found.
*/
protected int indexOf(final Object gene) {
return _genes.indexOf(gene);
}
@Override
public int hashCode() {
return HashBuilder.of(getClass()).and(_genes).value();
}
@Override
public boolean equals(final Object obj) {
if (obj == this) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
final AbstractChromosome<?> chromosome = (AbstractChromosome<?>)obj;
return eq(_genes, chromosome._genes);
}
@Override
public String toString() {
return _genes.toString();
}
/* *************************************************************************
* Property access methods
* ************************************************************************/
/**
* Return a {@link Function} which returns the first {@link Gene} from this
* {@link Chromosome}.
*/
static <G extends Gene<?, G>, C extends Chromosome<G>>
Function<C, G> gene() {
return new Function<C, G>() {
@Override public G apply(final C value) {
return value.getGene();
}
};
}
/**
* Return a {@link Function} which returns the {@link Gene} with the given
* {@code index} from this {@link Chromosome}.
*/
static <G extends Gene<?, G>, C extends Chromosome<G>>
Function<C, G> gene(final int index) {
return new Function<C, G>() {
@Override public G apply(final C value) {
return value.getGene(index);
}
};
}
/**
* Return a {@link Function} which returns the gene array from this
* {@link Chromosome}.
*/
static <G extends Gene<?, G>, C extends Chromosome<G>>
Function<C, ISeq<G>> genes() {
return new Function<C, ISeq<G>>() {
@Override public ISeq<G> apply(final C value) {
return value.toSeq();
}
};
}
}