org.jgap.gp.function.CharacterProvider.java Source code

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Here is the source code for org.jgap.gp.function.CharacterProvider.java

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/*
 * This file is part of JGAP.
 *
 * JGAP offers a dual license model containing the LGPL as well as the MPL.
 *
 * For licensing information please see the file license.txt included with JGAP
 * or have a look at the top of class org.jgap.Chromosome which representatively
 * includes the JGAP license policy applicable for any file delivered with JGAP.
 */
package org.jgap.gp.function;

import org.apache.commons.lang.builder.*;
import org.jgap.*;
import org.jgap.gp.*;
import org.jgap.gp.impl.*;
import org.jgap.util.*;

/**
 * Returns a single character out of a set of given characters. The decision
 * which character to return is controlled by a child of this command which in
 * turn returns an integer index.
 *
 * @author Klaus Meffert
 * @since 3.4.3
 */
public class CharacterProvider extends CommandGene implements ICloneable {
    /** String containing the CVS revision. Read out via reflection!*/
    private final static String CVS_REVISION = "$Revision: 1.2 $";

    /**
     * Alphabet of valid characters.
     */
    private String m_alphabet;

    public CharacterProvider(final GPConfiguration a_conf, Class a_returnType, String a_alphabet)
            throws InvalidConfigurationException {
        this(a_conf, a_returnType, a_alphabet, 0);
    }

    public CharacterProvider(final GPConfiguration a_conf, Class a_returnType, String a_alphabet,
            int a_subReturnType) throws InvalidConfigurationException {
        super(a_conf, 1, a_returnType, a_subReturnType, null);
        if (a_alphabet == null || a_alphabet.length() < 1) {
            throw new IllegalArgumentException("Alphabet must not be empty!");
        }
        m_alphabet = a_alphabet;
    }

    public String toString() {
        return "character(" + m_alphabet + ")";
    }

    /**
     * @return textual name of this command
     *
     * @author Klaus Meffert
     * @since 3.2
     */
    public String getName() {
        return "Character";
    }

    public Object execute_object(ProgramChromosome c, int n, Object[] args) {
        int index = c.execute_int(n, 0, args);
        try {
            return m_alphabet.charAt(index);
        } catch (ArrayIndexOutOfBoundsException iex) {
            throw new IllegalStateException("CharacterProvider: child returned invalid index");
        }
    }

    /**
     * The compareTo-method.
     *
     * @param a_other the other object to compare
     * @return -1, 0, 1
     *
     * @author Klaus Meffert
     * @since 3.4.3
     */
    public int compareTo(Object a_other) {
        int result = super.compareTo(a_other);
        if (result != 0) {
            return result;
        }
        CharacterProvider other = (CharacterProvider) a_other;
        return new CompareToBuilder().append(m_alphabet, other.m_alphabet).toComparison();
    }

    /**
     * The equals-method.
     *
     * @param a_other the other object to compare
     * @return true if the objects are seen as equal
     *
     * @author Klaus Meffert
     * @since 3.4.3
     */
    public boolean equals(Object a_other) {
        try {
            CharacterProvider other = (CharacterProvider) a_other;
            return super.equals(a_other) && new EqualsBuilder().append(m_alphabet, other.m_alphabet).isEquals();
        } catch (ClassCastException cex) {
            return false;
        }
    }

    /**
     * Clones the object. Simple and straight forward implementation here.
     *
     * @return cloned instance of this object
     *
     * @author Klaus Meffert
     * @since 3.4.3
     */
    public Object clone() {
        try {
            CharacterProvider result = new CharacterProvider(getGPConfiguration(), getReturnType(), m_alphabet,
                    getSubReturnType());
            return result;
        } catch (Exception ex) {
            throw new CloneException(ex);
        }
    }
}