src/main/java/org/apache/commons/lang/math/Range.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.commons.lang.math;

import org.apache.commons.lang.text.StrBuilder;

/**
 * <p><code>Range</code> represents a range of numbers of the same type.</p>
 * 
 * <p>Specific subclasses hold the range values as different types. Each
 * subclass should be immutable and {@link java.io.Serializable Serializable}
 * if possible.</p>
 *
 * @author Apache Software Foundation
 * @since 2.0
 * @version $Id$
 */
public abstract class Range {

    /**
     * <p>Constructs a new range.</p>
     */
    public Range() {
        super();
    }

    // Accessors
    //--------------------------------------------------------------------

    /**
     * <p>Gets the minimum number in this range.</p>
     *
     * @return the minimum number in this range
     */
    public abstract Number getMinimumNumber();

    /**
     * <p>Gets the minimum number in this range as a <code>long</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the minimum number in this range
     */
    public long getMinimumLong() {
        return getMinimumNumber().longValue();
    }

    /**
     * <p>Gets the minimum number in this range as a <code>int</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the minimum number in this range
     */
    public int getMinimumInteger() {
        return getMinimumNumber().intValue();
    }

    /**
     * <p>Gets the minimum number in this range as a <code>double</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the minimum number in this range
     */
    public double getMinimumDouble() {
        return getMinimumNumber().doubleValue();
    }

    /**
     * <p>Gets the minimum number in this range as a <code>float</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the minimum number in this range
     */
    public float getMinimumFloat() {
        return getMinimumNumber().floatValue();
    }

    /**
     * <p>Gets the maximum number in this range.</p>
     *
     * @return the maximum number in this range
     */
    public abstract Number getMaximumNumber();

    /**
     * <p>Gets the maximum number in this range as a <code>long</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMaximumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the maximum number in this range
     */
    public long getMaximumLong() {
        return getMaximumNumber().longValue();
    }

    /**
     * <p>Gets the maximum number in this range as a <code>int</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMaximumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the maximum number in this range
     */
    public int getMaximumInteger() {
        return getMaximumNumber().intValue();
    }

    /**
     * <p>Gets the maximum number in this range as a <code>double</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMaximumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the maximum number in this range
     */
    public double getMaximumDouble() {
        return getMaximumNumber().doubleValue();
    }

    /**
     * <p>Gets the maximum number in this range as a <code>float</code>.</p>
     * 
     * <p>This implementation uses the {@link #getMaximumNumber()} method. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the maximum number in this range
     */
    public float getMaximumFloat() {
        return getMaximumNumber().floatValue();
    }

    // Include tests
    //--------------------------------------------------------------------
    
    /**
     * <p>Tests whether the specified <code>Number</code> occurs within
     * this range.</p>
     * 
     * <p>The exact comparison implementation varies by subclass. It is
     * intended that an <code>int</code> specific subclass will compare using
     * <code>int</code> comparison.</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     *
     * @param number  the number to test, may be <code>null</code>
     * @return <code>true</code> if the specified number occurs within this range
     * @throws IllegalArgumentException if the <code>Number</code> cannot be compared
     */
    public abstract boolean containsNumber(Number number);

    /**
     * <p>Tests whether the specified <code>Number</code> occurs within
     * this range using <code>long</code> comparison..</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     * 
     * <p>This implementation forwards to the {@link #containsLong(long)} method.</p>
     *
     * @param value  the long to test, may be <code>null</code>
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>long</code> comparison
     */
    public boolean containsLong(Number value) {
        if (value == null) {
            return false;
        }
        return containsLong(value.longValue());
    }

    /**
     * <p>Tests whether the specified <code>long</code> occurs within
     * this range using <code>long</code> comparison.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumLong()} and 
     * {@link #getMaximumLong()} methods and should be good for most uses.</p>
     * 
     * @param value  the long to test
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>long</code> comparison
     */
    public boolean containsLong(long value) {
        return value >= getMinimumLong() && value <= getMaximumLong();
    }

    /**
     * <p>Tests whether the specified <code>Number</code> occurs within
     * this range using <code>int</code> comparison..</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     * 
     * <p>This implementation forwards to the {@link #containsInteger(int)} method.</p>
     *
     * @param value  the integer to test, may be <code>null</code>
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>int</code> comparison
     */
    public boolean containsInteger(Number value) {
        if (value == null) {
            return false;
        }
        return containsInteger(value.intValue());
    }

    /**
     * <p>Tests whether the specified <code>int</code> occurs within
     * this range using <code>int</code> comparison.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumInteger()} and 
     * {@link #getMaximumInteger()} methods and should be good for most uses.</p>
     * 
     * @param value  the int to test
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>int</code> comparison
     */
    public boolean containsInteger(int value) {
        return value >= getMinimumInteger() && value <= getMaximumInteger();
    }

    /**
     * <p>Tests whether the specified <code>Number</code> occurs within
     * this range using <code>double</code> comparison..</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     * 
     * <p>This implementation forwards to the {@link #containsDouble(double)} method.</p>
     *
     * @param value  the double to test, may be <code>null</code>
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>double</code> comparison
     */
    public boolean containsDouble(Number value) {
        if (value == null) {
            return false;
        }
        return containsDouble(value.doubleValue());
    }

    /**
     * <p>Tests whether the specified <code>double</code> occurs within
     * this range using <code>double</code> comparison.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumDouble()} and 
     * {@link #getMaximumDouble()} methods and should be good for most uses.</p>
     * 
     * @param value  the double to test
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>double</code> comparison
     */
    public boolean containsDouble(double value) {
        int compareMin = NumberUtils.compare(getMinimumDouble(), value);
        int compareMax = NumberUtils.compare(getMaximumDouble(), value);
        return compareMin <= 0 && compareMax >= 0;
    }

    /**
     * <p>Tests whether the specified <code>Number</code> occurs within
     * this range using <code>float</code> comparison.</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     * 
     * <p>This implementation forwards to the {@link #containsFloat(float)} method.</p>
     *
     * @param value  the float to test, may be <code>null</code>
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>float</code> comparison
     */
    public boolean containsFloat(Number value) {
        if (value == null) {
            return false;
        }
        return containsFloat(value.floatValue());
    }

    /**
     * <p>Tests whether the specified <code>float</code> occurs within
     * this range using <code>float</code> comparison.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumFloat()} and 
     * {@link #getMaximumFloat()} methods and should be good for most uses.</p>
     * 
     * @param value  the float to test
     * @return <code>true</code> if the specified number occurs within this
     *  range by <code>float</code> comparison
     */
    public boolean containsFloat(float value) {
        int compareMin = NumberUtils.compare(getMinimumFloat(), value);
        int compareMax = NumberUtils.compare(getMaximumFloat(), value);
        return compareMin <= 0 && compareMax >= 0;
    }

    // Range tests
    //--------------------------------------------------------------------

    /**
     * <p>Tests whether the specified range occurs entirely within this range.</p>
     * 
     * <p>The exact comparison implementation varies by subclass. It is
     * intended that an <code>int</code> specific subclass will compare using
     * <code>int</code> comparison.</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     * 
     * <p>This implementation uses the {@link #containsNumber(Number)} method.
     * Subclasses may be able to optimise this.</p>
     *
     * @param range  the range to test, may be <code>null</code>
     * @return <code>true</code> if the specified range occurs entirely within
     *  this range; otherwise, <code>false</code>
     * @throws IllegalArgumentException if the <code>Range</code> cannot be compared
     */
    public boolean containsRange(Range range) {
        if (range == null) {
            return false;
        }
        return containsNumber(range.getMinimumNumber()) 
            && containsNumber(range.getMaximumNumber());
    }

    /**
     * <p>Tests whether the specified range overlaps with this range.</p>
     * 
     * <p>The exact comparison implementation varies by subclass. It is
     * intended that an <code>int</code> specific subclass will compare using
     * <code>int</code> comparison.</p>
     * 
     * <p><code>null</code> is handled and returns <code>false</code>.</p>
     * 
     * <p>This implementation uses the {@link #containsNumber(Number)} and
     * {@link #containsRange(Range)} methods.
     * Subclasses may be able to optimise this.</p>
     *
     * @param range  the range to test, may be <code>null</code>
     * @return <code>true</code> if the specified range overlaps with this
     *  range; otherwise, <code>false</code>
     * @throws IllegalArgumentException if the <code>Range</code> cannot be compared
     */
    public boolean overlapsRange(Range range) {
        if (range == null) {
            return false;
        }
        return range.containsNumber(getMinimumNumber())
            || range.containsNumber(getMaximumNumber())
            || containsNumber(range.getMinimumNumber());
    }

    // Basics
    //--------------------------------------------------------------------

    /**
     * <p>Compares this range to another object to test if they are equal.</p>.
     * 
     * <p>To be equal, the class, minimum and maximum must be equal.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} and 
     * {@link #getMaximumNumber()} methods. 
     * Subclasses may be able to optimise this.</p>
     *
     * @param obj the reference object with which to compare
     * @return <code>true</code> if this object is equal
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        } else if (obj == null || obj.getClass() != getClass()) {
            return false;
        } else {
            Range range = (Range) obj;
            return getMinimumNumber().equals(range.getMinimumNumber()) &&
                   getMaximumNumber().equals(range.getMaximumNumber());
        }
    }

    /**
     * <p>Gets a hashCode for the range.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} and 
     * {@link #getMaximumNumber()} methods. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return a hash code value for this object
     */
    public int hashCode() {
        int result = 17;
        result = 37 * result + getClass().hashCode();
        result = 37 * result + getMinimumNumber().hashCode();
        result = 37 * result + getMaximumNumber().hashCode();
        return result;
    }

    /**
     * <p>Gets the range as a <code>String</code>.</p>
     *
     * <p>The format of the String is 'Range[<i>min</i>,<i>max</i>]'.</p>
     * 
     * <p>This implementation uses the {@link #getMinimumNumber()} and 
     * {@link #getMaximumNumber()} methods. 
     * Subclasses may be able to optimise this.</p>
     *
     * @return the <code>String</code> representation of this range
     */
    public String toString() {
        StrBuilder buf = new StrBuilder(32);
        buf.append("Range[");
        buf.append(getMinimumNumber());
        buf.append(',');
        buf.append(getMaximumNumber());
        buf.append(']');
        return buf.toString();
    }

}