/*******************************************************************************
 * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v0.5 
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v05.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/
package net.sourceforge.phpdt.core.compiler;

/**
 * This class is a collection of helper methods to manipulate char arrays.
 * 
 * @since 2.1
 */
public final class CharOperation {

	/**
	 * Constant for an empty char array
	 */
	public static final char[] NO_CHAR = new char[0];

	/**
	 * Constant for an empty char array with two dimensions.
	 */
	public static final char[][] NO_CHAR_CHAR = new char[0][];

	/**
	 * Answers a new array with appending the suffix character at the end of the
	 * array. <br>
	 * <br>
	 * For example:<br>
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a', 'b' }
	 *     suffix = 'c'
	 *     =&gt; result = { 'a', 'b' , 'c' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = null
	 *     suffix = 'c'
	 *     =&gt; result = { 'c' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the array that is concanated with the suffix character
	 * @param suffix
	 *            the suffix character
	 * @return the new array
	 */
	public static final char[] append(char[] array, char suffix) {
		if (array == null)
			return new char[] { suffix };
		int length = array.length;
		System.arraycopy(array, 0, array = new char[length + 1], 0, length);
		array[length] = suffix;
		return array;
	}

	/**
	 * Append the given subarray to append to the target array starting at the
	 * given index in the target array. The start of the subarray is inclusive,
	 * the end is exclusive. Answers a new target array if it needs to grow,
	 * otherwise answers the same target array. <br>
	 * For example:<br>
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     target = { 'a', 'b', -1 }
	 *     index = 0
	 *     array = { 'c', 'd' }
	 *     start = 0
	 *     end = 1
	 *     =&gt; result = { 'a', 'b' , 'c' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     target = { 'a', 'b' }
	 *     index = 0
	 *     array = { 'c', 'd' }
	 *     start = 0
	 *     end = 1
	 *     =&gt; result = new { 'a', 'b' , 'c', -1 }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     target = { 'a', 'b', 'c' }
	 *     index = 1
	 *     array = { 'c', 'd', 'e', 'f' }
	 *     start = 1
	 *     end = 4
	 *     =&gt; result = new { 'a', 'd' , 'e', 'f', -1, -1 }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 */
	public static final char[] append(char[] target, int index, char[] array,
			int start, int end) {
		int targetLength = target.length;
		int subLength = end - start;
		int newTargetLength = subLength + index;
		if (newTargetLength > targetLength) {
			System.arraycopy(target, 0, target = new char[newTargetLength * 2],
					0, index);
		}
		System.arraycopy(array, start, target, index, subLength);
		return target;
	}

	/**
	 * Answers the concatenation of the two arrays. It answers null if the two
	 * arrays are null. If the first array is null, then the second array is
	 * returned. If the second array is null, then the first array is returned.
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = null
	 *     =&gt; result = null
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { ' a' } }
	 *     second = null
	 *     =&gt; result = { { ' a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = { { ' a' } }
	 *     =&gt; result = { { ' a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { ' b' } }
	 *     second = { { ' a' } }
	 *     =&gt; result = { { ' b' }, { ' a' } }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array to concatenate
	 * @param second
	 *            the second array to concatenate
	 * @return the concatenation of the two arrays, or null if the two arrays
	 *         are null.
	 */
	public static final char[][] arrayConcat(char[][] first, char[][] second) {
		if (first == null)
			return second;
		if (second == null)
			return first;

		int length1 = first.length;
		int length2 = second.length;
		char[][] result = new char[length1 + length2][];
		System.arraycopy(first, 0, result, 0, length1);
		System.arraycopy(second, 0, result, length1, length2);
		return result;
	}

	/**
	 * Answers a new array adding the second array at the end of first array. It
	 * answers null if the first and second are null. If the first array is
	 * null, then a new array char[][] is created with second. If the second
	 * array is null, then the first array is returned. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = { 'a' }
	 *     =&gt; result = { { ' a' } }
	 * </pre>
	 * 
	 * <li>
	 * 
	 * <pre>
	 *     first = { { ' a' } }
	 *     second = null
	 *     =&gt; result = { { ' a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { ' a' } }
	 *     second = { ' b' }
	 *     =&gt; result = { { ' a' } , { ' b' } }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array to concatenate
	 * @param second
	 *            the array to add at the end of the first array
	 * @return a new array adding the second array at the end of first array, or
	 *         null if the two arrays are null.
	 */
	public static final char[][] arrayConcat(char[][] first, char[] second) {
		if (second == null)
			return first;
		if (first == null)
			return new char[][] { second };

		int length = first.length;
		char[][] result = new char[length + 1][];
		System.arraycopy(first, 0, result, 0, length);
		result[length] = second;
		return result;
	}

	/**
	 * Answers the concatenation of the two arrays. It answers null if the two
	 * arrays are null. If the first array is null, then the second array is
	 * returned. If the second array is null, then the first array is returned.
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = { 'a' }
	 *     =&gt; result = { ' a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { ' a' }
	 *     second = null
	 *     =&gt; result = { ' a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { ' a' }
	 *     second = { ' b' }
	 *     =&gt; result = { ' a' , ' b' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array to concatenate
	 * @param second
	 *            the second array to concatenate
	 * @return the concatenation of the two arrays, or null if the two arrays
	 *         are null.
	 */
	public static final char[] concat(char[] first, char[] second) {
		if (first == null)
			return second;
		if (second == null)
			return first;

		int length1 = first.length;
		int length2 = second.length;
		char[] result = new char[length1 + length2];
		System.arraycopy(first, 0, result, 0, length1);
		System.arraycopy(second, 0, result, length1, length2);
		return result;
	}

	/**
	 * Answers the concatenation of the three arrays. It answers null if the
	 * three arrays are null. If first is null, it answers the concatenation of
	 * second and third. If second is null, it answers the concatenation of
	 * first and third. If third is null, it answers the concatenation of first
	 * and second. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = { 'a' }
	 *     third = { 'b' }
	 *     =&gt; result = { ' a', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'a' }
	 *     second = null
	 *     third = { 'b' }
	 *     =&gt; result = { ' a', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'a' }
	 *     second = { 'b' }
	 *     third = null
	 *     =&gt; result = { ' a', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = null
	 *     third = null
	 *     =&gt; result = null
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'a' }
	 *     second = { 'b' }
	 *     third = { 'c' }
	 *     =&gt; result = { 'a', 'b', 'c' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array to concatenate
	 * @param second
	 *            the second array to concatenate
	 * @param third
	 *            the third array to concatenate
	 * 
	 * @return the concatenation of the three arrays, or null if the three
	 *         arrays are null.
	 */
	public static final char[] concat(char[] first, char[] second, char[] third) {
		if (first == null)
			return concat(second, third);
		if (second == null)
			return concat(first, third);
		if (third == null)
			return concat(first, second);

		int length1 = first.length;
		int length2 = second.length;
		int length3 = third.length;
		char[] result = new char[length1 + length2 + length3];
		System.arraycopy(first, 0, result, 0, length1);
		System.arraycopy(second, 0, result, length1, length2);
		System.arraycopy(third, 0, result, length1 + length2, length3);
		return result;
	}

	/**
	 * Answers the concatenation of the two arrays inserting the separator
	 * character between the two arrays. It answers null if the two arrays are
	 * null. If the first array is null, then the second array is returned. If
	 * the second array is null, then the first array is returned. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = { 'a' }
	 *     separator = '/'
	 *     =&gt; result = { ' a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { ' a' }
	 *     second = null
	 *     separator = '/'
	 *     =&gt; result = { ' a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { ' a' }
	 *     second = { ' b' }
	 *     separator = '/'
	 *     =&gt; result = { ' a' , '/', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array to concatenate
	 * @param second
	 *            the second array to concatenate
	 * @param separator
	 *            the character to insert
	 * @return the concatenation of the two arrays inserting the separator
	 *         character between the two arrays , or null if the two arrays are
	 *         null.
	 */
	public static final char[] concat(char[] first, char[] second,
			char separator) {
		if (first == null)
			return second;
		if (second == null)
			return first;

		int length1 = first.length;
		if (length1 == 0)
			return second;
		int length2 = second.length;
		if (length2 == 0)
			return first;

		char[] result = new char[length1 + length2 + 1];
		System.arraycopy(first, 0, result, 0, length1);
		result[length1] = separator;
		System.arraycopy(second, 0, result, length1 + 1, length2);
		return result;
	}

	/**
	 * Answers the concatenation of the three arrays inserting the sep1
	 * character between the two arrays and sep2 between the last two. It
	 * answers null if the three arrays are null. If the first array is null,
	 * then it answers the concatenation of second and third inserting the sep2
	 * character between them. If the second array is null, then the first array
	 * is returned. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = { 'a' }
	 *     separator = '/'
	 *     =&gt; result = { ' a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { ' a' }
	 *     second = null
	 *     separator = '/'
	 *     =&gt; result = { ' a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { ' a' }
	 *     second = { ' b' }
	 *     separator = '/'
	 *     =&gt; result = { ' a' , '/', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array to concatenate
	 * @param second
	 *            the second array to concatenate
	 * @param separator
	 *            the character to insert
	 * @return the concatenation of the two arrays inserting the separator
	 *         character between the two arrays , or null if the two arrays are
	 *         null.
	 */
	public static final char[] concat(char[] first, char sep1, char[] second,
			char sep2, char[] third) {
		if (first == null)
			return concat(second, third, sep2);
		if (second == null)
			return concat(first, third, sep1);
		if (third == null)
			return concat(first, second, sep1);

		int length1 = first.length;
		int length2 = second.length;
		int length3 = third.length;
		char[] result = new char[length1 + length2 + length3 + 2];
		System.arraycopy(first, 0, result, 0, length1);
		result[length1] = sep1;
		System.arraycopy(second, 0, result, length1 + 1, length2);
		result[length1 + length2 + 1] = sep2;
		System.arraycopy(third, 0, result, length1 + length2 + 2, length3);
		return result;
	}

	/**
	 * Answers a new array with prepending the prefix character and appending
	 * the suffix character at the end of the array. If array is null, it
	 * answers a new array containing the prefix and the suffix characters. <br>
	 * <br>
	 * For example:<br>
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     prefix = 'a'
	 *     array = { 'b' }
	 *     suffix = 'c'
	 *     =&gt; result = { 'a', 'b' , 'c' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     prefix = 'a'
	 *     array = null
	 *     suffix = 'c'
	 *     =&gt; result = { 'a', 'c' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param prefix
	 *            the prefix character
	 * @param array
	 *            the array that is concanated with the prefix and suffix
	 *            characters
	 * @param suffix
	 *            the suffix character
	 * @return the new array
	 */
	public static final char[] concat(char prefix, char[] array, char suffix) {
		if (array == null)
			return new char[] { prefix, suffix };

		int length = array.length;
		char[] result = new char[length + 2];
		result[0] = prefix;
		System.arraycopy(array, 0, result, 1, length);
		result[length + 1] = suffix;
		return result;
	}

	/**
	 * Answers the concatenation of the given array parts using the given
	 * separator between each part and appending the given name at the end. <br>
	 * <br>
	 * For example:<br>
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     name = { 'c' }
	 *     array = { { 'a' }, { 'b' } }
	 *     separator = '.'
	 *     =&gt; result = { 'a', '.', 'b' , '.', 'c' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     name = null
	 *     array = { { 'a' }, { 'b' } }
	 *     separator = '.'
	 *     =&gt; result = { 'a', '.', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     name = { ' c' }
	 *     array = null
	 *     separator = '.'
	 *     =&gt; result = { 'c' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param name
	 *            the given name
	 * @param array
	 *            the given array
	 * @param separator
	 *            the given separator
	 * @return the concatenation of the given array parts using the given
	 *         separator between each part and appending the given name at the
	 *         end
	 */
	public static final char[] concatWith(char[] name, char[][] array,
			char separator) {
		int nameLength = name == null ? 0 : name.length;
		if (nameLength == 0)
			return concatWith(array, separator);

		int length = array == null ? 0 : array.length;
		if (length == 0)
			return name;

		int size = nameLength;
		int index = length;
		while (--index >= 0)
			if (array[index].length > 0)
				size += array[index].length + 1;
		char[] result = new char[size];
		index = size;
		for (int i = length - 1; i >= 0; i--) {
			int subLength = array[i].length;
			if (subLength > 0) {
				index -= subLength;
				System.arraycopy(array[i], 0, result, index, subLength);
				result[--index] = separator;
			}
		}
		System.arraycopy(name, 0, result, 0, nameLength);
		return result;
	}

	/**
	 * Answers the concatenation of the given array parts using the given
	 * separator between each part and appending the given name at the end. <br>
	 * <br>
	 * For example:<br>
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     name = { 'c' }
	 *     array = { { 'a' }, { 'b' } }
	 *     separator = '.'
	 *     =&gt; result = { 'a', '.', 'b' , '.', 'c' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     name = null
	 *     array = { { 'a' }, { 'b' } }
	 *     separator = '.'
	 *     =&gt; result = { 'a', '.', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     name = { ' c' }
	 *     array = null
	 *     separator = '.'
	 *     =&gt; result = { 'c' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the given array
	 * @param name
	 *            the given name
	 * @param separator
	 *            the given separator
	 * @return the concatenation of the given array parts using the given
	 *         separator between each part and appending the given name at the
	 *         end
	 */
	public static final char[] concatWith(char[][] array, char[] name,
			char separator) {
		int nameLength = name == null ? 0 : name.length;
		if (nameLength == 0)
			return concatWith(array, separator);

		int length = array == null ? 0 : array.length;
		if (length == 0)
			return name;

		int size = nameLength;
		int index = length;
		while (--index >= 0)
			if (array[index].length > 0)
				size += array[index].length + 1;
		char[] result = new char[size];
		index = 0;
		for (int i = 0; i < length; i++) {
			int subLength = array[i].length;
			if (subLength > 0) {
				System.arraycopy(array[i], 0, result, index, subLength);
				index += subLength;
				result[index++] = separator;
			}
		}
		System.arraycopy(name, 0, result, index, nameLength);
		return result;
	}

	/**
	 * Answers the concatenation of the given array parts using the given
	 * separator between each part. <br>
	 * <br>
	 * For example:<br>
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { { 'a' }, { 'b' } }
	 *     separator = '.'
	 *     =&gt; result = { 'a', '.', 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = null
	 *     separator = '.'
	 *     =&gt; result = { }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the given array
	 * @param separator
	 *            the given separator
	 * @return the concatenation of the given array parts using the given
	 *         separator between each part
	 */
	public static final char[] concatWith(char[][] array, char separator) {
		int length = array == null ? 0 : array.length;
		if (length == 0)
			return CharOperation.NO_CHAR;

		int size = length - 1;
		int index = length;
		while (--index >= 0) {
			if (array[index].length == 0)
				size--;
			else
				size += array[index].length;
		}
		if (size <= 0)
			return CharOperation.NO_CHAR;
		char[] result = new char[size];
		index = length;
		while (--index >= 0) {
			length = array[index].length;
			if (length > 0) {
				System.arraycopy(array[index], 0, result, (size -= length),
						length);
				if (--size >= 0)
					result[size] = separator;
			}
		}
		return result;
	}

	/**
	 * Answers true if the array contains an occurrence of character, false
	 * otherwise.
	 * 
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     character = 'c'
	 *     array = { { ' a' }, { ' b' } }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     character = 'a'
	 *     array = { { ' a' }, { ' b' } }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param character
	 *            the character to search
	 * @param array
	 *            the array in which the search is done
	 * @exception NullPointerException
	 *                if array is null.
	 * 
	 * @return true if the array contains an occurrence of character, false
	 *         otherwise.
	 */
	public static final boolean contains(char character, char[][] array) {
		for (int i = array.length; --i >= 0;) {
			char[] subarray = array[i];
			for (int j = subarray.length; --j >= 0;)
				if (subarray[j] == character)
					return true;
		}
		return false;
	}

	/**
	 * Answers true if the array contains an occurrence of character, false
	 * otherwise.
	 * 
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     character = 'c'
	 *     array = { ' b'  }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     character = 'a'
	 *     array = { ' a' , ' b' }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param character
	 *            the character to search
	 * @param array
	 *            the array in which the search is done
	 * @exception NullPointerException
	 *                if array is null.
	 * 
	 * @return true if the array contains an occurrence of character, false
	 *         otherwise.
	 */
	public static final boolean contains(char character, char[] array) {
		for (int i = array.length; --i >= 0;)
			if (array[i] == character)
				return true;
		return false;
	}

	/**
	 * Answers a deep copy of the toCopy array.
	 * 
	 * @param toCopy
	 *            the array to copy
	 * @return a deep copy of the toCopy array.
	 */
	public static final char[][] deepCopy(char[][] toCopy) {
		int toCopyLength = toCopy.length;
		char[][] result = new char[toCopyLength][];
		for (int i = 0; i < toCopyLength; i++) {
			char[] toElement = toCopy[i];
			int toElementLength = toElement.length;
			char[] resultElement = new char[toElementLength];
			System.arraycopy(toElement, 0, resultElement, 0, toElementLength);
			result[i] = resultElement;
		}
		return result;
	}

	/**
	 * Return true if array ends with the sequence of characters contained in
	 * toBeFound, otherwise false. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a', 'b', 'c', 'd' }
	 *     toBeFound = { 'b', 'c' }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a', 'b', 'c' }
	 *     toBeFound = { 'b', 'c' }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the array to check
	 * @param toBeFound
	 *            the array to find
	 * @exception NullPointerException
	 *                if array is null or toBeFound is null
	 * @return true if array ends with the sequence of characters contained in
	 *         toBeFound, otherwise false.
	 */
	public static final boolean endsWith(char[] array, char[] toBeFound) {
		int i = toBeFound.length;
		int j = array.length - i;

		if (j < 0)
			return false;
		while (--i >= 0)
			if (toBeFound[i] != array[i + j])
				return false;
		return true;
	}

	/**
	 * Answers true if the two arrays are identical character by character,
	 * otherwise false. The equality is case sensitive. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = null
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { } }
	 *     second = null
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { 'a' } }
	 *     second = { { 'a' } }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { 'A' } }
	 *     second = { { 'a' } }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array
	 * @param second
	 *            the second array
	 * @return true if the two arrays are identical character by character,
	 *         otherwise false
	 */
	public static final boolean equals(char[][] first, char[][] second) {
		if (first == second)
			return true;
		if (first == null || second == null)
			return false;
		if (first.length != second.length)
			return false;

		for (int i = first.length; --i >= 0;)
			if (!equals(first[i], second[i]))
				return false;
		return true;
	}

	/**
	 * If isCaseSensite is true, answers true if the two arrays are identical
	 * character by character, otherwise false. If it is false, answers true if
	 * the two arrays are identical character by character without checking the
	 * case, otherwise false. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = null
	 *     isCaseSensitive = true
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { } }
	 *     second = null
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { 'A' } }
	 *     second = { { 'a' } }
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { { 'A' } }
	 *     second = { { 'a' } }
	 *     isCaseSensitive = false
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array
	 * @param second
	 *            the second array
	 * @param isCaseSensitive
	 *            check whether or not the equality should be case sensitive
	 * @return true if the two arrays are identical character by character
	 *         according to the value of isCaseSensitive, otherwise false
	 */
	public static final boolean equals(char[][] first, char[][] second,
			boolean isCaseSensitive) {

		if (isCaseSensitive) {
			return equals(first, second);
		}
		if (first == second)
			return true;
		if (first == null || second == null)
			return false;
		if (first.length != second.length)
			return false;

		for (int i = first.length; --i >= 0;)
			if (!equals(first[i], second[i], false))
				return false;
		return true;
	}

	/**
	 * Answers true if the two arrays are identical character by character,
	 * otherwise false. The equality is case sensitive. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = null
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { }
	 *     second = null
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'a' }
	 *     second = { 'a' }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'a' }
	 *     second = { 'A' }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array
	 * @param second
	 *            the second array
	 * @return true if the two arrays are identical character by character,
	 *         otherwise false
	 */
	public static final boolean equals(char[] first, char[] second) {
		if (first == second)
			return true;
		if (first == null || second == null)
			return false;
		if (first.length != second.length)
			return false;

		for (int i = first.length; --i >= 0;)
			if (first[i] != second[i])
				return false;
		return true;
	}

	/**
	 * If isCaseSensite is true, answers true if the two arrays are identical
	 * character by character, otherwise false. If it is false, answers true if
	 * the two arrays are identical character by character without checking the
	 * case, otherwise false. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     first = null
	 *     second = null
	 *     isCaseSensitive = true
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { }
	 *     second = null
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'A' }
	 *     second = { 'a' }
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     first = { 'A' }
	 *     second = { 'a' }
	 *     isCaseSensitive = false
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param first
	 *            the first array
	 * @param second
	 *            the second array
	 * @param isCaseSensitive
	 *            check whether or not the equality should be case sensitive
	 * @return true if the two arrays are identical character by character
	 *         according to the value of isCaseSensitive, otherwise false
	 */
	public static final boolean equals(char[] first, char[] second,
			boolean isCaseSensitive) {

		if (isCaseSensitive) {
			return equals(first, second);
		}
		if (first == second)
			return true;
		if (first == null || second == null)
			return false;
		if (first.length != second.length)
			return false;

		for (int i = first.length; --i >= 0;)
			if (Character.toLowerCase(first[i]) != Character
					.toLowerCase(second[i]))
				return false;
		return true;
	}

	/**
	 * If isCaseSensite is true, the equality is case sensitive, otherwise it is
	 * case insensitive.
	 * 
	 * Answers true if the name contains the fragment at the starting index
	 * startIndex, otherwise false. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     fragment = { 'b', 'c' , 'd' }
	 *     name = { 'a', 'b', 'c' , 'd' }
	 *     startIndex = 1
	 *     isCaseSensitive = true
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     fragment = { 'b', 'c' , 'd' }
	 *     name = { 'a', 'b', 'C' , 'd' }
	 *     startIndex = 1
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     fragment = { 'b', 'c' , 'd' }
	 *     name = { 'a', 'b', 'C' , 'd' }
	 *     startIndex = 0
	 *     isCaseSensitive = false
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     fragment = { 'b', 'c' , 'd' }
	 *     name = { 'a', 'b'}
	 *     startIndex = 0
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param fragment
	 *            the fragment to check
	 * @param second
	 *            the array to check
	 * @param startIndex
	 *            the starting index
	 * @param isCaseSensitive
	 *            check whether or not the equality should be case sensitive
	 * @return true if the name contains the fragment at the starting index
	 *         startIndex according to the value of isCaseSensitive, otherwise
	 *         false.
	 * @exception NullPointerException
	 *                if fragment or name is null.
	 */
	public static final boolean fragmentEquals(char[] fragment, char[] name,
			int startIndex, boolean isCaseSensitive) {

		int max = fragment.length;
		if (name.length < max + startIndex)
			return false;
		if (isCaseSensitive) {
			for (int i = max; --i >= 0;)
				// assumes the prefix is not larger than the name
				if (fragment[i] != name[i + startIndex])
					return false;
			return true;
		}
		for (int i = max; --i >= 0;)
			// assumes the prefix is not larger than the name
			if (Character.toLowerCase(fragment[i]) != Character
					.toLowerCase(name[i + startIndex]))
				return false;
		return true;
	}

	/**
	 * Answers a hashcode for the array
	 * 
	 * @param array
	 *            the array for which a hashcode is required
	 * @return the hashcode
	 * @exception NullPointerException
	 *                if array is null
	 */
	public static final int hashCode(char[] array) {
		int hash = 0;
		int offset = 0;
		int length = array.length;
		if (length < 16) {
			for (int i = length; i > 0; i--)
				hash = (hash * 37) + array[offset++];
		} else {
			// only sample some characters
			int skip = length / 8;
			for (int i = length; i > 0; i -= skip, offset += skip)
				hash = (hash * 39) + array[offset];
		}
		return hash & 0x7FFFFFFF;
	}

	/**
	 * Answers true if c is a whitespace according to the JLS (&#92;u000a,
	 * &#92;u000c, &#92;u000d, &#92;u0009), otherwise false. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     c = ' '
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     c = ' \u3000'
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param c
	 *            the character to check
	 * @return true if c is a whitespace according to the JLS, otherwise false.
	 */
	public static boolean isWhitespace(char c) {
		switch (c) {
		case 10: /* \ u000a: LINE FEED */
		case 12: /* \ u000c: FORM FEED */
		case 13: /* \ u000d: CARRIAGE RETURN */
		case 32: /* \ u0020: SPACE */
		case 9: /* \ u0009: HORIZONTAL TABULATION */
			return true;
		default:
			return false;
		}
	}

	/**
	 * Answers the first index in the array for which the corresponding
	 * character is equal to toBeFound. Answers -1 if no occurrence of this
	 * character is found. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     result =&gt; 2
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'e'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the character to search
	 * @param array
	 *            the array to be searched
	 * @return the first index in the array for which the corresponding
	 *         character is equal to toBeFound, -1 otherwise
	 * @exception NullPointerException
	 *                if array is null
	 */
	public static final int indexOf(char toBeFound, char[] array) {
		for (int i = 0; i < array.length; i++)
			if (toBeFound == array[i])
				return i;
		return -1;
	}

	/**
	 * Answers the first index in the array for which the corresponding
	 * character is equal to toBeFound starting the search at index start.
	 * Answers -1 if no occurrence of this character is found. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     start = 2
	 *     result =&gt; 2
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     start = 3
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'e'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     start = 1
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the character to search
	 * @param array
	 *            the array to be searched
	 * @param start
	 *            the starting index
	 * @return the first index in the array for which the corresponding
	 *         character is equal to toBeFound, -1 otherwise
	 * @exception NullPointerException
	 *                if array is null
	 * @exception ArrayIndexOutOfBoundsException
	 *                if start is lower than 0
	 */
	public static final int indexOf(char toBeFound, char[] array, int start) {
		for (int i = start; i < array.length; i++)
			if (toBeFound == array[i])
				return i;
		return -1;
	}

	/**
	 * Answers the last index in the array for which the corresponding character
	 * is equal to toBeFound starting from the end of the array. Answers -1 if
	 * no occurrence of this character is found. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd' , 'c', 'e' }
	 *     result =&gt; 4
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'e'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the character to search
	 * @param array
	 *            the array to be searched
	 * @return the last index in the array for which the corresponding character
	 *         is equal to toBeFound starting from the end of the array, -1
	 *         otherwise
	 * @exception NullPointerException
	 *                if array is null
	 */
	public static final int lastIndexOf(char toBeFound, char[] array) {
		for (int i = array.length; --i >= 0;)
			if (toBeFound == array[i])
				return i;
		return -1;
	}

	/**
	 * Answers the last index in the array for which the corresponding character
	 * is equal to toBeFound stopping at the index startIndex. Answers -1 if no
	 * occurrence of this character is found. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     startIndex = 2
	 *     result =&gt; 2
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd', 'e' }
	 *     startIndex = 3
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'e'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     startIndex = 0
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the character to search
	 * @param array
	 *            the array to be searched
	 * @param startIndex
	 *            the stopping index
	 * @return the last index in the array for which the corresponding character
	 *         is equal to toBeFound stopping at the index startIndex, -1
	 *         otherwise
	 * @exception NullPointerException
	 *                if array is null
	 * @exception ArrayIndexOutOfBoundsException
	 *                if startIndex is lower than 0
	 */
	public static final int lastIndexOf(char toBeFound, char[] array,
			int startIndex) {
		for (int i = array.length; --i >= startIndex;)
			if (toBeFound == array[i])
				return i;
		return -1;
	}

	/**
	 * Answers the last index in the array for which the corresponding character
	 * is equal to toBeFound starting from endIndex to startIndex. Answers -1 if
	 * no occurrence of this character is found. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     startIndex = 2
	 *     endIndex = 2
	 *     result =&gt; 2
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { ' a', 'b', 'c', 'd', 'e' }
	 *     startIndex = 3
	 *     endIndex = 4
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'e'
	 *     array = { ' a', 'b', 'c', 'd' }
	 *     startIndex = 0
	 *     endIndex = 3
	 *     result =&gt; -1
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the character to search
	 * @param array
	 *            the array to be searched
	 * @param startIndex
	 *            the stopping index
	 * @param endIndex
	 *            the starting index
	 * @return the last index in the array for which the corresponding character
	 *         is equal to toBeFound starting from endIndex to startIndex, -1
	 *         otherwise
	 * @exception NullPointerException
	 *                if array is null
	 * @exception ArrayIndexOutOfBoundsException
	 *                if endIndex is greater or equals to array length or
	 *                starting is lower than 0
	 */
	public static final int lastIndexOf(char toBeFound, char[] array,
			int startIndex, int endIndex) {
		for (int i = endIndex; --i >= startIndex;)
			if (toBeFound == array[i])
				return i;
		return -1;
	}

	/**
	 * Answers the last portion of a name given a separator. <br>
	 * <br>
	 * For example,
	 * 
	 * <pre>
	 *  	lastSegment(&quot;java.lang.Object&quot;.toCharArray(),'.') --&gt; Object
	 * </pre>
	 * 
	 * @param array
	 *            the array
	 * @param separator
	 *            the given separator
	 * @return the last portion of a name given a separator
	 * @exception NullPointerException
	 *                if array is null
	 */
	final static public char[] lastSegment(char[] array, char separator) {
		int pos = lastIndexOf(separator, array);
		if (pos < 0)
			return array;
		return subarray(array, pos + 1, array.length);
	}

	/**
	 * Answers true if the pattern matches the given name, false otherwise. This
	 * char[] pattern matching accepts wild-cards '*' and '?'.
	 * 
	 * When not case sensitive, the pattern is assumed to already be lowercased,
	 * the name will be lowercased character per character as comparing. If name
	 * is null, the answer is false. If pattern is null, the answer is true if
	 * name is not null. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     pattern = { '?', 'b', '*' }
	 *     name = { 'a', 'b', 'c' , 'd' }
	 *     isCaseSensitive = true
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     pattern = { '?', 'b', '?' }
	 *     name = { 'a', 'b', 'c' , 'd' }
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     pattern = { 'b', '*' }
	 *     name = { 'a', 'b', 'c' , 'd' }
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param pattern
	 *            the given pattern
	 * @param name
	 *            the given name
	 * @param isCaseSensitive
	 *            flag to know whether or not the matching should be case
	 *            sensitive
	 * @return true if the pattern matches the given name, false otherwise
	 */
	public static final boolean match(char[] pattern, char[] name,
			boolean isCaseSensitive) {

		if (name == null)
			return false; // null name cannot match
		if (pattern == null)
			return true; // null pattern is equivalent to '*'

		return match(pattern, 0, pattern.length, name, 0, name.length,
				isCaseSensitive);
	}

	/**
	 * Answers true if the a sub-pattern matches the subpart of the given name,
	 * false otherwise. char[] pattern matching, accepting wild-cards '*' and
	 * '?'. Can match only subset of name/pattern. end positions are
	 * non-inclusive. The subpattern is defined by the patternStart and
	 * pattternEnd positions. When not case sensitive, the pattern is assumed to
	 * already be lowercased, the name will be lowercased character per
	 * character as comparing. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     pattern = { '?', 'b', '*' }
	 *     patternStart = 1
	 *     patternEnd = 3
	 *     name = { 'a', 'b', 'c' , 'd' }
	 *     nameStart = 1
	 *     nameEnd = 4
	 *     isCaseSensitive = true
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     pattern = { '?', 'b', '*' }
	 *     patternStart = 1
	 *     patternEnd = 2
	 *     name = { 'a', 'b', 'c' , 'd' }
	 *     nameStart = 1
	 *     nameEnd = 2
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param pattern
	 *            the given pattern
	 * @param patternStart
	 *            the given pattern start
	 * @param patternEnd
	 *            the given pattern end
	 * @param name
	 *            the given name
	 * @param nameStart
	 *            the given name start
	 * @param nameEnd
	 *            the given name end
	 * @param isCaseSensitive
	 *            flag to know if the matching should be case sensitive
	 * @return true if the a sub-pattern matches the subpart of the given name,
	 *         false otherwise
	 */
	public static final boolean match(char[] pattern, int patternStart,
			int patternEnd, char[] name, int nameStart, int nameEnd,
			boolean isCaseSensitive) {

		if (name == null)
			return false; // null name cannot match
		if (pattern == null)
			return true; // null pattern is equivalent to '*'
		int iPattern = patternStart;
		int iName = nameStart;

		if (patternEnd < 0)
			patternEnd = pattern.length;
		if (nameEnd < 0)
			nameEnd = name.length;

		/* check first segment */
		char patternChar = 0;
		while ((iPattern < patternEnd)
				&& (patternChar = pattern[iPattern]) != '*') {
			if (iName == nameEnd)
				return false;
			if (patternChar != (isCaseSensitive ? name[iName] : Character
					.toLowerCase(name[iName]))
					&& patternChar != '?') {
				return false;
			}
			iName++;
			iPattern++;
		}
		/* check sequence of star+segment */
		int segmentStart;
		if (patternChar == '*') {
			segmentStart = ++iPattern; // skip star
		} else {
			segmentStart = 0; // force iName check
		}
		int prefixStart = iName;
		checkSegment: while (iName < nameEnd) {
			if (iPattern == patternEnd) {
				iPattern = segmentStart; // mismatch - restart current
											// segment
				iName = ++prefixStart;
				continue checkSegment;
			}
			/* segment is ending */
			if ((patternChar = pattern[iPattern]) == '*') {
				segmentStart = ++iPattern; // skip start
				if (segmentStart == patternEnd) {
					return true;
				}
				prefixStart = iName;
				continue checkSegment;
			}
			/* check current name character */
			if ((isCaseSensitive ? name[iName] : Character
					.toLowerCase(name[iName])) != patternChar
					&& patternChar != '?') {
				iPattern = segmentStart; // mismatch - restart current
											// segment
				iName = ++prefixStart;
				continue checkSegment;
			}
			iName++;
			iPattern++;
		}

		return (segmentStart == patternEnd)
				|| (iName == nameEnd && iPattern == patternEnd)
				|| (iPattern == patternEnd - 1 && pattern[iPattern] == '*');
	}

	/**
	 * Answers true if the pattern matches the filepath using the pathSepatator,
	 * false otherwise.
	 * 
	 * Path char[] pattern matching, accepting wild-cards '**', '*' and '?'
	 * (using Ant directory tasks conventions, also see
	 * "http://jakarta.apache.org/ant/manual/dirtasks.html#defaultexcludes").
	 * Path pattern matching is enhancing regular pattern matching in supporting
	 * extra rule where '**' represent any folder combination. Special rules: -
	 * foo\ is equivalent to foo\** - *.php is equivalent to **\*.php When not
	 * case sensitive, the pattern is assumed to already be lowercased, the name
	 * will be lowercased character per character as comparing.
	 * 
	 * @param pattern
	 *            the given pattern
	 * @param filepath
	 *            the given path
	 * @param isCaseSensitive
	 *            to find out whether or not the matching should be case
	 *            sensitive
	 * @param pathSeparator
	 *            the given path separator
	 * @return true if the pattern matches the filepath using the pathSepatator,
	 *         false otherwise
	 */
	public static final boolean pathMatch(char[] pattern, char[] filepath,
			boolean isCaseSensitive, char pathSeparator) {

		if (filepath == null)
			return false; // null name cannot match
		if (pattern == null)
			return true; // null pattern is equivalent to '*'

		// special case: pattern foo is equivalent to **\foo (not absolute)
		boolean freeLeadingDoubleStar;

		// offsets inside pattern
		int pSegmentStart, pLength = pattern.length;

		if (freeLeadingDoubleStar = pattern[0] != pathSeparator) {
			pSegmentStart = 0;
		} else {
			pSegmentStart = 1;
		}
		int pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
				pSegmentStart + 1);
		if (pSegmentEnd < 0)
			pSegmentEnd = pLength;

		// special case: pattern foo\ is equivalent to foo\**
		boolean freeTrailingDoubleStar = pattern[pLength - 1] == pathSeparator;

		// offsets inside filepath
		int fSegmentStart, fLength = filepath.length;
		if (filepath[0] != pathSeparator) {
			fSegmentStart = 0;
		} else {
			fSegmentStart = 1;
		}
		if (fSegmentStart != pSegmentStart) {
			return false; // both must start with a separator or none.
		}
		int fSegmentEnd = CharOperation.indexOf(pathSeparator, filepath,
				fSegmentStart + 1);
		if (fSegmentEnd < 0)
			fSegmentEnd = fLength;

		// first segments
		while (pSegmentStart < pLength
				&& !freeLeadingDoubleStar
				&& !(pSegmentEnd == pLength && freeTrailingDoubleStar || (pSegmentEnd == pSegmentStart + 2
						&& pattern[pSegmentStart] == '*' && pattern[pSegmentStart + 1] == '*'))) {

			if (fSegmentStart >= fLength)
				return false;
			if (!CharOperation.match(pattern, pSegmentStart, pSegmentEnd,
					filepath, fSegmentStart, fSegmentEnd, isCaseSensitive)) {
				return false;
			}

			// jump to next segment
			pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
					pSegmentStart = pSegmentEnd + 1);
			// skip separator
			if (pSegmentEnd < 0)
				pSegmentEnd = pLength;

			fSegmentEnd = CharOperation.indexOf(pathSeparator, filepath,
					fSegmentStart = fSegmentEnd + 1);
			// skip separator
			if (fSegmentEnd < 0)
				fSegmentEnd = fLength;
		}

		/* check sequence of doubleStar+segment */
		int pSegmentRestart;
		if ((pSegmentStart >= pLength && freeTrailingDoubleStar)
				|| (pSegmentEnd == pSegmentStart + 2
						&& pattern[pSegmentStart] == '*' && pattern[pSegmentStart + 1] == '*')) {
			pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
					pSegmentStart = pSegmentEnd + 1);
			// skip separator
			if (pSegmentEnd < 0)
				pSegmentEnd = pLength;
			pSegmentRestart = pSegmentStart;
		} else {
			pSegmentRestart = 0; // force fSegmentStart check
		}
		int fSegmentRestart = fSegmentStart;
		checkSegment: while (fSegmentStart < fLength) {

			if (pSegmentStart >= pLength) {
				if (freeTrailingDoubleStar)
					return true;
				// mismatch - restart current path segment
				pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
						pSegmentStart = pSegmentRestart);
				if (pSegmentEnd < 0)
					pSegmentEnd = pLength;

				fSegmentRestart = CharOperation.indexOf(pathSeparator,
						filepath, fSegmentRestart + 1);
				// skip separator
				if (fSegmentRestart < 0) {
					fSegmentRestart = fLength;
				} else {
					fSegmentRestart++;
				}
				fSegmentEnd = CharOperation.indexOf(pathSeparator, filepath,
						fSegmentStart = fSegmentRestart);
				if (fSegmentEnd < 0)
					fSegmentEnd = fLength;
				continue checkSegment;
			}

			/* path segment is ending */
			if (pSegmentEnd == pSegmentStart + 2
					&& pattern[pSegmentStart] == '*'
					&& pattern[pSegmentStart + 1] == '*') {
				pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
						pSegmentStart = pSegmentEnd + 1);
				// skip separator
				if (pSegmentEnd < 0)
					pSegmentEnd = pLength;
				pSegmentRestart = pSegmentStart;
				fSegmentRestart = fSegmentStart;
				if (pSegmentStart >= pLength)
					return true;
				continue checkSegment;
			}
			/* chech current path segment */
			if (!CharOperation.match(pattern, pSegmentStart, pSegmentEnd,
					filepath, fSegmentStart, fSegmentEnd, isCaseSensitive)) {
				// mismatch - restart current path segment
				pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
						pSegmentStart = pSegmentRestart);
				if (pSegmentEnd < 0)
					pSegmentEnd = pLength;

				fSegmentRestart = CharOperation.indexOf(pathSeparator,
						filepath, fSegmentRestart + 1);
				// skip separator
				if (fSegmentRestart < 0) {
					fSegmentRestart = fLength;
				} else {
					fSegmentRestart++;
				}
				fSegmentEnd = CharOperation.indexOf(pathSeparator, filepath,
						fSegmentStart = fSegmentRestart);
				if (fSegmentEnd < 0)
					fSegmentEnd = fLength;
				continue checkSegment;
			}
			// jump to next segment
			pSegmentEnd = CharOperation.indexOf(pathSeparator, pattern,
					pSegmentStart = pSegmentEnd + 1);
			// skip separator
			if (pSegmentEnd < 0)
				pSegmentEnd = pLength;

			fSegmentEnd = CharOperation.indexOf(pathSeparator, filepath,
					fSegmentStart = fSegmentEnd + 1);
			// skip separator
			if (fSegmentEnd < 0)
				fSegmentEnd = fLength;
		}

		return (pSegmentRestart >= pSegmentEnd)
				|| (fSegmentStart >= fLength && pSegmentStart >= pLength)
				|| (pSegmentStart == pLength - 2
						&& pattern[pSegmentStart] == '*' && pattern[pSegmentStart + 1] == '*')
				|| (pSegmentStart == pLength && freeTrailingDoubleStar);
	}

	/**
	 * Answers the number of occurrences of the given character in the given
	 * array, 0 if any.
	 * 
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'b'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; 3
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; 0
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the given character
	 * @param array
	 *            the given array
	 * @return the number of occurrences of the given character in the given
	 *         array, 0 if any
	 * @exception NullPointerException
	 *                if array is null
	 */
	public static final int occurencesOf(char toBeFound, char[] array) {
		int count = 0;
		for (int i = 0; i < array.length; i++)
			if (toBeFound == array[i])
				count++;
		return count;
	}

	/**
	 * Answers the number of occurrences of the given character in the given
	 * array starting at the given index, 0 if any.
	 * 
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'b'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     start = 2
	 *     result =&gt; 2
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = 'c'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     start = 0
	 *     result =&gt; 0
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param toBeFound
	 *            the given character
	 * @param array
	 *            the given array
	 * @return the number of occurrences of the given character in the given
	 *         array, 0 if any
	 * @exception NullPointerException
	 *                if array is null
	 * @exception ArrayIndexOutOfBoundsException
	 *                if start is lower than 0
	 */
	public static final int occurencesOf(char toBeFound, char[] array, int start) {
		int count = 0;
		for (int i = start; i < array.length; i++)
			if (toBeFound == array[i])
				count++;
		return count;
	}

	/**
	 * Answers true if the given name starts with the given prefix, false
	 * otherwise. The comparison is case sensitive. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     prefix = { 'a' , 'b' }
	 *     name = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     prefix = { 'a' , 'c' }
	 *     name = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param prefix
	 *            the given prefix
	 * @param name
	 *            the given name
	 * @return true if the given name starts with the given prefix, false
	 *         otherwise
	 * @exception NullPointerException
	 *                if the given name is null or if the given prefix is null
	 */
	public static final boolean prefixEquals(char[] prefix, char[] name) {

		int max = prefix.length;
		if (name.length < max)
			return false;
		for (int i = max; --i >= 0;)
			// assumes the prefix is not larger than the name
			if (prefix[i] != name[i])
				return false;
		return true;
	}

	/**
	 * Answers true if the given name starts with the given prefix, false
	 * otherwise. isCaseSensitive is used to find out whether or not the
	 * comparison should be case sensitive. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     prefix = { 'a' , 'B' }
	 *     name = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     isCaseSensitive = false
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     prefix = { 'a' , 'B' }
	 *     name = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     isCaseSensitive = true
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param prefix
	 *            the given prefix
	 * @param name
	 *            the given name
	 * @param isCaseSensitive
	 *            to find out whether or not the comparison should be case
	 *            sensitive
	 * @return true if the given name starts with the given prefix, false
	 *         otherwise
	 * @exception NullPointerException
	 *                if the given name is null or if the given prefix is null
	 */
	public static final boolean prefixEquals(char[] prefix, char[] name,
			boolean isCaseSensitive) {

		int max = prefix.length;
		if (name.length < max)
			return false;
		if (isCaseSensitive) {
			for (int i = max; --i >= 0;)
				// assumes the prefix is not larger than the name
				if (prefix[i] != name[i])
					return false;
			return true;
		}

		for (int i = max; --i >= 0;)
			// assumes the prefix is not larger than the name
			if (Character.toLowerCase(prefix[i]) != Character
					.toLowerCase(name[i]))
				return false;
		return true;
	}

	/**
	 * Replace all occurrence of the character to be replaced with the
	 * remplacement character in the given array. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     toBeReplaced = 'b'
	 *     replacementChar = 'a'
	 *     result =&gt; No returned value, but array is now equals to { 'a' , 'a', 'a', 'a', 'a', 'a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     toBeReplaced = 'c'
	 *     replacementChar = 'a'
	 *     result =&gt; No returned value, but array is now equals to { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the given array
	 * @param toBeReplaced
	 *            the character to be replaced
	 * @param replacementChar
	 *            the replacement character
	 * @exception NullPointerException
	 *                if the given array is null
	 */
	public static final void replace(char[] array, char toBeReplaced,
			char replacementChar) {
		if (toBeReplaced != replacementChar) {
			for (int i = 0, max = array.length; i < max; i++) {
				if (array[i] == toBeReplaced)
					array[i] = replacementChar;
			}
		}
	}

	/**
	 * Answers a new array of characters with substitutions. No side-effect is
	 * operated on the original array, in case no substitution happened, then
	 * the result is the same as the original one. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     toBeReplaced = { 'b' }
	 *     replacementChar = { 'a', 'a' }
	 *     result =&gt; { 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     toBeReplaced = { 'c' }
	 *     replacementChar = { 'a' }
	 *     result =&gt; { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param the
	 *            given array
	 * @param toBeReplaced
	 *            characters to be replaced
	 * @param the
	 *            replacement characters
	 * @return a new array of characters with substitutions or the given array
	 *         if none
	 * @exception NullPointerException
	 *                if the given array is null
	 */
	public static final char[] replace(char[] array, char[] toBeReplaced,
			char[] replacementChars) {

		int max = array.length;
		int replacedLength = toBeReplaced.length;
		int replacementLength = replacementChars.length;

		int[] starts = new int[5];
		int occurrenceCount = 0;

		if (!equals(toBeReplaced, replacementChars)) {

			next: for (int i = 0; i < max; i++) {
				int j = 0;
				while (j < replacedLength) {
					if (i + j == max)
						continue next;
					if (array[i + j] != toBeReplaced[j++])
						continue next;
				}
				if (occurrenceCount == starts.length) {
					System.arraycopy(starts, 0,
							starts = new int[occurrenceCount * 2], 0,
							occurrenceCount);
				}
				starts[occurrenceCount++] = i;
			}
		}
		if (occurrenceCount == 0)
			return array;
		char[] result = new char[max + occurrenceCount
				* (replacementLength - replacedLength)];
		int inStart = 0, outStart = 0;
		for (int i = 0; i < occurrenceCount; i++) {
			int offset = starts[i] - inStart;
			System.arraycopy(array, inStart, result, outStart, offset);
			inStart += offset;
			outStart += offset;
			System.arraycopy(replacementChars, 0, result, outStart,
					replacementLength);
			inStart += replacedLength;
			outStart += replacementLength;
		}
		System.arraycopy(array, inStart, result, outStart, max - inStart);
		return result;
	}

	/**
	 * Return a new array which is the split of the given array using the given
	 * divider and triming each subarray to remove whitespaces equals to ' '.
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'b'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; { { 'a' }, {  }, { 'a' }, { 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'c'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; { { 'a', 'b', 'b', 'a', 'b', 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'b'
	 *     array = { 'a' , ' ', 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; { { 'a' }, {  }, { 'a' }, { 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'c'
	 *     array = { ' ', ' ', 'a' , 'b', 'b', 'a', 'b', 'a', ' ' }
	 *     result =&gt; { { 'a', 'b', 'b', 'a', 'b', 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param divider
	 *            the given divider
	 * @param array
	 *            the given array
	 * @return a new array which is the split of the given array using the given
	 *         divider and triming each subarray to remove whitespaces equals to ' '
	 */
	public static final char[][] splitAndTrimOn(char divider, char[] array) {
		int length = array == null ? 0 : array.length;
		if (length == 0)
			return NO_CHAR_CHAR;

		int wordCount = 1;
		for (int i = 0; i < length; i++)
			if (array[i] == divider)
				wordCount++;
		char[][] split = new char[wordCount][];
		int last = 0, currentWord = 0;
		for (int i = 0; i < length; i++) {
			if (array[i] == divider) {
				int start = last, end = i - 1;
				while (start < i && array[start] == ' ')
					start++;
				while (end > start && array[end] == ' ')
					end--;
				split[currentWord] = new char[end - start + 1];
				System.arraycopy(array, start, split[currentWord++], 0, end
						- start + 1);
				last = i + 1;
			}
		}
		int start = last, end = length - 1;
		while (start < length && array[start] == ' ')
			start++;
		while (end > start && array[end] == ' ')
			end--;
		split[currentWord] = new char[end - start + 1];
		System
				.arraycopy(array, start, split[currentWord++], 0, end - start
						+ 1);
		return split;
	}

	/**
	 * Return a new array which is the split of the given array using the given
	 * divider. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'b'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; { { 'a' }, {  }, { 'a' }, { 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'c'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; { { 'a', 'b', 'b', 'a', 'b', 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'c'
	 *     array = { ' ', ' ', 'a' , 'b', 'b', 'a', 'b', 'a', ' ' }
	 *     result =&gt; { { ' ', 'a', 'b', 'b', 'a', 'b', 'a', ' ' } }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param divider
	 *            the given divider
	 * @param array
	 *            the given array
	 * @return a new array which is the split of the given array using the given
	 *         divider
	 */
	public static final char[][] splitOn(char divider, char[] array) {
		int length = array == null ? 0 : array.length;
		if (length == 0)
			return NO_CHAR_CHAR;

		int wordCount = 1;
		for (int i = 0; i < length; i++)
			if (array[i] == divider)
				wordCount++;
		char[][] split = new char[wordCount][];
		int last = 0, currentWord = 0;
		for (int i = 0; i < length; i++) {
			if (array[i] == divider) {
				split[currentWord] = new char[i - last];
				System
						.arraycopy(array, last, split[currentWord++], 0, i
								- last);
				last = i + 1;
			}
		}
		split[currentWord] = new char[length - last];
		System.arraycopy(array, last, split[currentWord], 0, length - last);
		return split;
	}

	/**
	 * Return a new array which is the split of the given array using the given
	 * divider. The given end is exclusive and the given start is inclusive.
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     divider = 'b'
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     start = 2
	 *     end = 5
	 *     result =&gt; { {  }, {  }, { 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param divider
	 *            the given divider
	 * @param array
	 *            the given array
	 * @param start
	 *            the given starting index
	 * @param end
	 *            the given ending index
	 * @return a new array which is the split of the given array using the given
	 *         divider
	 * @exception ArrayIndexOutOfBoundsException
	 *                if start is lower than 0 or end is greater than the array
	 *                length
	 */
	public static final char[][] splitOn(char divider, char[] array, int start,
			int end) {
		int length = array == null ? 0 : array.length;
		if (length == 0 || start > end)
			return NO_CHAR_CHAR;

		int wordCount = 1;
		for (int i = start; i < end; i++)
			if (array[i] == divider)
				wordCount++;
		char[][] split = new char[wordCount][];
		int last = start, currentWord = 0;
		for (int i = start; i < end; i++) {
			if (array[i] == divider) {
				split[currentWord] = new char[i - last];
				System
						.arraycopy(array, last, split[currentWord++], 0, i
								- last);
				last = i + 1;
			}
		}
		split[currentWord] = new char[end - last];
		System.arraycopy(array, last, split[currentWord], 0, end - last);
		return split;
	}

	/**
	 * Answers true if the given array starts with the given characters, false
	 * otherwise. The comparison is case sensitive. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = { 'a' , 'b' }
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; true
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     toBeFound = { 'a' , 'c' }
	 *     array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 *     result =&gt; false
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the given array
	 * @param toBeFound
	 *            the given character to search
	 * @return true if the given array starts with the given characters, false
	 *         otherwise
	 * @exception NullPointerException
	 *                if the given array is null or if the given characters
	 *                array to be found is null
	 */
	public static final boolean startsWith(char[] array, char[] toBeFound) {
		int i = toBeFound.length;
		if (i > array.length)
			return false;
		while (--i >= 0)
			if (toBeFound[i] != array[i])
				return false;
		return true;
	}

	/**
	 * Answers a new array which is a copy of the given array starting at the
	 * given start and ending at the given end. The given start is inclusive and
	 * the given end is exclusive. Answers null if start is greater than end, if
	 * start is lower than 0 or if end is greater than the length of the given
	 * array. If end equals -1, it is converted to the array length. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { { 'a' } , { 'b' } }
	 *     start = 0
	 *     end = 1
	 *     result =&gt; { { 'a' } }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { { 'a' } , { 'b' } }
	 *     start = 0
	 *     end = -1
	 *     result =&gt; { { 'a' }, { 'b' } }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the given array
	 * @param start
	 *            the given starting index
	 * @param end
	 *            the given ending index
	 * @return a new array which is a copy of the given array starting at the
	 *         given start and ending at the given end
	 * @exception NullPointerException
	 *                if the given array is null
	 */
	public static final char[][] subarray(char[][] array, int start, int end) {
		if (end == -1)
			end = array.length;
		if (start > end)
			return null;
		if (start < 0)
			return null;
		if (end > array.length)
			return null;

		char[][] result = new char[end - start][];
		System.arraycopy(array, start, result, 0, end - start);
		return result;
	}

	/**
	 * Answers a new array which is a copy of the given array starting at the
	 * given start and ending at the given end. The given start is inclusive and
	 * the given end is exclusive. Answers null if start is greater than end, if
	 * start is lower than 0 or if end is greater than the length of the given
	 * array. If end equals -1, it is converted to the array length. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a' , 'b' }
	 *     start = 0
	 *     end = 1
	 *     result =&gt; { 'a' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'a', 'b' }
	 *     start = 0
	 *     end = -1
	 *     result =&gt; { 'a' , 'b' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param array
	 *            the given array
	 * @param start
	 *            the given starting index
	 * @param end
	 *            the given ending index
	 * @return a new array which is a copy of the given array starting at the
	 *         given start and ending at the given end
	 * @exception NullPointerException
	 *                if the given array is null
	 */
	public static final char[] subarray(char[] array, int start, int end) {
		if (end == -1)
			end = array.length;
		if (start > end)
			return null;
		if (start < 0)
			return null;
		if (end > array.length)
			return null;

		char[] result = new char[end - start];
		System.arraycopy(array, start, result, 0, end - start);
		return result;
	}

	/**
	 * Answers the result of a char[] conversion to lowercase. Answers null if
	 * the given chars array is null. <br>
	 * NOTE: if no conversion was necessary, then answers back the argument one.
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     chars = { 'a' , 'b' }
	 *     result =&gt; { 'a' , 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'A', 'b' }
	 *     result =&gt; { 'a' , 'b' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param chars
	 *            the chars to convert
	 * @return the result of a char[] conversion to lowercase
	 */
	final static public char[] toLowerCase(char[] chars) {
		if (chars == null)
			return null;
		int length = chars.length;
		char[] lowerChars = null;
		for (int i = 0; i < length; i++) {
			char c = chars[i];
			char lc = Character.toLowerCase(c);
			if ((c != lc) || (lowerChars != null)) {
				if (lowerChars == null) {
					System.arraycopy(chars, 0, lowerChars = new char[length],
							0, i);
				}
				lowerChars[i] = lc;
			}
		}
		return lowerChars == null ? chars : lowerChars;
	}

	/**
	 * Answers a new array removing leading and trailing spaces (' '). Answers
	 * the given array if there is no space characters to remove. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     chars = { ' ', 'a' , 'b', ' ',  ' ' }
	 *     result =&gt; { 'a' , 'b' }
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { 'A', 'b' }
	 *     result =&gt; { 'A' , 'b' }
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param chars
	 *            the given array
	 * @return a new array removing leading and trailing spaces (' ')
	 */
	final static public char[] trim(char[] chars) {

		if (chars == null)
			return null;

		int start = 0, length = chars.length, end = length - 1;
		while (start < length && chars[start] == ' ') {
			start++;
		}
		while (end > start && chars[end] == ' ') {
			end--;
		}
		if (start != 0 || end != length - 1) {
			return subarray(chars, start, end + 1);
		}
		return chars;
	}

	/**
	 * Answers a string which is the concatenation of the given array using the
	 * '.' as a separator. <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li>
	 * 
	 * <pre>
	 *     array = { { 'a' } , { 'b' } }
	 *     result =&gt; &quot;a.b&quot;
	 * </pre>
	 * 
	 * </li>
	 * <li>
	 * 
	 * <pre>
	 *     array = { { ' ',  'a' } , { 'b' } }
	 *     result =&gt; &quot; a.b&quot;
	 * </pre>
	 * 
	 * </li>
	 * </ol>
	 * 
	 * @param chars
	 *            the given array
	 * @return a string which is the concatenation of the given array using the
	 *         '.' as a separator
	 */
	final static public String toString(char[][] array) {
		char[] result = concatWith(array, '.');
		return new String(result);
	}
}
