/*******************************************************************************
 * Copyright (c) 2010 Alena Laskavaia and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Alena Laskavaia - initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.codan.internal.core;

/**
 * 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'
	 * => result = { 'a', 'b' , 'c' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = null
	 * suffix = 'c'
	 * => 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 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', '0' }
	 * index = 2
	 * array = { 'c', 'd' }
	 * start = 0
	 * end = 1
	 * => result = { 'a', 'b' , 'c' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * target = { 'a', 'b' }
	 * index = 2
	 * array = { 'c', 'd' }
	 * start = 0
	 * end = 1
	 * => result = { 'a', 'b' , 'c', '0', '0' , '0' } (new array)
	 * </pre></li>
	 * <li><pre>
	 * target = { 'a', 'b', 'c' }
	 * index = 1
	 * array = { 'c', 'd', 'e', 'f' }
	 * start = 1
	 * end = 4
	 * => result = { 'a', 'd' , 'e', 'f', '0', '0', '0', '0' } (new array)
	 * </pre></li>
	 * </ol>
	 *
	 * @param target
	 *        the given target
	 * @param index
	 *        the given index
	 * @param array
	 *        the given array
	 * @param start
	 *        the given start index
	 * @param end
	 *        the given end index
	 *
	 * @return the new array
	 * @throws NullPointerException
	 *         if the target array is null
	 */
	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
	 * => result = null
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { ' a' } }
	 * second = null
	 * => result = { { ' a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = null
	 * second = { { ' a' } }
	 * => result = { { ' a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { ' b' } }
	 * second = { { ' a' } }
	 * => 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' }
	 * => result = { { ' a' } }
	 * </pre>
	 * <li><pre>
	 * first = { { ' a' } }
	 * second = null
	 * => result = { { ' a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { ' a' } }
	 * second = { ' b' }
	 * => 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;
	}

	/**
	 * Compares the contents of the two arrays array and prefix. Returns
	 * <ul>
	 * <li>zero if the array starts with the prefix contents</li>
	 * <li>the difference between the first two characters that are not equal
	 * </li>
	 * <li>one if array length is lower than the prefix length and that the
	 * prefix starts with the
	 * array contents.</li>
	 * </ul>
	 * <p>
	 * For example:
	 * <ol>
	 * <li><pre>
	 * array = null
	 * prefix = null
	 * => result = NullPointerException
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'a', 'b', 'c', 'd', 'e' }
	 * prefix = { 'a', 'b', 'c'}
	 * => result = 0
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'a', 'b', 'c', 'd', 'e' }
	 * prefix = { 'a', 'B', 'c'}
	 * => result = 32
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'd', 'b', 'c', 'd', 'e' }
	 * prefix = { 'a', 'b', 'c'}
	 * => result = 3
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'a', 'b', 'c', 'd', 'e' }
	 * prefix = { 'd', 'b', 'c'}
	 * => result = -3
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'a', 'a', 'c', 'd', 'e' }
	 * prefix = { 'a', 'e', 'c'}
	 * => result = -4
	 * </pre>
	 * </li>
	 * </ol>
	 * </p>
	 *
	 * @param array
	 *        the given array
	 * @param prefix
	 *        the given prefix
	 * @return the result of the comparison
	 * @exception NullPointerException
	 *            if either array or prefix is null
	 */
	public static final int compareWith(char[] array, char[] prefix) {
		int arrayLength = array.length;
		int prefixLength = prefix.length;
		int min = Math.min(arrayLength, prefixLength);
		int i = 0;
		while (min-- != 0) {
			char c1 = array[i];
			char c2 = prefix[i++];
			if (c1 != c2)
				return c1 - c2;
		}
		if (prefixLength == i)
			return 0;
		return 1;
	}

	/**
	 * 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' }
	 * => result = { ' a' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { ' a' }
	 * second = null
	 * => result = { ' a' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { ' a' }
	 * second = { ' b' }
	 * => 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' }
	 * => result = { ' a', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * second = null
	 * third = { 'b' }
	 * => result = { ' a', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * second = { 'b' }
	 * third = null
	 * => result = { ' a', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = null
	 * second = null
	 * third = null
	 * => result = null
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * second = { 'b' }
	 * third = { 'c' }
	 * => 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 = '/'
	 * => result = { ' a' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { ' a' }
	 * second = null
	 * separator = '/'
	 * => result = { ' a' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { ' a' }
	 * second = { ' b' }
	 * separator = '/'
	 * => 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 it answers the concatenation of first
	 * and third inserting
	 * the sep1 character between them.
	 * If the third array is null, then it answers the concatenation of first
	 * and second inserting
	 * the sep1 character between them.
	 * <br>
	 * <br>
	 * For example:
	 * <ol>
	 * <li><pre>
	 * first = null
	 * sep1 = '/'
	 * second = { 'a' }
	 * sep2 = ':'
	 * third = { 'b' }
	 * => result = { ' a' , ':', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * sep1 = '/'
	 * second = null
	 * sep2 = ':'
	 * third = { 'b' }
	 * => result = { ' a' , '/', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * sep1 = '/'
	 * second = { 'b' }
	 * sep2 = ':'
	 * third = null
	 * => result = { ' a' , '/', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * sep1 = '/'
	 * second = { 'b' }
	 * sep2 = ':'
	 * third = { 'c' }
	 * => result = { ' a' , '/', 'b' , ':', 'c' }
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param first
	 *        the first array to concatenate
	 * @param sep1
	 *        the character to insert
	 * @param second
	 *        the second array to concatenate
	 * @param sep2
	 *        the character to insert
	 * @param third
	 *        the second array to concatenate
	 * @return the concatenation of the three arrays inserting the sep1
	 *         character between the
	 *         two arrays and sep2 between the last two.
	 */
	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'
	 * => result = { 'a', 'b' , 'c' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * prefix = 'a'
	 * array = null
	 * suffix = 'c'
	 * => 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 = '.'
	 * => result = { 'a', '.', 'b' , '.', 'c' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * name = null
	 * array = { { 'a' }, { 'b' } }
	 * separator = '.'
	 * => result = { 'a', '.', 'b' }
	 * </pre></li>
	 * <li><pre>
	 * name = { ' c' }
	 * array = null
	 * separator = '.'
	 * => 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);
		if (array == null)
			return name;
		final int length = 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 = '.'
	 * => result = { 'a', '.', 'b' , '.', 'c' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * name = null
	 * array = { { 'a' }, { 'b' } }
	 * separator = '.'
	 * => result = { 'a', '.', 'b' }
	 * </pre></li>
	 * <li><pre>
	 * name = { ' c' }
	 * array = null
	 * separator = '.'
	 * => 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);
		if (array == null)
			return name;
		final int length = 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 = '.'
	 * => result = { 'a', '.', 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = null
	 * separator = '.'
	 * => 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) {
		if (array == null)
			return CharOperation.NO_CHAR;
		int length = 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 => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * character = 'a'
	 * array = { { ' a' }, { ' b' } }
	 * result => true
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param character
	 *        the character to search
	 * @param array
	 *        the array in which the search is done
	 * @return true if the array contains an occurrence of character, false
	 *         otherwise.
	 * @exception NullPointerException
	 *            if array is null.
	 */
	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 => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * character = 'a'
	 * array = { ' a' , ' b' }
	 * result => true
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param character
	 *        the character to search
	 * @param array
	 *        the array in which the search is done
	 * @return true if the array contains an occurrence of character, false
	 *         otherwise.
	 * @exception NullPointerException
	 *            if array is null.
	 */
	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 => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'a', 'b', 'c' }
	 * toBeFound = { 'b', 'c' }
	 * result => true
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param array
	 *        the array to check
	 * @param toBeFound
	 *        the array to find
	 * @return true if array ends with the sequence of characters contained in
	 *         toBeFound,
	 *         otherwise false.
	 * @exception NullPointerException
	 *            if array is null or toBeFound is null
	 */
	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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { } }
	 * second = null
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { 'a' } }
	 * second = { { 'a' } }
	 * result => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { 'A' } }
	 * second = { { 'a' } }
	 * result => 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { } }
	 * second = null
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { 'A' } }
	 * second = { { 'a' } }
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { { 'A' } }
	 * second = { { 'a' } }
	 * isCaseSensitive = false
	 * result => 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { }
	 * second = null
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * second = { 'a' }
	 * result => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'a' }
	 * second = { 'A' }
	 * result => 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { }
	 * second = null
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'A' }
	 * second = { 'a' }
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * first = { 'A' }
	 * second = { 'a' }
	 * isCaseSensitive = false
	 * result => 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * fragment = { 'b', 'c' , 'd' }
	 * name = { 'a', 'b', 'C' , 'd' }
	 * startIndex = 1
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * fragment = { 'b', 'c' , 'd' }
	 * name = { 'a', 'b', 'C' , 'd' }
	 * startIndex = 0
	 * isCaseSensitive = false
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * fragment = { 'b', 'c' , 'd' }
	 * name = { 'a', 'b'}
	 * startIndex = 0
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param fragment
	 *        the fragment to check
	 * @param name
	 *        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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * c = '&#92;u3000'
	 * result => 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 => 2
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'e'
	 * array = { ' a', 'b', 'c', 'd' }
	 * result => -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 => 2
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'c'
	 * array = { ' a', 'b', 'c', 'd' }
	 * start = 3
	 * result => -1
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'e'
	 * array = { ' a', 'b', 'c', 'd' }
	 * start = 1
	 * result => -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 => 4
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'e'
	 * array = { ' a', 'b', 'c', 'd' }
	 * result => -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 => 2
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'c'
	 * array = { ' a', 'b', 'c', 'd', 'e' }
	 * startIndex = 3
	 * result => -1
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'e'
	 * array = { ' a', 'b', 'c', 'd' }
	 * startIndex = 0
	 * result => -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 => 2
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'c'
	 * array = { ' a', 'b', 'c', 'd', 'e' }
	 * startIndex = 3
	 * endIndex = 4
	 * result => -1
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'e'
	 * array = { ' a', 'b', 'c', 'd' }
	 * startIndex = 0
	 * endIndex = 3
	 * result => -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("java.lang.Object".toCharArray(),'.') --> 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * pattern = { '?', 'b', '?' }
	 * name = { 'a', 'b', 'c' , 'd' }
	 * isCaseSensitive = true
	 * result => false
	 * </pre>
	 * </li>
	 * <li><pre>
	 * pattern = { 'b', '*' }
	 * name = { 'a', 'b', 'c' , 'd' }
	 * isCaseSensitive = true
	 * result => 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, true);
	}

	/**
	 * 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * pattern = { '?', 'b', '*' }
	 * patternStart = 1
	 * patternEnd = 2
	 * name = { 'a', 'b', 'c' , 'd' }
	 * nameStart = 1
	 * nameEnd = 2
	 * isCaseSensitive = true
	 * result => 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) {
		return match(pattern, patternStart, patternEnd, name, nameStart, nameEnd, isCaseSensitive, false);
	}

	public static final boolean match(char[] pattern, int patternStart, int patternEnd, char[] name, int nameStart, int nameEnd,
			boolean isCaseSensitive, boolean allowEscaping) {
		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;
		boolean isEscaped = false;
		while ((iPattern < patternEnd) && ((patternChar = pattern[iPattern]) != '*' || (patternChar == '*' && isEscaped))) {
			if (allowEscaping && pattern[iPattern] == '\\' && !isEscaped) {
				iPattern++;
				isEscaped = true;
				continue;
			} else
				isEscaped = false;
			if (iName == nameEnd)
				return false;
			if (patternChar != (isCaseSensitive ? name[iName] : Character.toLowerCase(name[iName])) && patternChar != '?') {
				return false;
			}
			iName++;
			iPattern++;
			patternChar = 0;
		}
		/* 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\**
	 * - *.java is equivalent to **\*.java
	 * 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;
		freeLeadingDoubleStar = (pattern[0] != pathSeparator);
		if (freeLeadingDoubleStar) {
			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 {
			if (pSegmentStart >= pLength)
				return fSegmentStart >= fLength; // true if filepath is done too.
			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 => 3
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'c'
	 * array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * result => 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 (char element : array) {
			if (toBeFound == element)
				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 => 2
	 * </pre>
	 * </li>
	 * <li><pre>
	 * toBeFound = 'c'
	 * array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * start = 0
	 * result => 0
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param toBeFound the given character
	 * @param array the given array
	 * @param start the start position for the search
	 * @return the number of occurrences of the given character in the given array, or 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * prefix = { 'a' , 'c' }
	 * name = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * result => 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 => true
	 * </pre>
	 * </li>
	 * <li><pre>
	 * prefix = { 'a' , 'B' }
	 * name = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * isCaseSensitive = true
	 * result => 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 => 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 => 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 => { '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 => { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param array
	 *        the given array
	 * @param toBeReplaced
	 *        characters to be replaced
	 * @param replacementChars
	 *        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 => { { 'a' }, { }, { 'a' }, { 'a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * divider = 'c'
	 * array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * result => { { 'a', 'b', 'b', 'a', 'b', 'a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * divider = 'b'
	 * array = { 'a' , ' ', 'b', 'b', 'a', 'b', 'a' }
	 * result => { { 'a' }, { }, { 'a' }, { 'a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * divider = 'c'
	 * array = { ' ', ' ', 'a' , 'b', 'b', 'a', 'b', 'a', ' ' }
	 * result => { { '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) {
		if (array == null)
			return NO_CHAR_CHAR;
		final int length = 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 => { { 'a' }, { }, { 'a' }, { 'a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * divider = 'c'
	 * array = { 'a' , 'b', 'b', 'a', 'b', 'a' }
	 * result => { { 'a', 'b', 'b', 'a', 'b', 'a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * divider = 'c'
	 * array = { ' ', ' ', 'a' , 'b', 'b', 'a', 'b', 'a', ' ' }
	 * result => { { ' ', '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) {
		if (array == null)
			return NO_CHAR_CHAR;
		final int length = 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 => { { }, { }, { '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) {
		if (array == null)
			return NO_CHAR_CHAR;
		final int length = 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 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 => { { 'a' } }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { { 'a' } , { 'b' } }
	 * start = 0
	 * end = -1
	 * result => { { '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 => { 'a' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'a', 'b' }
	 * start = 0
	 * end = -1
	 * result => { '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 => { 'a' , 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'A', 'b' }
	 * result => { '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 => { 'a' , 'b' }
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { 'A', 'b' }
	 * result => { '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 => "a.b"
	 * </pre>
	 * </li>
	 * <li><pre>
	 * array = { { ' ', 'a' } , { 'b' } }
	 * result => " a.b"
	 * </pre>
	 * </li>
	 * </ol>
	 *
	 * @param array
	 *        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);
	}
}
