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   *  This file is part of AndroidIDE.
   *
   *  AndroidIDE is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id: XString.java,v 1.2.4.1 2005/09/14 20:47:20 jeffsuttor Exp $
   */
  package jaxp.sun.org.apache.xpath.internal.objects;
  
  import java.util.Locale;
  
  import jaxp.sun.org.apache.xml.internal.dtm.DTM;
  import jaxp.sun.org.apache.xml.internal.utils.XMLCharacterRecognizer;
  import jaxp.sun.org.apache.xml.internal.utils.XMLString;
  import jaxp.sun.org.apache.xml.internal.utils.XMLStringFactory;
  import jaxp.sun.org.apache.xml.internal.utils.WrappedRuntimeException;
  import jaxp.sun.org.apache.xpath.internal.ExpressionOwner;
  import jaxp.sun.org.apache.xpath.internal.XPathContext;
  import jaxp.sun.org.apache.xpath.internal.XPathVisitable;
  import jaxp.sun.org.apache.xpath.internal.XPathVisitor;
  import jaxp.xml.transform.TransformerException;
  
  /**
   * This class represents an XPath string object, and is capable of
   * converting the string to other types, such as a number.
   * @xsl.usage general
   */
  public class XString extends XObject implements XMLString
  {
      static final long serialVersionUID = 2020470518395094525L;
  
    /** Empty string XString object */
    public static final XString EMPTYSTRING = new XString("");
  
    /**
     * Construct a XString object.  This constructor exists for derived classes.
     *
     * @param val String object this will wrap.
     */
    protected XString(Object val)
    {
      super(val);
    }
  
    /**
     * Construct a XNodeSet object.
     *
     * @param val String object this will wrap.
     */
    public XString(String val)
    {
      super(val);
    }
  
    /**
     * Tell that this is a CLASS_STRING.
     *
     * @return type CLASS_STRING
     */
    public int getType()
    {
      return CLASS_STRING;
    }
  
    /**
     * Given a request type, return the equivalent string.
     * For diagnostic purposes.
     *
     * @return type string "#STRING"
     */
    public String getTypeString()
    {
      return "#STRING";
    }
  
    /**
     * Tell if this object contains a java String object.
     *
     * @return true if this XMLString can return a string without creating one.
     */
    public boolean hasString()
    {
      return true;
    }
  
    /**
     * Cast result object to a number.
     *
     * @return 0.0 if this string is null, numeric value of this string
     * or NaN
     */
    public double num()
    {
      return toDouble();
    }
  
    /**
     * Convert a string to a double -- Allowed input is in fixed
     * notation ddd.fff.
     *
     * @return A double value representation of the string, or return Double.NaN
     * if the string can not be converted.
     */
    public double toDouble()
    {
      /* XMLCharacterRecognizer.isWhiteSpace(char c) methods treats the following
       * characters as white space characters.
       * ht - horizontal tab, nl - newline , cr - carriage return and sp - space
       * trim() methods by default also takes care of these white space characters
       * So trim() method is used to remove leading and trailing white spaces.
       */
          XMLString s = trim();
          double result = Double.NaN;
          for (int i = 0; i < s.length(); i++)
          {
                  char c = s.charAt(i);
      if (c != '-' && c != '.' && ( c < 0X30 || c > 0x39)) {
              // The character is not a '-' or a '.' or a digit
              // then return NaN because something is wrong.
                          return result;
          }
          }
          try
          {
                  result = Double.parseDouble(s.toString());
          } catch (NumberFormatException e){}
  
          return result;
  }
  
    /**
     * Cast result object to a boolean.
     *
     * @return True if the length of this string object is greater
     * than 0.
     */
    public boolean bool()
    {
      return str().length() > 0;
    }
  
    /**
     * Cast result object to a string.
     *
     * @return The string this wraps or the empty string if null
     */
    public XMLString xstr()
    {
      return this;
    }
  
    /**
     * Cast result object to a string.
     *
     * @return The string this wraps or the empty string if null
     */
    public String str()
    {
      return (null != m_obj) ? ((String) m_obj) : "";
    }
  
    /**
     * Cast result object to a result tree fragment.
     *
     * @param support Xpath context to use for the conversion
     *
     * @return A document fragment with this string as a child node
     */
    public int rtf(XPathContext support)
    {
  
      DTM frag = support.createDocumentFragment();
  
      frag.appendTextChild(str());
  
      return frag.getDocument();
    }
  
    /**
     * Directly call the
     * characters method on the passed ContentHandler for the
     * string-value. Multiple calls to the
     * ContentHandler's characters methods may well occur for a single call to
     * this method.
     *
     * @param ch A non-null reference to a ContentHandler.
     *
     * @throws org.xml.sax.SAXException
     */
    public void dispatchCharactersEvents(org.xml.sax.ContentHandler ch)
            throws org.xml.sax.SAXException
    {
  
      String str = str();
  
      ch.characters(str.toCharArray(), 0, str.length());
    }
  
    /**
     * Directly call the
     * comment method on the passed LexicalHandler for the
     * string-value.
     *
     * @param lh A non-null reference to a LexicalHandler.
     *
     * @throws org.xml.sax.SAXException
     */
    public void dispatchAsComment(org.xml.sax.ext.LexicalHandler lh)
            throws org.xml.sax.SAXException
    {
  
      String str = str();
  
      lh.comment(str.toCharArray(), 0, str.length());
    }
  
    /**
     * Returns the length of this string.
     *
     * @return  the length of the sequence of characters represented by this
     *          object.
     */
    public int length()
    {
      return str().length();
    }
  
    /**
     * Returns the character at the specified index. An index ranges
     * from <code>0</code> to <code>length() - 1</code>. The first character
     * of the sequence is at index <code>0</code>, the next at index
     * <code>1</code>, and so on, as for array indexing.
     *
     * @param      index   the index of the character.
     * @return     the character at the specified index of this string.
     *             The first character is at index <code>0</code>.
     * @exception  IndexOutOfBoundsException  if the <code>index</code>
     *             argument is negative or not less than the length of this
     *             string.
     */
    public char charAt(int index)
    {
      return str().charAt(index);
    }
  
    /**
     * Copies characters from this string into the destination character
     * array.
     *
     * @param      srcBegin   index of the first character in the string
     *                        to copy.
     * @param      srcEnd     index after the last character in the string
     *                        to copy.
     * @param      dst        the destination array.
     * @param      dstBegin   the start offset in the destination array.
     * @exception IndexOutOfBoundsException If any of the following
     *            is true:
     *            <ul><li><code>srcBegin</code> is negative.
     *            <li><code>srcBegin</code> is greater than <code>srcEnd</code>
     *            <li><code>srcEnd</code> is greater than the length of this
     *                string
     *            <li><code>dstBegin</code> is negative
     *            <li><code>dstBegin+(srcEnd-srcBegin)</code> is larger than
     *                <code>dst.length</code></ul>
     * @exception NullPointerException if <code>dst</code> is <code>null</code>
     */
    public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin)
    {
      str().getChars(srcBegin, srcEnd, dst, dstBegin);
    }
  
    /**
     * Tell if two objects are functionally equal.
     *
     * @param obj2 Object to compare this to
     *
     * @return true if the two objects are equal
     *
     * @throws TransformerException
     */
    public boolean equals(XObject obj2)
    {
  
      // In order to handle the 'all' semantics of
      // nodeset comparisons, we always call the
      // nodeset function.
      int t = obj2.getType();
      try
      {
              if (XObject.CLASS_NODESET == t)
                return obj2.equals(this);
              // If at least one object to be compared is a boolean, then each object
              // to be compared is converted to a boolean as if by applying the
              // boolean function.
              else if(XObject.CLASS_BOOLEAN == t)
                  return obj2.bool() == bool();
              // Otherwise, if at least one object to be compared is a number, then each object
              // to be compared is converted to a number as if by applying the number function.
              else if(XObject.CLASS_NUMBER == t)
                  return obj2.num() == num();
      }
      catch(TransformerException te)
      {
          throw new WrappedRuntimeException(te);
      }
  
      // Otherwise, both objects to be compared are converted to strings as
      // if by applying the string function.
      return xstr().equals(obj2.xstr());
    }
  
     /**
     * Compares this string to the specified <code>String</code>.
     * The result is <code>true</code> if and only if the argument is not
     * <code>null</code> and is a <code>String</code> object that represents
     * the same sequence of characters as this object.
     *
     * @param   obj2   the object to compare this <code>String</code> against.
     * @return  <code>true</code> if the <code>String</code>s are equal;
     *          <code>false</code> otherwise.
     * @see     java.lang.String#compareTo(java.lang.String)
     * @see     java.lang.String#equalsIgnoreCase(java.lang.String)
     */
    public boolean equals(String obj2) {
      return str().equals(obj2);
    }
  
    /**
     * Compares this string to the specified object.
     * The result is <code>true</code> if and only if the argument is not
     * <code>null</code> and is a <code>String</code> object that represents
     * the same sequence of characters as this object.
     *
     * @param obj2   the object to compare this <code>String</code>
     *                     against.
     * @return  <code>true</code> if the <code>String </code>are equal;
     *          <code>false</code> otherwise.
     * @see     java.lang.String#compareTo(java.lang.String)
     * @see     java.lang.String#equalsIgnoreCase(java.lang.String)
     */
    public boolean equals(XMLString obj2)
    {
      if (obj2 != null) {
        if (!obj2.hasString()) {
          return obj2.equals(str());
        } else {
          return str().equals(obj2.toString());
        }
      }
      return false;
    }
  
    /**
     * Compares this string to the specified object.
     * The result is <code>true</code> if and only if the argument is not
     * <code>null</code> and is a <code>String</code> object that represents
     * the same sequence of characters as this object.
     *
     * @param   obj2       the object to compare this <code>String</code>
     *                     against.
     * @return  <code>true</code> if the <code>String </code>are equal;
     *          <code>false</code> otherwise.
     * @see     java.lang.String#compareTo(java.lang.String)
     * @see     java.lang.String#equalsIgnoreCase(java.lang.String)
     */
    public boolean equals(Object obj2)
    {
  
      if (null == obj2)
        return false;
  
        // In order to handle the 'all' semantics of
        // nodeset comparisons, we always call the
        // nodeset function.
      else if (obj2 instanceof XNodeSet)
        return obj2.equals(this);
      else if(obj2 instanceof XNumber)
          return obj2.equals(this);
      else
        return str().equals(obj2.toString());
    }
  
    /**
     * Compares this <code>String</code> to another <code>String</code>,
     * ignoring case considerations.  Two strings are considered equal
     * ignoring case if they are of the same length, and corresponding
     * characters in the two strings are equal ignoring case.
     *
     * @param   anotherString   the <code>String</code> to compare this
     *                          <code>String</code> against.
     * @return  <code>true</code> if the argument is not <code>null</code>
     *          and the <code>String</code>s are equal,
     *          ignoring case; <code>false</code> otherwise.
     * @see     #equals(Object)
     * @see     java.lang.Character#toLowerCase(char)
     * @see java.lang.Character#toUpperCase(char)
     */
    public boolean equalsIgnoreCase(String anotherString)
    {
      return str().equalsIgnoreCase(anotherString);
    }
  
    /**
     * Compares two strings lexicographically.
     *
     * @param   xstr   the <code>String</code> to be compared.
     *
     * @return  the value <code>0</code> if the argument string is equal to
     *          this string; a value less than <code>0</code> if this string
     *          is lexicographically less than the string argument; and a
     *          value greater than <code>0</code> if this string is
     *          lexicographically greater than the string argument.
     * @exception java.lang.NullPointerException if <code>anotherString</code>
     *          is <code>null</code>.
     */
    public int compareTo(XMLString xstr)
    {
  
      int len1 = this.length();
      int len2 = xstr.length();
      int n = Math.min(len1, len2);
      int i = 0;
      int j = 0;
  
      while (n-- != 0)
      {
        char c1 = this.charAt(i);
        char c2 = xstr.charAt(j);
  
        if (c1 != c2)
        {
          return c1 - c2;
        }
  
        i++;
        j++;
      }
  
      return len1 - len2;
    }
  
    /**
     * Compares two strings lexicographically, ignoring case considerations.
     * This method returns an integer whose sign is that of
     * <code>this.toUpperCase().toLowerCase().compareTo(
     * str.toUpperCase().toLowerCase())</code>.
     * <p>
     * Note that this method does <em>not</em> take locale into account,
     * and will result in an unsatisfactory ordering for certain locales.
     * The java.text package provides <em>collators</em> to allow
     * locale-sensitive ordering.
     *
     * @param   str   the <code>String</code> to be compared.
     * @return  a negative integer, zero, or a positive integer as the
     *          the specified String is greater than, equal to, or less
     *          than this String, ignoring case considerations.
     * @see     java.text.Collator#compare(String, String)
     * @since   1.2
     */
    public int compareToIgnoreCase(XMLString str)
    {
      // %REVIEW%  Like it says, @since 1.2. Doesn't exist in earlier
      // versions of Java, hence we can't yet shell out to it. We can implement
      // it as character-by-character compare, but doing so efficiently
      // is likely to be (ahem) interesting.
      //
      // However, since nobody is actually _using_ this method yet:
      //    return str().compareToIgnoreCase(str.toString());
  
      throw new WrappedRuntimeException(
        new java.lang.NoSuchMethodException(
          "Java 1.2 method, not yet implemented"));
    }
  
    /**
     * Tests if this string starts with the specified prefix beginning
     * a specified index.
     *
     * @param   prefix    the prefix.
     * @param   toffset   where to begin looking in the string.
     * @return  <code>true</code> if the character sequence represented by the
     *          argument is a prefix of the substring of this object starting
     *          at index <code>toffset</code>; <code>false</code> otherwise.
     *          The result is <code>false</code> if <code>toffset</code> is
     *          negative or greater than the length of this
     *          <code>String</code> object; otherwise the result is the same
     *          as the result of the expression
     *          <pre>
     *          this.subString(toffset).startsWith(prefix)
     *          </pre>
     * @exception java.lang.NullPointerException if <code>prefix</code> is
     *          <code>null</code>.
     */
    public boolean startsWith(String prefix, int toffset)
    {
      return str().startsWith(prefix, toffset);
    }
  
    /**
     * Tests if this string starts with the specified prefix.
     *
     * @param   prefix   the prefix.
     * @return  <code>true</code> if the character sequence represented by the
     *          argument is a prefix of the character sequence represented by
     *          this string; <code>false</code> otherwise.
     *          Note also that <code>true</code> will be returned if the
     *          argument is an empty string or is equal to this
     *          <code>String</code> object as determined by the
     *          {@link #equals(Object)} method.
     * @exception java.lang.NullPointerException if <code>prefix</code> is
     *          <code>null</code>.
     */
    public boolean startsWith(String prefix)
    {
      return startsWith(prefix, 0);
    }
  
    /**
     * Tests if this string starts with the specified prefix beginning
     * a specified index.
     *
     * @param   prefix    the prefix.
     * @param   toffset   where to begin looking in the string.
     * @return  <code>true</code> if the character sequence represented by the
     *          argument is a prefix of the substring of this object starting
     *          at index <code>toffset</code>; <code>false</code> otherwise.
     *          The result is <code>false</code> if <code>toffset</code> is
     *          negative or greater than the length of this
     *          <code>String</code> object; otherwise the result is the same
     *          as the result of the expression
     *          <pre>
     *          this.subString(toffset).startsWith(prefix)
     *          </pre>
     * @exception java.lang.NullPointerException if <code>prefix</code> is
     *          <code>null</code>.
     */
    public boolean startsWith(XMLString prefix, int toffset)
    {
  
      int to = toffset;
      int tlim = this.length();
      int po = 0;
      int pc = prefix.length();
  
      // Note: toffset might be near -1>>>1.
      if ((toffset < 0) || (toffset > tlim - pc))
      {
        return false;
      }
  
      while (--pc >= 0)
      {
        if (this.charAt(to) != prefix.charAt(po))
        {
          return false;
        }
  
        to++;
        po++;
      }
  
      return true;
    }
  
    /**
     * Tests if this string starts with the specified prefix.
     *
     * @param   prefix   the prefix.
     * @return  <code>true</code> if the character sequence represented by the
     *          argument is a prefix of the character sequence represented by
     *          this string; <code>false</code> otherwise.
     *          Note also that <code>true</code> will be returned if the
     *          argument is an empty string or is equal to this
     *          <code>String</code> object as determined by the
     *          {@link #equals(Object)} method.
     * @exception java.lang.NullPointerException if <code>prefix</code> is
     *          <code>null</code>.
     */
    public boolean startsWith(XMLString prefix)
    {
      return startsWith(prefix, 0);
    }
  
    /**
     * Tests if this string ends with the specified suffix.
     *
     * @param   suffix   the suffix.
     * @return  <code>true</code> if the character sequence represented by the
     *          argument is a suffix of the character sequence represented by
     *          this object; <code>false</code> otherwise. Note that the
     *          result will be <code>true</code> if the argument is the
     *          empty string or is equal to this <code>String</code> object
     *          as determined by the {@link #equals(Object)} method.
     * @exception java.lang.NullPointerException if <code>suffix</code> is
     *          <code>null</code>.
     */
    public boolean endsWith(String suffix)
    {
      return str().endsWith(suffix);
    }
  
    /**
     * Returns a hashcode for this string. The hashcode for a
     * <code>String</code> object is computed as
     * <blockquote><pre>
     * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
     * </pre></blockquote>
     * using <code>int</code> arithmetic, where <code>s[i]</code> is the
     * <i>i</i>th character of the string, <code>n</code> is the length of
     * the string, and <code>^</code> indicates exponentiation.
     * (The hash value of the empty string is zero.)
     *
     * @return  a hash code value for this object.
     */
    public int hashCode()
    {
      return str().hashCode();
    }
  
    /**
     * Returns the index within this string of the first occurrence of the
     * specified character. If a character with value <code>ch</code> occurs
     * in the character sequence represented by this <code>String</code>
     * object, then the index of the first such occurrence is returned --
     * that is, the smallest value <i>k</i> such that:
     * <blockquote><pre>
     * this.charAt(<i>k</i>) == ch
     * </pre></blockquote>
     * is <code>true</code>. If no such character occurs in this string,
     * then <code>-1</code> is returned.
     *
     * @param   ch   a character.
     * @return  the index of the first occurrence of the character in the
     *          character sequence represented by this object, or
     *          <code>-1</code> if the character does not occur.
     */
    public int indexOf(int ch)
    {
      return str().indexOf(ch);
    }
  
    /**
     * Returns the index within this string of the first occurrence of the
     * specified character, starting the search at the specified index.
     * <p>
     * If a character with value <code>ch</code> occurs in the character
     * sequence represented by this <code>String</code> object at an index
     * no smaller than <code>fromIndex</code>, then the index of the first
     * such occurrence is returned--that is, the smallest value <i>k</i>
     * such that:
     * <blockquote><pre>
     * (this.charAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex)
     * </pre></blockquote>
     * is true. If no such character occurs in this string at or after
     * position <code>fromIndex</code>, then <code>-1</code> is returned.
     * <p>
     * There is no restriction on the value of <code>fromIndex</code>. If it
     * is negative, it has the same effect as if it were zero: this entire
     * string may be searched. If it is greater than the length of this
     * string, it has the same effect as if it were equal to the length of
     * this string: <code>-1</code> is returned.
     *
     * @param   ch          a character.
     * @param   fromIndex   the index to start the search from.
     * @return  the index of the first occurrence of the character in the
     *          character sequence represented by this object that is greater
     *          than or equal to <code>fromIndex</code>, or <code>-1</code>
     *          if the character does not occur.
     */
    public int indexOf(int ch, int fromIndex)
    {
      return str().indexOf(ch, fromIndex);
    }
  
    /**
     * Returns the index within this string of the last occurrence of the
     * specified character. That is, the index returned is the largest
     * value <i>k</i> such that:
     * <blockquote><pre>
     * this.charAt(<i>k</i>) == ch
     * </pre></blockquote>
     * is true.
     * The String is searched backwards starting at the last character.
     *
     * @param   ch   a character.
     * @return  the index of the last occurrence of the character in the
     *          character sequence represented by this object, or
     *          <code>-1</code> if the character does not occur.
     */
    public int lastIndexOf(int ch)
    {
      return str().lastIndexOf(ch);
    }
  
    /**
     * Returns the index within this string of the last occurrence of the
     * specified character, searching backward starting at the specified
     * index. That is, the index returned is the largest value <i>k</i>
     * such that:
     * <blockquote><pre>
     * this.charAt(k) == ch) && (k <= fromIndex)
     * </pre></blockquote>
     * is true.
     *
     * @param   ch          a character.
     * @param   fromIndex   the index to start the search from. There is no
     *          restriction on the value of <code>fromIndex</code>. If it is
     *          greater than or equal to the length of this string, it has
     *          the same effect as if it were equal to one less than the
     *          length of this string: this entire string may be searched.
     *          If it is negative, it has the same effect as if it were -1:
     *          -1 is returned.
     * @return  the index of the last occurrence of the character in the
     *          character sequence represented by this object that is less
     *          than or equal to <code>fromIndex</code>, or <code>-1</code>
     *          if the character does not occur before that point.
     */
    public int lastIndexOf(int ch, int fromIndex)
    {
      return str().lastIndexOf(ch, fromIndex);
    }
  
    /**
     * Returns the index within this string of the first occurrence of the
     * specified substring. The integer returned is the smallest value
     * <i>k</i> such that:
     * <blockquote><pre>
     * this.startsWith(str, <i>k</i>)
     * </pre></blockquote>
     * is <code>true</code>.
     *
     * @param   str   any string.
     * @return  if the string argument occurs as a substring within this
     *          object, then the index of the first character of the first
     *          such substring is returned; if it does not occur as a
     *          substring, <code>-1</code> is returned.
     * @exception java.lang.NullPointerException if <code>str</code> is
     *          <code>null</code>.
     */
    public int indexOf(String str)
    {
      return str().indexOf(str);
    }
  
    /**
     * Returns the index within this string of the first occurrence of the
     * specified substring. The integer returned is the smallest value
     * <i>k</i> such that:
     * <blockquote><pre>
     * this.startsWith(str, <i>k</i>)
     * </pre></blockquote>
     * is <code>true</code>.
     *
     * @param   str   any string.
     * @return  if the string argument occurs as a substring within this
     *          object, then the index of the first character of the first
     *          such substring is returned; if it does not occur as a
     *          substring, <code>-1</code> is returned.
     * @exception java.lang.NullPointerException if <code>str</code> is
     *          <code>null</code>.
     */
    public int indexOf(XMLString str)
    {
      return str().indexOf(str.toString());
    }
  
    /**
     * Returns the index within this string of the first occurrence of the
     * specified substring, starting at the specified index. The integer
     * returned is the smallest value <i>k</i> such that:
     * <blockquote><pre>
     * this.startsWith(str, <i>k</i>) && (<i>k</i> >= fromIndex)
     * </pre></blockquote>
     * is <code>true</code>.
     * <p>
     * There is no restriction on the value of <code>fromIndex</code>. If
     * it is negative, it has the same effect as if it were zero: this entire
     * string may be searched. If it is greater than the length of this
     * string, it has the same effect as if it were equal to the length of
     * this string: <code>-1</code> is returned.
     *
     * @param   str         the substring to search for.
     * @param   fromIndex   the index to start the search from.
     * @return  If the string argument occurs as a substring within this
     *          object at a starting index no smaller than
     *          <code>fromIndex</code>, then the index of the first character
     *          of the first such substring is returned. If it does not occur
     *          as a substring starting at <code>fromIndex</code> or beyond,
     *          <code>-1</code> is returned.
     * @exception java.lang.NullPointerException if <code>str</code> is
     *          <code>null</code>
     */
    public int indexOf(String str, int fromIndex)
    {
      return str().indexOf(str, fromIndex);
    }
  
    /**
     * Returns the index within this string of the rightmost occurrence
     * of the specified substring.  The rightmost empty string "" is
     * considered to occur at the index value <code>this.length()</code>.
     * The returned index is the largest value <i>k</i> such that
     * <blockquote><pre>
     * this.startsWith(str, k)
     * </pre></blockquote>
     * is true.
     *
     * @param   str   the substring to search for.
     * @return  if the string argument occurs one or more times as a substring
     *          within this object, then the index of the first character of
     *          the last such substring is returned. If it does not occur as
     *          a substring, <code>-1</code> is returned.
     * @exception java.lang.NullPointerException  if <code>str</code> is
     *          <code>null</code>.
     */
    public int lastIndexOf(String str)
    {
      return str().lastIndexOf(str);
    }
  
    /**
     * Returns the index within this string of the last occurrence of
     * the specified substring.
     *
     * @param   str         the substring to search for.
     * @param   fromIndex   the index to start the search from. There is no
     *          restriction on the value of fromIndex. If it is greater than
     *          the length of this string, it has the same effect as if it
     *          were equal to the length of this string: this entire string
     *          may be searched. If it is negative, it has the same effect
     *          as if it were -1: -1 is returned.
     * @return  If the string argument occurs one or more times as a substring
     *          within this object at a starting index no greater than
     *          <code>fromIndex</code>, then the index of the first character of
     *          the last such substring is returned. If it does not occur as a
     *          substring starting at <code>fromIndex</code> or earlier,
     *          <code>-1</code> is returned.
     * @exception java.lang.NullPointerException if <code>str</code> is
     *          <code>null</code>.
     */
    public int lastIndexOf(String str, int fromIndex)
    {
      return str().lastIndexOf(str, fromIndex);
    }
  
    /**
     * Returns a new string that is a substring of this string. The
     * substring begins with the character at the specified index and
     * extends to the end of this string. <p>
     * Examples:
     * <blockquote><pre>
     * "unhappy".substring(2) returns "happy"
     * "Harbison".substring(3) returns "bison"
     * "emptiness".substring(9) returns "" (an empty string)
     * </pre></blockquote>
     *
     * @param      beginIndex   the beginning index, inclusive.
     * @return     the specified substring.
     * @exception  IndexOutOfBoundsException  if
     *             <code>beginIndex</code> is negative or larger than the
     *             length of this <code>String</code> object.
     */
    public XMLString substring(int beginIndex)
    {
      return new XString(str().substring(beginIndex));
    }
  
    /**
     * Returns a new string that is a substring of this string. The
     * substring begins at the specified <code>beginIndex</code> and
     * extends to the character at index <code>endIndex - 1</code>.
     * Thus the length of the substring is <code>endIndex-beginIndex</code>.
     *
     * @param      beginIndex   the beginning index, inclusive.
     * @param      endIndex     the ending index, exclusive.
     * @return     the specified substring.
     * @exception  IndexOutOfBoundsException  if the
     *             <code>beginIndex</code> is negative, or
     *             <code>endIndex</code> is larger than the length of
     *             this <code>String</code> object, or
     *             <code>beginIndex</code> is larger than
     *             <code>endIndex</code>.
     */
    public XMLString substring(int beginIndex, int endIndex)
    {
      return new XString(str().substring(beginIndex, endIndex));
    }
  
    /**
     * Concatenates the specified string to the end of this string.
     *
     * @param   str   the <code>String</code> that is concatenated to the end
     *                of this <code>String</code>.
     * @return  a string that represents the concatenation of this object's
     *          characters followed by the string argument's characters.
     * @exception java.lang.NullPointerException if <code>str</code> is
     *          <code>null</code>.
     */
    public XMLString concat(String str)
    {
  
      // %REVIEW% Make an FSB here?
      return new XString(str().concat(str));
    }
  
    /**
     * Converts all of the characters in this <code>String</code> to lower
     * case using the rules of the given <code>Locale</code>.
     *
     * @param locale use the case transformation rules for this locale
     * @return the String, converted to lowercase.
     * @see     java.lang.Character#toLowerCase(char)
     * @see     java.lang.String#toUpperCase(Locale)
     */
    public XMLString toLowerCase(Locale locale)
    {
      return new XString(str().toLowerCase(locale));
    }
  
    /**
     * Converts all of the characters in this <code>String</code> to lower
     * case using the rules of the default locale, which is returned
     * by <code>Locale.getDefault</code>.
     * <p>
     *
     * @return  the string, converted to lowercase.
     * @see     java.lang.Character#toLowerCase(char)
     * @see     java.lang.String#toLowerCase(Locale)
     */
    public XMLString toLowerCase()
    {
      return new XString(str().toLowerCase());
    }
  
    /**
     * Converts all of the characters in this <code>String</code> to upper
     * case using the rules of the given locale.
     * @param locale use the case transformation rules for this locale
     * @return the String, converted to uppercase.
     * @see     java.lang.Character#toUpperCase(char)
     * @see     java.lang.String#toLowerCase(Locale)
     */
    public XMLString toUpperCase(Locale locale)
    {
      return new XString(str().toUpperCase(locale));
    }
  
    /**
     * Converts all of the characters in this <code>String</code> to upper
     * case using the rules of the default locale, which is returned
     * by <code>Locale.getDefault</code>.
     *
     * <p>
     * If no character in this string has a different uppercase version,
     * based on calling the <code>toUpperCase</code> method defined by
     * <code>Character</code>, then the original string is returned.
     * <p>
     * Otherwise, this method creates a new <code>String</code> object
     * representing a character sequence identical in length to the
     * character sequence represented by this <code>String</code> object and
     * with every character equal to the result of applying the method
     * <code>Character.toUpperCase</code> to the corresponding character of
     * this <code>String</code> object. <p>
     * Examples:
     * <blockquote><pre>
     * "Fahrvergn&uuml;gen".toUpperCase() returns "FAHRVERGN&Uuml;GEN"
     * "Visit Ljubinje!".toUpperCase() returns "VISIT LJUBINJE!"
     * </pre></blockquote>
     *
     * @return  the string, converted to uppercase.
     * @see     java.lang.Character#toUpperCase(char)
     * @see     java.lang.String#toUpperCase(Locale)
     */
    public XMLString toUpperCase()
    {
      return new XString(str().toUpperCase());
    }
  
    /**
     * Removes white space from both ends of this string.
     *
     * @return  this string, with white space removed from the front and end.
     */
    public XMLString trim()
    {
      return new XString(str().trim());
    }
  
    /**
     * Returns whether the specified <var>ch</var> conforms to the XML 1.0 definition
     * of whitespace.  Refer to <A href="http://www.w3.org/TR/1998/REC-xml-19980210#NT-S">
     * the definition of <CODE>S</CODE></A> for details.
     * @param   ch      Character to check as XML whitespace.
     * @return          =true if <var>ch</var> is XML whitespace; otherwise =false.
     */
    private static boolean isSpace(char ch)
    {
      return XMLCharacterRecognizer.isWhiteSpace(ch);  // Take the easy way out for now.
    }
  
    /**
     * Conditionally trim all leading and trailing whitespace in the specified String.
     * All strings of white space are
     * replaced by a single space character (#x20), except spaces after punctuation which
     * receive double spaces if doublePunctuationSpaces is true.
     * This function may be useful to a formatter, but to get first class
     * results, the formatter should probably do it's own white space handling
     * based on the semantics of the formatting object.
     *
     * @param   trimHead    Trim leading whitespace?
     * @param   trimTail    Trim trailing whitespace?
     * @param   doublePunctuationSpaces    Use double spaces for punctuation?
     * @return              The trimmed string.
     */
    public XMLString fixWhiteSpace(boolean trimHead, boolean trimTail,
                                   boolean doublePunctuationSpaces)
    {
  
      // %OPT% !!!!!!!
      int len = this.length();
      char[] buf = new char[len];
  
      this.getChars(0, len, buf, 0);
  
      boolean edit = false;
      int s;
  
      for (s = 0; s < len; s++)
      {
        if (isSpace(buf[s]))
        {
          break;
        }
      }
  
      /* replace S to ' '. and ' '+ -> single ' '. */
      int d = s;
      boolean pres = false;
  
      for (; s < len; s++)
      {
        char c = buf[s];
  
        if (isSpace(c))
        {
          if (!pres)
          {
            if (' ' != c)
            {
              edit = true;
            }
  
            buf[d++] = ' ';
  
            if (doublePunctuationSpaces && (s != 0))
            {
              char prevChar = buf[s - 1];
  
              if (!((prevChar == '.') || (prevChar == '!')
                    || (prevChar == '?')))
              {
                pres = true;
              }
            }
            else
            {
              pres = true;
            }
          }
          else
          {
            edit = true;
            pres = true;
          }
        }
        else
        {
          buf[d++] = c;
          pres = false;
        }
      }
  
      if (trimTail && 1 <= d && ' ' == buf[d - 1])
      {
        edit = true;
  
        d--;
      }
  
      int start = 0;
  
      if (trimHead && 0 < d && ' ' == buf[0])
      {
        edit = true;
  
        start++;
      }
  
      XMLStringFactory xsf = XMLStringFactoryImpl.getFactory();
  
      return edit ? xsf.newstr(new String(buf, start, d - start)) : this;
    }
  
    /**
     * @see XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
     */
    public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
    {
          visitor.visitStringLiteral(owner, this);
    }
  
  }
  