path: root/plugins/SmileyAdd/src/regexp/WCPattern.h

#ifndef __WCPATTERN_H__
#define __WCPATTERN_H__

class WCMatcher;
class NFAUNode;
class NFAQuantifierUNode;

/**
  This pattern class is very similar in functionality to Java's
  java.util.regex.WCPattern class. The pattern class represents an immutable
  regular expression object. Instead of having a single object contain both the
  regular expression object and the matching object, instead the two objects are
  split apart. The {@link WCMatcher WCMatcher} class represents the maching
  object.

  The WCPattern class works primarily off of "compiled" patterns. A typical
  instantiation of a regular expression looks like:

  <pre>
  WCPattern * p = WCPattern::compile(L"a*b");
  WCMatcher * m = p->createWCMatcher(L"aaaaaab");
  if (m->matches()) ...
  </pre>

  However, if you do not need to use a pattern more than once, it is often times
  okay to use the WCPattern's static methods insteads. An example looks like this:

  <pre>
  if (WCPattern::matches(L"a*b", L"aaaab")) { ... }
  </pre>

  This class does not currently support unicode. The unicode update for this
  class is coming soon.

  This class is partially immutable. It is completely safe to call createWCMatcher
  concurrently in different threads, but the other functions (e.g. split) should
  not be called concurrently on the same <code>WCPattern</code>.

  <table border="0" cellpadding="1" cellspacing="0">
    <tr align="left" bgcolor="#CCCCFF">
      <td>
        <b>Construct</b>
      </td>
      <td>
        <b>Matches</b>
      </th>
    </tr>
    <tr>
      <td colspan="2">
      &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Characters</b>
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x</i></code>
      </td>
      <td>
        The character <code><i>x</i></code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\\</code>
      </td>
      <td>
        The character <code>\</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\0<i>nn</i></code>
      </td>
      <td>
        The character with octal ASCII value <code><i>nn</i></code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\0<i>nnn</i></code>
      </td>
      <td>
        The character with octal ASCII value <code><i>nnn</i></code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\x<i>hh</i></code>
      </td>
      <td>
        The character with hexadecimal ASCII value <code><i>hh</i></code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\t</code>
      </td>
      <td>
        A tab character
      </td>
    </tr>
    <tr>
      <td>
        <code>\r</code>
      </td>
      <td>
        A carriage return character
      </td>
    </tr>
    <tr>
      <td>
        <code>\n</code>
      </td>
      <td>
        A new-line character
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td>
        <b>Character Classes</b>
      </td>
    </tr>
    <tr>
      <td>
        <code>[abc]</code>
      </td>
      <td>
        Either <code>a</code>, <code>b</code>, or <code>c</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[^abc]</code>
      </td>
      <td>
        Any character but <code>a</code>, <code>b</code>, or <code>c</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[a-zA-Z]</code>
      </td>
      <td>
        Any character ranging from <code>a</code> thru <code>z</code>, or
        <code>A</code> thru <code>Z</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[^a-zA-Z]</code>
      </td>
      <td>
        Any character except those ranging from <code>a</code> thru
        <code>z</code>, or <code>A</code> thru <code>Z</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[a\-z]</code>
      </td>
      <td>
        Either <code>a</code>, <code>-</code>, or <code>z</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[a-z[A-Z]]</code>
      </td>
      <td>
        Same as <code>[a-zA-Z]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[a-z&&[g-i]]</code>
      </td>
      <td>
        Any character in the intersection of <code>a-z</code> and
        <code>g-i</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>[a-z&&[^g-i]]</code>
      </td>
      <td>
        Any character in <code>a-z</code> and not in <code>g-i</code>
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Prefefined character classes</b>
      </td>
    </tr>
    <tr>
      <td>
        <code><b>.</b></code>
      </td>
      <td>
        Any character. Multiline matching must be compiled into the pattern for
        <code><b>.</b></code> to match a <code>\r</code> or a <code>\n</code>.
        Even if multiline matching is enabled, <code><b>.</b></code> will not
        match a <code>\r\n</code>, only a <code>\r</code> or a <code>\n</code>.
      </td>
    </tr>
    <tr>
      <td>
        <code>\d</code>
      </td>
      <td>
        <code>[0-9]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\D</code>
      </td>
      <td>
        <code>[^\d]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\s</code>
      </td>
      <td>
        <code>[&nbsp;\t\r\n\x0B]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\S</code>
      </td>
      <td>
        <code>[^\s]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\w</code>
      </td>
      <td>
        <code>[a-zA-Z0-9_]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\W</code>
      </td>
      <td>
        <code>[^\w]</code>
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>POSIX character classes
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{Lower}</code>
      </td>
      <td>
        <code>[a-z]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{Upper}</code>
      </td>
      <td>
        <code>[A-Z]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{ASCII}</code>
      </td>
      <td>
        <code>[\x00-\x7F]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{Alpha}</code>
      </td>
      <td>
        <code>[a-zA-Z]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{Digit}</code>
      </td>
      <td>
        <code>[0-9]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{Alnum}</code>
      </td>
      <td>
        <code>[\w&&[^_]]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{Punct}</code>
      </td>
      <td>
        <code>[!"#$%&'()*+,-./:;&lt;=&gt;?@[\]^_`{|}~]</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\p{XDigit}</code>
      </td>
      <td>
        <code>[a-fA-F0-9]</code>
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Boundary Matches</b>
      </td>
    </tr>
    <tr>
      <td>
        <code>^</code>
      </td>
      <td>
        The beginning of a line. Also matches the beginning of input.
      </td>
    </tr>
    <tr>
      <td>
        <code>$</code>
      </td>
      <td>
        The end of a line. Also matches the end of input.
      </td>
    </tr>
    <tr>
      <td>
        <code>\b</code>
      </td>
      <td>
        A word boundary
      </td>
    </tr>
    <tr>
      <td>
        <code>\B</code>
      </td>
      <td>
        A non word boundary
      </td>
    </tr>
    <tr>
      <td>
        <code>\A</code>
      </td>
      <td>
        The beginning of input
      </td>
    </tr>
    <tr>
      <td>
        <code>\G</code>
      </td>
      <td>
        The end of the previous match. Ensures that a "next" match will only
        happen if it begins with the character immediately following the end of
        the "current" match.
      </td>
    </tr>
    <tr>
      <td>
        <code>\Z</code>
      </td>
      <td>
        The end of input. Will also match if there is a single trailing
        <code>\r\n</code>, a single trailing <code>\r</code>, or a single
        trailing <code>\n</code>.
      </td>
    </tr>
    <tr>
      <td>
        <code>\z</code>
      </td>
      <td>
        The end of input
      </td>
    </tr>
    <tr>
      <td>
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Greedy Quantifiers</b>
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x?</i></code>
      </td>
      <td>
        <i>x</i>, either zero times or one time
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x*</i></code>
      </td>
      <td>
        <i>x</i>, zero or more times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x+</i></code>
      </td>
      <td>
        <i>x</i>, one or more times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n}</i></code>
      </td>
      <td>
        <i>x</i>, exactly n times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n,}</i></code>
      </td>
      <td>
        <i>x</i>, at least <code><i>n</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{,m}</i></code>
      </td>
      <td>
        <i>x</i>, at most <code><i>m</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n,m}</i></code>
      </td>
      <td>
        <i>x</i>, at least <code><i>n</i></code> times and at most
        <code><i>m</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Possessive Quantifiers</b>
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x?+</i></code>
      </td>
      <td>
        <i>x</i>, either zero times or one time
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x*+</i></code>
      </td>
      <td>
        <i>x</i>, zero or more times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x++</i></code>
      </td>
      <td>
        <i>x</i>, one or more times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n}+</i></code>
      </td>
      <td>
        <i>x</i>, exactly n times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n,}+</i></code>
      </td>
      <td>
        <i>x</i>, at least <code><i>n</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{,m}+</i></code>
      </td>
      <td>
        <i>x</i>, at most <code><i>m</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n,m}+</i></code>
      </td>
      <td>
        <i>x</i>, at least <code><i>n</i></code> times and at most
        <code><i>m</i></code> times
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Reluctant Quantifiers</b>
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x??</i></code>
      </td>
      <td>
        <i>x</i>, either zero times or one time
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x*?</i></code>
      </td>
      <td>
        <i>x</i>, zero or more times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x+?</i></code>
      </td>
      <td>
        <i>x</i>, one or more times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n}?</i></code>
      </td>
      <td>
        <i>x</i>, exactly n times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n,}?</i></code>
      </td>
      <td>
        <i>x</i>, at least <code><i>n</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{,m}?</i></code>
      </td>
      <td>
        <i>x</i>, at most <code><i>m</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x{n,m}?</i></code>
      </td>
      <td>
        <i>x</i>, at least <code><i>n</i></code> times and at most
        <code><i>m</i></code> times
      </td>
    </tr>
    <tr>
      <td>
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Operators</b>
      </td>
    </tr>
    <tr>
      <td>
        <code><i>xy</i></code>
      </td>
      <td>
        <code><i>x</i></code> then <code><i>y</i></code>
      </td>
    </tr>
    <tr>
      <td>
        <code><i>x</i></code>|<code><i>y</i></code>
      </td>
      <td>
        <code><i>x</i></code> or <code><i>y</i></code>
      </td>
    </tr>
    <tr>
      <td>
        <code>(<i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i></code> as a capturing group
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Quoting</b>
      </td>
    </tr>
    <tr>
      <td>
        <code>\Q</code>
      </td>
      <td>
        Nothing, but treat every character (including \s) literally until a
        matching <code>\E</code>
      </td>
    </tr>
    <tr>
      <td>
        <code>\E</code>
      </td>
      <td>
        Nothing, but ends its matching <code>\Q</code>
      </td>
    </tr>
    <tr>
      <td>
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Special Constructs</b>
      </td>
    </tr>
    <tr>
      <td>
        <code>(?:<i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i></code>, but not as a capturing group
      </td>
    </tr>
    <tr>
      <td>
        <code>(?=<i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i></code>, via positive lookahead. This means that the
        expression will match only if it is trailed by <code><i>x</i></code>.
        It will not "eat" any of the characters matched by
        <code><i>x</i></code>.
      </td>
    </tr>
    <tr>
      <td>
        <code>(?!<i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i></code>, via negative lookahead. This means that the
        expression will match only if it is not trailed by
        <code><i>x</i></code>. It will not "eat" any of the characters
        matched by <code><i>x</i></code>.
      </td>
    </tr>
    <tr>
      <td>
        <code>(?<=<i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i></code>, via positive lookbehind. <code><i>x</i></code>
        cannot contain any quantifiers.
      </td>
    </tr>
    <tr>
      <td>
        <code>(?<!<i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i></code>, via negative lookbehind. <code><i>x</i></code>
        cannot contain any quantifiers.
      </td>
    </tr>
    <tr>
      <td>
        <code>(?><i>x</i>)</code>
      </td>
      <td>
        <code><i>x</i>{1}+</code>
      </td>
    </tr>
    <tr>
      <td colspan="2">
        &nbsp;
      </td>
    </tr>
    <tr>
      <td colspan="2">
        <b>Registered Expression Matching</b>
      </td>
    </tr>
    <tr>
      <td>
        <code>{<i>x</i>}</code>
      </td>
      <td>
        The registered pattern <code><i>x</i></code>
      </td>
    </tr>
  </table>

  <hr>

   <i>Begin Text Extracted And Modified From java.util.regex.WCPattern documentation</i>

   <h4> Backslashes, escapes, and quoting </h4>

   <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
   constructs, as defined in the table above, as well as to quote characters
   that otherwise would be interpreted as unescaped constructs.  Thus the
   expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
   left brace.

   <p> It is an error to use a backslash prior to any alphabetic character that
   does not denote an escaped construct; these are reserved for future
   extensions to the regular-expression language.  A backslash may be used
   prior to a non-alphabetic character regardless of whether that character is
   part of an unescaped construct.

   <p>It is necessary to double backslashes in string literals that represent
   regular expressions to protect them from interpretation by a compiler.  The
   string literal <tt>"&#92;b"</tt>, for example, matches a single backspace
   character when interpreted as a regular expression, while
   <tt>"&#92;&#92;b"</tt> matches a word boundary.  The string litera
    <tt>"&#92;(hello&#92;)"</tt> is illegal and leads to a compile-time error;
    in order to match the string <tt>(hello)</tt> the string literal
    <tt>"&#92;&#92;(hello&#92;&#92;)"</tt> must be used.

   <h4> Character Classes </h4>

      <p> Character classes may appear within other character classes, and
      may be composed by the union operator (implicit) and the intersection
      operator (<tt>&amp;&amp;</tt>).
      The union operator denotes a class that contains every character that is
      in at least one of its operand classes.  The intersection operator
      denotes a class that contains every character that is in both of its
      operand classes.

      <p> The precedence of character-class operators is as follows, from
      highest to lowest:

      <blockquote><table border="0" cellpadding="1" cellspacing="0"
                   summary="Precedence of character class operators.">

        <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
            <td>Literal escape&nbsp;&nbsp;&nbsp;&nbsp;</td>
            <td><tt>\x</tt></td></tr>
        <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
            <td>Range</td>
            <td><tt>a-z</tt></td></tr>
        <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
            <td>Grouping</td>
            <td><tt>[...]</tt></td></tr>
        <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
            <td>Intersection</td>
            <td><tt>[a-z&&[aeiou]]</tt></td></tr>
        <tr><th>5&nbsp;&nbsp;&nbsp;&nbsp;</th>
            <td>Union</td>
            <td><tt>[a-e][i-u]<tt></td></tr>
      </table></blockquote>

      <p> Note that a different set of metacharacters are in effect inside
      a character class than outside a character class. For instance, the
      regular expression <tt>.</tt> loses its special meaning inside a
      character class, while the expression <tt>-</tt> becomes a range
      forming metacharacter.

   <a name="lt">

   <a name="cg">
   <h4> Groups and capturing </h4>

   <p> Capturing groups are numbered by counting their opening parentheses from
   left to right.  In the expression <tt>((A)(B(C)))</tt>, for example, there
   are four such groups: </p>

   <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">

   <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
       <td><tt>((A)(B(C)))</tt></td></tr>
   <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
       <td><tt>(A)</tt></td></tr>
   <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
       <td><tt>(B(C))</tt></td></tr>

   <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
       <td><tt>(C)</tt></td></tr>
   </table></blockquote>

   <p> Group zero always stands for the entire expression.

   <p> Capturing groups are so named because, during a match, each subsequence
   of the input sequence that matches such a group is saved.  The captured
   subsequence may be used later in the expression, via a back reference, and
   may also be retrieved from the matcher once the match operation is complete.

   <p> The captured input associated with a group is always the subsequence
   that the group most recently matched.  If a group is evaluated a second time
   because of quantification then its previously-captured value, if any, will
   be retained if the second evaluation fails.  Matching the string
   <tt>L"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
   group two set to <tt>L"b"</tt>.  All captured input is discarded at the
   beginning of each match.

   <p> Groups beginning with <tt>(?</tt> are pure, <i>non-capturing</i> groups
   that do not capture text and do not count towards the group total.


   <h4> WC support </h4>

   <p> Coming Soon.

   <h4> Comparison to Perl 5 </h4>

   <p>The <code>WCPattern</code> engine performs traditional NFA-based matching
   with ordered alternation as occurs in Perl 5.

   <p> Perl constructs not supported by this class: </p>

   <ul>

      <li><p> The conditional constructs <tt>(?{</tt><i>X</i><tt>})</tt> and
      <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
      </p></li>

      <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
      and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>

      <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>

      <li><p> The preprocessing operations <tt>\l</tt> <tt>&#92;u</tt>,
      <tt>\L</tt>, and <tt>\U</tt>.  </p></li>

      <li><p> Embedded flags</p></li>

   </ul>

   <p> Constructs supported by this class but not by Perl: </p>

   <ul>

      <li><p> Possessive quantifiers, which greedily match as much as they can
      and do not back off, even when doing so would allow the overall match to
      succeed.  </p></li>

      <li><p> Character-class union and intersection as described
      above.</p></li>

   </ul>

   <p> Notable differences from Perl: </p>

   <ul>

      <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
      as back references; a backslash-escaped number greater than <tt>9</tt> is
      treated as a back reference if at least that many subexpressions exist,
      otherwise it is interpreted, if possible, as an octal escape.  In this
      class octal escapes must always begin with a zero. In this class,
      <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
      references, and a larger number is accepted as a back reference if at
      least that many subexpressions exist at that point in the regular
      expression, otherwise the parser will drop digits until the number is
      smaller or equal to the existing number of groups or it is one digit.
      </p></li>

      <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
      where the last match left off.  This functionality is provided implicitly
      by the <CODE>WCMatcher</CODE> class: Repeated invocations of the
      <code>find</code> method will resume where the last match left off,
      unless the matcher is reset.  </p></li>

      <li><p> Perl is forgiving about malformed matching constructs, as in the
      expression <tt>*a</tt>, as well as dangling brackets, as in the
      expression <tt>abc]</tt>, and treats them as literals.  This
      class also strict and will not compile a pattern when dangling characters
      are encountered.</p></li>

   </ul>


   <p> For a more precise description of the behavior of regular expression
   constructs, please see <a href="http://www.oreilly.com/catalog/regex2/">
   <i>Mastering Regular Expressions, 2nd Edition</i>, Jeffrey E. F. Friedl,
   O'Reilly and Associates, 2002.</a>
   </p>
  <P>

  <i>End Text Extracted And Modified From java.util.regex.WCPattern documentation</i>

  <hr>

  @author    Jeffery Stuart
  @since     March 2003, Stable Since November 2004
  @version   1.07.00
  @memo      A class used to represent "PERL 5"-ish regular expressions
 */
class WCPattern
{
	friend class WCMatcher;
	friend class NFAUNode;
	friend class NFAQuantifierUNode;
private:
	/**
	  This constructor should not be called directly. Those wishing to use the
	  WCPattern class should instead use the {@link compile compile} method.

	  @param rhs The pattern to compile
	  @memo Creates a new pattern from the regular expression in <code>rhs</code>.
	  */
	WCPattern(const CMString & rhs);
protected:
	/**
	  This currently is not used, so don't try to do anything with it.
	  @memo Holds all the compiled patterns for quick access.
	  */
	static std::map<CMString, WCPattern *> compiledWCPatterns;
	/**
	  Holds all of the registered patterns as strings. Due to certain problems
	  with compilation of patterns, especially with capturing groups, this seemed
	  to be the best way to do it.
	  */
	static std::map<CMString, std::pair<CMString, unsigned long> > registeredWCPatterns;
protected:
	/**
	  Holds all the NFA nodes used. This makes deletion of a pattern, as well as
	  clean-up from an unsuccessful compile much easier and faster.
	  */
	std::map<NFAUNode*, bool> nodes;
	/**
	  Used when methods like split are called. The matcher class uses a lot of
	  dynamic memeory, so having an instance increases speedup of certain
	  operations.
	  */
	WCMatcher * matcher;
	/**
	  The front node of the NFA.
	  */
	NFAUNode * head;
	/**
	  The actual regular expression we rerpesent
	  */
	CMString pattern;
	/**
	  Flag used during compilation. Once the pattern is successfully compiled,
	  <code>error</code> is no longer used.
	  */
	bool error;
	/**
	  Used during compilation to keep track of the current index into
	  <code>{@link pattern pattern}<code>.  Once the pattern is successfully
	  compiled, <code>error</code> is no longer used.
	  */
	int curInd;
	/**
	  The number of capture groups this contains.
	  */
	int groupCount;
	/**
	  The number of non-capture groups this contains.
	  */
	int nonCapGroupCount;
	/**
	  The flags specified when this was compiled.
	  */
	unsigned long flags;
protected:
	/**
	  Raises an error during compilation. Compilation will cease at that point
	  and compile will return <code>NULL</code>.
	  */
	void raiseError();
	/**
	  Convenience function for registering a node in <code>nodes</code>.
	  @param node The node to register
	  @return The registered node
	  */
	NFAUNode * registerNode(NFAUNode * node);

	/**
	  Calculates the union of two strings. This function will first sort the
	  strings and then use a simple selection algorithm to find the union.
	  @param s1 The first "class" to union
	  @param s2 The second "class" to union
	  @return A new string containing all unique characters. Each character
	  must have appeared in one or both of <code>s1</code> and
	  <code>s2</code>.
	  */
	CMString classUnion(CMString s1, CMString s2)  const;
	/**
	  Calculates the intersection of two strings. This function will first sort
	  the strings and then use a simple selection algorithm to find the
	  intersection.
	  @param s1 The first "class" to intersect
	  @param s2 The second "class" to intersect
	  @return A new string containing all unique characters. Each character
	  must have appeared both <code>s1</code> and <code>s2</code>.
	  */
	CMString classIntersect(CMString s1, CMString s2)  const;
	/**
	  Calculates the negation of a string. The negation is the set of all
	  characters between <code>\x00</code> and <code>\xFF</code> not
	  contained in <code>s1</code>.
	  @param s1 The "class" to be negated.
	  @param s2 The second "class" to intersect
	  @return A new string containing all unique characters. Each character
	  must have appeared both <code>s1</code> and <code>s2</code>.
	  */
	CMString classNegate(CMString s1)                  const;
	/**
	  Creates a new "class" representing the range from <code>low</code> thru
	  <code>hi</code>. This function will wrap if <code>low</code> &gt;
	  <code>hi</code>. This is a feature, not a buf. Sometimes it is useful
	  to be able to say [\x70-\x10] instead of [\x70-\x7F\x00-\x10].
	  @param low The beginning character
	  @param hi  The ending character
	  @return A new string containing all the characters from low thru hi.
	  */
	CMString classCreateRange(wchar_t low, wchar_t hi)         const;

	/**
	  Extracts a decimal number from the substring of member-variable
	  <code>{@link pattern pattern}<code> starting at <code>start</code> and
	  ending at <code>end</code>.
	  @param start The starting index in <code>{@link pattern pattern}<code>
	  @param end The last index in <code>{@link pattern pattern}<code>
	  @return The decimal number in <code>{@link pattern pattern}<code>
	  */
	int getInt(int start, int end);
	/**
	  Parses a <code>{n,m}</code> string out of the member-variable
	  <code>{@link pattern pattern}<code> stores the result in <code>sNum</code>
	  and <code>eNum</code>.
	  @param sNum Output parameter. The minimum number of matches required
	  by the curly quantifier are stored here.
	  @param eNum Output parameter. The maximum number of matches allowed
	  by the curly quantifier are stored here.
	  @return Success/Failure. Fails when the curly does not have the proper
	  syntax
	  */
	bool quantifyCurly(int & sNum, int & eNum);
	/**
	  Tries to quantify the currently parsed group. If the group being parsed
	  is indeed quantified in the member-variable
	  <code>{@link pattern pattern}<code>, then the NFA is modified accordingly.
	  @param start  The starting node of the current group being parsed
	  @param stop   The ending node of the current group being parsed
	  @param gn     The group number of the current group being parsed
	  @return       The node representing the starting node of the group. If the
	  group becomes quantified, then this node is not necessarily
	  a GroupHead node.
	  */
	NFAUNode * quantifyGroup(NFAUNode * start, NFAUNode * stop, const int gn);

	/**
	  Tries to quantify the last parsed expression. If the character was indeed
	  quantified, then the NFA is modified accordingly.
	  @param newNode The recently created expression node
	  @return The node representing the last parsed expression. If the
	  expression was quantified, <code>return value != newNode</code>
	  */
	NFAUNode * quantify(NFAUNode * newNode);
	/**
	  Parses the current class being examined in
	  <code>{@link pattern pattern}</code>.
	  @return A string of unique characters contained in the current class being
	  parsed
	  */
	CMString parseClass();
	/**
	  Parses the current POSIX class being examined in
	  <code>{@link pattern pattern}</code>.
	  @return A string of unique characters representing the POSIX class being
	  parsed
	  */
	CMString parsePosix();
	/**
	  Returns a string containing the octal character being parsed
	  @return The string contained the octal value being parsed
	  */
	CMString parseOctal();
	/**
	  Returns a string containing the hex character being parsed
	  @return The string contained the hex value being parsed
	  */
	CMString parseHex();
	/**
	  Returns a new node representing the back reference being parsed
	  @return The new node representing the back reference being parsed
	  */
	NFAUNode *   parseBackref();
	/**
	  Parses the escape sequence currently being examined. Determines if the
	  escape sequence is a class, a single character, or the beginning of a
	  quotation sequence.
	  @param inv Output parameter. Whether or not to invert the returned class
	  @param quo Output parameter. Whether or not this sequence starts a
	  quotation.
	  @return The characters represented by the class
	  */
	CMString parseEscape(bool & inv, bool & quo);
	/**
	  Parses a supposed registered pattern currently under compilation. If the
	  sequence of characters does point to a registered pattern, then the
	  registered pattern is appended to <code>*end<code>. The registered pattern
	  is parsed with the current compilation flags.
	  @param end The ending node of the thus-far compiled pattern
	  @return The new end node of the current pattern
	  */
	NFAUNode * parseRegisteredWCPattern(NFAUNode ** end);
	/**
	  Parses a lookbehind expression. Appends the necessary nodes
	  <code>*end</code>.
	  @param pos Positive or negative look behind
	  @param end The ending node of the current pattern
	  @return The new end node of the current pattern
	  */
	NFAUNode * parseBehind(const bool pos, NFAUNode ** end);
	/**
	  Parses the current expression and tacks on nodes until a \E is found.
	  @return The end of the current pattern
	  */
	NFAUNode * parseQuote();
	/**
	  Parses <code>{@link pattern pattern}</code>. This function is called
	  recursively when an or (<code>|</code>) or a group is encountered.
	  @param inParen Are we currently parsing inside a group
	  @param inOr Are we currently parsing one side of an or (<code>|</code>)
	  @param end The end of the current expression
	  @return The starting node of the NFA constructed from this parse
	  */
	NFAUNode * parse(const bool inParen = 0, const bool inOr = 0, NFAUNode ** end = NULL);
public:
	/// We should match regardless of case
	const static unsigned long CASE_INSENSITIVE;
	/// We are implicitly quoted
	const static unsigned long LITERAL;
	/// @memo We should treat a <code><b>.</b></code> as [\x00-\x7F]
	const static unsigned long DOT_MATCHES_ALL;
	/** <code>^</code> and <code>$</code> should anchor to the beginning and
		 ending of lines, not all input
		 */
	const static unsigned long MULTILINE_MATCHING;
	/** When enabled, only instances of <code>\n</codes> are recognized as
		 line terminators
		 */
	const static unsigned long UNIX_LINE_MODE;
	/// The absolute minimum number of matches a quantifier can match (0)
	const static int MIN_QMATCH;
	/// The absolute maximum number of matches a quantifier can match (0x7FFFFFFF)
	const static int MAX_QMATCH;
public:
	/**
	  Call this function to compile a regular expression into a
	  <code>WCPattern</code> object. Special values can be assigned to
	  <code>mode</code> when certain non-standard behaviors are expected from
	  the <code>WCPattern</code> object.
	  @param pattern The regular expression to compile
	  @param mode    A bitwise or of flags signalling what special behaviors are
	  wanted from this <code>WCPattern</code> object
	  @return If successful, <code>compile</code> returns a <code>WCPattern</code>
	  pointer. Upon failure, <code>compile</code> returns
	  <code>NULL</code>
	  */
	static WCPattern                    * compile(const CMString & pattern,
		const unsigned long mode = 0);
	/**
	  Dont use this function. This function will compile a pattern, and cache
	  the result. This will eventually be used as an optimization when people
	  just want to call static methods using the same pattern over and over
	  instead of first compiling the pattern and then using the compiled
	  instance for matching.
	  @param pattern The regular expression to compile
	  @param mode    A bitwise or of flags signalling what special behaviors are
	  wanted from this <code>WCPattern</code> object
	  @return If successful, <code>compileAndKeep</code> returns a
	  <code>WCPattern</code> pointer. Upon failure, <code>compile</code>
	  returns <code>NULL</code>.
	  */
	static WCPattern                    * compileAndKeep(const CMString & pattern,
		const unsigned long mode = 0);

	/**
	  Searches through <code>replace</code> and replaces all substrings matched
	  by <code>pattern</code> with <code>str</code>. <code>str</code> may
	  contain backreferences (e.g. <code>\1</code>) to capture groups. A typical
	  invocation looks like:
	  <p>
	  <code>
	  WCPattern::replace(L"(a+)b(c+)", L"abcccbbabcbabc", L"\\2b\\1");
	  </code>
	  <p>
	  which would replace <code>abcccbbabcbabc</code> with
	  <code>cccbabbcbabcba</code>.
	  @param pattern          The regular expression
	  @param str              The replacement text
	  @param replacementText  The string in which to perform replacements
	  @param mode             The special mode requested of the <code>WCPattern</code>
	  during the replacement process
	  @return The text with the replacement string substituted where necessary
	  */
	static CMString                  replace(const CMString & pattern,
		const CMString & str,
		const CMString & replacementText,
		const unsigned long mode = 0);

	/**
	  Splits the specified string over occurrences of the specified pattern.
	  Empty strings can be optionally ignored. The number of strings returned is
	  configurable. A typical invocation looks like:
	  <p>
	  <code>
	  CMString str(strSize, 0);<br>
	  FILE * fp = fopen(fileName, "r");<br>
	  fread((char*)str.data(), strSize * 2, 1, fp);<br>
	  fclose(fp);<br>
	  <br>
	  std::vector&lt;CMString&gt; lines = WCPattern::split(L"[\r\n]+", str, true);<br>
	  <br>
	  </code>

	  @param pattern    The regular expression
	  @param replace    The string to split
	  @param keepEmptys Whether or not to keep empty strings
	  @param limit      The maximum number of splits to make
	  @param mode       The special mode requested of the <code>WCPattern</code>
	  during the split process
	  @return All substrings of <code>str</code> split across <code>pattern</code>.
	  */
	static std::vector<CMString>     split(const CMString & pattern,
		const CMString & str,
		const bool keepEmptys = 0,
		const unsigned long limit = 0,
		const unsigned long mode = 0);

	/**
	  Finds all the instances of the specified pattern within the string. You
	  should be careful to only pass patterns with a minimum length of one. For
	  example, the pattern <code>a*</code> can be matched by an empty string, so
	  instead you should pass <code>a+</code> since at least one character must
	  be matched. A typical invocation of <code>findAll</code> looks like:
	  <p>
	  <code>
	  std::vector&lt;td::string&gt; numbers = WCPattern::findAll(L"\\d+", string);
	  </code>
	  <p>

	  @param pattern  The pattern for which to search
	  @param str      The string to search
	  @param mode     The special mode requested of the <code>WCPattern</code>
	  during the find process
	  @return All instances of <code>pattern</code> in <code>str</code>
	  */
	static std::vector<CMString>     findAll(const CMString & pattern,
		const CMString & str,
		const unsigned long mode = 0);

	/**
	  Determines if an entire string matches the specified pattern

	  @param pattern  The pattern for to match
	  @param str      The string to match
	  @param mode     The special mode requested of the <code>WCPattern</code>
	  during the replacement process
	  @return True if <code>str</code> is recognized by <code>pattern</code>
	  */
	static bool                         matches(const CMString & pattern,
		const CMString & str,
		const unsigned long mode = 0);

	/**
	  Registers a pattern under a specific name for use in later compilations.
	  A typical invocation and later use looks like:
	  <p>
	  <code>
	  WCPattern::registerWCPattern(L"ip", L"(?:\\d{1,3}\\.){3}\\d{1,3}");<br>
	  WCPattern * p1 = WCPattern::compile(L"{ip}:\\d+");<br>
	  WCPattern * p2 = WCPattern::compile(L"Connection from ({ip}) on port \\d+");<br>
	  </code>
	  <p>
	  Multiple calls to <code>registerWCPattern</code> with the same
	  <code>name</code> will result in the pattern getting overwritten.

	  @param name     The name to give to the pattern
	  @param pattern  The pattern to register
	  @param mode     Any special flags to use when compiling pattern
	  @return Success/Failure. Fails only if <code>pattern</code> has invalid
	  syntax
	  */
	static bool                         registerWCPattern(const CMString & name,
		const CMString & pattern,
		const unsigned long mode = 0);

	/**
	  Clears the pattern registry
	  */
	static void                         unregisterWCPatterns();
	/**
	  Don't use
	  */
	static void                         clearWCPatternCache();

	/**
	  Searches through a string for the <code>n<sup>th</sup></code> match of the
	  given pattern in the string. Match indeces start at zero, not one.
	  A typical invocation looks like this:
	  <p>
	  <code>
	  std::pair&lt;CMString, int&gt; match = WCPattern::findNthMatch(L"\\d{1,3}", L"192.168.1.101:22", 1);<br>
	  wprintf(L"%s %i\n", match.first.c_str(), match.second);<br>
	  <br>
	  Output: 168 4<br>
	  <br>

	  @param pattern  The pattern for which to search
	  @param str      The string to search
	  @param matchNum Which match to find
	  @param mode     Any special flags to use during the matching process
	  @return A string and an integer. The string is the string matched. The
	  integer is the starting location of the matched string in
	  <code>str</code>. You can check for success/failure by making sure
	  that the integer returned is greater than or equal to zero.
	  */
	static std::pair<CMString, int>  findNthMatch(const CMString & pattern,
		const CMString & str,
		const int matchNum,
		const unsigned long mode = 0);
public:
	/**
	  Deletes all NFA nodes allocated during compilation
	  */
	~WCPattern();

	CMString               replace(const CMString & str,
		const CMString & replacementText);
	std::vector<CMString>  split(const CMString & str, const bool keepEmptys = 0,
		const unsigned long limit = 0);
	std::vector<CMString>  findAll(const CMString & str);
	bool                       matches(const CMString & str);
	/**
	  Returns the flags used during compilation of this pattern
	  @return The flags used during compilation of this pattern
	  */
	unsigned long             getFlags() const;
	/**
	  Returns the regular expression this pattern represents
	  @return The regular expression this pattern represents
	  */
	CMString               getWCPattern() const;
	/**
	  Creates a matcher object using the specified string and this pattern.
	  @param str The string to match against
	  @return A new matcher using object using this pattern and the specified
	  string
	  */
	WCMatcher                 * createWCMatcher(const CMString & str);
};

class NFAUNode
{
	friend class WCMatcher;
public:
	NFAUNode * next;
	NFAUNode();
	virtual ~NFAUNode();
	virtual void findAllNodes(std::map<NFAUNode*, bool> & soFar);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const = 0;
	inline virtual bool isGroupHeadNode()     const { return false; }
	inline virtual bool isStartOfInputNode()  const { return false; }
};
class NFACharUNode : public NFAUNode
{
protected:
	wchar_t ch;
public:
	NFACharUNode(const wchar_t c);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFACICharUNode : public NFAUNode
{
protected:
	wchar_t ch;
public:
	NFACICharUNode(const wchar_t c);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAStartUNode : public NFAUNode
{
public:
	NFAStartUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAEndUNode : public NFAUNode
{
public:
	NFAEndUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAQuantifierUNode : public NFAUNode
{
public:
	int min, max;
	NFAUNode * inner;
	virtual void findAllNodes(std::map<NFAUNode*, bool> & soFar);
	NFAQuantifierUNode(WCPattern * pat, NFAUNode * internal,
		const int minMatch = WCPattern::MIN_QMATCH,
		const int maxMatch = WCPattern::MAX_QMATCH);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAGreedyQuantifierUNode : public NFAQuantifierUNode
{
public:
	NFAGreedyQuantifierUNode(WCPattern * pat, NFAUNode * internal,
		const int minMatch = WCPattern::MIN_QMATCH,
		const int maxMatch = WCPattern::MAX_QMATCH);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
	virtual int matchInternal(const CMString & str, WCMatcher * matcher, const int curInd, const int soFar) const;
};
class NFALazyQuantifierUNode : public NFAQuantifierUNode
{
public:
	NFALazyQuantifierUNode(WCPattern * pat, NFAUNode * internal,
		const int minMatch = WCPattern::MIN_QMATCH,
		const int maxMatch = WCPattern::MAX_QMATCH);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAPossessiveQuantifierUNode : public NFAQuantifierUNode
{
public:
	NFAPossessiveQuantifierUNode(WCPattern * pat, NFAUNode * internal,
		const int minMatch = WCPattern::MIN_QMATCH,
		const int maxMatch = WCPattern::MAX_QMATCH);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAAcceptUNode : public NFAUNode
{
public:
	NFAAcceptUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAClassUNode : public NFAUNode
{
public:
	bool inv;
	std::map<wchar_t, bool> vals;
	NFAClassUNode(const bool invert = 0);
	NFAClassUNode(const CMString & clazz, const bool invert);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFACIClassUNode : public NFAUNode
{
public:
	bool inv;
	std::map<wchar_t, bool> vals;
	NFACIClassUNode(const bool invert = 0);
	NFACIClassUNode(const CMString & clazz, const bool invert);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFASubStartUNode : public NFAUNode
{
public:
	NFASubStartUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAOrUNode : public NFAUNode
{
public:
	NFAUNode * one;
	NFAUNode * two;
	NFAOrUNode(NFAUNode * first, NFAUNode * second);
	virtual void findAllNodes(std::map<NFAUNode*, bool> & soFar);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAQuoteUNode : public NFAUNode
{
public:
	CMString qStr;
	NFAQuoteUNode(const CMString & quoted);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFACIQuoteUNode : public NFAUNode
{
public:
	CMString qStr;
	NFACIQuoteUNode(const CMString & quoted);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFALookAheadUNode : public NFAUNode
{
public:
	bool pos;
	NFAUNode * inner;
	NFALookAheadUNode(NFAUNode * internal, const bool positive);
	virtual void findAllNodes(std::map<NFAUNode*, bool> & soFar);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFALookBehindUNode : public NFAUNode
{
public:
	bool pos;
	CMString mStr;
	NFALookBehindUNode(const CMString & str, const bool positive);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAStartOfLineUNode : public NFAUNode
{
public:
	NFAStartOfLineUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAEndOfLineUNode : public NFAUNode
{
public:
	NFAEndOfLineUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAReferenceUNode : public NFAUNode
{
public:
	int gi;
	NFAReferenceUNode(const int groupIndex);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAStartOfInputUNode : public NFAUNode
{
public:
	NFAStartOfInputUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
	inline virtual bool isStartOfInputNode()  const { return false; }
};
class NFAEndOfInputUNode : public NFAUNode
{
public:
	bool term;
	NFAEndOfInputUNode(const bool lookForTerm);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAWordBoundaryUNode : public NFAUNode
{
public:
	bool pos;
	NFAWordBoundaryUNode(const bool positive);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAEndOfMatchUNode : public NFAUNode
{
public:
	NFAEndOfMatchUNode();
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAGroupHeadUNode : public NFAUNode
{
public:
	int gi;
	NFAGroupHeadUNode(const int groupIndex);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
	inline virtual bool isGroupHeadNode()     const { return false; }
};
class NFAGroupTailUNode : public NFAUNode
{
public:
	int gi;
	NFAGroupTailUNode(const int groupIndex);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAGroupLoopPrologueUNode : public NFAUNode
{
public:
	int gi;
	NFAGroupLoopPrologueUNode(const int groupIndex);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};
class NFAGroupLoopUNode : public NFAUNode
{
public:
	int gi, min, max, type;
	NFAUNode * inner;
	NFAGroupLoopUNode(NFAUNode * internal, const int minMatch,
		const int maxMatch, const int groupIndex, const int matchType);
	virtual void findAllNodes(std::map<NFAUNode*, bool> & soFar);
	virtual int match(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
	int matchGreedy(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
	int matchLazy(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
	int matchPossessive(const CMString & str, WCMatcher * matcher, const int curInd = 0) const;
};

#endif