/**
  From the author (Jeff Stuart)
  "
  Let me start by saying this file is pretty big. If you feel up to it, you can
  try making changes yourself, but you would be better off to just email me at
  stuart@cs.ucdavis.edu if you think there is a bug, or have something useful you
  would like added. This project is very "near and dear" to me, so I am fairly
  quick to make bug fixes. The header files for Pattern and Matcher are fairly
  well documented and the function names are pretty self-explanatory, but if you
  are having any trouble, feel free to email me at stuart@cs.ucdavis.edu.

  If you email me, make sure you put something like C++RE in the subject because
  I tend to delete email if I don't recognize the name and the subject is
  something like "I Need Your Help" or "Got A Second" or "I Found It".
  "
 */

/*
  Detailed documentation is provided in this class' header file

  @author   Jeffery Stuart
  @since    November 2004
  @version  1.07.00
*/

#define to_lower(a) (char)(unsigned)CharLowerA((LPSTR)static_cast<unsigned char>(a))
#define is_alpha IsCharAlphaA

#ifdef _WIN32
  #pragma warning(push)
  #pragma warning(disable:4996)
  #define str_icmp lstrcmpiA
#else
  #define str_icmp strcasecmp
#endif

#include <Pattern.h>
#include <Matcher.h>
#include <cstring>
#include <algorithm>

std::map<bkstring, Pattern *> Pattern::compiledPatterns;
std::map<bkstring, std::pair<bkstring, unsigned long> > Pattern::registeredPatterns;

const int Pattern::MIN_QMATCH = 0x00000000;
const int Pattern::MAX_QMATCH = 0x7FFFFFFF;

const unsigned long Pattern::CASE_INSENSITIVE       = 0x01;
const unsigned long Pattern::LITERAL                = 0x02;
const unsigned long Pattern::DOT_MATCHES_ALL        = 0x04;
const unsigned long Pattern::MULTILINE_MATCHING     = 0x08;
const unsigned long Pattern::UNIX_LINE_MODE         = 0x10;

Pattern::Pattern(const bkstring & rhs)
{
  matcher = NULL;
  pattern = rhs;
  curInd = 0;
  groupCount = 0;
  nonCapGroupCount = 0;
  error = 0;
  head = NULL;
}
// convenience function in case we want to add any extra debugging output
void Pattern::raiseError()
{
/*  switch (pattern[curInd - 1])
  {
  case '*':
  case ')':
  case '+':
  case '?':
  case ']':
  case '}':
    fprintf(stderr, "%s\n%*c^\n", pattern.c_str(), curInd - 1, ' ');
    fprintf(stderr, "Syntax Error near here. Possible unescaped meta character.\n");
    break;
  default:
    fprintf(stderr, "%s\n%*c^\n", pattern.c_str(), curInd - 1, ' ');
    fprintf(stderr, "Syntax Error near here. \n");
    break;
  }*/
  error = 1;
}
NFANode * Pattern::registerNode(NFANode * node)
{
  nodes[node] = 1;
  return node;
}

bkstring Pattern::classUnion      (bkstring s1, bkstring s2)  const
{
  char out[300];
  std::sort(s1.begin(), s1.end());
  std::sort(s2.begin(), s2.end());
  *std::set_union(s1.begin(), s1.end(), s2.begin(), s2.end(), out) = 0;
  return out;
}
bkstring Pattern::classIntersect  (bkstring s1, bkstring s2)  const
{
  char out[300];
  std::sort(s1.begin(), s1.end());
  std::sort(s2.begin(), s2.end());
  *std::set_intersection(s1.begin(), s1.end(), s2.begin(), s2.end(), out) = 0;
  return out;
}
bkstring Pattern::classNegate     (bkstring s1)                  const
{
  char out[300];
  int i, ind = 0;
  std::map<char, bool> m;

  for (i = 0; i < (int)s1.size(); ++i) m[s1[i]] = 1;
  for (i = 0xFF; i >= 0; --i) if (m.find((char)i) == m.end()) out[ind++] = (char)i;
  out[ind] = 0;
  return bkstring(out, ind);
}
bkstring Pattern::classCreateRange(char low, char hi)    const
{
  char out[300];
  int ind = 0;
  while (low != hi) out[ind++] = low++;
  out[ind++] = low;
  return bkstring(out, ind);
}

int Pattern::getInt(int start, int end)
{
  int ret = 0;
  for (; start <= end; ++start) ret = ret * 10 + (pattern[start] - '0');
  return ret;
}
bool Pattern::quantifyCurly(int & sNum, int & eNum)
{
  bool good = 1;
  int i, ci = curInd + 1;
  int commaInd = ci, endInd = ci, len = (int)pattern.size();
  sNum = eNum = 0;

  while (endInd   < len     && pattern[endInd  ] != '}') ++endInd;
  while (commaInd < endInd  && pattern[commaInd] != ',') ++commaInd;
  if (endInd >= len) { raiseError(); return 0; }
  for (i = ci; good && i < endInd; ++i) if (i != commaInd && !isdigit(pattern[i])) good = 0;
  if (!good && commaInd < endInd) { raiseError(); return 0; }
  if (!good) return 0;
  /* so now everything in here is either a comma (and there is at most one comma) or a digit */
  if (commaInd == ci) // {,*}
  {
    if (endInd == commaInd + 1)    { sNum = MIN_QMATCH;               eNum = MAX_QMATCH;                        } // {,} = *
    else                           { sNum = MIN_QMATCH;               eNum = getInt(commaInd + 1, endInd - 1);  } // {,+}
  }
  else if (commaInd == endInd - 1) { sNum = getInt(ci, commaInd - 1); eNum = MAX_QMATCH;                        } // {+,}
  else if (commaInd == endInd)     { sNum = getInt(ci, endInd - 1);   eNum = sNum;                              } // {+}
  else                             { sNum = getInt(ci, commaInd - 1); eNum = getInt(commaInd + 1, endInd - 1);  } // {+,+}
  curInd = endInd + 1;
  return 1;
}
NFANode * Pattern::quantifyGroup(NFANode * start, NFANode * stop, const int gn)
{
  NFANode * newNode = NULL;
  int type = 0;

  if (curInd < (int)pattern.size())
  {
    char ch = (curInd + 1 >= (int)pattern.size()) ? -1 : pattern[curInd + 1];
    switch (pattern[curInd])
    {
    case '*':
      ++curInd;
      switch (ch)
      {
      case '?': ++curInd; type = 1; break;
      case '+': ++curInd; type = 2; break;
      }
      newNode = registerNode(new NFAGroupLoopPrologueNode(gn));
      newNode->next = registerNode(new NFAGroupLoopNode(start, MIN_QMATCH, MAX_QMATCH, gn, type));
      stop->next = newNode->next;
      return newNode;
    case '?':
      ++curInd;
      switch (ch)
      {
      case '?': ++curInd; type = 1; break;
      case '+': ++curInd; type = 2; break;
      }
      newNode = registerNode(new NFAGroupLoopPrologueNode(gn));
      newNode->next = registerNode(new NFAGroupLoopNode(start, MIN_QMATCH, 1, gn, type));
      stop->next = newNode->next;
      return newNode;
    case '+':
      ++curInd;
      switch (ch)
      {
      case '?': ++curInd; type = 1; break;
      case '+': ++curInd; type = 2; break;
      }
      newNode = registerNode(new NFAGroupLoopPrologueNode(gn));
      newNode->next = registerNode(new NFAGroupLoopNode(start, 1, MAX_QMATCH, gn, type));
      stop->next = newNode->next;
      return newNode;
    case '{':
      {
        int s, e;
        if (quantifyCurly(s, e))
        {
          ch = (curInd < (int)pattern.size()) ? pattern[curInd] : -1;
          switch (ch)
          {
          case '?': ++curInd; type = 1; break;
          case '+': ++curInd; type = 2; break;
          }
          newNode = registerNode(new NFAGroupLoopPrologueNode(gn));
          newNode->next = registerNode(new NFAGroupLoopNode(start, s, e, gn, type));
          stop->next = newNode->next;
          return newNode;
        }
      }
    default:
      break;
    }
  }
  return NULL;
}

NFANode * Pattern::quantify(NFANode * newNode)
{
  if (curInd < (int)pattern.size())
  {
    char ch = (curInd + 1 >= (int)pattern.size()) ? -1 : pattern[curInd + 1];
    switch (pattern[curInd])
    {
    case '*':
      ++curInd;
      switch (ch)
      {
      case '?': ++curInd; newNode = registerNode(new NFALazyQuantifierNode      (this, newNode, MIN_QMATCH, MAX_QMATCH)); break;
      case '+': ++curInd; newNode = registerNode(new NFAPossessiveQuantifierNode(this, newNode, MIN_QMATCH, MAX_QMATCH)); break;
      default:            newNode = registerNode(new NFAGreedyQuantifierNode    (this, newNode, MIN_QMATCH, MAX_QMATCH)); break;
      }
      break;
    case '?':
      ++curInd;
      switch (ch)
      {
      case '?': ++curInd; newNode = registerNode(new NFALazyQuantifierNode      (this, newNode, MIN_QMATCH, 1)); break;
      case '+': ++curInd; newNode = registerNode(new NFAPossessiveQuantifierNode(this, newNode, MIN_QMATCH, 1)); break;
      default:            newNode = registerNode(new NFAGreedyQuantifierNode    (this, newNode, MIN_QMATCH, 1)); break;
      }
      break;
    case '+':
      ++curInd;
      switch (ch)
      {
      case '?': ++curInd; newNode = registerNode(new NFALazyQuantifierNode      (this, newNode, 1, MAX_QMATCH)); break;
      case '+': ++curInd; newNode = registerNode(new NFAPossessiveQuantifierNode(this, newNode, 1, MAX_QMATCH)); break;
      default:            newNode = registerNode(new NFAGreedyQuantifierNode    (this, newNode, 1, MAX_QMATCH)); break;
      }
      break;
    case '{':
      {
        int s, e;
        if (quantifyCurly(s, e))
        {
          ch = (curInd < (int)pattern.size()) ? pattern[curInd] : -1;
          switch (ch)
          {
          case '?': ++curInd; newNode = registerNode(new NFALazyQuantifierNode      (this, newNode, s, e)); break;
          case '+': ++curInd; newNode = registerNode(new NFAPossessiveQuantifierNode(this, newNode, s, e)); break;
          default:            newNode = registerNode(new NFAGreedyQuantifierNode    (this, newNode, s, e)); break;
          }
        }
      }
      break;
    default:
      break;
    }
  }
  return newNode;
}
bkstring Pattern::parseClass()
{
  bkstring t, ret = "";
  char ch, c1, c2;
  bool inv = 0, neg = 0, quo = 0;

  if (curInd < (int)pattern.size() && pattern[curInd] == '^')
  {
    ++curInd;
    neg = 1;
  }
  while (curInd < (int)pattern.size() && pattern[curInd] != ']')
  {
    ch = pattern[curInd++];
    if (ch == '[')
    {
      t = parseClass();
      ret = classUnion(ret, t);
    }
    /*else if (ch == '-')
    {
      raiseError();
      curInd = pattern.size();
    }*/
    else if (ch == '&' && curInd < (int)pattern.size() && pattern[curInd] == '&')
    {
      if (pattern[++curInd] != '[')
      {
        raiseError();
        curInd = (int)pattern.size();
      }
      else
      {
        ++curInd;
        t = parseClass();
        ret = classIntersect(ret, t);
      }
    }
    else if (ch == '\\')
    {
      t = parseEscape(inv, quo);
      if (quo)
      {
        raiseError();
        curInd = (int)pattern.size();
      }
      else if (inv || t.size() > 1) // cant be part of a range (a-z)
      {
        if (inv) t = classNegate(t);
        ret = classUnion(ret, t);
      }
      else if (curInd < (int)pattern.size() && pattern[curInd] == '-') // part of a range (a-z)
      {
        c1 = t[0];
        ++curInd;
        if (curInd >= (int)pattern.size()) raiseError();
        else
        {
          c2 = pattern[curInd++];
          if (c2 == '\\')
          {
            t = parseEscape(inv, quo);
            if (quo)
            {
              raiseError();
              curInd = (int)pattern.size();
            }
            else if (inv || t.size() > 1) raiseError();
            else ret = classUnion(ret, classCreateRange(c1, c2));
          }
          else if (c2 == '[' || c2 == ']' || c2 == '-' || c2 == '&')
          {
            raiseError();
            curInd = (int)pattern.size();
          }
          else ret = classUnion(ret, classCreateRange(c1, c2));
        }
      }
      else
      {
        ret = classUnion(ret, t);
      }
    }
    else if (curInd < (int)pattern.size() && pattern[curInd] == '-')
    {
      c1 = ch;
      ++curInd;
      if (curInd >= (int)pattern.size()) raiseError();
      else
      {
        c2 = pattern[curInd++];
        if (c2 == '\\')
        {
          t = parseEscape(inv, quo);
          if (quo)
          {
            raiseError();
            curInd = (int)pattern.size();
          }
          else if (inv || t.size() > 1) raiseError();
          else ret = classUnion(ret, classCreateRange(c1, c2));
        }
        else if (c2 == '[' || c2 == ']' || c2 == '-' || c2 == '&')
        {
          raiseError();
          curInd = (int)pattern.size();
        }
        else
        {
          ret = classUnion(ret, classCreateRange(c1, c2));
        }
      }
    }
    else
    {
      ret += " ";
      ret[ret.size() - 1] = ch;
    }
  }
  if (curInd >= (int)pattern.size() || pattern[curInd] != ']')
  {
    raiseError();
    ret = "";
  }
  else
  {
    ++curInd;
    if (neg) ret = classNegate(ret);
  }
  return ret;
}
bkstring Pattern::parsePosix()
{
  bkstring s7 = pattern.substr(curInd, 7);
  if (s7 == "{Lower}")  { curInd += 7; return "abcdefghijklmnopqrstuvwxyz";                                                                       }
  if (s7 == "{Upper}")  { curInd += 7; return "ABCDEFGHIJKLMNOPQRSTUVWXYZ";                                                                       }
  if (s7 == "{Alpha}")  { curInd += 7; return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";                                             }
  if (s7 == "{Digit}")  { curInd += 7; return "0123456789";                                                                                       }
  if (s7 == "{Alnum}")  { curInd += 7; return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";                                   }
  if (s7 == "{Punct}")  { curInd += 7; return "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~";                                                               }
  if (s7 == "{Graph}")  { curInd += 7; return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"; }
  if (s7 == "{Print}")  { curInd += 7; return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"; }
  if (s7 == "{Blank}")  { curInd += 7; return " \t";                                                                                              }
  if (s7 == "{Space}")  { curInd += 7; return " \t\n\x0B\f\r";                                                                                    }
  if (s7 == "{Cntrl}")
  {
	bkstring::value_type i;
    bkstring s = " ";

    for (i = 0; i < 5; ++i) s += s;
    s += " ";
    for (i = 0; i <= 0x1F; ++i) s[i] = i;
    s[0x20] = 0x7F;
    curInd += 7;
    return s;
  }
  if (s7 == "{ASCII}")
  {
    bkstring s(0x80, ' ');
    for (int i = 0; i <= 0x7f; ++i) s[i] = (bkstring::value_type)i;
    curInd += 7;
    return s;
  }
  if (pattern.substr(curInd, 8) == "{XDigit}") { curInd += 8; return "abcdefABCDEF0123456789"; }
  raiseError();
  return "";
}
NFANode * Pattern::parseBackref()
{
  #define is_dig(x) ((x) >= '0' && (x) <= '9')
  #define to_int(x) ((x) - '0')
  int ci = curInd;
  int oldRef = 0, ref = 0;

  while (ci < (int)pattern.size() && is_dig(pattern[ci]) && (ref < 10 || ref < groupCount))
  {
    oldRef = ref;
    ref = ref * 10 + to_int(pattern[ci++]);
  }
  if (ci == (int)pattern.size())
  {
    oldRef = ref;
    ++ci;
  }
  if (oldRef < 0 || ci <= curInd)
  {
    raiseError();
    return registerNode(new NFAReferenceNode(-1));
  }
  curInd = ci;
  return registerNode(new NFAReferenceNode(ref));

  #undef is_dig
  #undef to_int
}
bkstring Pattern::parseOctal()
{
  #define islowoc(x)  ((x) >= '0' && (x) <= '3')
  #define isoc(x)     ((x) >= '0' && (x) <= '7')
  #define fromoc(x)   ((x) - '0')
  int ci = curInd;
  char ch1 = (ci + 0 < (int)pattern.size()) ? pattern[ci + 0] : -1;
  char ch2 = (ci + 1 < (int)pattern.size()) ? pattern[ci + 1] : -1;
  char ch3 = (ci + 2 < (int)pattern.size()) ? pattern[ci + 2] : -1;
  bkstring s = " ";

  if (islowoc(ch1) && isoc(ch2))
  {
    curInd += 2;
    s[0] = fromoc(ch1) * 8 + fromoc(ch2);
    if (isoc(ch3))
    {
      ++curInd;
      s[0] = s[0] * 8 + fromoc(ch3);
    }
  }
  else if (isoc(ch1) && isoc(ch2))
  {
    curInd += 2;
    s[0] = fromoc(ch1) * 8 + fromoc(ch2);
  }
  else raiseError();

  return s;
  #undef islowoc
  #undef isoc
  #undef fromoc
}
bkstring Pattern::parseHex()
{
  #define to_low(x)   (((x) >= 'A' && (x) <= 'Z') ? ((x) - 'A' + 'a') : (x))
  #define is_dig(x)   ((x) >= '0' && (x) <= '9')
  #define is_hex(x)   (is_dig(x) || (to_low(x) >= 'a' && to_low(x) <= 'f'))
  #define to_int(x)   ((is_dig(x)) ? ((x) - '0') : (to_low(x) - 'a' + 10))

  int ci = curInd;
  char ch1 = (ci + 0 < (int)pattern.size()) ? pattern[ci + 0] : -1;
  char ch2 = (ci + 1 < (int)pattern.size()) ? pattern[ci + 1] : -1;
  bkstring s = " ";

  if (is_hex(ch1) && is_hex(ch2))
  {
    curInd += 2;
    s[0] = (to_int(ch1) << 4 & 0xF0) | (to_int(ch2) & 0x0F);
  }

  return s;
  #undef to_low
  #undef is_dig
  #undef is_hex
  #undef to_int
}
bkstring Pattern::parseEscape(bool & inv, bool & quo)
{
  char ch = pattern[curInd++];
  bkstring classes = "";

  if (curInd > (int)pattern.size())
  {
    raiseError();
    return NULL;
  }

  quo = 0;
  inv = 0;
  switch (ch)
  {
  case 'p': classes = parsePosix();                                                         break;
  case 'P': classes = "!!"; classes += parsePosix();                                        break;
  case 'd': classes = "0123456789";                                                         break;
  case 'D': classes = "!!0123456789";                                                       break;
  case 's': classes = " \t\r\n\f";                                                          break;
  case 'S': classes = "!! \t\r\n\f";                                                        break;
  case 'w': classes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";    break;
  case 'W': classes = "!!abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";  break;
  case '0': classes = parseOctal(); break;
  case 'x': classes = parseHex();   break;

  case 'Q': quo = 1;        break;
  case 't': classes = "\t"; break;
  case 'r': classes = "\r"; break;
  case 'n': classes = "\n"; break;
  case 'f': classes = "\f"; break;
  case 'a': classes = "\a"; break;
  case 'e': classes = "\r"; break;
  default:  classes = " "; classes[0] = ch; break;
  }
  if (classes.substr(0, 2) == "!!")
  {
    classes = classes.substr(2);
    inv = 1;
  }
  return classes;
}
NFANode * Pattern::parseRegisteredPattern(NFANode ** end)
{
  int i, j;
  bkstring s;
  NFANode * ret = NULL;
  for (i = curInd; i < (int)pattern.size() && pattern[i] != '}'; ++i) { }
  if (pattern[i] != '}') { raiseError(); return NULL; }
  if (i == curInd + 1)   { raiseError(); return NULL; } // {}
  if (
      !(
        (pattern[curInd] >= 'a' && pattern[curInd] <= 'z') ||
        (pattern[curInd] >= 'A' && pattern[curInd] <= 'Z') ||
        (pattern[curInd] == '_')
       )
     )
  {
    raiseError();
    return NULL;
  }
  for (j = curInd; !error && j < i; ++j)
  {
    if (
        !(
          (pattern[j] >= 'a' && pattern[j] <= 'z') ||
          (pattern[j] >= 'A' && pattern[j] <= 'Z') ||
          (pattern[j] >= '0' && pattern[j] <= '9') ||
          (pattern[j] == '_')
         )
        )
    {
      raiseError();
      return NULL;
    }
  }
  s = pattern.substr(curInd, i - curInd);
  if (registeredPatterns.find(s) == registeredPatterns.end()) raiseError();
  else
  {
    unsigned long oflags = flags;
    bkstring op = pattern;
    int ci = i + 1;

    pattern = registeredPatterns[s].first;
    curInd = 0;
    flags = registeredPatterns[s].second;

    --groupCount;
    ret = parse(0, 0, end);

    pattern = op;
    curInd = ci;
    flags = oflags;
  }
  if (error) { *end = ret = NULL; }
  return ret;
}

// look behind should interpret everything as a literal (except \\) since the
// pattern must have a concrete length
NFANode * Pattern::parseBehind(const bool pos, NFANode ** end)
{
  bkstring t = "";
  while (curInd < (int)pattern.size() && pattern[curInd] != ')')
  {
    char ch = pattern[curInd++];
    t += " ";
    if (ch == '\\')
    {
      if (curInd + 1 >= (int)pattern.size())
      {
        raiseError();
        return *end = registerNode(new NFACharNode(' '));
      }
      ch = pattern[curInd++];
    }
    t[t.size() - 1] = ch;
  }
  if (curInd >= (int)pattern.size() || pattern[curInd] != ')') raiseError();
  else ++curInd;
  return *end = registerNode(new NFALookBehindNode(t, pos));
}
NFANode * Pattern::parseQuote()
{
  bool done = 0;
  bkstring s = "";

  while (!done)
  {
    if      (curInd >= (int)pattern.size())
    {
      raiseError();
      done = 1;
    }
    else if (pattern.substr(curInd, 2) == "\\E")
    {
      curInd += 2;
      done = 1;
    }
    else if (pattern[curInd] == '\\')
    {
      s += " ";
      s[s.size() - 1] = pattern[++curInd];
      ++curInd;
    }
    else
    {
      s += " ";
      s[s.size() - 1] = pattern[curInd++];
    }
  }
  if ((flags & Pattern::CASE_INSENSITIVE) != 0) return registerNode(new NFACIQuoteNode(s));
  return registerNode(new NFAQuoteNode(s));
}
NFANode * Pattern::parse(const bool inParen, const bool inOr, NFANode ** end)
{
  NFANode * start, * cur, * next = NULL;
  bkstring t;
  int grc = groupCount++;
  bool inv, quo;
  bool ahead = 0, pos = 0, noncap = 0, indep = 0;
  unsigned long oldFlags = flags;

  if (inParen)
  {
    if (pattern[curInd] == '?')
    {
      ++curInd;
      --groupCount;
      if      (pattern[curInd]           == ':')  { noncap = 1; ++curInd;     grc = --nonCapGroupCount; }
      else if (pattern[curInd]           == '=')  { ++curInd;     ahead = 1;  pos = 1;                  }
      else if (pattern[curInd]           == '!')  { ++curInd;     ahead = 1;  pos = 0;                  }
      else if (pattern.substr(curInd, 2) == "<=") { curInd += 2;  return parseBehind(1, end);           }
      else if (pattern.substr(curInd, 2) == "<!") { curInd += 2;  return parseBehind(0, end);           }
      else if (pattern[curInd]           == '>')  { ++curInd;     indep = 1;                            }
      else
      {
        bool negate = false, done = false;
        while (!done)
        {
          if (curInd >= (int)pattern.size())
          {
            raiseError();
            return NULL;
          }
          else if (negate)
          {
            switch (pattern[curInd])
            {
            case 'i': flags &= ~Pattern::CASE_INSENSITIVE;    break;
            case 'd': flags &= ~Pattern::UNIX_LINE_MODE;      break;
            case 'm': flags &= ~Pattern::MULTILINE_MATCHING;  break;
            case 's': flags &= ~Pattern::DOT_MATCHES_ALL;     break;
            case ':': done = true;                            break;
            case ')':
              ++curInd;
              *end = registerNode(new NFALookBehindNode("", true));
              return *end;
            case '-':
            default: raiseError(); return NULL;
            }
          }
          else
          {
            switch (pattern[curInd])
            {
            case 'i': flags |= Pattern::CASE_INSENSITIVE;     break;
            case 'd': flags |= Pattern::UNIX_LINE_MODE;       break;
            case 'm': flags |= Pattern::MULTILINE_MATCHING;   break;
            case 's': flags |= Pattern::DOT_MATCHES_ALL;      break;
            case ':': done = true;                            break;
            case '-': negate = true;                          break;
            case ')':
              ++curInd;
              *end = registerNode(new NFALookBehindNode("", true));
              return *end;
            default:  raiseError(); return NULL;
            }
          }
          ++curInd;
        }
        noncap = 1;
        grc = --nonCapGroupCount;
      }
      if (noncap) cur = start = registerNode(new NFAGroupHeadNode(grc));
      else        cur = start = registerNode(new NFASubStartNode);
    }
    else cur = start = registerNode(new NFAGroupHeadNode(grc));
  }
  else cur = start = registerNode(new NFASubStartNode);
  while (curInd < (int)pattern.size())
  {
    char ch = pattern[curInd++];

    next = NULL;
    if (error) return NULL;
    switch (ch)
    {
    case '^':
      if ((flags & Pattern::MULTILINE_MATCHING) != 0) next = registerNode(new NFAStartOfLineNode);
      else                                            next = registerNode(new NFAStartOfInputNode);
      break;
    case '$':
      if ((flags & Pattern::MULTILINE_MATCHING) != 0) next = registerNode(new NFAEndOfLineNode);
      else                                            next = registerNode(new NFAEndOfInputNode(0));
      break;
    case '|':
      --groupCount;
      cur->next = registerNode(new NFAAcceptNode);
      cur = start = registerNode(new NFAOrNode(start, parse(inParen, 1)));
      break;
    case '\\':
      if      (curInd < (int)pattern.size())
      {
        bool eoi = 0;
        switch (pattern[curInd])
        {
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9': next = parseBackref(); break;
        case 'A': ++curInd; next = registerNode(new NFAStartOfInputNode);     break;
        case 'B': ++curInd; next = registerNode(new NFAWordBoundaryNode(0));  break;
        case 'b': ++curInd; next = registerNode(new NFAWordBoundaryNode(1));  break;
        case 'G': ++curInd; next = registerNode(new NFAEndOfMatchNode);       break;
        case 'Z': eoi = 1;
        case 'z': ++curInd; next = registerNode(new NFAEndOfInputNode(eoi));  break;
        default:
          t = parseEscape(inv, quo);
          if (!quo)
          {
            if (t.size() > 1 || inv)
            {
              if ((flags & Pattern::CASE_INSENSITIVE) != 0) next = registerNode(new NFACIClassNode(t, inv));
              else                                          next = registerNode(new NFAClassNode(t, inv));
            }
            else
            {
              next = registerNode(new NFACharNode(t[0]));
            }
          }
          else
          {
            next = parseQuote();
          }
        }
      }
      else raiseError();
      break;
    case '[':
      if ((flags & Pattern::CASE_INSENSITIVE) == 0)
      {
        NFAClassNode * clazz = new NFAClassNode();
        bkstring s = parseClass();
        for (int i = 0; i < (int)s.size(); ++i) clazz->vals[s[i]] = 1;
        next = registerNode(clazz);
      }
      else
      {
        NFACIClassNode * clazz = new NFACIClassNode();
        bkstring s = parseClass();
        for (int i = 0; i < (int)s.size(); ++i) clazz->vals[to_lower(s[i])] = 1;
        next = registerNode(clazz);
      }
      break;
    case '.':
      {
        bool useN = 1, useR = 1;
        NFAClassNode * clazz = new NFAClassNode(1);
        if ((flags & Pattern::UNIX_LINE_MODE)  != 0) useR = 0;
        if ((flags & Pattern::DOT_MATCHES_ALL) != 0) useN = useR = 0;
        if (useN) clazz->vals['\n'] = 1;
        if (useR) clazz->vals['\r'] = 1;
        next = registerNode(clazz);
      }
      break;
    case '(':
      {
        NFANode * end, * t1, * t2;
        t1 = parse(1, 0, &end);
        if (!t1) raiseError();
        else if (t1->isGroupHeadNode() && (t2 = quantifyGroup(t1, end, grc)) != NULL)
        {
          cur->next = t2;
          cur = t2->next;
        }
        else
        {
          cur->next = t1;
          cur = end;
        }
      }
      break;
    case ')':
      if (!inParen) raiseError();
      else if (inOr)
      {
        --curInd;
        cur = cur->next = registerNode(new NFAAcceptNode);
        flags = oldFlags;
        return start;
      }
      else
      {
        if (ahead)
        {
          cur = cur->next = registerNode(new NFAAcceptNode);
          flags = oldFlags;
          return *end = registerNode(new NFALookAheadNode(start, pos));
        }
        else if (indep)
        {
          cur = cur->next = registerNode(new NFAAcceptNode);
          flags = oldFlags;
          return *end = registerNode(new NFAPossessiveQuantifierNode(this, start, 1, 1));
        }
        else // capping or noncapping, it doesnt matter
        {
          *end = cur = cur->next = registerNode(new NFAGroupTailNode(grc));
          next = quantifyGroup(start, *end, grc);
          if (next)
          {
            start = next;
            *end = next->next;
          }
          flags = oldFlags;
          return start;
        }
      }
      break;
    case '{': // registered pattern
      cur->next = parseRegisteredPattern(&next);
      if (cur->next) cur = next;
      break;
    case '*':
    case '+':
    case '?':
//    case '}':
//    case ']':
      raiseError();
      break;
    default:
      if ((flags & Pattern::CASE_INSENSITIVE) != 0) next = registerNode(new NFACICharNode(ch));
      else                                          next = registerNode(new NFACharNode(ch));
      break;
    }
    if (next)
    {
      cur = cur->next = quantify(next);
    }
  }
  if (inParen) raiseError();
  else
  {
    if (inOr) cur = cur->next = registerNode(new NFAAcceptNode);
    if (end) *end = cur;
  }

  flags = oldFlags;
  if (error) return NULL;

  return start;
}

Pattern * Pattern::compile(const bkstring & pattern, const unsigned long mode)
{
  Pattern * p = new Pattern(pattern);
  NFANode * end;

  p->flags = mode;
  if ((mode & Pattern::LITERAL) != 0)
  {
    p->head = p->registerNode(new NFAStartNode);
    if ((mode & Pattern::CASE_INSENSITIVE) != 0)  p->head->next = p->registerNode(new NFACIQuoteNode(pattern));
    else                                          p->head->next = p->registerNode(new NFAQuoteNode(pattern));
    p->head->next->next = p->registerNode(new NFAEndNode);
  }
  else
  {
    p->head = p->parse(0, 0, &end);
    if (!p->head)
    {
      delete p;
      p = NULL;
    }
    else
    {
      if (!(p->head && p->head->isStartOfInputNode()))
      {
        NFANode * n = p->registerNode(new NFAStartNode);
        n->next = p->head;
        p->head = n;
      }
      end->next = p->registerNode(new NFAEndNode);
    }
  }
  if (p != NULL)
  {
    p->matcher = new Matcher(p, "");
  }

  return p;
}

Pattern * Pattern::compileAndKeep(const bkstring & pattern, const unsigned long mode)
{
  Pattern * ret = NULL;
  std::map<bkstring, Pattern*>::iterator it = compiledPatterns.find(pattern);

  if (it != compiledPatterns.end())
  {
    ret = it->second;
  }
  else
  {
    ret = compile(pattern, mode);
    compiledPatterns[pattern] = ret;
  }

  return ret;
}
bkstring Pattern::replace(const bkstring & pattern, const bkstring & str,
                             const bkstring & replacementText, const unsigned long mode)
{
  bkstring ret;
  Pattern * p = Pattern::compile(pattern, mode);
  if (p)
  {
    ret = p->replace(str, replacementText);
    delete p;
  }
  return ret;
}

std::vector<bkstring> Pattern::split(const bkstring & pattern, const bkstring & str, const bool keepEmptys,
                              const unsigned long limit, const unsigned long mode)
{
  std::vector<bkstring> ret;
  Pattern * p = Pattern::compile(pattern, mode);
  if (p)
  {
    ret = p->split(str, keepEmptys, limit);
    delete p;
  }
  return ret;
}

std::vector<bkstring> Pattern::findAll(const bkstring & pattern, const bkstring & str, const unsigned long mode)
{
  std::vector<bkstring> ret;
  Pattern * p = Pattern::compile(pattern, mode);
  if (p)
  {
    ret = p->findAll(str);
    delete p;
  }
  return ret;
}

bool Pattern::matches(const bkstring & pattern, const bkstring & str, const unsigned long mode)
{
  bool ret = 0;
  Pattern * p = compile(pattern, mode);

  if (p)
  {
    ret = p->matches(str);
    delete p;
  }

  return ret;
}

bool Pattern::registerPattern(const bkstring & name, const bkstring & pattern, const unsigned long mode)
{
  Pattern * p = Pattern::compile(pattern, mode);
  if (!p) return 0;
  Pattern::registeredPatterns[name] = std::make_pair(pattern, mode);
  delete p;
  return 1;
}

void Pattern::unregisterPatterns()
{
  registeredPatterns.clear();
}
void Pattern::clearPatternCache()
{
  std::map<bkstring, Pattern*>::iterator it;
  for (it = compiledPatterns.begin(); it != compiledPatterns.end(); ++it)
  {
    delete it->second;
  }
  compiledPatterns.clear();
}

std::pair<bkstring, int>  Pattern::findNthMatch(const bkstring & pattern, const bkstring & str,
                                         const int matchNum, const unsigned long mode)
{
  std::pair<bkstring, int> ret;
  Pattern * p = Pattern::compile(pattern, mode);

  ret.second = -1;
  if (p)
  {
    int i = -1;
    p->matcher->setString(str);
    while (i < matchNum && p->matcher->findNextMatch()) { ++i; }
    if (i == matchNum && p->matcher->getStartingIndex() >= 0)
    {
      ret.first = p->matcher->getGroup(0);
      ret.second = p->matcher->getStartingIndex();
    }
    delete p;
  }

  return ret;
}

Pattern::~Pattern()
{
  if (matcher) delete matcher;
  for (std::map<NFANode*, bool>::iterator it = nodes.begin(); it != nodes.end(); ++it)
  {
    delete it->first;
  }
}
bkstring Pattern::replace(const bkstring & str, const bkstring & replacementText)
{
  int li = 0;
  bkstring ret = "";

  matcher->setString(str);
  while (matcher->findNextMatch())
  {
    ret += str.substr(li, matcher->getStartingIndex() - li);
    ret += matcher->replaceWithGroups(replacementText);
    li = matcher->getEndingIndex();
  }
  ret += str.substr(li);

  return ret;
}
std::vector<bkstring> Pattern::split(const bkstring & str, const bool keepEmptys, const unsigned long limit)
{
  unsigned long lim = (limit == 0 ? MAX_QMATCH : limit);
  int li = 0;
  std::vector<bkstring> ret;

  matcher->setString(str);

  while (matcher->findNextMatch() && ret.size() < lim)
  {
    if (matcher->getStartingIndex() == 0 && keepEmptys) ret.push_back("");
    if ((matcher->getStartingIndex() != matcher->getEndingIndex()) || keepEmptys)
    {
      if (li != matcher->getStartingIndex() || keepEmptys)
      {
        ret.push_back(str.substr(li, matcher->getStartingIndex() - li));
      }
      li = matcher->getEndingIndex();
    }
  }
  if (li < (int)str.size()) ret.push_back(str.substr(li));

  return ret;
}
std::vector<bkstring> Pattern::findAll(const bkstring & str)
{
  matcher->setString(str);
  return matcher->findAll();
}
bool Pattern::matches(const bkstring & str)
{
  matcher->setString(str);
  return matcher->matches();
}
unsigned long Pattern::getFlags() const
{
  return flags;
}
bkstring Pattern::getPattern() const
{
  return pattern;
}
Matcher * Pattern::createMatcher(const bkstring & str)
{
  return new Matcher(this, str);
}

// NFANode

NFANode::NFANode() { next = NULL; }
NFANode::~NFANode() { }
void NFANode::findAllNodes(std::map<NFANode*, bool> & soFar)
{
  if (soFar.find(this) == soFar.end()) return;
  soFar[this] = 1;
  if (next) next->findAllNodes(soFar);
}

// NFACharNode

NFACharNode::NFACharNode(const char c) { ch = c; }
int NFACharNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd < (int)str.size() && str[curInd] == ch) return next->match(str, matcher, curInd + 1);
  return -1;
}

// NFACICharNode

NFACICharNode::NFACICharNode(const char c) { ch = to_lower(c); }
int NFACICharNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd < (int)str.size() && to_lower(str[curInd]) == ch) return next->match(str, matcher, curInd + 1);
  return -1;
}

// NFAStartNode

NFAStartNode::NFAStartNode() { }
int NFAStartNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int ret = -1, ci = curInd;

  matcher->starts[0] = curInd;
  if ((matcher->getFlags() & Matcher::MATCH_ENTIRE_STRING) == (unsigned int)Matcher::MATCH_ENTIRE_STRING)
  {
    if (curInd != 0)
    {
      matcher->starts[0] = -1;
      return -1;
    }
    return next->match(str, matcher, 0);
  }
  while ((ret = next->match(str, matcher, ci)) == -1 && ci < (int)str.size())
  {
    matcher->clearGroups();
    matcher->starts[0] = ++ci;
  }
  if (ret < 0) matcher->starts[0] = -1;
  return ret;
}

// NFAEndNode

NFAEndNode::NFAEndNode() { }
int NFAEndNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  matcher->ends[0] = curInd;
  if ((matcher->getFlags() & Matcher::MATCH_ENTIRE_STRING) != 0)
  {
    if (curInd == (int)str.size()) return curInd;
    matcher->ends[0] = -1;
    return -1;
  }
  return curInd;
}

// NFAQuantifierNode

void NFAQuantifierNode::findAllNodes(std::map<NFANode*, bool> & soFar)
{
  inner->findAllNodes(soFar);
  NFANode::findAllNodes(soFar);
}
NFAQuantifierNode::NFAQuantifierNode(Pattern * pat, NFANode * internal, const int minMatch, const int maxMatch)
{
  inner = internal;
  inner->next = pat->registerNode(new NFAAcceptNode);
  min = (minMatch < Pattern::MIN_QMATCH) ? Pattern::MIN_QMATCH : minMatch;
  max = (maxMatch > Pattern::MAX_QMATCH) ? Pattern::MAX_QMATCH : maxMatch;
}

int NFAQuantifierNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int i0, i1, i2 = 0;

  i0 = i1 = curInd;
  while (i2 < min)
  {

    ++i2;
    i1 = inner->match(str, matcher, i0);
    if (i1 <= i0) return i1; // i1 < i0 means i1 is -1
    i0 = i1;
  }

  return i1;
}
// NFAGreedyQuantifierNode

NFAGreedyQuantifierNode::NFAGreedyQuantifierNode(Pattern * pat, NFANode * internal, const int minMatch, const int maxMatch)
                        : NFAQuantifierNode(pat, internal, minMatch, maxMatch) { }
int NFAGreedyQuantifierNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int t = NFAQuantifierNode::match(str, matcher, curInd);
  if (t != -1) return matchInternal(str, matcher, t, min);
  return t;
}
int NFAGreedyQuantifierNode::matchInternal(const bkstring & str, Matcher * matcher, const int curInd, const int soFar) const
{
  if (soFar >= max) return next->match(str, matcher, curInd);

  int i, j;

  i = inner->match(str, matcher, curInd);
  if (i != -1)
  {
    j = matchInternal(str, matcher, i, soFar + 1);
    if (j != -1) return j;
  }
  return next->match(str, matcher, curInd);
}

// NFALazyQuantifierNode

NFALazyQuantifierNode::NFALazyQuantifierNode(Pattern * pat, NFANode * internal, const int minMatch, const int maxMatch)
                      : NFAQuantifierNode(pat, internal, minMatch, maxMatch) { }
int NFALazyQuantifierNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int i, j, m = NFAQuantifierNode::match(str, matcher, curInd);

  if (m == -1) return -1;

  for (i = min; i < max; ++i)
  {
    j = next->match(str, matcher, m);
    if (j == -1)
    {
      j = inner->match(str, matcher, m);
      // if j < m, then j is -1, so we bail.
      // if j == m, then we would just go and call next->match on the same index,
      // but it already failed trying to match right there, so we know we can
      // just bail
      if (j <= m) return -1;
      m = j;
    }
    else return j;
  }
  return next->match(str, matcher, m);
}

// NFAPossessiveQuantifierNode

NFAPossessiveQuantifierNode::NFAPossessiveQuantifierNode(Pattern * pat, NFANode * internal, const int minMatch, const int maxMatch)
                            : NFAQuantifierNode(pat, internal, minMatch, maxMatch) { }
int NFAPossessiveQuantifierNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int i, j, m = NFAQuantifierNode::match(str, matcher, curInd);

  if (m == -1) return -1;
  for (i = min; i < max; ++i)
  {
    j = inner->match(str, matcher, m);
    if (j <= m) return next->match(str, matcher, m);
    m = j;
  }
  return next->match(str, matcher, m);
}

// NFAAcceptNode

NFAAcceptNode::NFAAcceptNode() { }
int NFAAcceptNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (!next) return curInd;
  else return next->match(str, matcher, curInd);
}

// NFAClassNode

NFAClassNode::NFAClassNode(const bool invert)
{
  inv = invert;
}
NFAClassNode::NFAClassNode(const bkstring & clazz, const bool invert)
{
  inv = invert;
  for (int i = 0; i < (int)clazz.size(); ++i) vals[clazz[i]] = 1;
}
int NFAClassNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd < (int)str.size() && ((vals.find(str[curInd]) != vals.end()) ^ inv))
  {
    return next->match(str, matcher, curInd + 1);
  }
  return -1;
}

// NFACIClassNode

NFACIClassNode::NFACIClassNode(const bool invert)
{
  inv = invert;
}
NFACIClassNode::NFACIClassNode(const bkstring & clazz, const bool invert)
{
  inv = invert;
  for (int i = 0; i < (int)clazz.size(); ++i) vals[to_lower(clazz[i])] = 1;
}
int NFACIClassNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd < (int)str.size() && ((vals.find(to_lower(str[curInd])) != vals.end()) ^ inv))
  {
    return next->match(str, matcher, curInd + 1);
  }
  return -1;
}

// NFASubStartNode

NFASubStartNode::NFASubStartNode() { }
int NFASubStartNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  return next->match(str, matcher, curInd);
}

// NFAOrNode

NFAOrNode::NFAOrNode(NFANode * first, NFANode * second) : one(first), two(second) { }
void NFAOrNode::findAllNodes(std::map<NFANode*, bool> & soFar)
{
  if (one) one->findAllNodes(soFar);
  if (two) two->findAllNodes(soFar);
  NFANode::findAllNodes(soFar);
}
int NFAOrNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int ci = one->match(str, matcher, curInd);

  if (ci != -1) ci = next->match(str, matcher, ci);
  if (ci != -1) return ci;
  if (ci == -1) ci = two->match(str, matcher, curInd);
  if (ci != -1) ci = next->match(str, matcher, ci);
  return ci;
}

// NFAQuoteNode

NFAQuoteNode::NFAQuoteNode(const bkstring & quoted) : qStr(quoted) { }
int NFAQuoteNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd + qStr.size() > str.size())       return -1;
  if (str.substr(curInd, qStr.size()) != qStr) return -1;
  return next->match(str, matcher, curInd + qStr.size());
}

// NFACIQuoteNode

NFACIQuoteNode::NFACIQuoteNode(const bkstring & quoted) : qStr(quoted) { }
int NFACIQuoteNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd + qStr.size() > str.size()) return -1;
  if (str_icmp(str.substr(curInd, qStr.size()).c_str(),  qStr.c_str())) return -1;
  return next->match(str, matcher, qStr.size());
}

// NFALookAheadNode

NFALookAheadNode::NFALookAheadNode(NFANode * internal, const bool positive) : NFANode(), pos(positive), inner(internal) { }
void NFALookAheadNode::findAllNodes(std::map<NFANode*, bool> & soFar)
{
  if (inner) inner->findAllNodes(soFar);
  NFANode::findAllNodes(soFar);
}
int NFALookAheadNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  return ((inner->match(str, matcher, curInd) == -1) ^ pos) ? next->match(str, matcher, curInd) : -1;
}

// NFALookBehindNode

NFALookBehindNode::NFALookBehindNode(const bkstring & str, const bool positive) : pos(positive), mStr(str) { }
int NFALookBehindNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (pos)
  {
    if (curInd < (int)mStr.size()) return -1;
    if (str.substr(curInd - mStr.size(), mStr.size()) == mStr) return next->match(str, matcher, curInd);
  }
  else
  {
    if (curInd < (int)mStr.size()) return next->match(str, matcher, curInd);
    if (str.substr(curInd - mStr.size(), mStr.size()) == mStr) return -1;
     return next->match(str, matcher, curInd);
  }
  return -1;
}

// NFAStartOfLineNode

NFAStartOfLineNode::NFAStartOfLineNode() { }
int NFAStartOfLineNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd == 0 || str[curInd - 1] == '\n' || str[curInd - 1] == '\r')
  {
    return next->match(str, matcher, curInd);
  }
  return -1;
}

// NFAEndOfLineNode

NFAEndOfLineNode::NFAEndOfLineNode() { }
int NFAEndOfLineNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd >= (int)str.size() || str[curInd] == '\n' || str[curInd] == '\r')
  {
    return next->match(str, matcher, curInd);
  }
  return -1;
}

// NFAReferenceNode

NFAReferenceNode::NFAReferenceNode(const int groupIndex) : gi(groupIndex) { }
int NFAReferenceNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int len = matcher->ends[gi] - matcher->starts[gi];
  int ni = -1;
  if      (gi < 1 || matcher->ends[gi] < matcher->starts[gi] || len == 0)   ni = curInd;
  else if (curInd + len > (int)str.size())                                  return -1;
  else if (str.substr(curInd, len) != str.substr(matcher->starts[gi], len)) return -1;
  else                                                                      ni = curInd + len;

  return next->match(str, matcher, ni);
}

// NFAStartOfInputNode

NFAStartOfInputNode::NFAStartOfInputNode() { }
int NFAStartOfInputNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd == 0) return next->match(str, matcher, curInd);
  return -1;
}

// NFAEndOfInputNode

NFAEndOfInputNode::NFAEndOfInputNode(const bool lookForTerm) : term(lookForTerm) { }
int NFAEndOfInputNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int len = (int)str.size();
  if      (curInd == len) return next->match(str, matcher, curInd);
  else if (term)
  {
    if      (curInd == len - 1 && (str[curInd] == '\r' || str[curInd] == '\n'))
    {
      return next->match(str, matcher, curInd);
    }
    else if (curInd == len - 2 && str.substr(curInd, 2) == "\r\n")
    {
      return next->match(str, matcher, curInd);
    }
  }
  return -1;
}

// NFAWordBoundaryNode

NFAWordBoundaryNode::NFAWordBoundaryNode(const bool positive) : pos(positive) { }
int NFAWordBoundaryNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int len = (int)str.size();

  char c1 = (curInd - 1 < len && curInd > 0) ? str[curInd - 1] : '\n';
  char c2 = (curInd     < len)               ? str[curInd    ] : '\n';

  if      (curInd == len) return next->match(str, matcher, curInd);
  bool ok = is_alpha(c1) != is_alpha(c2);
  if (ok && pos) return next->match(str, matcher, curInd);
  return -1;
}

// NFAEndOfMatchNode

NFAEndOfMatchNode::NFAEndOfMatchNode() { }
int NFAEndOfMatchNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  if (curInd == matcher->lm) return next->match(str, matcher, curInd);
  return -1;
}

// NFAGroupHeadNode

NFAGroupHeadNode::NFAGroupHeadNode(const int groupIndex) : gi(groupIndex) { }
int NFAGroupHeadNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int ret, o = matcher->starts[gi];

  matcher->starts[gi] = curInd;
  ret = next->match(str, matcher, curInd);
  if (ret < 0) matcher->starts[gi] = o;

  return ret;
}

// NFAGroupTailNode

NFAGroupTailNode::NFAGroupTailNode(const int groupIndex) : gi(groupIndex) { }
int NFAGroupTailNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int ret, o = matcher->ends[gi];

  matcher->ends[gi] = curInd;
  ret = next->match(str, matcher, curInd);
  if (ret < 0) matcher->ends[gi] = o;

  return ret;
}

// NFAGroupLoopPrologueNode

NFAGroupLoopPrologueNode::NFAGroupLoopPrologueNode(const int groupIndex) : gi(groupIndex) { }
int NFAGroupLoopPrologueNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int ret, o1 = matcher->groups[gi], o2 = matcher->groupPos[gi], o3 = matcher->groupIndeces[gi];

  matcher->groups[gi] = 0;
  matcher->groupPos[gi] = 0;
  matcher->groupIndeces[gi] = -1;
  ret = next->match(str, matcher, curInd);
  if (ret < 0)
  {
    matcher->groups[gi] = o1;
    matcher->groupPos[gi] = o2;
    matcher->groupIndeces[gi] = o3;
  }

  return ret;
}

// NFAGroupLoopNode

NFAGroupLoopNode::NFAGroupLoopNode(NFANode * internal, const int minMatch, const int maxMatch,
                                   const int groupIndex, const int matchType)
{
  inner = internal;
  min = minMatch;
  max = maxMatch;
  gi = groupIndex;
  type = matchType;
}
void NFAGroupLoopNode::findAllNodes(std::map<NFANode*, bool> & soFar)
{
  if (inner) inner->findAllNodes(soFar);
  NFANode::findAllNodes(soFar);
}
int NFAGroupLoopNode::match(const bkstring & str, Matcher * matcher, const int curInd) const
{
  bool b = (curInd > matcher->groupIndeces[gi]);

  if (b && matcher->groups[gi] < min)
  {
    ++matcher->groups[gi];
    int o = matcher->groupIndeces[gi];
    matcher->groupIndeces[gi] = curInd;
    int ret = inner->match(str, matcher, curInd);
    if (ret < 0)
    {
      matcher->groupIndeces[gi] = o;
      --matcher->groups[gi];
    }
    return ret;
  }
  else if (!b || matcher->groups[gi] >= max)
  {
    return next->match(str, matcher, curInd);
  }
  else
  {
    switch (type)
    {
    case 0: return matchGreedy(str, matcher, curInd);
    case 1: return matchLazy(str, matcher, curInd);
    case 2: return matchPossessive(str, matcher, curInd);
    }
  }
  return -1;
}
int NFAGroupLoopNode::matchGreedy(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int o = matcher->groupIndeces[gi];            // save our info for backtracking
  matcher->groupIndeces[gi] = curInd;           // move along
  ++matcher->groups[gi];
  int ret = inner->match(str, matcher, curInd); // match internally
  if (ret < 0)
  {                                             // if we failed, then restore info and match next
    --matcher->groups[gi];
    matcher->groupIndeces[gi] = o;
    ret = next->match(str, matcher, curInd);
  }
  return ret;
}
int NFAGroupLoopNode::matchLazy(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int ret = next->match(str, matcher, curInd);  // be lazy, just go on
  if (ret < 0)
  {
    int o = matcher->groupIndeces[gi];          // save info for backtracking
    matcher->groupIndeces[gi] = curInd;         // advance our position
    ++matcher->groups[gi];
    ret = inner->match(str, matcher, curInd);   // match our internal stuff
    if (ret < 0)                                // if we failed, then restore the info
    {
      --matcher->groups[gi];
      matcher->groupIndeces[gi] = o;
    }
  }
  return ret;
}
int NFAGroupLoopNode::matchPossessive(const bkstring & str, Matcher * matcher, const int curInd) const
{
  int o = matcher->groupIndeces[gi];            // save info for backtracking
  matcher->groupPos[gi] = matcher->groups[gi];  // set a flag stating we have matcher at least this much
  matcher->groupIndeces[gi] = curInd;           // move along
  ++matcher->groups[gi];
  int ret = inner->match(str, matcher, curInd); // try and match again
  if (ret < 0)
  {                                             // if we fail, back off, but to an extent
    --matcher->groups[gi];
    matcher->groupIndeces[gi] = o;
    if (matcher->groups[gi] == matcher->groupPos[gi]) ret = next->match(str, matcher, curInd);
  }
  return ret;
}

#ifdef _WIN32
  #pragma warning(pop)
#endif