text: /*
   * Secret Labs' Regular Expression Engine
   *
   * regular expression matching engine
   *
   * partial history:
   * 1999-10-24 fl  created (based on existing template matcher code)
   * 2000-03-06 fl  first alpha, sort of
   * 2000-08-01 fl  fixes for 1.6b1
   * 2000-08-07 fl  use PyOS_CheckStack() if available
   * 2000-09-20 fl  added expand method
   * 2001-03-20 fl  lots of fixes for 2.1b2
   * 2001-04-15 fl  export copyright as Python attribute, not global
   * 2001-04-28 fl  added __copy__ methods (work in progress)
   * 2001-05-14 fl  fixes for 1.5.2 compatibility
   * 2001-07-01 fl  added BIGCHARSET support (from Martin von Loewis)
   * 2001-10-18 fl  fixed group reset issue (from Matthew Mueller)
   * 2001-10-20 fl  added split primitive; reenable unicode for 1.6/2.0/2.1
   * 2001-10-21 fl  added sub/subn primitive
   * 2001-10-24 fl  added finditer primitive (for 2.2 only)
   * 2001-12-07 fl  fixed memory leak in sub/subn (Guido van Rossum)
   * 2002-11-09 fl  fixed empty sub/subn return type
   * 2003-04-18 mvl fully support 4-byte codes
   * 2003-10-17 gn  implemented non recursive scheme
   *
   * Copyright (c) 1997-2001 by Secret Labs AB.  All rights reserved.
   *
   * This version of the SRE library can be redistributed under CNRI's
   * Python 1.6 license.  For any other use, please contact Secret Labs
   * AB (info@pythonware.com).
   *
   * Portions of this engine have been developed in cooperation with
   * CNRI.  Hewlett-Packard provided funding for 1.6 integration and
   * other compatibility work.
   */
  
  #ifndef SRE_RECURSIVE
  
  static char copyright[] =
      " SRE 2.2.2 Copyright (c) 1997-2002 by Secret Labs AB ";
  
  #define PY_SSIZE_T_CLEAN
  
  #include "Python.h"
  #include "structmember.h" /* offsetof */
  
  #include "sre.h"
  
  #include <ctype.h>
  
  /* name of this module, minus the leading underscore */
  #if !defined(SRE_MODULE)
  #define SRE_MODULE "sre"
  #endif
  
  #define SRE_PY_MODULE "re"
  
  /* defining this one enables tracing */
  #undef VERBOSE
  
  #if PY_VERSION_HEX >= 0x01060000
  #if PY_VERSION_HEX  < 0x02020000 || defined(Py_USING_UNICODE)
  /* defining this enables unicode support (default under 1.6a1 and later) */
  #define HAVE_UNICODE
  #endif
  #endif
  
  /* -------------------------------------------------------------------- */
  /* optional features */
  
  /* enables fast searching */
  #define USE_FAST_SEARCH
  
  /* enables aggressive inlining (always on for Visual C) */
  #undef USE_INLINE
  
  /* enables copy/deepcopy handling (work in progress) */
  #undef USE_BUILTIN_COPY
  
  #if PY_VERSION_HEX < 0x01060000
  #define PyObject_DEL(op) PyMem_DEL((op))
  #endif
  
  /* -------------------------------------------------------------------- */
  
  #if defined(_MSC_VER)
  #pragma optimize("agtw", on) /* doesn't seem to make much difference... */
  #pragma warning(disable: 4710) /* who cares if functions are not inlined ;-) */
  /* fastest possible local call under MSVC */
  #define LOCAL(type) static __inline type __fastcall
  #elif defined(USE_INLINE)
  #define LOCAL(type) static inline type
  #else
  #define LOCAL(type) static type
  #endif
  
  /* error codes */
  #define SRE_ERROR_ILLEGAL -1 /* illegal opcode */
  #define SRE_ERROR_STATE -2 /* illegal state */
  #define SRE_ERROR_RECURSION_LIMIT -3 /* runaway recursion */
  #define SRE_ERROR_MEMORY -9 /* out of memory */
  #define SRE_ERROR_INTERRUPTED -10 /* signal handler raised exception */
  
  #if defined(VERBOSE)
  #define TRACE(v) printf v
  #else
  #define TRACE(v)
  #endif
  
  /* -------------------------------------------------------------------- */
  /* search engine state */
  
  /* default character predicates (run sre_chars.py to regenerate tables) */
  
  #define SRE_DIGIT_MASK 1
  #define SRE_SPACE_MASK 2
  #define SRE_LINEBREAK_MASK 4
  #define SRE_ALNUM_MASK 8
  #define SRE_WORD_MASK 16
  
  /* FIXME: this assumes ASCII.  create tables in init_sre() instead */
  
  static char sre_char_info[128] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 6, 2,
  2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 25, 25, 25, 25, 25, 25, 25, 25,
  25, 25, 0, 0, 0, 0, 0, 0, 0, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
  24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 0, 0,
  0, 0, 16, 0, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
  24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 0, 0, 0, 0, 0 };
  
  static char sre_char_lower[128] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
  10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
  27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
  44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
  61, 62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107,
  108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121,
  122, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105,
  106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
  120, 121, 122, 123, 124, 125, 126, 127 };
  
  #define SRE_IS_DIGIT(ch)\
      ((ch) < 128 ? (sre_char_info[(ch)] & SRE_DIGIT_MASK) : 0)
  #define SRE_IS_SPACE(ch)\
      ((ch) < 128 ? (sre_char_info[(ch)] & SRE_SPACE_MASK) : 0)
  #define SRE_IS_LINEBREAK(ch)\
      ((ch) < 128 ? (sre_char_info[(ch)] & SRE_LINEBREAK_MASK) : 0)
  #define SRE_IS_ALNUM(ch)\
      ((ch) < 128 ? (sre_char_info[(ch)] & SRE_ALNUM_MASK) : 0)
  #define SRE_IS_WORD(ch)\
      ((ch) < 128 ? (sre_char_info[(ch)] & SRE_WORD_MASK) : 0)
  
  static unsigned int sre_lower(unsigned int ch)
  {
      return ((ch) < 128 ? (unsigned int)sre_char_lower[ch] : ch);
  }
  
  /* locale-specific character predicates */
  /* !(c & ~N) == (c < N+1) for any unsigned c, this avoids
   * warnings when c's type supports only numbers < N+1 */
  #define SRE_LOC_IS_DIGIT(ch) (!((ch) & ~255) ? isdigit((ch)) : 0)
  #define SRE_LOC_IS_SPACE(ch) (!((ch) & ~255) ? isspace((ch)) : 0)
  #define SRE_LOC_IS_LINEBREAK(ch) ((ch) == '\n')
  #define SRE_LOC_IS_ALNUM(ch) (!((ch) & ~255) ? isalnum((ch)) : 0)
  #define SRE_LOC_IS_WORD(ch) (SRE_LOC_IS_ALNUM((ch)) || (ch) == '_')
  
  static unsigned int sre_lower_locale(unsigned int ch)
  {
      return ((ch) < 256 ? (unsigned int)tolower((ch)) : ch);
  }
  
  /* unicode-specific character predicates */
  
  #if defined(HAVE_UNICODE)
  
  #define SRE_UNI_IS_DIGIT(ch) Py_UNICODE_ISDECIMAL((Py_UNICODE)(ch))
  #define SRE_UNI_IS_SPACE(ch) Py_UNICODE_ISSPACE((Py_UNICODE)(ch))
  #define SRE_UNI_IS_LINEBREAK(ch) Py_UNICODE_ISLINEBREAK((Py_UNICODE)(ch))
  #define SRE_UNI_IS_ALNUM(ch) Py_UNICODE_ISALNUM((Py_UNICODE)(ch))
  #define SRE_UNI_IS_WORD(ch) (SRE_UNI_IS_ALNUM((ch)) || (ch) == '_')
  
  static unsigned int sre_lower_unicode(unsigned int ch)
  {
      return (unsigned int) Py_UNICODE_TOLOWER((Py_UNICODE)(ch));
  }
  
  #endif
  
  LOCAL(int)
  sre_category(SRE_CODE category, unsigned int ch)
  {
      switch (category) {
  
      case SRE_CATEGORY_DIGIT:
          return SRE_IS_DIGIT(ch);
      case SRE_CATEGORY_NOT_DIGIT:
          return !SRE_IS_DIGIT(ch);
      case SRE_CATEGORY_SPACE:
          return SRE_IS_SPACE(ch);
      case SRE_CATEGORY_NOT_SPACE:
          return !SRE_IS_SPACE(ch);
      case SRE_CATEGORY_WORD:
          return SRE_IS_WORD(ch);
      case SRE_CATEGORY_NOT_WORD:
          return !SRE_IS_WORD(ch);
      case SRE_CATEGORY_LINEBREAK:
          return SRE_IS_LINEBREAK(ch);
      case SRE_CATEGORY_NOT_LINEBREAK:
          return !SRE_IS_LINEBREAK(ch);
  
      case SRE_CATEGORY_LOC_WORD:
          return SRE_LOC_IS_WORD(ch);
      case SRE_CATEGORY_LOC_NOT_WORD:
          return !SRE_LOC_IS_WORD(ch);
  
  #if defined(HAVE_UNICODE)
      case SRE_CATEGORY_UNI_DIGIT:
          return SRE_UNI_IS_DIGIT(ch);
      case SRE_CATEGORY_UNI_NOT_DIGIT:
          return !SRE_UNI_IS_DIGIT(ch);
      case SRE_CATEGORY_UNI_SPACE:
          return SRE_UNI_IS_SPACE(ch);
      case SRE_CATEGORY_UNI_NOT_SPACE:
          return !SRE_UNI_IS_SPACE(ch);
      case SRE_CATEGORY_UNI_WORD:
          return SRE_UNI_IS_WORD(ch);
      case SRE_CATEGORY_UNI_NOT_WORD:
          return !SRE_UNI_IS_WORD(ch);
      case SRE_CATEGORY_UNI_LINEBREAK:
          return SRE_UNI_IS_LINEBREAK(ch);
      case SRE_CATEGORY_UNI_NOT_LINEBREAK:
          return !SRE_UNI_IS_LINEBREAK(ch);
  #else
      case SRE_CATEGORY_UNI_DIGIT:
          return SRE_IS_DIGIT(ch);
      case SRE_CATEGORY_UNI_NOT_DIGIT:
          return !SRE_IS_DIGIT(ch);
      case SRE_CATEGORY_UNI_SPACE:
          return SRE_IS_SPACE(ch);
      case SRE_CATEGORY_UNI_NOT_SPACE:
          return !SRE_IS_SPACE(ch);
      case SRE_CATEGORY_UNI_WORD:
          return SRE_LOC_IS_WORD(ch);
      case SRE_CATEGORY_UNI_NOT_WORD:
          return !SRE_LOC_IS_WORD(ch);
      case SRE_CATEGORY_UNI_LINEBREAK:
          return SRE_IS_LINEBREAK(ch);
      case SRE_CATEGORY_UNI_NOT_LINEBREAK:
          return !SRE_IS_LINEBREAK(ch);
  #endif
      }
      return 0;
  }
  
  /* helpers */
  
  static void
  data_stack_dealloc(SRE_STATE* state)
  {
      if (state->data_stack) {
          PyMem_FREE(state->data_stack);
          state->data_stack = NULL;
      }
      state->data_stack_size = state->data_stack_base = 0;
  }
  
  static int
  data_stack_grow(SRE_STATE* state, Py_ssize_t size)
  {
      Py_ssize_t minsize, cursize;
      minsize = state->data_stack_base+size;
      cursize = state->data_stack_size;
      if (cursize < minsize) {
          void* stack;
          cursize = minsize+minsize/4+1024;
          TRACE(("allocate/grow stack %d\n", cursize));
          stack = PyMem_REALLOC(state->data_stack, cursize);
          if (!stack) {
              data_stack_dealloc(state);
              return SRE_ERROR_MEMORY;
          }
          state->data_stack = (char *)stack;
          state->data_stack_size = cursize;
      }
      return 0;
  }
  
  /* generate 8-bit version */
  
  #define SRE_CHAR unsigned char
  #define SRE_AT sre_at
  #define SRE_COUNT sre_count
  #define SRE_CHARSET sre_charset
  #define SRE_INFO sre_info
  #define SRE_MATCH sre_match
  #define SRE_MATCH_CONTEXT sre_match_context
  #define SRE_SEARCH sre_search
  #define SRE_LITERAL_TEMPLATE sre_literal_template
  
  #if defined(HAVE_UNICODE)
  
  #define SRE_RECURSIVE
  #include "_sre.c"
  #undef SRE_RECURSIVE
  
  #undef SRE_LITERAL_TEMPLATE
  #undef SRE_SEARCH
  #undef SRE_MATCH
  #undef SRE_MATCH_CONTEXT
  #undef SRE_INFO
  #undef SRE_CHARSET
  #undef SRE_COUNT
  #undef SRE_AT
  #undef SRE_CHAR
  
  /* generate 16-bit unicode version */
  
  #define SRE_CHAR Py_UNICODE
  #define SRE_AT sre_uat
  #define SRE_COUNT sre_ucount
  #define SRE_CHARSET sre_ucharset
  #define SRE_INFO sre_uinfo
  #define SRE_MATCH sre_umatch
  #define SRE_MATCH_CONTEXT sre_umatch_context
  #define SRE_SEARCH sre_usearch
  #define SRE_LITERAL_TEMPLATE sre_uliteral_template
  #endif
  
  #endif /* SRE_RECURSIVE */
  
  /* -------------------------------------------------------------------- */
  /* String matching engine */
  
  /* the following section is compiled twice, with different character
     settings */
  
  LOCAL(int)
  SRE_AT(SRE_STATE* state, SRE_CHAR* ptr, SRE_CODE at)
  {
      /* check if pointer is at given position */
  
      Py_ssize_t thisp, thatp;
  
      switch (at) {
  
      case SRE_AT_BEGINNING:
      case SRE_AT_BEGINNING_STRING:
          return ((void*) ptr == state->beginning);
  
      case SRE_AT_BEGINNING_LINE:
          return ((void*) ptr == state->beginning ||
                  SRE_IS_LINEBREAK((int) ptr[-1]));
  
      case SRE_AT_END:
          return (((void*) (ptr+1) == state->end &&
                   SRE_IS_LINEBREAK((int) ptr[0])) ||
                  ((void*) ptr == state->end));
  
      case SRE_AT_END_LINE:
          return ((void*) ptr == state->end ||
                  SRE_IS_LINEBREAK((int) ptr[0]));
  
      case SRE_AT_END_STRING:
          return ((void*) ptr == state->end);
  
      case SRE_AT_BOUNDARY:
          if (state->beginning == state->end)
              return 0;
          thatp = ((void*) ptr > state->beginning) ?
              SRE_IS_WORD((int) ptr[-1]) : 0;
          thisp = ((void*) ptr < state->end) ?
              SRE_IS_WORD((int) ptr[0]) : 0;
          return thisp != thatp;
  
      case SRE_AT_NON_BOUNDARY:
          if (state->beginning == state->end)
              return 0;
          thatp = ((void*) ptr > state->beginning) ?
              SRE_IS_WORD((int) ptr[-1]) : 0;
          thisp = ((void*) ptr < state->end) ?
              SRE_IS_WORD((int) ptr[0]) : 0;
          return thisp == thatp;
  
      case SRE_AT_LOC_BOUNDARY:
          if (state->beginning == state->end)
              return 0;
          thatp = ((void*) ptr > state->beginning) ?
              SRE_LOC_IS_WORD((int) ptr[-1]) : 0;
          thisp = ((void*) ptr < state->end) ?
              SRE_LOC_IS_WORD((int) ptr[0]) : 0;
          return thisp != thatp;
  
      case SRE_AT_LOC_NON_BOUNDARY:
          if (state->beginning == state->end)
              return 0;
          thatp = ((void*) ptr > state->beginning) ?
              SRE_LOC_IS_WORD((int) ptr[-1]) : 0;
          thisp = ((void*) ptr < state->end) ?
              SRE_LOC_IS_WORD((int) ptr[0]) : 0;
          return thisp == thatp;
  
  #if defined(HAVE_UNICODE)
      case SRE_AT_UNI_BOUNDARY:
          if (state->beginning == state->end)
              return 0;
          thatp = ((void*) ptr > state->beginning) ?
              SRE_UNI_IS_WORD((int) ptr[-1]) : 0;
          thisp = ((void*) ptr < state->end) ?
              SRE_UNI_IS_WORD((int) ptr[0]) : 0;
          return thisp != thatp;
  
      case SRE_AT_UNI_NON_BOUNDARY:
          if (state->beginning == state->end)
              return 0;
          thatp = ((void*) ptr > state->beginning) ?
              SRE_UNI_IS_WORD((int) ptr[-1]) : 0;
          thisp = ((void*) ptr < state->end) ?
              SRE_UNI_IS_WORD((int) ptr[0]) : 0;
          return thisp == thatp;
  #endif
  
      }
  
      return 0;
  }
  
  LOCAL(int)
  SRE_CHARSET(SRE_CODE* set, SRE_CODE ch)
  {
      /* check if character is a member of the given set */
  
      int ok = 1;
  
      for (;;) {
          switch (*set++) {
  
          case SRE_OP_FAILURE:
              return !ok;
  
          case SRE_OP_LITERAL:
              /* <LITERAL> <code> */
              if (ch == set[0])
                  return ok;
              set++;
              break;
  
          case SRE_OP_CATEGORY:
              /* <CATEGORY> <code> */
              if (sre_category(set[0], (int) ch))
                  return ok;
              set += 1;
              break;
  
          case SRE_OP_CHARSET:
              if (sizeof(SRE_CODE) == 2) {
                  /* <CHARSET> <bitmap> (16 bits per code word) */
                  if (ch < 256 && (set[ch >> 4] & (1 << (ch & 15))))
                      return ok;
                  set += 16;
              }
              else {
                  /* <CHARSET> <bitmap> (32 bits per code word) */
                  if (ch < 256 && (set[ch >> 5] & (1 << (ch & 31))))
                      return ok;
                  set += 8;
              }
              break;
  
          case SRE_OP_RANGE:
              /* <RANGE> <lower> <upper> */
              if (set[0] <= ch && ch <= set[1])
                  return ok;
              set += 2;
              break;
  
          case SRE_OP_NEGATE:
              ok = !ok;
              break;
  
          case SRE_OP_BIGCHARSET:
              /* <BIGCHARSET> <blockcount> <256 blockindices> <blocks> */
          {
              Py_ssize_t count, block;
              count = *(set++);
  
              if (sizeof(SRE_CODE) == 2) {
                  block = ((unsigned char*)set)[ch >> 8];
                  set += 128;
                  if (set[block*16 + ((ch & 255)>>4)] & (1 << (ch & 15)))
                      return ok;
                  set += count*16;
              }
              else {
                  /* !(c & ~N) == (c < N+1) for any unsigned c, this avoids
                   * warnings when c's type supports only numbers < N+1 */
                  if (!(ch & ~65535))
                      block = ((unsigned char*)set)[ch >> 8];
                  else
                      block = -1;
                  set += 64;
                  if (block >=0 &&
                      (set[block*8 + ((ch & 255)>>5)] & (1 << (ch & 31))))
                      return ok;
                  set += count*8;
              }
              break;
          }
  
          default:
              /* internal error -- there's not much we can do about it
                 here, so let's just pretend it didn't match... */
              return 0;
          }
      }
  }
  
  LOCAL(Py_ssize_t) SRE_MATCH(SRE_STATE* state, SRE_CODE* pattern);
  
  LOCAL(Py_ssize_t)
  SRE_COUNT(SRE_STATE* state, SRE_CODE* pattern, Py_ssize_t maxcount)
  {
      SRE_CODE chr;
      SRE_CHAR* ptr = (SRE_CHAR *)state->ptr;
      SRE_CHAR* end = (SRE_CHAR *)state->end;
      Py_ssize_t i;
  
      /* adjust end */
      if (maxcount < end - ptr && maxcount != 65535)
          end = ptr + maxcount;
  
      switch (pattern[0]) {
  
      case SRE_OP_IN:
          /* repeated set */
          TRACE(("|%p|%p|COUNT IN\n", pattern, ptr));
          while (ptr < end && SRE_CHARSET(pattern + 2, *ptr))
              ptr++;
          break;
  
      case SRE_OP_ANY:
          /* repeated dot wildcard. */
          TRACE(("|%p|%p|COUNT ANY\n", pattern, ptr));
          while (ptr < end && !SRE_IS_LINEBREAK(*ptr))
              ptr++;
          break;
  
      case SRE_OP_ANY_ALL:
          /* repeated dot wildcard.  skip to the end of the target
             string, and backtrack from there */
          TRACE(("|%p|%p|COUNT ANY_ALL\n", pattern, ptr));
          ptr = end;
          break;
  
      case SRE_OP_LITERAL:
          /* repeated literal */
          chr = pattern[1];
          TRACE(("|%p|%p|COUNT LITERAL %d\n", pattern, ptr, chr));
          while (ptr < end && (SRE_CODE) *ptr == chr)
              ptr++;
          break;
  
      case SRE_OP_LITERAL_IGNORE:
          /* repeated literal */
          chr = pattern[1];
          TRACE(("|%p|%p|COUNT LITERAL_IGNORE %d\n", pattern, ptr, chr));
          while (ptr < end && (SRE_CODE) state->lower(*ptr) == chr)
              ptr++;
          break;
  
      case SRE_OP_NOT_LITERAL:
          /* repeated non-literal */
          chr = pattern[1];
          TRACE(("|%p|%p|COUNT NOT_LITERAL %d\n", pattern, ptr, chr));
          while (ptr < end && (SRE_CODE) *ptr != chr)
              ptr++;
          break;
  
      case SRE_OP_NOT_LITERAL_IGNORE:
          /* repeated non-literal */
          chr = pattern[1];
          TRACE(("|%p|%p|COUNT NOT_LITERAL_IGNORE %d\n", pattern, ptr, chr));
          while (ptr < end && (SRE_CODE) state->lower(*ptr) != chr)
              ptr++;
          break;
  
      default:
          /* repeated single character pattern */
          TRACE(("|%p|%p|COUNT SUBPATTERN\n", pattern, ptr));
          while ((SRE_CHAR*) state->ptr < end) {
              i = SRE_MATCH(state, pattern);
              if (i < 0)
                  return i;
              if (!i)
                  break;
          }
          TRACE(("|%p|%p|COUNT %d\n", pattern, ptr,
                 (SRE_CHAR*) state->ptr - ptr));
          return (SRE_CHAR*) state->ptr - ptr;
      }
  
      TRACE(("|%p|%p|COUNT %d\n", pattern, ptr, ptr - (SRE_CHAR*) state->ptr));
      return ptr - (SRE_CHAR*) state->ptr;
  }
  
  #if 0 /* not used in this release */
  LOCAL(int)
  SRE_INFO(SRE_STATE* state, SRE_CODE* pattern)
  {
      /* check if an SRE_OP_INFO block matches at the current position.
         returns the number of SRE_CODE objects to skip if successful, 0
         if no match */
  
      SRE_CHAR* end = state->end;
      SRE_CHAR* ptr = state->ptr;
      Py_ssize_t i;
  
      /* check minimal length */
      if (pattern[3] && (end - ptr) < pattern[3])
          return 0;
  
      /* check known prefix */
      if (pattern[2] & SRE_INFO_PREFIX && pattern[5] > 1) {
          /* <length> <skip> <prefix data> <overlap data> */
          for (i = 0; i < pattern[5]; i++)
              if ((SRE_CODE) ptr[i] != pattern[7 + i])
                  return 0;
          return pattern[0] + 2 * pattern[6];
      }
      return pattern[0];
  }
  #endif
  
  /* The macros below should be used to protect recursive SRE_MATCH()
   * calls that *failed* and do *not* return immediately (IOW, those
   * that will backtrack). Explaining:
   *
   * - Recursive SRE_MATCH() returned true: that's usually a success
   *   (besides atypical cases like ASSERT_NOT), therefore there's no
   *   reason to restore lastmark;
   *
   * - Recursive SRE_MATCH() returned false but the current SRE_MATCH()
   *   is returning to the caller: If the current SRE_MATCH() is the
   *   top function of the recursion, returning false will be a matching
   *   failure, and it doesn't matter where lastmark is pointing to.
   *   If it's *not* the top function, it will be a recursive SRE_MATCH()
   *   failure by itself, and the calling SRE_MATCH() will have to deal
   *   with the failure by the same rules explained here (it will restore
   *   lastmark by itself if necessary);
   *
   * - Recursive SRE_MATCH() returned false, and will continue the
   *   outside 'for' loop: must be protected when breaking, since the next
   *   OP could potentially depend on lastmark;
   *
   * - Recursive SRE_MATCH() returned false, and will be called again
   *   inside a local for/while loop: must be protected between each
   *   loop iteration, since the recursive SRE_MATCH() could do anything,
   *   and could potentially depend on lastmark.
   *
   * For more information, check the discussion at SF patch #712900.
   */
  #define LASTMARK_SAVE()     \
      do { \
          ctx->lastmark = state->lastmark; \
          ctx->lastindex = state->lastindex; \
      } while (0)
  #define LASTMARK_RESTORE()  \
      do { \
          state->lastmark = ctx->lastmark; \
          state->lastindex = ctx->lastindex; \
      } while (0)
  
  #define RETURN_ERROR(i) do { return i; } while(0)
  #define RETURN_FAILURE do { ret = 0; goto exit; } while(0)
  #define RETURN_SUCCESS do { ret = 1; goto exit; } while(0)
  
  #define RETURN_ON_ERROR(i) \
      do { if (i < 0) RETURN_ERROR(i); } while (0)
  #define RETURN_ON_SUCCESS(i) \
      do { RETURN_ON_ERROR(i); if (i > 0) RETURN_SUCCESS; } while (0)
  #define RETURN_ON_FAILURE(i) \
      do { RETURN_ON_ERROR(i); if (i == 0) RETURN_FAILURE; } while (0)
  
  #define SFY(x) #x
  
  #define DATA_STACK_ALLOC(state, type, ptr) \
  do { \
      alloc_pos = state->data_stack_base; \
      TRACE(("allocating %s in %d (%d)\n", \
             SFY(type), alloc_pos, sizeof(type))); \
      if (state->data_stack_size < alloc_pos+sizeof(type)) { \
          int j = data_stack_grow(state, sizeof(type)); \
          if (j < 0) return j; \
          if (ctx_pos != -1) \
              DATA_STACK_LOOKUP_AT(state, SRE_MATCH_CONTEXT, ctx, ctx_pos); \
      } \
      ptr = (type*)(state->data_stack+alloc_pos); \
      state->data_stack_base += sizeof(type); \
  } while (0)
  
  #define DATA_STACK_LOOKUP_AT(state, type, ptr, pos) \
  do { \
      TRACE(("looking up %s at %d\n", SFY(type), pos)); \
      ptr = (type*)(state->data_stack+pos); \
  } while (0)
  
  #define DATA_STACK_PUSH(state, data, size) \
  do { \
      TRACE(("copy data in %p to %d (%d)\n", \
             data, state->data_stack_base, size)); \
      if (state->data_stack_size < state->data_stack_base+size) { \
          int j = data_stack_grow(state, size); \
          if (j < 0) return j; \
          if (ctx_pos != -1) \
              DATA_STACK_LOOKUP_AT(state, SRE_MATCH_CONTEXT, ctx, ctx_pos); \
      } \
      memcpy(state->data_stack+state->data_stack_base, data, size); \
      state->data_stack_base += size; \
  } while (0)
  
  #define DATA_STACK_POP(state, data, size, discard) \
  do { \
      TRACE(("copy data to %p from %d (%d)\n", \
             data, state->data_stack_base-size, size)); \
      memcpy(data, state->data_stack+state->data_stack_base-size, size); \
      if (discard) \
          state->data_stack_base -= size; \
  } while (0)
  
  #define DATA_STACK_POP_DISCARD(state, size) \
  do { \
      TRACE(("discard data from %d (%d)\n", \
             state->data_stack_base-size, size)); \
      state->data_stack_base -= size; \
  } while(0)
  
  #define DATA_PUSH(x) \
      DATA_STACK_PUSH(state, (x), sizeof(*(x)))
  #define DATA_POP(x) \
      DATA_STACK_POP(state, (x), sizeof(*(x)), 1)
  #define DATA_POP_DISCARD(x) \
      DATA_STACK_POP_DISCARD(state, sizeof(*(x)))
  #define DATA_ALLOC(t,p) \
      DATA_STACK_ALLOC(state, t, p)
  #define DATA_LOOKUP_AT(t,p,pos) \
      DATA_STACK_LOOKUP_AT(state,t,p,pos)
  
  #define MARK_PUSH(lastmark) \
      do if (lastmark > 0) { \
          i = lastmark; /* ctx->lastmark may change if reallocated */ \
          DATA_STACK_PUSH(state, state->mark, (i+1)*sizeof(void*)); \
      } while (0)
  #define MARK_POP(lastmark) \
      do if (lastmark > 0) { \
          DATA_STACK_POP(state, state->mark, (lastmark+1)*sizeof(void*), 1); \
      } while (0)
  #define MARK_POP_KEEP(lastmark) \
      do if (lastmark > 0) { \
          DATA_STACK_POP(state, state->mark, (lastmark+1)*sizeof(void*), 0); \
      } while (0)
  #define MARK_POP_DISCARD(lastmark) \
      do if (lastmark > 0) { \
          DATA_STACK_POP_DISCARD(state, (lastmark+1)*sizeof(void*)); \
      } while (0)
  
  #define JUMP_NONE            0
  #define JUMP_MAX_UNTIL_1     1
  #define JUMP_MAX_UNTIL_2     2
  #define JUMP_MAX_UNTIL_3     3
  #define JUMP_MIN_UNTIL_1     4
  #define JUMP_MIN_UNTIL_2     5
  #define JUMP_MIN_UNTIL_3     6
  #define JUMP_REPEAT          7
  #define JUMP_REPEAT_ONE_1    8
  #define JUMP_REPEAT_ONE_2    9
  #define JUMP_MIN_REPEAT_ONE  10
  #define JUMP_BRANCH          11
  #define JUMP_ASSERT          12
  #define JUMP_ASSERT_NOT      13
  
  #define DO_JUMP(jumpvalue, jumplabel, nextpattern) \
      DATA_ALLOC(SRE_MATCH_CONTEXT, nextctx); \
      nextctx->last_ctx_pos = ctx_pos; \
      nextctx->jump = jumpvalue; \
      nextctx->pattern = nextpattern; \
      ctx_pos = alloc_pos; \
      ctx = nextctx; \
      goto entrance; \
      jumplabel: \
      while (0) /* gcc doesn't like labels at end of scopes */ \
  
  typedef struct {
      Py_ssize_t last_ctx_pos;
      Py_ssize_t jump;
      SRE_CHAR* ptr;
      SRE_CODE* pattern;
      Py_ssize_t count;
      Py_ssize_t lastmark;
      Py_ssize_t lastindex;
      union {
          SRE_CODE chr;
          SRE_REPEAT* rep;
      } u;
  } SRE_MATCH_CONTEXT;
  
  /* check if string matches the given pattern.  returns <0 for
     error, 0 for failure, and 1 for success */
  LOCAL(Py_ssize_t)
  SRE_MATCH(SRE_STATE* state, SRE_CODE* pattern)
  {
      SRE_CHAR* end = (SRE_CHAR *)state->end;
      Py_ssize_t alloc_pos, ctx_pos = -1;
      Py_ssize_t i, ret = 0;
      Py_ssize_t jump;
      unsigned int sigcount=0;
  
      SRE_MATCH_CONTEXT* ctx;
      SRE_MATCH_CONTEXT* nextctx;
  
      TRACE(("|%p|%p|ENTER\n", pattern, state->ptr));
  
      DATA_ALLOC(SRE_MATCH_CONTEXT, ctx);
      ctx->last_ctx_pos = -1;
      ctx->jump = JUMP_NONE;
      ctx->pattern = pattern;
      ctx_pos = alloc_pos;
  
  entrance:
  
      ctx->ptr = (SRE_CHAR *)state->ptr;
  
      if (ctx->pattern[0] == SRE_OP_INFO) {
          /* optimization info block */
          /* <INFO> <1=skip> <2=flags> <3=min> ... */
          if (ctx->pattern[3] && (end - ctx->ptr) < ctx->pattern[3]) {
              TRACE(("reject (got %d chars, need %d)\n",
                     (end - ctx->ptr), ctx->pattern[3]));
              RETURN_FAILURE;
          }
          ctx->pattern += ctx->pattern[1] + 1;
      }
  
      for (;;) {
          ++sigcount;
          if ((0 == (sigcount & 0xfff)) && PyErr_CheckSignals())
              RETURN_ERROR(SRE_ERROR_INTERRUPTED);
  
          switch (*ctx->pattern++) {
  
          case SRE_OP_MARK:
              /* set mark */
              /* <MARK> <gid> */
              TRACE(("|%p|%p|MARK %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[0]));
              i = ctx->pattern[0];
              if (i & 1)
                  state->lastindex = i/2 + 1;
              if (i > state->lastmark) {
                  /* state->lastmark is the highest valid index in the
                     state->mark array.  If it is increased by more than 1,
                     the intervening marks must be set to NULL to signal
                     that these marks have not been encountered. */
                  Py_ssize_t j = state->lastmark + 1;
                  while (j < i)
                      state->mark[j++] = NULL;
                  state->lastmark = i;
              }
              state->mark[i] = ctx->ptr;
              ctx->pattern++;
              break;
  
          case SRE_OP_LITERAL:
              /* match literal string */
              /* <LITERAL> <code> */
              TRACE(("|%p|%p|LITERAL %d\n", ctx->pattern,
                     ctx->ptr, *ctx->pattern));
              if (ctx->ptr >= end || (SRE_CODE) ctx->ptr[0] != ctx->pattern[0])
                  RETURN_FAILURE;
              ctx->pattern++;
              ctx->ptr++;
              break;
  
          case SRE_OP_NOT_LITERAL:
              /* match anything that is not literal character */
              /* <NOT_LITERAL> <code> */
              TRACE(("|%p|%p|NOT_LITERAL %d\n", ctx->pattern,
                     ctx->ptr, *ctx->pattern));
              if (ctx->ptr >= end || (SRE_CODE) ctx->ptr[0] == ctx->pattern[0])
                  RETURN_FAILURE;
              ctx->pattern++;
              ctx->ptr++;
              break;
  
          case SRE_OP_SUCCESS:
              /* end of pattern */
              TRACE(("|%p|%p|SUCCESS\n", ctx->pattern, ctx->ptr));
              state->ptr = ctx->ptr;
              RETURN_SUCCESS;
  
          case SRE_OP_AT:
              /* match at given position */
              /* <AT> <code> */
              TRACE(("|%p|%p|AT %d\n", ctx->pattern, ctx->ptr, *ctx->pattern));
              if (!SRE_AT(state, ctx->ptr, *ctx->pattern))
                  RETURN_FAILURE;
              ctx->pattern++;
              break;
  
          case SRE_OP_CATEGORY:
              /* match at given category */
              /* <CATEGORY> <code> */
              TRACE(("|%p|%p|CATEGORY %d\n", ctx->pattern,
                     ctx->ptr, *ctx->pattern));
              if (ctx->ptr >= end || !sre_category(ctx->pattern[0], ctx->ptr[0]))
                  RETURN_FAILURE;
              ctx->pattern++;
              ctx->ptr++;
              break;
  
          case SRE_OP_ANY:
              /* match anything (except a newline) */
              /* <ANY> */
              TRACE(("|%p|%p|ANY\n", ctx->pattern, ctx->ptr));
              if (ctx->ptr >= end || SRE_IS_LINEBREAK(ctx->ptr[0]))
                  RETURN_FAILURE;
              ctx->ptr++;
              break;
  
          case SRE_OP_ANY_ALL:
              /* match anything */
              /* <ANY_ALL> */
              TRACE(("|%p|%p|ANY_ALL\n", ctx->pattern, ctx->ptr));
              if (ctx->ptr >= end)
                  RETURN_FAILURE;
              ctx->ptr++;
              break;
  
          case SRE_OP_IN:
              /* match set member (or non_member) */
              /* <IN> <skip> <set> */
              TRACE(("|%p|%p|IN\n", ctx->pattern, ctx->ptr));
              if (ctx->ptr >= end || !SRE_CHARSET(ctx->pattern + 1, *ctx->ptr))
                  RETURN_FAILURE;
              ctx->pattern += ctx->pattern[0];
              ctx->ptr++;
              break;
  
          case SRE_OP_LITERAL_IGNORE:
              TRACE(("|%p|%p|LITERAL_IGNORE %d\n",
                     ctx->pattern, ctx->ptr, ctx->pattern[0]));
              if (ctx->ptr >= end ||
                  state->lower(*ctx->ptr) != state->lower(*ctx->pattern))
                  RETURN_FAILURE;
              ctx->pattern++;
              ctx->ptr++;
              break;
  
          case SRE_OP_NOT_LITERAL_IGNORE:
              TRACE(("|%p|%p|NOT_LITERAL_IGNORE %d\n",
                     ctx->pattern, ctx->ptr, *ctx->pattern));
              if (ctx->ptr >= end ||
                  state->lower(*ctx->ptr) == state->lower(*ctx->pattern))
                  RETURN_FAILURE;
              ctx->pattern++;
              ctx->ptr++;
              break;
  
          case SRE_OP_IN_IGNORE:
              TRACE(("|%p|%p|IN_IGNORE\n", ctx->pattern, ctx->ptr));
              if (ctx->ptr >= end
                  || !SRE_CHARSET(ctx->pattern+1,
                                  (SRE_CODE)state->lower(*ctx->ptr)))
                  RETURN_FAILURE;
              ctx->pattern += ctx->pattern[0];
              ctx->ptr++;
              break;
  
          case SRE_OP_JUMP:
          case SRE_OP_INFO:
              /* jump forward */
              /* <JUMP> <offset> */
              TRACE(("|%p|%p|JUMP %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[0]));
              ctx->pattern += ctx->pattern[0];
              break;
  
          case SRE_OP_BRANCH:
              /* alternation */
              /* <BRANCH> <0=skip> code <JUMP> ... <NULL> */
              TRACE(("|%p|%p|BRANCH\n", ctx->pattern, ctx->ptr));
              LASTMARK_SAVE();
              ctx->u.rep = state->repeat;
              if (ctx->u.rep)
                  MARK_PUSH(ctx->lastmark);
              for (; ctx->pattern[0]; ctx->pattern += ctx->pattern[0]) {
                  if (ctx->pattern[1] == SRE_OP_LITERAL &&
                      (ctx->ptr >= end ||
                       (SRE_CODE) *ctx->ptr != ctx->pattern[2]))
                      continue;
                  if (ctx->pattern[1] == SRE_OP_IN &&
                      (ctx->ptr >= end ||
                       !SRE_CHARSET(ctx->pattern + 3, (SRE_CODE) *ctx->ptr)))
                      continue;
                  state->ptr = ctx->ptr;
                  DO_JUMP(JUMP_BRANCH, jump_branch, ctx->pattern+1);
                  if (ret) {
                      if (ctx->u.rep)
                          MARK_POP_DISCARD(ctx->lastmark);
                      RETURN_ON_ERROR(ret);
                      RETURN_SUCCESS;
                  }
                  if (ctx->u.rep)
                      MARK_POP_KEEP(ctx->lastmark);
                  LASTMARK_RESTORE();
              }
              if (ctx->u.rep)
                  MARK_POP_DISCARD(ctx->lastmark);
              RETURN_FAILURE;
  
          case SRE_OP_REPEAT_ONE:
              /* match repeated sequence (maximizing regexp) */
  
              /* this operator only works if the repeated item is
                 exactly one character wide, and we're not already
                 collecting backtracking points.  for other cases,
                 use the MAX_REPEAT operator */
  
              /* <REPEAT_ONE> <skip> <1=min> <2=max> item <SUCCESS> tail */
  
              TRACE(("|%p|%p|REPEAT_ONE %d %d\n", ctx->pattern, ctx->ptr,
                     ctx->pattern[1], ctx->pattern[2]));
  
              if (ctx->ptr + ctx->pattern[1] > end)
                  RETURN_FAILURE; /* cannot match */
  
              state->ptr = ctx->ptr;
  
              ret = SRE_COUNT(state, ctx->pattern+3, ctx->pattern[2]);
              RETURN_ON_ERROR(ret);
              DATA_LOOKUP_AT(SRE_MATCH_CONTEXT, ctx, ctx_pos);
              ctx->count = ret;
              ctx->ptr += ctx->count;
  
              /* when we arrive here, count contains the number of
                 matches, and ctx->ptr points to the tail of the target
                 string.  check if the rest of the pattern matches,
                 and backtrack if not. */
  
              if (ctx->count < (Py_ssize_t) ctx->pattern[1])
                  RETURN_FAILURE;
  
              if (ctx->pattern[ctx->pattern[0]] == SRE_OP_SUCCESS) {
                  /* tail is empty.  we're finished */
                  state->ptr = ctx->ptr;
                  RETURN_SUCCESS;
              }
  
              LASTMARK_SAVE();
  
              if (ctx->pattern[ctx->pattern[0]] == SRE_OP_LITERAL) {
                  /* tail starts with a literal. skip positions where
                     the rest of the pattern cannot possibly match */
                  ctx->u.chr = ctx->pattern[ctx->pattern[0]+1];
                  for (;;) {
                      while (ctx->count >= (Py_ssize_t) ctx->pattern[1] &&
                             (ctx->ptr >= end || *ctx->ptr != ctx->u.chr)) {
                          ctx->ptr--;
                          ctx->count--;
                      }
                      if (ctx->count < (Py_ssize_t) ctx->pattern[1])
                          break;
                      state->ptr = ctx->ptr;
                      DO_JUMP(JUMP_REPEAT_ONE_1, jump_repeat_one_1,
                              ctx->pattern+ctx->pattern[0]);
                      if (ret) {
                          RETURN_ON_ERROR(ret);
                          RETURN_SUCCESS;
                      }
  
                      LASTMARK_RESTORE();
  
                      ctx->ptr--;
                      ctx->count--;
                  }
  
              } else {
                  /* general case */
                  while (ctx->count >= (Py_ssize_t) ctx->pattern[1]) {
                      state->ptr = ctx->ptr;
                      DO_JUMP(JUMP_REPEAT_ONE_2, jump_repeat_one_2,
                              ctx->pattern+ctx->pattern[0]);
                      if (ret) {
                          RETURN_ON_ERROR(ret);
                          RETURN_SUCCESS;
                      }
                      ctx->ptr--;
                      ctx->count--;
                      LASTMARK_RESTORE();
                  }
              }
              RETURN_FAILURE;
  
          case SRE_OP_MIN_REPEAT_ONE:
              /* match repeated sequence (minimizing regexp) */
  
              /* this operator only works if the repeated item is
                 exactly one character wide, and we're not already
                 collecting backtracking points.  for other cases,
                 use the MIN_REPEAT operator */
  
              /* <MIN_REPEAT_ONE> <skip> <1=min> <2=max> item <SUCCESS> tail */
  
              TRACE(("|%p|%p|MIN_REPEAT_ONE %d %d\n", ctx->pattern, ctx->ptr,
                     ctx->pattern[1], ctx->pattern[2]));
  
              if (ctx->ptr + ctx->pattern[1] > end)
                  RETURN_FAILURE; /* cannot match */
  
              state->ptr = ctx->ptr;
  
              if (ctx->pattern[1] == 0)
                  ctx->count = 0;
              else {
                  /* count using pattern min as the maximum */
                  ret = SRE_COUNT(state, ctx->pattern+3, ctx->pattern[1]);
                  RETURN_ON_ERROR(ret);
                  DATA_LOOKUP_AT(SRE_MATCH_CONTEXT, ctx, ctx_pos);
                  if (ret < (Py_ssize_t) ctx->pattern[1])
                      /* didn't match minimum number of times */
                      RETURN_FAILURE;
                  /* advance past minimum matches of repeat */
                  ctx->count = ret;
                  ctx->ptr += ctx->count;
              }
  
              if (ctx->pattern[ctx->pattern[0]] == SRE_OP_SUCCESS) {
                  /* tail is empty.  we're finished */
                  state->ptr = ctx->ptr;
                  RETURN_SUCCESS;
  
              } else {
                  /* general case */
                  LASTMARK_SAVE();
                  while ((Py_ssize_t)ctx->pattern[2] == 65535
                         || ctx->count <= (Py_ssize_t)ctx->pattern[2]) {
                      state->ptr = ctx->ptr;
                      DO_JUMP(JUMP_MIN_REPEAT_ONE,jump_min_repeat_one,
                              ctx->pattern+ctx->pattern[0]);
                      if (ret) {
                          RETURN_ON_ERROR(ret);
                          RETURN_SUCCESS;
                      }
                      state->ptr = ctx->ptr;
                      ret = SRE_COUNT(state, ctx->pattern+3, 1);
                      RETURN_ON_ERROR(ret);
                      DATA_LOOKUP_AT(SRE_MATCH_CONTEXT, ctx, ctx_pos);
                      if (ret == 0)
                          break;
                      assert(ret == 1);
                      ctx->ptr++;
                      ctx->count++;
                      LASTMARK_RESTORE();
                  }
              }
              RETURN_FAILURE;
  
          case SRE_OP_REPEAT:
              /* create repeat context.  all the hard work is done
                 by the UNTIL operator (MAX_UNTIL, MIN_UNTIL) */
              /* <REPEAT> <skip> <1=min> <2=max> item <UNTIL> tail */
              TRACE(("|%p|%p|REPEAT %d %d\n", ctx->pattern, ctx->ptr,
                     ctx->pattern[1], ctx->pattern[2]));
  
              /* install new repeat context */
              ctx->u.rep = (SRE_REPEAT*) PyObject_MALLOC(sizeof(*ctx->u.rep));
              if (!ctx->u.rep) {
                  PyErr_NoMemory();
                  RETURN_FAILURE;
              }
              ctx->u.rep->count = -1;
              ctx->u.rep->pattern = ctx->pattern;
              ctx->u.rep->prev = state->repeat;
              ctx->u.rep->last_ptr = NULL;
              state->repeat = ctx->u.rep;
  
              state->ptr = ctx->ptr;
              DO_JUMP(JUMP_REPEAT, jump_repeat, ctx->pattern+ctx->pattern[0]);
              state->repeat = ctx->u.rep->prev;
              PyObject_FREE(ctx->u.rep);
  
              if (ret) {
                  RETURN_ON_ERROR(ret);
                  RETURN_SUCCESS;
              }
              RETURN_FAILURE;
  
          case SRE_OP_MAX_UNTIL:
              /* maximizing repeat */
              /* <REPEAT> <skip> <1=min> <2=max> item <MAX_UNTIL> tail */
  
              /* FIXME: we probably need to deal with zero-width
                 matches in here... */
  
              ctx->u.rep = state->repeat;
              if (!ctx->u.rep)
                  RETURN_ERROR(SRE_ERROR_STATE);
  
              state->ptr = ctx->ptr;
  
              ctx->count = ctx->u.rep->count+1;
  
              TRACE(("|%p|%p|MAX_UNTIL %d\n", ctx->pattern,
                     ctx->ptr, ctx->count));
  
              if (ctx->count < ctx->u.rep->pattern[1]) {
                  /* not enough matches */
                  ctx->u.rep->count = ctx->count;
                  DO_JUMP(JUMP_MAX_UNTIL_1, jump_max_until_1,
                          ctx->u.rep->pattern+3);
                  if (ret) {
                      RETURN_ON_ERROR(ret);
                      RETURN_SUCCESS;
                  }
                  ctx->u.rep->count = ctx->count-1;
                  state->ptr = ctx->ptr;
                  RETURN_FAILURE;
              }
  
              if ((ctx->count < ctx->u.rep->pattern[2] ||
                  ctx->u.rep->pattern[2] == 65535) &&
                  state->ptr != ctx->u.rep->last_ptr) {
                  /* we may have enough matches, but if we can
                     match another item, do so */
                  ctx->u.rep->count = ctx->count;
                  LASTMARK_SAVE();
                  MARK_PUSH(ctx->lastmark);
                  /* zero-width match protection */
                  DATA_PUSH(&ctx->u.rep->last_ptr);
                  ctx->u.rep->last_ptr = state->ptr;
                  DO_JUMP(JUMP_MAX_UNTIL_2, jump_max_until_2,
                          ctx->u.rep->pattern+3);
                  DATA_POP(&ctx->u.rep->last_ptr);
                  if (ret) {
                      MARK_POP_DISCARD(ctx->lastmark);
                      RETURN_ON_ERROR(ret);
                      RETURN_SUCCESS;
                  }
                  MARK_POP(ctx->lastmark);
                  LASTMARK_RESTORE();
                  ctx->u.rep->count = ctx->count-1;
                  state->ptr = ctx->ptr;
              }
  
              /* cannot match more repeated items here.  make sure the
                 tail matches */
              state->repeat = ctx->u.rep->prev;
              DO_JUMP(JUMP_MAX_UNTIL_3, jump_max_until_3, ctx->pattern);
              RETURN_ON_SUCCESS(ret);
              state->repeat = ctx->u.rep;
              state->ptr = ctx->ptr;
              RETURN_FAILURE;
  
          case SRE_OP_MIN_UNTIL:
              /* minimizing repeat */
              /* <REPEAT> <skip> <1=min> <2=max> item <MIN_UNTIL> tail */
  
              ctx->u.rep = state->repeat;
              if (!ctx->u.rep)
                  RETURN_ERROR(SRE_ERROR_STATE);
  
              state->ptr = ctx->ptr;
  
              ctx->count = ctx->u.rep->count+1;
  
              TRACE(("|%p|%p|MIN_UNTIL %d %p\n", ctx->pattern,
                     ctx->ptr, ctx->count, ctx->u.rep->pattern));
  
              if (ctx->count < ctx->u.rep->pattern[1]) {
                  /* not enough matches */
                  ctx->u.rep->count = ctx->count;
                  DO_JUMP(JUMP_MIN_UNTIL_1, jump_min_until_1,
                          ctx->u.rep->pattern+3);
                  if (ret) {
                      RETURN_ON_ERROR(ret);
                      RETURN_SUCCESS;
                  }
                  ctx->u.rep->count = ctx->count-1;
                  state->ptr = ctx->ptr;
                  RETURN_FAILURE;
              }
  
              LASTMARK_SAVE();
  
              /* see if the tail matches */
              state->repeat = ctx->u.rep->prev;
              DO_JUMP(JUMP_MIN_UNTIL_2, jump_min_until_2, ctx->pattern);
              if (ret) {
                  RETURN_ON_ERROR(ret);
                  RETURN_SUCCESS;
              }
  
              state->repeat = ctx->u.rep;
              state->ptr = ctx->ptr;
  
              LASTMARK_RESTORE();
  
              if (ctx->count >= ctx->u.rep->pattern[2]
                  && ctx->u.rep->pattern[2] != 65535)
                  RETURN_FAILURE;
  
              ctx->u.rep->count = ctx->count;
              DO_JUMP(JUMP_MIN_UNTIL_3,jump_min_until_3,
                      ctx->u.rep->pattern+3);
              if (ret) {
                  RETURN_ON_ERROR(ret);
                  RETURN_SUCCESS;
              }
              ctx->u.rep->count = ctx->count-1;
              state->ptr = ctx->ptr;
              RETURN_FAILURE;
  
          case SRE_OP_GROUPREF:
              /* match backreference */
              TRACE(("|%p|%p|GROUPREF %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[0]));
              i = ctx->pattern[0];
              {
                  Py_ssize_t groupref = i+i;
                  if (groupref >= state->lastmark) {
                      RETURN_FAILURE;
                  } else {
                      SRE_CHAR* p = (SRE_CHAR*) state->mark[groupref];
                      SRE_CHAR* e = (SRE_CHAR*) state->mark[groupref+1];
                      if (!p || !e || e < p)
                          RETURN_FAILURE;
                      while (p < e) {
                          if (ctx->ptr >= end || *ctx->ptr != *p)
                              RETURN_FAILURE;
                          p++; ctx->ptr++;
                      }
                  }
              }
              ctx->pattern++;
              break;
  
          case SRE_OP_GROUPREF_IGNORE:
              /* match backreference */
              TRACE(("|%p|%p|GROUPREF_IGNORE %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[0]));
              i = ctx->pattern[0];
              {
                  Py_ssize_t groupref = i+i;
                  if (groupref >= state->lastmark) {
                      RETURN_FAILURE;
                  } else {
                      SRE_CHAR* p = (SRE_CHAR*) state->mark[groupref];
                      SRE_CHAR* e = (SRE_CHAR*) state->mark[groupref+1];
                      if (!p || !e || e < p)
                          RETURN_FAILURE;
                      while (p < e) {
                          if (ctx->ptr >= end ||
                              state->lower(*ctx->ptr) != state->lower(*p))
                              RETURN_FAILURE;
                          p++; ctx->ptr++;
                      }
                  }
              }
              ctx->pattern++;
              break;
  
          case SRE_OP_GROUPREF_EXISTS:
              TRACE(("|%p|%p|GROUPREF_EXISTS %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[0]));
              /* <GROUPREF_EXISTS> <group> <skip> codeyes <JUMP> codeno ... */
              i = ctx->pattern[0];
              {
                  Py_ssize_t groupref = i+i;
                  if (groupref >= state->lastmark) {
                      ctx->pattern += ctx->pattern[1];
                      break;
                  } else {
                      SRE_CHAR* p = (SRE_CHAR*) state->mark[groupref];
                      SRE_CHAR* e = (SRE_CHAR*) state->mark[groupref+1];
                      if (!p || !e || e < p) {
                          ctx->pattern += ctx->pattern[1];
                          break;
                      }
                  }
              }
              ctx->pattern += 2;
              break;
  
          case SRE_OP_ASSERT:
              /* assert subpattern */
              /* <ASSERT> <skip> <back> <pattern> */
              TRACE(("|%p|%p|ASSERT %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[1]));
              state->ptr = ctx->ptr - ctx->pattern[1];
              if (state->ptr < state->beginning)
                  RETURN_FAILURE;
              DO_JUMP(JUMP_ASSERT, jump_assert, ctx->pattern+2);
              RETURN_ON_FAILURE(ret);
              ctx->pattern += ctx->pattern[0];
              break;
  
          case SRE_OP_ASSERT_NOT:
              /* assert not subpattern */
              /* <ASSERT_NOT> <skip> <back> <pattern> */
              TRACE(("|%p|%p|ASSERT_NOT %d\n", ctx->pattern,
                     ctx->ptr, ctx->pattern[1]));
              state->ptr = ctx->ptr - ctx->pattern[1];
              if (state->ptr >= state->beginning) {
                  DO_JUMP(JUMP_ASSERT_NOT, jump_assert_not, ctx->pattern+2);
                  if (ret) {
                      RETURN_ON_ERROR(ret);
                      RETURN_FAILURE;
                  }
              }
              ctx->pattern += ctx->pattern[0];
              break;
  
          case SRE_OP_FAILURE:
              /* immediate failure */
              TRACE(("|%p|%p|FAILURE\n", ctx->pattern, ctx->ptr));
              RETURN_FAILURE;
  
          default:
              TRACE(("|%p|%p|UNKNOWN %d\n", ctx->pattern, ctx->ptr,
                     ctx->pattern[-1]));
              RETURN_ERROR(SRE_ERROR_ILLEGAL);
          }
      }
  
  exit:
      ctx_pos = ctx->last_ctx_pos;
      jump = ctx->jump;
      DATA_POP_DISCARD(ctx);
      if (ctx_pos == -1)
          return ret;
      DATA_LOOKUP_AT(SRE_MATCH_CONTEXT, ctx, ctx_pos);
  
      switch (jump) {
          case JUMP_MAX_UNTIL_2:
              TRACE(("|%p|%p|JUMP_MAX_UNTIL_2\n", ctx->pattern, ctx->ptr));
              goto jump_max_until_2;
          case JUMP_MAX_UNTIL_3:
              TRACE(("|%p|%p|JUMP_MAX_UNTIL_3\n", ctx->pattern, ctx->ptr));
              goto jump_max_until_3;
          case JUMP_MIN_UNTIL_2:
              TRACE(("|%p|%p|JUMP_MIN_UNTIL_2\n", ctx->pattern, ctx->ptr));
              goto jump_min_until_2;
          case JUMP_MIN_UNTIL_3:
              TRACE(("|%p|%p|JUMP_MIN_UNTIL_3\n", ctx->pattern, ctx->ptr));
              goto jump_min_until_3;
          case JUMP_BRANCH:
              TRACE(("|%p|%p|JUMP_BRANCH\n", ctx->pattern, ctx->ptr));
              goto jump_branch;
          case JUMP_MAX_UNTIL_1:
              TRACE(("|%p|%p|JUMP_MAX_UNTIL_1\n", ctx->pattern, ctx->ptr));
              goto jump_max_until_1;
          case JUMP_MIN_UNTIL_1:
              TRACE(("|%p|%p|JUMP_MIN_UNTIL_1\n", ctx->pattern, ctx->ptr));
              goto jump_min_until_1;
          case JUMP_REPEAT:
              TRACE(("|%p|%p|JUMP_REPEAT\n", ctx->pattern, ctx->ptr));
              goto jump_repeat;
          case JUMP_REPEAT_ONE_1:
              TRACE(("|%p|%p|JUMP_REPEAT_ONE_1\n", ctx->pattern, ctx->ptr));
              goto jump_repeat_one_1;
          case JUMP_REPEAT_ONE_2:
              TRACE(("|%p|%p|JUMP_REPEAT_ONE_2\n", ctx->pattern, ctx->ptr));
              goto jump_repeat_one_2;
          case JUMP_MIN_REPEAT_ONE:
              TRACE(("|%p|%p|JUMP_MIN_REPEAT_ONE\n", ctx->pattern, ctx->ptr));
              goto jump_min_repeat_one;
          case JUMP_ASSERT:
              TRACE(("|%p|%p|JUMP_ASSERT\n", ctx->pattern, ctx->ptr));
              goto jump_assert;
          case JUMP_ASSERT_NOT:
              TRACE(("|%p|%p|JUMP_ASSERT_NOT\n", ctx->pattern, ctx->ptr));
              goto jump_assert_not;
          case JUMP_NONE:
              TRACE(("|%p|%p|RETURN %d\n", ctx->pattern, ctx->ptr, ret));
              break;
      }
  
      return ret; /* should never get here */
  }
  
  LOCAL(Py_ssize_t)
  SRE_SEARCH(SRE_STATE* state, SRE_CODE* pattern)
  {
      SRE_CHAR* ptr = (SRE_CHAR *)state->start;
      SRE_CHAR* end = (SRE_CHAR *)state->end;
      Py_ssize_t status = 0;
      Py_ssize_t prefix_len = 0;
      Py_ssize_t prefix_skip = 0;
      SRE_CODE* prefix = NULL;
      SRE_CODE* charset = NULL;
      SRE_CODE* overlap = NULL;
      int flags = 0;
  
      if (pattern[0] == SRE_OP_INFO) {
          /* optimization info block */
          /* <INFO> <1=skip> <2=flags> <3=min> <4=max> <5=prefix info>  */
  
          flags = pattern[2];
  
          if (pattern[3] > 1) {
              /* adjust end point (but make sure we leave at least one
                 character in there, so literal search will work) */
              end -= pattern[3]-1;
              if (end <= ptr)
                  end = ptr+1;
          }
  
          if (flags & SRE_INFO_PREFIX) {
              /* pattern starts with a known prefix */
              /* <length> <skip> <prefix data> <overlap data> */
              prefix_len = pattern[5];
              prefix_skip = pattern[6];
              prefix = pattern + 7;
              overlap = prefix + prefix_len - 1;
          } else if (flags & SRE_INFO_CHARSET)
              /* pattern starts with a character from a known set */
              /* <charset> */
              charset = pattern + 5;
  
          pattern += 1 + pattern[1];
      }
  
      TRACE(("prefix = %p %d %d\n", prefix, prefix_len, prefix_skip));
      TRACE(("charset = %p\n", charset));
  
  #if defined(USE_FAST_SEARCH)
      if (prefix_len > 1) {
          /* pattern starts with a known prefix.  use the overlap
             table to skip forward as fast as we possibly can */
          Py_ssize_t i = 0;
          end = (SRE_CHAR *)state->end;
          while (ptr < end) {
              for (;;) {
                  if ((SRE_CODE) ptr[0] != prefix[i]) {
                      if (!i)
                          break;
                      else
                          i = overlap[i];
                  } else {
                      if (++i == prefix_len) {
                          /* found a potential match */
                          TRACE(("|%p|%p|SEARCH SCAN\n", pattern, ptr));
                          state->start = ptr + 1 - prefix_len;
                          state->ptr = ptr + 1 - prefix_len + prefix_skip;
                          if (flags & SRE_INFO_LITERAL)
                              return 1; /* we got all of it */
                          status = SRE_MATCH(state, pattern + 2*prefix_skip);
                          if (status != 0)
                              return status;
                          /* close but no cigar -- try again */
                          i = overlap[i];
                      }
                      break;
                  }
              }
              ptr++;
          }
          return 0;
      }
  #endif
  
      if (pattern[0] == SRE_OP_LITERAL) {
          /* pattern starts with a literal character.  this is used
             for short prefixes, and if fast search is disabled */
          SRE_CODE chr = pattern[1];
          end = (SRE_CHAR *)state->end;
          for (;;) {
              while (ptr < end && (SRE_CODE) ptr[0] != chr)
                  ptr++;
              if (ptr >= end)
                  return 0;
              TRACE(("|%p|%p|SEARCH LITERAL\n", pattern, ptr));
              state->start = ptr;
              state->ptr = ++ptr;
              if (flags & SRE_INFO_LITERAL)
                  return 1; /* we got all of it */
              status = SRE_MATCH(state, pattern + 2);
              if (status != 0)
                  break;
          }
      } else if (charset) {
          /* pattern starts with a character from a known set */
          end = (SRE_CHAR *)state->end;
          for (;;) {
              while (ptr < end && !SRE_CHARSET(charset, ptr[0]))
                  ptr++;
              if (ptr >= end)
                  return 0;
              TRACE(("|%p|%p|SEARCH CHARSET\n", pattern, ptr));
              state->start = ptr;
              state->ptr = ptr;
              status = SRE_MATCH(state, pattern);
              if (status != 0)
                  break;
              ptr++;
          }
      } else
          /* general case */
          while (ptr <= end) {
              TRACE(("|%p|%p|SEARCH\n", pattern, ptr));
              state->start = state->ptr = ptr++;
              status = SRE_MATCH(state, pattern);
              if (status != 0)
                  break;
          }
  
      return status;
  }
  
  LOCAL(int)
  SRE_LITERAL_TEMPLATE(SRE_CHAR* ptr, Py_ssize_t len)
  {
      /* check if given string is a literal template (i.e. no escapes) */
      while (len-- > 0)
          if (*ptr++ == '\\')
              return 0;
      return 1;
  }
  
  #if !defined(SRE_RECURSIVE)
  
  /* -------------------------------------------------------------------- */
  /* factories and destructors */
  
  /* see sre.h for object declarations */
  static PyObject*pattern_new_match(PatternObject*, SRE_STATE*, int);
  static PyObject*pattern_scanner(PatternObject*, PyObject*);
  
  static PyObject *
  sre_codesize(PyObject* self, PyObject *unused)
  {
      return Py_BuildValue("l", sizeof(SRE_CODE));
  }
  
  static PyObject *
  sre_getlower(PyObject* self, PyObject* args)
  {
      int character, flags;
      if (!PyArg_ParseTuple(args, "ii", &character, &flags))
          return NULL;
      if (flags & SRE_FLAG_LOCALE)
          return Py_BuildValue("i", sre_lower_locale(character));
      if (flags & SRE_FLAG_UNICODE)
  #if defined(HAVE_UNICODE)
          return Py_BuildValue("i", sre_lower_unicode(character));
  #else
          return Py_BuildValue("i", sre_lower_locale(character));
  #endif
      return Py_BuildValue("i", sre_lower(character));
  }
  
  LOCAL(void)
  state_reset(SRE_STATE* state)
  {
      /* FIXME: dynamic! */
      /*memset(state->mark, 0, sizeof(*state->mark) * SRE_MARK_SIZE);*/
  
      state->lastmark = -1;
      state->lastindex = -1;
  
      state->repeat = NULL;
  
      data_stack_dealloc(state);
  }
  
  static void*
  getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize)
  {
      /* given a python object, return a data pointer, a length (in
         characters), and a character size.  return NULL if the object
         is not a string (or not compatible) */
  
      PyBufferProcs *buffer;
      Py_ssize_t size, bytes;
      int charsize;
      void* ptr;
  
  #if defined(HAVE_UNICODE)
      if (PyUnicode_Check(string)) {
          /* unicode strings doesn't always support the buffer interface */
          ptr = (void*) PyUnicode_AS_DATA(string);
          /* bytes = PyUnicode_GET_DATA_SIZE(string); */
          size = PyUnicode_GET_SIZE(string);
          charsize = sizeof(Py_UNICODE);
  
      } else {
  #endif
  
      /* get pointer to string buffer */
      buffer = Py_TYPE(string)->tp_as_buffer;
      if (!buffer || !buffer->bf_getreadbuffer || !buffer->bf_getsegcount ||
          buffer->bf_getsegcount(string, NULL) != 1) {
          PyErr_SetString(PyExc_TypeError, "expected string or buffer");
          return NULL;
      }
  
      /* determine buffer size */
      bytes = buffer->bf_getreadbuffer(string, 0, &ptr);
      if (bytes < 0) {
          PyErr_SetString(PyExc_TypeError, "buffer has negative size");
          return NULL;
      }
  
      /* determine character size */
  #if PY_VERSION_HEX >= 0x01060000
      size = PyObject_Size(string);
  #else
      size = PyObject_Length(string);
  #endif
  
      if (PyString_Check(string) || bytes == size)
          charsize = 1;
  #if defined(HAVE_UNICODE)
      else if (bytes == (Py_ssize_t) (size * sizeof(Py_UNICODE)))
          charsize = sizeof(Py_UNICODE);
  #endif
      else {
          PyErr_SetString(PyExc_TypeError, "buffer size mismatch");
          return NULL;
      }
  
  #if defined(HAVE_UNICODE)
      }
  #endif
  
      *p_length = size;
      *p_charsize = charsize;
  
      return ptr;
  }
  
  LOCAL(PyObject*)
  state_init(SRE_STATE* state, PatternObject* pattern, PyObject* string,
             Py_ssize_t start, Py_ssize_t end)
  {
      /* prepare state object */
  
      Py_ssize_t length;
      int charsize;
      void* ptr;
  
      memset(state, 0, sizeof(SRE_STATE));
  
      state->lastmark = -1;
      state->lastindex = -1;
  
      ptr = getstring(string, &length, &charsize);
      if (!ptr)
          return NULL;
  
      /* adjust boundaries */
      if (start < 0)
          start = 0;
      else if (start > length)
          start = length;
  
      if (end < 0)
          end = 0;
      else if (end > length)
          end = length;
  
      state->charsize = charsize;
  
      state->beginning = ptr;
  
      state->start = (void*) ((char*) ptr + start * state->charsize);
      state->end = (void*) ((char*) ptr + end * state->charsize);
  
      Py_INCREF(string);
      state->string = string;
      state->pos = start;
      state->endpos = end;
  
      if (pattern->flags & SRE_FLAG_LOCALE)
          state->lower = sre_lower_locale;
      else if (pattern->flags & SRE_FLAG_UNICODE)
  #if defined(HAVE_UNICODE)
          state->lower = sre_lower_unicode;
  #else
          state->lower = sre_lower_locale;
  #endif
      else
          state->lower = sre_lower;
  
      return string;
  }
  
  LOCAL(void)
  state_fini(SRE_STATE* state)
  {
      Py_XDECREF(state->string);
      data_stack_dealloc(state);
  }
  
  /* calculate offset from start of string */
  #define STATE_OFFSET(state, member)\
      (((char*)(member) - (char*)(state)->beginning) / (state)->charsize)
  
  LOCAL(PyObject*)
  state_getslice(SRE_STATE* state, Py_ssize_t index, PyObject* string, int empty)
  {
      Py_ssize_t i, j;
  
      index = (index - 1) * 2;
  
      if (string == Py_None || index >= state->lastmark || !state->mark[index] || !state->mark[index+1]) {
          if (empty)
              /* want empty string */
              i = j = 0;
          else {
              Py_INCREF(Py_None);
              return Py_None;
          }
      } else {
          i = STATE_OFFSET(state, state->mark[index]);
          j = STATE_OFFSET(state, state->mark[index+1]);
      }
  
      return PySequence_GetSlice(string, i, j);
  }
  
  static void
  pattern_error(int status)
  {
      switch (status) {
      case SRE_ERROR_RECURSION_LIMIT:
          PyErr_SetString(
              PyExc_RuntimeError,
              "maximum recursion limit exceeded"
              );
          break;
      case SRE_ERROR_MEMORY:
          PyErr_NoMemory();
          break;
      case SRE_ERROR_INTERRUPTED:
      /* An exception has already been raised, so let it fly */
          break;
      default:
          /* other error codes indicate compiler/engine bugs */
          PyErr_SetString(
              PyExc_RuntimeError,
              "internal error in regular expression engine"
              );
      }
  }
  
  static void
  pattern_dealloc(PatternObject* self)
  {
      if (self->weakreflist != NULL)
          PyObject_ClearWeakRefs((PyObject *) self);
      Py_XDECREF(self->pattern);
      Py_XDECREF(self->groupindex);
      Py_XDECREF(self->indexgroup);
      PyObject_DEL(self);
  }
  
  static PyObject*
  pattern_match(PatternObject* self, PyObject* args, PyObject* kw)
  {
      SRE_STATE state;
      int status;
  
      PyObject* string;
      Py_ssize_t start = 0;
      Py_ssize_t end = PY_SSIZE_T_MAX;
      static char* kwlist[] = { "pattern", "pos", "endpos", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "O|nn:match", kwlist,
                                       &string, &start, &end))
          return NULL;
  
      string = state_init(&state, self, string, start, end);
      if (!string)
          return NULL;
  
      state.ptr = state.start;
  
      TRACE(("|%p|%p|MATCH\n", PatternObject_GetCode(self), state.ptr));
  
      if (state.charsize == 1) {
          status = sre_match(&state, PatternObject_GetCode(self));
      } else {
  #if defined(HAVE_UNICODE)
          status = sre_umatch(&state, PatternObject_GetCode(self));
  #endif
      }
  
      TRACE(("|%p|%p|END\n", PatternObject_GetCode(self), state.ptr));
      if (PyErr_Occurred())
          return NULL;
  
      state_fini(&state);
  
      return pattern_new_match(self, &state, status);
  }
  
  static PyObject*
  pattern_search(PatternObject* self, PyObject* args, PyObject* kw)
  {
      SRE_STATE state;
      int status;
  
      PyObject* string;
      Py_ssize_t start = 0;
      Py_ssize_t end = PY_SSIZE_T_MAX;
      static char* kwlist[] = { "pattern", "pos", "endpos", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "O|nn:search", kwlist,
                                       &string, &start, &end))
          return NULL;
  
      string = state_init(&state, self, string, start, end);
      if (!string)
          return NULL;
  
      TRACE(("|%p|%p|SEARCH\n", PatternObject_GetCode(self), state.ptr));
  
      if (state.charsize == 1) {
          status = sre_search(&state, PatternObject_GetCode(self));
      } else {
  #if defined(HAVE_UNICODE)
          status = sre_usearch(&state, PatternObject_GetCode(self));
  #endif
      }
  
      TRACE(("|%p|%p|END\n", PatternObject_GetCode(self), state.ptr));
  
      state_fini(&state);
  
      if (PyErr_Occurred())
          return NULL;
  
      return pattern_new_match(self, &state, status);
  }
  
  static PyObject*
  call(char* module, char* function, PyObject* args)
  {
      PyObject* name;
      PyObject* mod;
      PyObject* func;
      PyObject* result;
  
      if (!args)
          return NULL;
      name = PyString_FromString(module);
      if (!name)
          return NULL;
      mod = PyImport_Import(name);
      Py_DECREF(name);
      if (!mod)
          return NULL;
      func = PyObject_GetAttrString(mod, function);
      Py_DECREF(mod);
      if (!func)
          return NULL;
      result = PyObject_CallObject(func, args);
      Py_DECREF(func);
      Py_DECREF(args);
      return result;
  }
  
  #ifdef USE_BUILTIN_COPY
  static int
  deepcopy(PyObject** object, PyObject* memo)
  {
      PyObject* copy;
  
      copy = call(
          "copy", "deepcopy",
          PyTuple_Pack(2, *object, memo)
          );
      if (!copy)
          return 0;
  
      Py_DECREF(*object);
      *object = copy;
  
      return 1; /* success */
  }
  #endif
  
  static PyObject*
  join_list(PyObject* list, PyObject* string)
  {
      /* join list elements */
  
      PyObject* joiner;
  #if PY_VERSION_HEX >= 0x01060000
      PyObject* function;
      PyObject* args;
  #endif
      PyObject* result;
  
      joiner = PySequence_GetSlice(string, 0, 0);
      if (!joiner)
          return NULL;
  
      if (PyList_GET_SIZE(list) == 0) {
          Py_DECREF(list);
          return joiner;
      }
  
  #if PY_VERSION_HEX >= 0x01060000
      function = PyObject_GetAttrString(joiner, "join");
      if (!function) {
          Py_DECREF(joiner);
          return NULL;
      }
      args = PyTuple_New(1);
      if (!args) {
          Py_DECREF(function);
          Py_DECREF(joiner);
          return NULL;
      }
      PyTuple_SET_ITEM(args, 0, list);
      result = PyObject_CallObject(function, args);
      Py_DECREF(args); /* also removes list */
      Py_DECREF(function);
  #else
      result = call(
          "string", "join",
          PyTuple_Pack(2, list, joiner)
          );
  #endif
      Py_DECREF(joiner);
  
      return result;
  }
  
  static PyObject*
  pattern_findall(PatternObject* self, PyObject* args, PyObject* kw)
  {
      SRE_STATE state;
      PyObject* list;
      int status;
      Py_ssize_t i, b, e;
  
      PyObject* string;
      Py_ssize_t start = 0;
      Py_ssize_t end = PY_SSIZE_T_MAX;
      static char* kwlist[] = { "source", "pos", "endpos", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "O|nn:findall", kwlist,
                                       &string, &start, &end))
          return NULL;
  
      string = state_init(&state, self, string, start, end);
      if (!string)
          return NULL;
  
      list = PyList_New(0);
      if (!list) {
          state_fini(&state);
          return NULL;
      }
  
      while (state.start <= state.end) {
  
          PyObject* item;
  
          state_reset(&state);
  
          state.ptr = state.start;
  
          if (state.charsize == 1) {
              status = sre_search(&state, PatternObject_GetCode(self));
          } else {
  #if defined(HAVE_UNICODE)
              status = sre_usearch(&state, PatternObject_GetCode(self));
  #endif
          }
  
  	if (PyErr_Occurred())
  	    goto error;
  
          if (status <= 0) {
              if (status == 0)
                  break;
              pattern_error(status);
              goto error;
          }
  
          /* don't bother to build a match object */
          switch (self->groups) {
          case 0:
              b = STATE_OFFSET(&state, state.start);
              e = STATE_OFFSET(&state, state.ptr);
              item = PySequence_GetSlice(string, b, e);
              if (!item)
                  goto error;
              break;
          case 1:
              item = state_getslice(&state, 1, string, 1);
              if (!item)
                  goto error;
              break;
          default:
              item = PyTuple_New(self->groups);
              if (!item)
                  goto error;
              for (i = 0; i < self->groups; i++) {
                  PyObject* o = state_getslice(&state, i+1, string, 1);
                  if (!o) {
                      Py_DECREF(item);
                      goto error;
                  }
                  PyTuple_SET_ITEM(item, i, o);
              }
              break;
          }
  
          status = PyList_Append(list, item);
          Py_DECREF(item);
          if (status < 0)
              goto error;
  
          if (state.ptr == state.start)
              state.start = (void*) ((char*) state.ptr + state.charsize);
          else
              state.start = state.ptr;
  
      }
  
      state_fini(&state);
      return list;
  
  error:
      Py_DECREF(list);
      state_fini(&state);
      return NULL;
  
  }
  
  #if PY_VERSION_HEX >= 0x02020000
  static PyObject*
  pattern_finditer(PatternObject* pattern, PyObject* args)
  {
      PyObject* scanner;
      PyObject* search;
      PyObject* iterator;
  
      scanner = pattern_scanner(pattern, args);
      if (!scanner)
          return NULL;
  
      search = PyObject_GetAttrString(scanner, "search");
      Py_DECREF(scanner);
      if (!search)
          return NULL;
  
      iterator = PyCallIter_New(search, Py_None);
      Py_DECREF(search);
  
      return iterator;
  }
  #endif
  
  static PyObject*
  pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
  {
      SRE_STATE state;
      PyObject* list;
      PyObject* item;
      int status;
      Py_ssize_t n;
      Py_ssize_t i;
      void* last;
  
      PyObject* string;
      Py_ssize_t maxsplit = 0;
      static char* kwlist[] = { "source", "maxsplit", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "O|n:split", kwlist,
                                       &string, &maxsplit))
          return NULL;
  
      string = state_init(&state, self, string, 0, PY_SSIZE_T_MAX);
      if (!string)
          return NULL;
  
      list = PyList_New(0);
      if (!list) {
          state_fini(&state);
          return NULL;
      }
  
      n = 0;
      last = state.start;
  
      while (!maxsplit || n < maxsplit) {
  
          state_reset(&state);
  
          state.ptr = state.start;
  
          if (state.charsize == 1) {
              status = sre_search(&state, PatternObject_GetCode(self));
          } else {
  #if defined(HAVE_UNICODE)
              status = sre_usearch(&state, PatternObject_GetCode(self));
  #endif
          }
  
  	if (PyErr_Occurred())
  	    goto error;
  
          if (status <= 0) {
              if (status == 0)
                  break;
              pattern_error(status);
              goto error;
          }
  
          if (state.start == state.ptr) {
              if (last == state.end)
                  break;
              /* skip one character */
              state.start = (void*) ((char*) state.ptr + state.charsize);
              continue;
          }
  
          /* get segment before this match */
          item = PySequence_GetSlice(
              string, STATE_OFFSET(&state, last),
              STATE_OFFSET(&state, state.start)
              );
          if (!item)
              goto error;
          status = PyList_Append(list, item);
          Py_DECREF(item);
          if (status < 0)
              goto error;
  
          /* add groups (if any) */
          for (i = 0; i < self->groups; i++) {
              item = state_getslice(&state, i+1, string, 0);
              if (!item)
                  goto error;
              status = PyList_Append(list, item);
              Py_DECREF(item);
              if (status < 0)
                  goto error;
          }
  
          n = n + 1;
  
          last = state.start = state.ptr;
  
      }
  
      /* get segment following last match (even if empty) */
      item = PySequence_GetSlice(
          string, STATE_OFFSET(&state, last), state.endpos
          );
      if (!item)
          goto error;
      status = PyList_Append(list, item);
      Py_DECREF(item);
      if (status < 0)
          goto error;
  
      state_fini(&state);
      return list;
  
  error:
      Py_DECREF(list);
      state_fini(&state);
      return NULL;
  
  }
  
  static PyObject*
  pattern_subx(PatternObject* self, PyObject* ptemplate, PyObject* string,
               Py_ssize_t count, Py_ssize_t subn)
  {
      SRE_STATE state;
      PyObject* list;
      PyObject* item;
      PyObject* filter;
      PyObject* args;
      PyObject* match;
      void* ptr;
      int status;
      Py_ssize_t n;
      Py_ssize_t i, b, e;
      int bint;
      int filter_is_callable;
  
      if (PyCallable_Check(ptemplate)) {
          /* sub/subn takes either a function or a template */
          filter = ptemplate;
          Py_INCREF(filter);
          filter_is_callable = 1;
      } else {
          /* if not callable, check if it's a literal string */
          int literal;
          ptr = getstring(ptemplate, &n, &bint);
          b = bint;
          if (ptr) {
              if (b == 1) {
  		    literal = sre_literal_template((unsigned char *)ptr, n);
              } else {
  #if defined(HAVE_UNICODE)
  		    literal = sre_uliteral_template((Py_UNICODE *)ptr, n);
  #endif
              }
          } else {
              PyErr_Clear();
              literal = 0;
          }
          if (literal) {
              filter = ptemplate;
              Py_INCREF(filter);
              filter_is_callable = 0;
          } else {
              /* not a literal; hand it over to the template compiler */
              filter = call(
                  SRE_PY_MODULE, "_subx",
                  PyTuple_Pack(2, self, ptemplate)
                  );
              if (!filter)
                  return NULL;
              filter_is_callable = PyCallable_Check(filter);
          }
      }
  
      string = state_init(&state, self, string, 0, PY_SSIZE_T_MAX);
      if (!string) {
          Py_DECREF(filter);
          return NULL;
      }
  
      list = PyList_New(0);
      if (!list) {
          Py_DECREF(filter);
          state_fini(&state);
          return NULL;
      }
  
      n = i = 0;
  
      while (!count || n < count) {
  
          state_reset(&state);
  
          state.ptr = state.start;
  
          if (state.charsize == 1) {
              status = sre_search(&state, PatternObject_GetCode(self));
          } else {
  #if defined(HAVE_UNICODE)
              status = sre_usearch(&state, PatternObject_GetCode(self));
  #endif
          }
  
  	if (PyErr_Occurred())
  	    goto error;
  
          if (status <= 0) {
              if (status == 0)
                  break;
              pattern_error(status);
              goto error;
          }
  
          b = STATE_OFFSET(&state, state.start);
          e = STATE_OFFSET(&state, state.ptr);
  
          if (i < b) {
              /* get segment before this match */
              item = PySequence_GetSlice(string, i, b);
              if (!item)
                  goto error;
              status = PyList_Append(list, item);
              Py_DECREF(item);
              if (status < 0)
                  goto error;
  
          } else if (i == b && i == e && n > 0)
              /* ignore empty match on latest position */
              goto next;
  
          if (filter_is_callable) {
              /* pass match object through filter */
              match = pattern_new_match(self, &state, 1);
              if (!match)
                  goto error;
              args = PyTuple_Pack(1, match);
              if (!args) {
                  Py_DECREF(match);
                  goto error;
              }
              item = PyObject_CallObject(filter, args);
              Py_DECREF(args);
              Py_DECREF(match);
              if (!item)
                  goto error;
          } else {
              /* filter is literal string */
              item = filter;
              Py_INCREF(item);
          }
  
          /* add to list */
          if (item != Py_None) {
              status = PyList_Append(list, item);
              Py_DECREF(item);
              if (status < 0)
                  goto error;
          }
  
          i = e;
          n = n + 1;
  
  next:
          /* move on */
          if (state.ptr == state.start)
              state.start = (void*) ((char*) state.ptr + state.charsize);
          else
              state.start = state.ptr;
  
      }
  
      /* get segment following last match */
      if (i < state.endpos) {
          item = PySequence_GetSlice(string, i, state.endpos);
          if (!item)
              goto error;
          status = PyList_Append(list, item);
          Py_DECREF(item);
          if (status < 0)
              goto error;
      }
  
      state_fini(&state);
  
      Py_DECREF(filter);
  
      /* convert list to single string (also removes list) */
      item = join_list(list, string);
  
      if (!item)
          return NULL;
  
      if (subn)
          return Py_BuildValue("Ni", item, n);
  
      return item;
  
  error:
      Py_DECREF(list);
      state_fini(&state);
      Py_DECREF(filter);
      return NULL;
  
  }
  
  static PyObject*
  pattern_sub(PatternObject* self, PyObject* args, PyObject* kw)
  {
      PyObject* ptemplate;
      PyObject* string;
      Py_ssize_t count = 0;
      static char* kwlist[] = { "repl", "string", "count", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "OO|n:sub", kwlist,
                                       &ptemplate, &string, &count))
          return NULL;
  
      return pattern_subx(self, ptemplate, string, count, 0);
  }
  
  static PyObject*
  pattern_subn(PatternObject* self, PyObject* args, PyObject* kw)
  {
      PyObject* ptemplate;
      PyObject* string;
      Py_ssize_t count = 0;
      static char* kwlist[] = { "repl", "string", "count", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "OO|n:subn", kwlist,
                                       &ptemplate, &string, &count))
          return NULL;
  
      return pattern_subx(self, ptemplate, string, count, 1);
  }
  
  static PyObject*
  pattern_copy(PatternObject* self, PyObject *unused)
  {
  #ifdef USE_BUILTIN_COPY
      PatternObject* copy;
      int offset;
  
      copy = PyObject_NEW_VAR(PatternObject, &Pattern_Type, self->codesize);
      if (!copy)
          return NULL;
  
      offset = offsetof(PatternObject, groups);
  
      Py_XINCREF(self->groupindex);
      Py_XINCREF(self->indexgroup);
      Py_XINCREF(self->pattern);
  
      memcpy((char*) copy + offset, (char*) self + offset,
             sizeof(PatternObject) + self->codesize * sizeof(SRE_CODE) - offset);
      copy->weakreflist = NULL;
  
      return (PyObject*) copy;
  #else
      PyErr_SetString(PyExc_TypeError, "cannot copy this pattern object");
      return NULL;
  #endif
  }
  
  static PyObject*
  pattern_deepcopy(PatternObject* self, PyObject* memo)
  {
  #ifdef USE_BUILTIN_COPY
      PatternObject* copy;
  
      copy = (PatternObject*) pattern_copy(self);
      if (!copy)
          return NULL;
  
      if (!deepcopy(&copy->groupindex, memo) ||
          !deepcopy(&copy->indexgroup, memo) ||
          !deepcopy(&copy->pattern, memo)) {
          Py_DECREF(copy);
          return NULL;
      }
  
  #else
      PyErr_SetString(PyExc_TypeError, "cannot deepcopy this pattern object");
      return NULL;
  #endif
  }
  
  PyDoc_STRVAR(pattern_match_doc,
  "match(string[, pos[, endpos]]) --> match object or None.\n\
      Matches zero or more characters at the beginning of the string");
  
  PyDoc_STRVAR(pattern_search_doc,
  "search(string[, pos[, endpos]]) --> match object or None.\n\
      Scan through string looking for a match, and return a corresponding\n\
      MatchObject instance. Return None if no position in the string matches.");
  
  PyDoc_STRVAR(pattern_split_doc,
  "split(string[, maxsplit = 0])  --> list.\n\
      Split string by the occurrences of pattern.");
  
  PyDoc_STRVAR(pattern_findall_doc,
  "findall(string[, pos[, endpos]]) --> list.\n\
     Return a list of all non-overlapping matches of pattern in string.");
  
  PyDoc_STRVAR(pattern_finditer_doc,
  "finditer(string[, pos[, endpos]]) --> iterator.\n\
      Return an iterator over all non-overlapping matches for the \n\
      RE pattern in string. For each match, the iterator returns a\n\
      match object.");
  
  PyDoc_STRVAR(pattern_sub_doc,
  "sub(repl, string[, count = 0]) --> newstring\n\
      Return the string obtained by replacing the leftmost non-overlapping\n\
      occurrences of pattern in string by the replacement repl.");
  
  PyDoc_STRVAR(pattern_subn_doc,
  "subn(repl, string[, count = 0]) --> (newstring, number of subs)\n\
      Return the tuple (new_string, number_of_subs_made) found by replacing\n\
      the leftmost non-overlapping occurrences of pattern with the\n\
      replacement repl.");
  
  PyDoc_STRVAR(pattern_doc, "Compiled regular expression objects");
  
  static PyMethodDef pattern_methods[] = {
      {"match", (PyCFunction) pattern_match, METH_VARARGS|METH_KEYWORDS,
  	pattern_match_doc},
      {"search", (PyCFunction) pattern_search, METH_VARARGS|METH_KEYWORDS,
  	pattern_search_doc},
      {"sub", (PyCFunction) pattern_sub, METH_VARARGS|METH_KEYWORDS,
  	pattern_sub_doc},
      {"subn", (PyCFunction) pattern_subn, METH_VARARGS|METH_KEYWORDS,
  	pattern_subn_doc},
      {"split", (PyCFunction) pattern_split, METH_VARARGS|METH_KEYWORDS,
  	pattern_split_doc},
      {"findall", (PyCFunction) pattern_findall, METH_VARARGS|METH_KEYWORDS,
  	pattern_findall_doc},
  #if PY_VERSION_HEX >= 0x02020000
      {"finditer", (PyCFunction) pattern_finditer, METH_VARARGS,
  	pattern_finditer_doc},
  #endif
      {"scanner", (PyCFunction) pattern_scanner, METH_VARARGS},
      {"__copy__", (PyCFunction) pattern_copy, METH_NOARGS},
      {"__deepcopy__", (PyCFunction) pattern_deepcopy, METH_O},
      {NULL, NULL}
  };
  
  #define PAT_OFF(x) offsetof(PatternObject, x)
  static PyMemberDef pattern_members[] = {
      {"pattern",    T_OBJECT,    PAT_OFF(pattern),       READONLY},
      {"flags",      T_INT,       PAT_OFF(flags),         READONLY},
      {"groups",     T_PYSSIZET,  PAT_OFF(groups),        READONLY},
      {"groupindex", T_OBJECT,    PAT_OFF(groupindex),    READONLY},
      {NULL}  /* Sentinel */
  };
  
  statichere PyTypeObject Pattern_Type = {
      PyObject_HEAD_INIT(NULL)
      0, "_" SRE_MODULE ".SRE_Pattern",
      sizeof(PatternObject), sizeof(SRE_CODE),
      (destructor)pattern_dealloc, /*tp_dealloc*/
      0,                                  /* tp_print */
      0,                                  /* tp_getattrn */
      0,					/* tp_setattr */
      0,					/* tp_compare */
      0,					/* tp_repr */
      0,					/* tp_as_number */
      0,					/* tp_as_sequence */
      0,					/* tp_as_mapping */
      0,					/* tp_hash */
      0,					/* tp_call */
      0,					/* tp_str */
      0,					/* tp_getattro */
      0,					/* tp_setattro */
      0,					/* tp_as_buffer */
      Py_TPFLAGS_DEFAULT,		        /* tp_flags */
      pattern_doc,			/* tp_doc */
      0,					/* tp_traverse */
      0,					/* tp_clear */
      0,					/* tp_richcompare */
      offsetof(PatternObject, weakreflist),	/* tp_weaklistoffset */
      0,					/* tp_iter */
      0,					/* tp_iternext */
      pattern_methods,			/* tp_methods */
      pattern_members,			/* tp_members */
  };
  
  static int _validate(PatternObject *self); /* Forward */
  
  static PyObject *
  _compile(PyObject* self_, PyObject* args)
  {
      /* "compile" pattern descriptor to pattern object */
  
      PatternObject* self;
      Py_ssize_t i, n;
  
      PyObject* pattern;
      int flags = 0;
      PyObject* code;
      Py_ssize_t groups = 0;
      PyObject* groupindex = NULL;
      PyObject* indexgroup = NULL;
      if (!PyArg_ParseTuple(args, "OiO!|nOO", &pattern, &flags,
                            &PyList_Type, &code, &groups,
                            &groupindex, &indexgroup))
          return NULL;
  
      n = PyList_GET_SIZE(code);
      /* coverity[ampersand_in_size] */
      self = PyObject_NEW_VAR(PatternObject, &Pattern_Type, n);
      if (!self)
          return NULL;
      self->weakreflist = NULL;
      self->pattern = NULL;
      self->groupindex = NULL;
      self->indexgroup = NULL;
  
      self->codesize = n;
  
      for (i = 0; i < n; i++) {
          PyObject *o = PyList_GET_ITEM(code, i);
          unsigned long value = PyInt_Check(o) ? (unsigned long)PyInt_AsLong(o)
                                                : PyLong_AsUnsignedLong(o);
          self->code[i] = (SRE_CODE) value;
          if ((unsigned long) self->code[i] != value) {
              PyErr_SetString(PyExc_OverflowError,
                              "regular expression code size limit exceeded");
              break;
          }
      }
  
      if (PyErr_Occurred()) {
          Py_DECREF(self);
          return NULL;
      }
  
      Py_INCREF(pattern);
      self->pattern = pattern;
  
      self->flags = flags;
  
      self->groups = groups;
  
      Py_XINCREF(groupindex);
      self->groupindex = groupindex;
  
      Py_XINCREF(indexgroup);
      self->indexgroup = indexgroup;
  
      self->weakreflist = NULL;
  
      if (!_validate(self)) {
          Py_DECREF(self);
          return NULL;
      }
  
      return (PyObject*) self;
  }
  
  /* -------------------------------------------------------------------- */
  /* Code validation */
  
  /* To learn more about this code, have a look at the _compile() function in
     Lib/sre_compile.py.  The validation functions below checks the code array
     for conformance with the code patterns generated there.
  
     The nice thing about the generated code is that it is position-independent:
     all jumps are relative jumps forward.  Also, jumps don't cross each other:
     the target of a later jump is always earlier than the target of an earlier
     jump.  IOW, this is okay:
  
     J---------J-------T--------T
      \         \_____/        /
       \______________________/
  
     but this is not:
  
     J---------J-------T--------T
      \_________\_____/        /
                 \____________/
  
     It also helps that SRE_CODE is always an unsigned type, either 2 bytes or 4
     bytes wide (the latter if Python is compiled for "wide" unicode support).
  */
  
  /* Defining this one enables tracing of the validator */
  #undef VVERBOSE
  
  /* Trace macro for the validator */
  #if defined(VVERBOSE)
  #define VTRACE(v) printf v
  #else
  #define VTRACE(v) do {} while(0)  /* do nothing */
  #endif
  
  /* Report failure */
  #define FAIL do { VTRACE(("FAIL: %d\n", __LINE__)); return 0; } while (0)
  
  /* Extract opcode, argument, or skip count from code array */
  #define GET_OP                                          \
      do {                                                \
          VTRACE(("%p: ", code));                         \
          if (code >= end) FAIL;                          \
          op = *code++;                                   \
          VTRACE(("%lu (op)\n", (unsigned long)op));      \
      } while (0)
  #define GET_ARG                                         \
      do {                                                \
          VTRACE(("%p= ", code));                         \
          if (code >= end) FAIL;                          \
          arg = *code++;                                  \
          VTRACE(("%lu (arg)\n", (unsigned long)arg));    \
      } while (0)
  #define GET_SKIP_ADJ(adj)                               \
      do {                                                \
          VTRACE(("%p= ", code));                         \
          if (code >= end) FAIL;                          \
          skip = *code;                                   \
          VTRACE(("%lu (skip to %p)\n",                   \
                 (unsigned long)skip, code+skip));        \
          if (code+skip-adj < code || code+skip-adj > end)\
              FAIL;                                       \
          code++;                                         \
      } while (0)
  #define GET_SKIP GET_SKIP_ADJ(0)
  
  static int
  _validate_charset(SRE_CODE *code, SRE_CODE *end)
  {
      /* Some variables are manipulated by the macros above */
      SRE_CODE op;
      SRE_CODE arg;
      SRE_CODE offset;
      int i;
  
      while (code < end) {
          GET_OP;
          switch (op) {
  
          case SRE_OP_NEGATE:
              break;
  
          case SRE_OP_LITERAL:
              GET_ARG;
              break;
  
          case SRE_OP_RANGE:
              GET_ARG;
              GET_ARG;
              break;
  
          case SRE_OP_CHARSET:
              offset = 32/sizeof(SRE_CODE); /* 32-byte bitmap */
              if (code+offset < code || code+offset > end)
                  FAIL;
              code += offset;
              break;
  
          case SRE_OP_BIGCHARSET:
              GET_ARG; /* Number of blocks */
              offset = 256/sizeof(SRE_CODE); /* 256-byte table */
              if (code+offset < code || code+offset > end)
                  FAIL;
              /* Make sure that each byte points to a valid block */
              for (i = 0; i < 256; i++) {
                  if (((unsigned char *)code)[i] >= arg)
                      FAIL;
              }
              code += offset;
              offset = arg * 32/sizeof(SRE_CODE); /* 32-byte bitmap times arg */
              if (code+offset < code || code+offset > end)
                  FAIL;
              code += offset;
              break;
  
          case SRE_OP_CATEGORY:
              GET_ARG;
              switch (arg) {
              case SRE_CATEGORY_DIGIT:
              case SRE_CATEGORY_NOT_DIGIT:
              case SRE_CATEGORY_SPACE:
              case SRE_CATEGORY_NOT_SPACE:
              case SRE_CATEGORY_WORD:
              case SRE_CATEGORY_NOT_WORD:
              case SRE_CATEGORY_LINEBREAK:
              case SRE_CATEGORY_NOT_LINEBREAK:
              case SRE_CATEGORY_LOC_WORD:
              case SRE_CATEGORY_LOC_NOT_WORD:
              case SRE_CATEGORY_UNI_DIGIT:
              case SRE_CATEGORY_UNI_NOT_DIGIT:
              case SRE_CATEGORY_UNI_SPACE:
              case SRE_CATEGORY_UNI_NOT_SPACE:
              case SRE_CATEGORY_UNI_WORD:
              case SRE_CATEGORY_UNI_NOT_WORD:
              case SRE_CATEGORY_UNI_LINEBREAK:
              case SRE_CATEGORY_UNI_NOT_LINEBREAK:
                  break;
              default:
                  FAIL;
              }
              break;
  
          default:
              FAIL;
  
          }
      }
  
      return 1;
  }
  
  static int
  _validate_inner(SRE_CODE *code, SRE_CODE *end, Py_ssize_t groups)
  {
      /* Some variables are manipulated by the macros above */
      SRE_CODE op;
      SRE_CODE arg;
      SRE_CODE skip;
  
      VTRACE(("code=%p, end=%p\n", code, end));
  
      if (code > end)
          FAIL;
  
      while (code < end) {
          GET_OP;
          switch (op) {
  
          case SRE_OP_MARK:
              /* We don't check whether marks are properly nested; the
                 sre_match() code is robust even if they don't, and the worst
                 you can get is nonsensical match results. */
              GET_ARG;
              if (arg > 2*groups+1) {
                  VTRACE(("arg=%d, groups=%d\n", (int)arg, (int)groups));
                  FAIL;
              }
              break;
  
          case SRE_OP_LITERAL:
          case SRE_OP_NOT_LITERAL:
          case SRE_OP_LITERAL_IGNORE:
          case SRE_OP_NOT_LITERAL_IGNORE:
              GET_ARG;
              /* The arg is just a character, nothing to check */
              break;
  
          case SRE_OP_SUCCESS:
          case SRE_OP_FAILURE:
              /* Nothing to check; these normally end the matching process */
              break;
  
          case SRE_OP_AT:
              GET_ARG;
              switch (arg) {
              case SRE_AT_BEGINNING:
              case SRE_AT_BEGINNING_STRING:
              case SRE_AT_BEGINNING_LINE:
              case SRE_AT_END:
              case SRE_AT_END_LINE:
              case SRE_AT_END_STRING:
              case SRE_AT_BOUNDARY:
              case SRE_AT_NON_BOUNDARY:
              case SRE_AT_LOC_BOUNDARY:
              case SRE_AT_LOC_NON_BOUNDARY:
              case SRE_AT_UNI_BOUNDARY:
              case SRE_AT_UNI_NON_BOUNDARY:
                  break;
              default:
                  FAIL;
              }
              break;
  
          case SRE_OP_ANY:
          case SRE_OP_ANY_ALL:
              /* These have no operands */
              break;
  
          case SRE_OP_IN:
          case SRE_OP_IN_IGNORE:
              GET_SKIP;
              /* Stop 1 before the end; we check the FAILURE below */
              if (!_validate_charset(code, code+skip-2))
                  FAIL;
              if (code[skip-2] != SRE_OP_FAILURE)
                  FAIL;
              code += skip-1;
              break;
  
          case SRE_OP_INFO:
              {
                  /* A minimal info field is
                     <INFO> <1=skip> <2=flags> <3=min> <4=max>;
                     If SRE_INFO_PREFIX or SRE_INFO_CHARSET is in the flags,
                     more follows. */
                  SRE_CODE flags, i;
                  SRE_CODE *newcode;
                  GET_SKIP;
                  newcode = code+skip-1;
                  GET_ARG; flags = arg;
                  GET_ARG; /* min */
                  GET_ARG; /* max */
                  /* Check that only valid flags are present */
                  if ((flags & ~(SRE_INFO_PREFIX |
                                 SRE_INFO_LITERAL |
                                 SRE_INFO_CHARSET)) != 0)
                      FAIL;
                  /* PREFIX and CHARSET are mutually exclusive */
                  if ((flags & SRE_INFO_PREFIX) &&
                      (flags & SRE_INFO_CHARSET))
                      FAIL;
                  /* LITERAL implies PREFIX */
                  if ((flags & SRE_INFO_LITERAL) &&
                      !(flags & SRE_INFO_PREFIX))
                      FAIL;
                  /* Validate the prefix */
                  if (flags & SRE_INFO_PREFIX) {
                      SRE_CODE prefix_len;
                      GET_ARG; prefix_len = arg;
                      GET_ARG; /* prefix skip */
                      /* Here comes the prefix string */
                      if (code+prefix_len < code || code+prefix_len > newcode)
                          FAIL;
                      code += prefix_len;
                      /* And here comes the overlap table */
                      if (code+prefix_len < code || code+prefix_len > newcode)
                          FAIL;
                      /* Each overlap value should be < prefix_len */
                      for (i = 0; i < prefix_len; i++) {
                          if (code[i] >= prefix_len)
                              FAIL;
                      }
                      code += prefix_len;
                  }
                  /* Validate the charset */
                  if (flags & SRE_INFO_CHARSET) {
                      if (!_validate_charset(code, newcode-1))
                          FAIL;
                      if (newcode[-1] != SRE_OP_FAILURE)
                          FAIL;
                      code = newcode;
                  }
                  else if (code != newcode) {
                    VTRACE(("code=%p, newcode=%p\n", code, newcode));
                      FAIL;
                  }
              }
              break;
  
          case SRE_OP_BRANCH:
              {
                  SRE_CODE *target = NULL;
                  for (;;) {
                      GET_SKIP;
                      if (skip == 0)
                          break;
                      /* Stop 2 before the end; we check the JUMP below */
                      if (!_validate_inner(code, code+skip-3, groups))
                          FAIL;
                      code += skip-3;
                      /* Check that it ends with a JUMP, and that each JUMP
                         has the same target */
                      GET_OP;
                      if (op != SRE_OP_JUMP)
                          FAIL;
                      GET_SKIP;
                      if (target == NULL)
                          target = code+skip-1;
                      else if (code+skip-1 != target)
                          FAIL;
                  }
              }
              break;
  
          case SRE_OP_REPEAT_ONE:
          case SRE_OP_MIN_REPEAT_ONE:
              {
                  SRE_CODE min, max;
                  GET_SKIP;
                  GET_ARG; min = arg;
                  GET_ARG; max = arg;
                  if (min > max)
                      FAIL;
  #ifdef Py_UNICODE_WIDE
                  if (max > 65535)
                      FAIL;
  #endif
                  if (!_validate_inner(code, code+skip-4, groups))
                      FAIL;
                  code += skip-4;
                  GET_OP;
                  if (op != SRE_OP_SUCCESS)
                      FAIL;
              }
              break;
  
          case SRE_OP_REPEAT:
              {
                  SRE_CODE min, max;
                  GET_SKIP;
                  GET_ARG; min = arg;
                  GET_ARG; max = arg;
                  if (min > max)
                      FAIL;
  #ifdef Py_UNICODE_WIDE
                  if (max > 65535)
                      FAIL;
  #endif
                  if (!_validate_inner(code, code+skip-3, groups))
                      FAIL;
                  code += skip-3;
                  GET_OP;
                  if (op != SRE_OP_MAX_UNTIL && op != SRE_OP_MIN_UNTIL)
                      FAIL;
              }
              break;
  
          case SRE_OP_GROUPREF:
          case SRE_OP_GROUPREF_IGNORE:
              GET_ARG;
              if (arg >= groups)
                  FAIL;
              break;
  
          case SRE_OP_GROUPREF_EXISTS:
              /* The regex syntax for this is: '(?(group)then|else)', where
                 'group' is either an integer group number or a group name,
                 'then' and 'else' are sub-regexes, and 'else' is optional. */
              GET_ARG;
              if (arg >= groups)
                  FAIL;
              GET_SKIP_ADJ(1);
              code--; /* The skip is relative to the first arg! */
              /* There are two possibilities here: if there is both a 'then'
                 part and an 'else' part, the generated code looks like:
  
                 GROUPREF_EXISTS
                 <group>
                 <skipyes>
                 ...then part...
                 JUMP
                 <skipno>
                 (<skipyes> jumps here)
                 ...else part...
                 (<skipno> jumps here)
  
                 If there is only a 'then' part, it looks like:
  
                 GROUPREF_EXISTS
                 <group>
                 <skip>
                 ...then part...
                 (<skip> jumps here)
  
                 There is no direct way to decide which it is, and we don't want
                 to allow arbitrary jumps anywhere in the code; so we just look
                 for a JUMP opcode preceding our skip target.
              */
              if (skip >= 3 && code+skip-3 >= code &&
                  code[skip-3] == SRE_OP_JUMP)
              {
                  VTRACE(("both then and else parts present\n"));
                  if (!_validate_inner(code+1, code+skip-3, groups))
                      FAIL;
                  code += skip-2; /* Position after JUMP, at <skipno> */
                  GET_SKIP;
                  if (!_validate_inner(code, code+skip-1, groups))
                      FAIL;
                  code += skip-1;
              }
              else {
                  VTRACE(("only a then part present\n"));
                  if (!_validate_inner(code+1, code+skip-1, groups))
                      FAIL;
                  code += skip-1;
              }
              break;
  
          case SRE_OP_ASSERT:
          case SRE_OP_ASSERT_NOT:
              GET_SKIP;
              GET_ARG; /* 0 for lookahead, width for lookbehind */
              code--; /* Back up over arg to simplify math below */
              if (arg & 0x80000000)
                  FAIL; /* Width too large */
              /* Stop 1 before the end; we check the SUCCESS below */
              if (!_validate_inner(code+1, code+skip-2, groups))
                  FAIL;
              code += skip-2;
              GET_OP;
              if (op != SRE_OP_SUCCESS)
                  FAIL;
              break;
  
          default:
              FAIL;
  
          }
      }
  
      VTRACE(("okay\n"));
      return 1;
  }
  
  static int
  _validate_outer(SRE_CODE *code, SRE_CODE *end, Py_ssize_t groups)
  {
      if (groups < 0 || groups > 100 || code >= end || end[-1] != SRE_OP_SUCCESS)
          FAIL;
      if (groups == 0)  /* fix for simplejson */
          groups = 100; /* 100 groups should always be safe */
      return _validate_inner(code, end-1, groups);
  }
  
  static int
  _validate(PatternObject *self)
  {
      if (!_validate_outer(self->code, self->code+self->codesize, self->groups))
      {
          PyErr_SetString(PyExc_RuntimeError, "invalid SRE code");
          return 0;
      }
      else
          VTRACE(("Success!\n"));
      return 1;
  }
  
  /* -------------------------------------------------------------------- */
  /* match methods */
  
  static void
  match_dealloc(MatchObject* self)
  {
      Py_XDECREF(self->regs);
      Py_XDECREF(self->string);
      Py_DECREF(self->pattern);
      PyObject_DEL(self);
  }
  
  static PyObject*
  match_getslice_by_index(MatchObject* self, Py_ssize_t index, PyObject* def)
  {
      if (index < 0 || index >= self->groups) {
          /* raise IndexError if we were given a bad group number */
          PyErr_SetString(
              PyExc_IndexError,
              "no such group"
              );
          return NULL;
      }
  
      index *= 2;
  
      if (self->string == Py_None || self->mark[index] < 0) {
          /* return default value if the string or group is undefined */
          Py_INCREF(def);
          return def;
      }
  
      return PySequence_GetSlice(
          self->string, self->mark[index], self->mark[index+1]
          );
  }
  
  static Py_ssize_t
  match_getindex(MatchObject* self, PyObject* index)
  {
      Py_ssize_t i;
  
      if (PyInt_Check(index))
          return PyInt_AsSsize_t(index);
  
      i = -1;
  
      if (self->pattern->groupindex) {
          index = PyObject_GetItem(self->pattern->groupindex, index);
          if (index) {
              if (PyInt_Check(index) || PyLong_Check(index))
                  i = PyInt_AsSsize_t(index);
              Py_DECREF(index);
          } else
              PyErr_Clear();
      }
  
      return i;
  }
  
  static PyObject*
  match_getslice(MatchObject* self, PyObject* index, PyObject* def)
  {
      return match_getslice_by_index(self, match_getindex(self, index), def);
  }
  
  static PyObject*
  match_expand(MatchObject* self, PyObject* ptemplate)
  {
      /* delegate to Python code */
      return call(
          SRE_PY_MODULE, "_expand",
          PyTuple_Pack(3, self->pattern, self, ptemplate)
          );
  }
  
  static PyObject*
  match_group(MatchObject* self, PyObject* args)
  {
      PyObject* result;
      Py_ssize_t i, size;
  
      size = PyTuple_GET_SIZE(args);
  
      switch (size) {
      case 0:
          result = match_getslice(self, Py_False, Py_None);
          break;
      case 1:
          result = match_getslice(self, PyTuple_GET_ITEM(args, 0), Py_None);
          break;
      default:
          /* fetch multiple items */
          result = PyTuple_New(size);
          if (!result)
              return NULL;
          for (i = 0; i < size; i++) {
              PyObject* item = match_getslice(
                  self, PyTuple_GET_ITEM(args, i), Py_None
                  );
              if (!item) {
                  Py_DECREF(result);
                  return NULL;
              }
              PyTuple_SET_ITEM(result, i, item);
          }
          break;
      }
      return result;
  }
  
  static PyObject*
  match_groups(MatchObject* self, PyObject* args, PyObject* kw)
  {
      PyObject* result;
      Py_ssize_t index;
  
      PyObject* def = Py_None;
      static char* kwlist[] = { "default", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "|O:groups", kwlist, &def))
          return NULL;
  
      result = PyTuple_New(self->groups-1);
      if (!result)
          return NULL;
  
      for (index = 1; index < self->groups; index++) {
          PyObject* item;
          item = match_getslice_by_index(self, index, def);
          if (!item) {
              Py_DECREF(result);
              return NULL;
          }
          PyTuple_SET_ITEM(result, index-1, item);
      }
  
      return result;
  }
  
  static PyObject*
  match_groupdict(MatchObject* self, PyObject* args, PyObject* kw)
  {
      PyObject* result;
      PyObject* keys;
      Py_ssize_t index;
  
      PyObject* def = Py_None;
      static char* kwlist[] = { "default", NULL };
      if (!PyArg_ParseTupleAndKeywords(args, kw, "|O:groupdict", kwlist, &def))
          return NULL;
  
      result = PyDict_New();
      if (!result || !self->pattern->groupindex)
          return result;
  
      keys = PyMapping_Keys(self->pattern->groupindex);
      if (!keys)
          goto failed;
  
      for (index = 0; index < PyList_GET_SIZE(keys); index++) {
          int status;
          PyObject* key;
          PyObject* value;
          key = PyList_GET_ITEM(keys, index);
          if (!key)
              goto failed;
          value = match_getslice(self, key, def);
          if (!value) {
              Py_DECREF(key);
              goto failed;
          }
          status = PyDict_SetItem(result, key, value);
          Py_DECREF(value);
          if (status < 0)
              goto failed;
      }
  
      Py_DECREF(keys);
  
      return result;
  
  failed:
      Py_XDECREF(keys);
      Py_DECREF(result);
      return NULL;
  }
  
  static PyObject*
  match_start(MatchObject* self, PyObject* args)
  {
      Py_ssize_t index;
  
      PyObject* index_ = Py_False; /* zero */
      if (!PyArg_UnpackTuple(args, "start", 0, 1, &index_))
          return NULL;
  
      index = match_getindex(self, index_);
  
      if (index < 0 || index >= self->groups) {
          PyErr_SetString(
              PyExc_IndexError,
              "no such group"
              );
          return NULL;
      }
  
      /* mark is -1 if group is undefined */
      return Py_BuildValue("i", self->mark[index*2]);
  }
  
  static PyObject*
  match_end(MatchObject* self, PyObject* args)
  {
      Py_ssize_t index;
  
      PyObject* index_ = Py_False; /* zero */
      if (!PyArg_UnpackTuple(args, "end", 0, 1, &index_))
          return NULL;
  
      index = match_getindex(self, index_);
  
      if (index < 0 || index >= self->groups) {
          PyErr_SetString(
              PyExc_IndexError,
              "no such group"
              );
          return NULL;
      }
  
      /* mark is -1 if group is undefined */
      return Py_BuildValue("i", self->mark[index*2+1]);
  }
  
  LOCAL(PyObject*)
  _pair(Py_ssize_t i1, Py_ssize_t i2)
  {
      PyObject* pair;
      PyObject* item;
  
      pair = PyTuple_New(2);
      if (!pair)
          return NULL;
  
      item = PyInt_FromSsize_t(i1);
      if (!item)
          goto error;
      PyTuple_SET_ITEM(pair, 0, item);
  
      item = PyInt_FromSsize_t(i2);
      if (!item)
          goto error;
      PyTuple_SET_ITEM(pair, 1, item);
  
      return pair;
  
    error:
      Py_DECREF(pair);
      return NULL;
  }
  
  static PyObject*
  match_span(MatchObject* self, PyObject* args)
  {
      Py_ssize_t index;
  
      PyObject* index_ = Py_False; /* zero */
      if (!PyArg_UnpackTuple(args, "span", 0, 1, &index_))
          return NULL;
  
      index = match_getindex(self, index_);
  
      if (index < 0 || index >= self->groups) {
          PyErr_SetString(
              PyExc_IndexError,
              "no such group"
              );
          return NULL;
      }
  
      /* marks are -1 if group is undefined */
      return _pair(self->mark[index*2], self->mark[index*2+1]);
  }
  
  static PyObject*
  match_regs(MatchObject* self)
  {
      PyObject* regs;
      PyObject* item;
      Py_ssize_t index;
  
      regs = PyTuple_New(self->groups);
      if (!regs)
          return NULL;
  
      for (index = 0; index < self->groups; index++) {
          item = _pair(self->mark[index*2], self->mark[index*2+1]);
          if (!item) {
              Py_DECREF(regs);
              return NULL;
          }
          PyTuple_SET_ITEM(regs, index, item);
      }
  
      Py_INCREF(regs);
      self->regs = regs;
  
      return regs;
  }
  
  static PyObject*
  match_copy(MatchObject* self, PyObject *unused)
  {
  #ifdef USE_BUILTIN_COPY
      MatchObject* copy;
      Py_ssize_t slots, offset;
  
      slots = 2 * (self->pattern->groups+1);
  
      copy = PyObject_NEW_VAR(MatchObject, &Match_Type, slots);
      if (!copy)
          return NULL;
  
      /* this value a constant, but any compiler should be able to
         figure that out all by itself */
      offset = offsetof(MatchObject, string);
  
      Py_XINCREF(self->pattern);
      Py_XINCREF(self->string);
      Py_XINCREF(self->regs);
  
      memcpy((char*) copy + offset, (char*) self + offset,
             sizeof(MatchObject) + slots * sizeof(Py_ssize_t) - offset);
  
      return (PyObject*) copy;
  #else
      PyErr_SetString(PyExc_TypeError, "cannot copy this match object");
      return NULL;
  #endif
  }
  
  static PyObject*
  match_deepcopy(MatchObject* self, PyObject* memo)
  {
  #ifdef USE_BUILTIN_COPY
      MatchObject* copy;
  
      copy = (MatchObject*) match_copy(self);
      if (!copy)
          return NULL;
  
      if (!deepcopy((PyObject**) &copy->pattern, memo) ||
          !deepcopy(&copy->string, memo) ||
          !deepcopy(&copy->regs, memo)) {
          Py_DECREF(copy);
          return NULL;
      }
  
  #else
      PyErr_SetString(PyExc_TypeError, "cannot deepcopy this match object");
      return NULL;
  #endif
  }
  
  static struct PyMethodDef match_methods[] = {
      {"group", (PyCFunction) match_group, METH_VARARGS},
      {"start", (PyCFunction) match_start, METH_VARARGS},
      {"end", (PyCFunction) match_end, METH_VARARGS},
      {"span", (PyCFunction) match_span, METH_VARARGS},
      {"groups", (PyCFunction) match_groups, METH_VARARGS|METH_KEYWORDS},
      {"groupdict", (PyCFunction) match_groupdict, METH_VARARGS|METH_KEYWORDS},
      {"expand", (PyCFunction) match_expand, METH_O},
      {"__copy__", (PyCFunction) match_copy, METH_NOARGS},
      {"__deepcopy__", (PyCFunction) match_deepcopy, METH_O},
      {NULL, NULL}
  };
  
  static PyObject *
  match_lastindex_get(MatchObject *self)
  {
      if (self->lastindex >= 0)
  	return Py_BuildValue("i", self->lastindex);
      Py_INCREF(Py_None);
      return Py_None;
  }
  
  static PyObject *
  match_lastgroup_get(MatchObject *self)
  {
      if (self->pattern->indexgroup && self->lastindex >= 0) {
          PyObject* result = PySequence_GetItem(
              self->pattern->indexgroup, self->lastindex
              );
          if (result)
              return result;
          PyErr_Clear();
      }
      Py_INCREF(Py_None);
      return Py_None;
  }
  
  static PyObject *
  match_regs_get(MatchObject *self)
  {
      if (self->regs) {
          Py_INCREF(self->regs);
          return self->regs;
      } else
          return match_regs(self);
  }
  
  static PyGetSetDef match_getset[] = {
      {"lastindex", (getter)match_lastindex_get, (setter)NULL},
      {"lastgroup", (getter)match_lastgroup_get, (setter)NULL},
      {"regs",      (getter)match_regs_get,      (setter)NULL},
      {NULL}
  };
  
  #define MATCH_OFF(x) offsetof(MatchObject, x)
  static PyMemberDef match_members[] = {
      {"string",  T_OBJECT,   MATCH_OFF(string),  READONLY},
      {"re",      T_OBJECT,   MATCH_OFF(pattern), READONLY},
      {"pos",     T_PYSSIZET, MATCH_OFF(pos),     READONLY},
      {"endpos",  T_PYSSIZET, MATCH_OFF(endpos),  READONLY},
      {NULL}
  };
  
  
  /* FIXME: implement setattr("string", None) as a special case (to
     detach the associated string, if any */
  
  static PyTypeObject Match_Type = {
      PyVarObject_HEAD_INIT(NULL, 0)
      "_" SRE_MODULE ".SRE_Match",
      sizeof(MatchObject), sizeof(Py_ssize_t),
      (destructor)match_dealloc,  /* tp_dealloc */
      0,                          /* tp_print */
      0,                          /* tp_getattr */
      0,                          /* tp_setattr */
      0,                          /* tp_compare */
      0,                          /* tp_repr */
      0,                          /* tp_as_number */
      0,                          /* tp_as_sequence */
      0,                          /* tp_as_mapping */
      0,                          /* tp_hash */
      0,                          /* tp_call */
      0,                          /* tp_str */
      0,                          /* tp_getattro */
      0,                          /* tp_setattro */
      0,                          /* tp_as_buffer */
      Py_TPFLAGS_DEFAULT,
      0,                          /* tp_doc */
      0,                          /* tp_traverse */
      0,                          /* tp_clear */
      0,                          /* tp_richcompare */
      0,                          /* tp_weaklistoffset */
      0,                          /* tp_iter */
      0,                          /* tp_iternext */
      match_methods,		/* tp_methods */
      match_members,		/* tp_members */
      match_getset,  	        /* tp_getset */
  };
  
  static PyObject*
  pattern_new_match(PatternObject* pattern, SRE_STATE* state, int status)
  {
      /* create match object (from state object) */
  
      MatchObject* match;
      Py_ssize_t i, j;
      char* base;
      int n;
  
      if (status > 0) {
  
          /* create match object (with room for extra group marks) */
          /* coverity[ampersand_in_size] */
          match = PyObject_NEW_VAR(MatchObject, &Match_Type,
                                   2*(pattern->groups+1));
          if (!match)
              return NULL;
  
          Py_INCREF(pattern);
          match->pattern = pattern;
  
          Py_INCREF(state->string);
          match->string = state->string;
  
          match->regs = NULL;
          match->groups = pattern->groups+1;
  
          /* fill in group slices */
  
          base = (char*) state->beginning;
          n = state->charsize;
  
          match->mark[0] = ((char*) state->start - base) / n;
          match->mark[1] = ((char*) state->ptr - base) / n;
  
          for (i = j = 0; i < pattern->groups; i++, j+=2)
              if (j+1 <= state->lastmark && state->mark[j] && state->mark[j+1]) {
                  match->mark[j+2] = ((char*) state->mark[j] - base) / n;
                  match->mark[j+3] = ((char*) state->mark[j+1] - base) / n;
              } else
                  match->mark[j+2] = match->mark[j+3] = -1; /* undefined */
  
          match->pos = state->pos;
          match->endpos = state->endpos;
  
          match->lastindex = state->lastindex;
  
          return (PyObject*) match;
  
      } else if (status == 0) {
  
          /* no match */
          Py_INCREF(Py_None);
          return Py_None;
  
      }
  
      /* internal error */
      pattern_error(status);
      return NULL;
  }
  
  
  /* -------------------------------------------------------------------- */
  /* scanner methods (experimental) */
  
  static void
  scanner_dealloc(ScannerObject* self)
  {
      state_fini(&self->state);
      Py_XDECREF(self->pattern);
      PyObject_DEL(self);
  }
  
  static PyObject*
  scanner_match(ScannerObject* self, PyObject *unused)
  {
      SRE_STATE* state = &self->state;
      PyObject* match;
      int status;
  
      state_reset(state);
  
      state->ptr = state->start;
  
      if (state->charsize == 1) {
          status = sre_match(state, PatternObject_GetCode(self->pattern));
      } else {
  #if defined(HAVE_UNICODE)
          status = sre_umatch(state, PatternObject_GetCode(self->pattern));
  #endif
      }
      if (PyErr_Occurred())
          return NULL;
  
      match = pattern_new_match((PatternObject*) self->pattern,
                                 state, status);
  
      if (status == 0 || state->ptr == state->start)
          state->start = (void*) ((char*) state->ptr + state->charsize);
      else
          state->start = state->ptr;
  
      return match;
  }
  
  
  static PyObject*
  scanner_search(ScannerObject* self, PyObject *unused)
  {
      SRE_STATE* state = &self->state;
      PyObject* match;
      int status;
  
      state_reset(state);
  
      state->ptr = state->start;
  
      if (state->charsize == 1) {
          status = sre_search(state, PatternObject_GetCode(self->pattern));
      } else {
  #if defined(HAVE_UNICODE)
          status = sre_usearch(state, PatternObject_GetCode(self->pattern));
  #endif
      }
      if (PyErr_Occurred())
          return NULL;
  
      match = pattern_new_match((PatternObject*) self->pattern,
                                 state, status);
  
      if (status == 0 || state->ptr == state->start)
          state->start = (void*) ((char*) state->ptr + state->charsize);
      else
          state->start = state->ptr;
  
      return match;
  }
  
  static PyMethodDef scanner_methods[] = {
      {"match", (PyCFunction) scanner_match, METH_NOARGS},
      {"search", (PyCFunction) scanner_search, METH_NOARGS},
      {NULL, NULL}
  };
  
  #define SCAN_OFF(x) offsetof(ScannerObject, x)
  static PyMemberDef scanner_members[] = {
      {"pattern",	T_OBJECT,	SCAN_OFF(pattern),	READONLY},
      {NULL}  /* Sentinel */
  };
  
  statichere PyTypeObject Scanner_Type = {
      PyObject_HEAD_INIT(NULL)
      0, "_" SRE_MODULE ".SRE_Scanner",
      sizeof(ScannerObject), 0,
      (destructor)scanner_dealloc, /*tp_dealloc*/
      0,				/* tp_print */
      0,				/* tp_getattr */
      0,				/* tp_setattr */
      0,				/* tp_reserved */
      0,				/* tp_repr */
      0,				/* tp_as_number */
      0,				/* tp_as_sequence */
      0,				/* tp_as_mapping */
      0,				/* tp_hash */
      0,				/* tp_call */
      0,				/* tp_str */
      0,				/* tp_getattro */
      0,				/* tp_setattro */
      0,				/* tp_as_buffer */
      Py_TPFLAGS_DEFAULT,		/* tp_flags */
      0,				/* tp_doc */
      0,				/* tp_traverse */
      0,				/* tp_clear */
      0,				/* tp_richcompare */
      0,				/* tp_weaklistoffset */
      0,				/* tp_iter */
      0,				/* tp_iternext */
      scanner_methods,		/* tp_methods */
      scanner_members,		/* tp_members */
      0,				/* tp_getset */
  };
  
  static PyObject*
  pattern_scanner(PatternObject* pattern, PyObject* args)
  {
      /* create search state object */
  
      ScannerObject* self;
  
      PyObject* string;
      Py_ssize_t start = 0;
      Py_ssize_t end = PY_SSIZE_T_MAX;
      if (!PyArg_ParseTuple(args, "O|nn:scanner", &string, &start, &end))
          return NULL;
  
      /* create scanner object */
      self = PyObject_NEW(ScannerObject, &Scanner_Type);
      if (!self)
          return NULL;
      self->pattern = NULL;
  
      string = state_init(&self->state, pattern, string, start, end);
      if (!string) {
          Py_DECREF(self);
          return NULL;
      }
  
      Py_INCREF(pattern);
      self->pattern = (PyObject*) pattern;
  
      return (PyObject*) self;
  }
  
  static PyMethodDef _functions[] = {
      {"compile", _compile, METH_VARARGS},
      {"getcodesize", sre_codesize, METH_NOARGS},
      {"getlower", sre_getlower, METH_VARARGS},
      {NULL, NULL}
  };
  
  #if PY_VERSION_HEX < 0x02030000
  DL_EXPORT(void) init_sre(void)
  #else
  PyMODINIT_FUNC init_sre(void)
  #endif
  {
      PyObject* m;
      PyObject* d;
      PyObject* x;
  
      /* Patch object types */
      if (PyType_Ready(&Pattern_Type) || PyType_Ready(&Match_Type) ||
          PyType_Ready(&Scanner_Type))
          return;
  
      m = Py_InitModule("_" SRE_MODULE, _functions);
      if (m == NULL)
      	return;
      d = PyModule_GetDict(m);
  
      x = PyInt_FromLong(SRE_MAGIC);
      if (x) {
          PyDict_SetItemString(d, "MAGIC", x);
          Py_DECREF(x);
      }
  
      x = PyInt_FromLong(sizeof(SRE_CODE));
      if (x) {
          PyDict_SetItemString(d, "CODESIZE", x);
          Py_DECREF(x);
      }
  
      x = PyString_FromString(copyright);
      if (x) {
          PyDict_SetItemString(d, "copyright", x);
          Py_DECREF(x);
      }
  }
  
  #endif /* !defined(SRE_RECURSIVE) */
  
  /* vim:ts=4:sw=4:et
  */
  