text: /*
   *
   * Copyright (c) 1998-2002
   * John Maddock
   *
   * Use, modification and distribution are subject to the 
   * Boost Software License, Version 1.0. (See accompanying file 
   * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   *
   */
  
   /*
    *   LOCATION:    see http://www.boost.org for most recent version.
    *   FILE         states.cpp
    *   VERSION      see <boost/version.hpp>
    *   DESCRIPTION: Declares internal state machine structures.
    */
  
  #ifndef BOOST_REGEX_V4_STATES_HPP
  #define BOOST_REGEX_V4_STATES_HPP
  
  #ifdef BOOST_MSVC
  #pragma warning(push)
  #pragma warning(disable: 4103)
  #endif
  #ifdef BOOST_HAS_ABI_HEADERS
  #  include BOOST_ABI_PREFIX
  #endif
  #ifdef BOOST_MSVC
  #pragma warning(pop)
  #endif
  
  namespace boost{
  namespace BOOST_REGEX_DETAIL_NS{
  
  /*** mask_type *******************************************************
  Whenever we have a choice of two alternatives, we use an array of bytes
  to indicate which of the two alternatives it is possible to take for any
  given input character.  If mask_take is set, then we can take the next 
  state, and if mask_skip is set then we can take the alternative.
  ***********************************************************************/
  enum mask_type
  {
     mask_take = 1,
     mask_skip = 2,
     mask_init = 4,
     mask_any = mask_skip | mask_take,
     mask_all = mask_any
  };
  
  /*** helpers **********************************************************
  These helpers let us use function overload resolution to detect whether
  we have narrow or wide character strings:
  ***********************************************************************/
  struct _narrow_type{};
  struct _wide_type{};
  template <class charT> struct is_byte;
  template<>             struct is_byte<char>         { typedef _narrow_type width_type; };
  template<>             struct is_byte<unsigned char>{ typedef _narrow_type width_type; };
  template<>             struct is_byte<signed char>  { typedef _narrow_type width_type; };
  template <class charT> struct is_byte               { typedef _wide_type width_type; };
  
  /*** enum syntax_element_type ******************************************
  Every record in the state machine falls into one of the following types:
  ***********************************************************************/
  enum syntax_element_type
  {
     // start of a marked sub-expression, or perl-style (?...) extension
     syntax_element_startmark = 0,
     // end of a marked sub-expression, or perl-style (?...) extension
     syntax_element_endmark = syntax_element_startmark + 1,
     // any sequence of literal characters
     syntax_element_literal = syntax_element_endmark + 1,
     // start of line assertion: ^
     syntax_element_start_line = syntax_element_literal + 1,
     // end of line assertion $
     syntax_element_end_line = syntax_element_start_line + 1,
     // match any character: .
     syntax_element_wild = syntax_element_end_line + 1,
     // end of expression: we have a match when we get here
     syntax_element_match = syntax_element_wild + 1,
     // perl style word boundary: \b
     syntax_element_word_boundary = syntax_element_match + 1,
     // perl style within word boundary: \B
     syntax_element_within_word = syntax_element_word_boundary + 1,
     // start of word assertion: \<
     syntax_element_word_start = syntax_element_within_word + 1,
     // end of word assertion: \>
     syntax_element_word_end = syntax_element_word_start + 1,
     // start of buffer assertion: \`
     syntax_element_buffer_start = syntax_element_word_end + 1,
     // end of buffer assertion: \'
     syntax_element_buffer_end = syntax_element_buffer_start + 1,
     // backreference to previously matched sub-expression
     syntax_element_backref = syntax_element_buffer_end + 1,
     // either a wide character set [..] or one with multicharacter collating elements:
     syntax_element_long_set = syntax_element_backref + 1,
     // narrow character set: [...]
     syntax_element_set = syntax_element_long_set + 1,
     // jump to a new state in the machine:
     syntax_element_jump = syntax_element_set + 1,
     // choose between two production states:
     syntax_element_alt = syntax_element_jump + 1,
     // a repeat
     syntax_element_rep = syntax_element_alt + 1,
     // match a combining character sequence
     syntax_element_combining = syntax_element_rep + 1,
     // perl style soft buffer end: \z
     syntax_element_soft_buffer_end = syntax_element_combining + 1,
     // perl style continuation: \G
     syntax_element_restart_continue = syntax_element_soft_buffer_end + 1,
     // single character repeats:
     syntax_element_dot_rep = syntax_element_restart_continue + 1,
     syntax_element_char_rep = syntax_element_dot_rep + 1,
     syntax_element_short_set_rep = syntax_element_char_rep + 1,
     syntax_element_long_set_rep = syntax_element_short_set_rep + 1,
     // a backstep for lookbehind repeats:
     syntax_element_backstep = syntax_element_long_set_rep + 1,
     // an assertion that a mark was matched:
     syntax_element_assert_backref = syntax_element_backstep + 1,
     syntax_element_toggle_case = syntax_element_assert_backref + 1,
     // a recursive expression:
     syntax_element_recurse = syntax_element_toggle_case + 1,
     // Verbs:
     syntax_element_fail = syntax_element_recurse + 1,
     syntax_element_accept = syntax_element_fail + 1,
     syntax_element_commit = syntax_element_accept + 1,
     syntax_element_then = syntax_element_commit + 1
  };
  
  #ifdef BOOST_REGEX_DEBUG
  // dwa 09/26/00 - This is needed to suppress warnings about an ambiguous conversion
  std::ostream& operator<<(std::ostream&, syntax_element_type);
  #endif
  
  struct re_syntax_base;
  
  /*** union offset_type ************************************************
  Points to another state in the machine.  During machine construction
  we use integral offsets, but these are converted to pointers before
  execution of the machine.
  ***********************************************************************/
  union offset_type
  {
     re_syntax_base*   p;
     std::ptrdiff_t    i;
  };
  
  /*** struct re_syntax_base ********************************************
  Base class for all states in the machine.
  ***********************************************************************/
  struct re_syntax_base
  {
     syntax_element_type   type;         // what kind of state this is
     offset_type           next;         // next state in the machine
  };
  
  /*** struct re_brace **************************************************
  A marked parenthesis.
  ***********************************************************************/
  struct re_brace : public re_syntax_base
  {
     // The index to match, can be zero (don't mark the sub-expression)
     // or negative (for perl style (?...) extentions):
     int index;
     bool icase;
  };
  
  /*** struct re_dot **************************************************
  Match anything.
  ***********************************************************************/
  enum
  {
     dont_care = 1,
     force_not_newline = 0,
     force_newline = 2,
  
     test_not_newline = 2,
     test_newline = 3
  };
  struct re_dot : public re_syntax_base
  {
     unsigned char mask;
  };
  
  /*** struct re_literal ************************************************
  A string of literals, following this structure will be an 
  array of characters: charT[length]
  ***********************************************************************/
  struct re_literal : public re_syntax_base
  {
     unsigned int length;
  };
  
  /*** struct re_case ************************************************
  Indicates whether we are moving to a case insensive block or not
  ***********************************************************************/
  struct re_case : public re_syntax_base
  {
     bool icase;
  };
  
  /*** struct re_set_long ***********************************************
  A wide character set of characters, following this structure will be
  an array of type charT:
  First csingles null-terminated strings
  Then 2 * cranges NULL terminated strings
  Then cequivalents NULL terminated strings
  ***********************************************************************/
  template <class mask_type>
  struct re_set_long : public re_syntax_base
  {
     unsigned int            csingles, cranges, cequivalents;
     mask_type               cclasses;
     mask_type               cnclasses;
     bool                    isnot;
     bool                    singleton;
  };
  
  /*** struct re_set ****************************************************
  A set of narrow-characters, matches any of _map which is none-zero
  ***********************************************************************/
  struct re_set : public re_syntax_base
  {
     unsigned char _map[1 << CHAR_BIT];
  };
  
  /*** struct re_jump ***************************************************
  Jump to a new location in the machine (not next).
  ***********************************************************************/
  struct re_jump : public re_syntax_base
  {
     offset_type     alt;                 // location to jump to
  };
  
  /*** struct re_alt ***************************************************
  Jump to a new location in the machine (possibly next).
  ***********************************************************************/
  struct re_alt : public re_jump
  {
     unsigned char   _map[1 << CHAR_BIT]; // which characters can take the jump
     unsigned int    can_be_null;         // true if we match a NULL string
  };
  
  /*** struct re_repeat *************************************************
  Repeat a section of the machine
  ***********************************************************************/
  struct re_repeat : public re_alt
  {
     std::size_t   min, max;  // min and max allowable repeats
     int           state_id;        // Unique identifier for this repeat
     bool          leading;   // True if this repeat is at the start of the machine (lets us optimize some searches)
     bool          greedy;    // True if this is a greedy repeat
  };
  
  /*** struct re_recurse ************************************************
  Recurse to a particular subexpression.
  **********************************************************************/
  struct re_recurse : public re_jump
  {
     int state_id;             // identifier of first nested repeat within the recursion.
  };
  
  /*** struct re_commit *************************************************
  Used for the PRUNE, SKIP and COMMIT verbs which basically differ only in what happens
  if no match is found and we start searching forward.
  **********************************************************************/
  enum commit_type
  {
     commit_prune,
     commit_skip,
     commit_commit
  };
  struct re_commit : public re_syntax_base
  {
     commit_type action;
  };
  
  /*** enum re_jump_size_type *******************************************
  Provides compiled size of re_jump structure (allowing for trailing alignment).
  We provide this so we know how manybytes to insert when constructing the machine
  (The value of padding_mask is defined in regex_raw_buffer.hpp).
  ***********************************************************************/
  enum re_jump_size_type
  {
     re_jump_size = (sizeof(re_jump) + padding_mask) & ~(padding_mask),
     re_repeater_size = (sizeof(re_repeat) + padding_mask) & ~(padding_mask),
     re_alt_size = (sizeof(re_alt) + padding_mask) & ~(padding_mask)
  };
  
  /*** proc re_is_set_member *********************************************
  Forward declaration: we'll need this one later...
  ***********************************************************************/
  
  template<class charT, class traits>
  struct regex_data;
  
  template <class iterator, class charT, class traits_type, class char_classT>
  iterator BOOST_REGEX_CALL re_is_set_member(iterator next, 
                            iterator last, 
                            const re_set_long<char_classT>* set_, 
                            const regex_data<charT, traits_type>& e, bool icase);
  
  } // namespace BOOST_REGEX_DETAIL_NS
  
  } // namespace boost
  
  #ifdef BOOST_MSVC
  #pragma warning(push)
  #pragma warning(disable: 4103)
  #endif
  #ifdef BOOST_HAS_ABI_HEADERS
  #  include BOOST_ABI_SUFFIX
  #endif
  #ifdef BOOST_MSVC
  #pragma warning(pop)
  #endif
  
  #endif
  
  
  