/*

 *

 * 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_HAS_ABI_HEADERS

#  include BOOST_ABI_PREFIX

#endif

namespace boost{

namespace re_detail{

/*** 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

};

#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;

};

/*** 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           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

};

/*** 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 re_detail

} // namespace boost

#ifdef BOOST_HAS_ABI_HEADERS

#  include BOOST_ABI_SUFFIX

#endif

#endif