regexp_defs.h

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/*
 * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
 *
 * This is NOT the original regular expression code as written by Henry
 * Spencer.  This code has been modified specifically for use with Vim, and
 * should not be used apart from compiling Vim.  If you want a good regular
 * expression library, get the original code.
 *
 * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
 */
 
#ifndef NVIM_REGEXP_DEFS_H
#define NVIM_REGEXP_DEFS_H
 
#include <stdbool.h>
 
#include "nvim/pos.h"
#include "nvim/profile.h"
#include "nvim/types.h"
 
/*
 * The number of sub-matches is limited to 10.
 * The first one (index 0) is the whole match, referenced with "\0".
 * The second one (index 1) is the first sub-match, referenced with "\1".
 * This goes up to the tenth (index 9), referenced with "\9".
 */
#define NSUBEXP  10
 
/*
 * In the NFA engine: how many braces are allowed.
 * TODO(RE): Use dynamic memory allocation instead of static, like here
 */
#define NFA_MAX_BRACES 20
 
// In the NFA engine: how many states are allowed.
#define NFA_MAX_STATES 100000
#define NFA_TOO_EXPENSIVE (-1)
 
// Which regexp engine to use? Needed for vim_regcomp().
// Must match with 'regexpengine'.
#define AUTOMATIC_ENGINE    0
#define BACKTRACKING_ENGINE 1
#define NFA_ENGINE          2
 
typedef struct regengine regengine_T;
typedef struct regprog regprog_T;
typedef struct reg_extmatch reg_extmatch_T;
 
typedef struct {
  regprog_T *regprog;
  lpos_T startpos[NSUBEXP];
  lpos_T endpos[NSUBEXP];
  int rmm_ic;
  colnr_T rmm_maxcol;  
} regmmatch_T;
 
#include "nvim/buffer_defs.h"
 
/*
 * Structure returned by vim_regcomp() to pass on to vim_regexec().
 * This is the general structure. For the actual matcher, two specific
 * structures are used. See code below.
 */
struct regprog {
  regengine_T *engine;
  unsigned regflags;
  unsigned re_engine;  
  unsigned re_flags;   
  bool re_in_use;      
};
 
/*
 * Structure used by the back track matcher.
 * These fields are only to be used in regexp.c!
 * See regexp.c for an explanation.
 */
typedef struct {
  // These four members implement regprog_T.
  regengine_T *engine;
  unsigned regflags;
  unsigned re_engine;
  unsigned re_flags;
  bool re_in_use;
 
  int regstart;
  char_u reganch;
  char_u *regmust;
  int regmlen;
  char_u reghasz;
  char_u program[1];                    // actually longer..
} bt_regprog_T;
 
// Structure representing a NFA state.
// An NFA state may have no outgoing edge, when it is a NFA_MATCH state.
typedef struct nfa_state nfa_state_T;
struct nfa_state {
  int c;
  nfa_state_T *out;
  nfa_state_T *out1;
  int id;
  int lastlist[2];                   // 0: normal, 1: recursive
  int val;
};
 
/*
 * Structure used by the NFA matcher.
 */
typedef struct {
  // These four members implement regprog_T.
  regengine_T *engine;
  unsigned regflags;
  unsigned re_engine;
  unsigned re_flags;
  bool re_in_use;
 
  nfa_state_T *start;           // points into state[]
 
  int reganch;                          // pattern starts with ^
  int regstart;                         // char at start of pattern
  char_u *match_text;      // plain text to match with
 
  int has_zend;                         // pattern contains \ze
  int has_backref;                      // pattern contains \1 .. \9
  int reghasz;
  char_u *pattern;
  int nsubexp;                          // number of ()
  int nstate;
  nfa_state_T state[1];                 // actually longer..
} nfa_regprog_T;
 
/*
 * Structure to be used for single-line matching.
 * Sub-match "no" starts at "startp[no]" and ends just before "endp[no]".
 * When there is no match, the pointer is NULL.
 */
typedef struct {
  regprog_T *regprog;
  char_u *startp[NSUBEXP];
  char_u *endp[NSUBEXP];
  bool rm_ic;
} regmatch_T;
 
/*
 * Structure used to store external references: "\z\(\)" to "\z\1".
 * Use a reference count to avoid the need to copy this around.  When it goes
 * from 1 to zero the matches need to be freed.
 */
struct reg_extmatch {
  int16_t refcnt;
  char_u *matches[NSUBEXP];
};
 
struct regengine {
  regprog_T *(*regcomp)(char_u *, int);
  void (*regfree)(regprog_T *);
  int (*regexec_nl)(regmatch_T *, char_u *, colnr_T, bool);
  long (*regexec_multi)(regmmatch_T *, win_T *, buf_T *, linenr_T, colnr_T, proftime_T *, int *);
  // char_u *expr;
};
 
#endif  // NVIM_REGEXP_DEFS_H