summaryrefslogtreecommitdiff
path: root/src/regexp.h
blob: 57623386157607419567d6b511425d01dd6b0864 (plain)
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
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * 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 _REGEXP_H
#define _REGEXP_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;

/*
 * 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.
 */
typedef struct regprog
{
    regengine_T		*engine;
    unsigned		regflags;
    unsigned		re_engine;   // automatic, backtracking or nfa engine
    unsigned		re_flags;    // second argument for vim_regcomp()
    int			re_in_use;   // prog is being executed
} regprog_T;

/*
 * 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;
    int			re_in_use;

    int			regstart;
    char_u		reganch;
    char_u		*regmust;
    int			regmlen;
#ifdef FEAT_SYN_HL
    char_u		reghasz;
#endif
    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 three members implement regprog_T
    regengine_T		*engine;
    unsigned		regflags;
    unsigned		re_engine;
    unsigned		re_flags;
    int			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
#ifdef FEAT_SYN_HL
    int			reghasz;
#endif
    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];
    int			rm_ic;
} regmatch_T;

/*
 * Structure to be used for multi-line matching.
 * Sub-match "no" starts in line "startpos[no].lnum" column "startpos[no].col"
 * and ends in line "endpos[no].lnum" just before column "endpos[no].col".
 * The line numbers are relative to the first line, thus startpos[0].lnum is
 * always 0.
 * When there is no match, the line number is -1.
 */
typedef struct
{
    regprog_T		*regprog;
    lpos_T		startpos[NSUBEXP];
    lpos_T		endpos[NSUBEXP];
    int			rmm_ic;
    colnr_T		rmm_maxcol;	// when not zero: maximum column
} regmmatch_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.
 */
typedef struct
{
    short		refcnt;
    char_u		*matches[NSUBEXP];
} reg_extmatch_T;

struct regengine
{
    regprog_T	*(*regcomp)(char_u*, int);
    void	(*regfree)(regprog_T *);
    int		(*regexec_nl)(regmatch_T *, char_u *, colnr_T, int);
    long	(*regexec_multi)(regmmatch_T *, win_T *, buf_T *, linenr_T, colnr_T, proftime_T *, int *);
    char_u	*expr;
};

#endif	// _REGEXP_H