root/regex/regex2.h

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INCLUDED FROM


/*
 * First, the stuff that ends up in the outside-world include file
 = #ifdef WIN32
 = #define API_EXPORT(type)    __declspec(dllexport) type __stdcall
 = #else
 = #define API_EXPORT(type)    type
 = #endif
 =
 = typedef off_t regoff_t;
 = typedef struct {
 =      int re_magic;
 =      size_t re_nsub;         // number of parenthesized subexpressions
 =      const unsigned char *re_endp;   // end pointer for REG_PEND
 =      struct re_guts *re_g;   // none of your business :-)
 = } regex_t;
 = typedef struct {
 =      regoff_t rm_so;         // start of match
 =      regoff_t rm_eo;         // end of match
 = } regmatch_t;
 */
/*
 * internals of regex_t
 */
#define MAGIC1  ((('r'^0200)<<8) | 'e')

/*
 * The internal representation is a *strip*, a sequence of
 * operators ending with an endmarker.  (Some terminology etc. is a
 * historical relic of earlier versions which used multiple strips.)
 * Certain oddities in the representation are there to permit running
 * the machinery backwards; in particular, any deviation from sequential
 * flow must be marked at both its source and its destination.  Some
 * fine points:
 *
 * - OPLUS_ and O_PLUS are *inside* the loop they create.
 * - OQUEST_ and O_QUEST are *outside* the bypass they create.
 * - OCH_ and O_CH are *outside* the multi-way branch they create, while
 *   OOR1 and OOR2 are respectively the end and the beginning of one of
 *   the branches.  Note that there is an implicit OOR2 following OCH_
 *   and an implicit OOR1 preceding O_CH.
 *
 * In state representations, an operator's bit is on to signify a state
 * immediately *preceding* "execution" of that operator.
 */
typedef long sop;               /* strip operator */
typedef long sopno;
#define OPRMASK 0x7c000000
#define OPDMASK 0x03ffffff
#define OPSHIFT (26)
#define OP(n)   ((n)&OPRMASK)
#define OPND(n) ((n)&OPDMASK)
#define SOP(op, opnd)   ((op)|(opnd))
/* operators                       meaning      operand                 */
/*                                              (back, fwd are offsets) */
#define OEND    (1<<OPSHIFT)    /* endmarker    -                       */
#define OCHAR   (2<<OPSHIFT)    /* character    unsigned char           */
#define OBOL    (3<<OPSHIFT)    /* left anchor  -                       */
#define OEOL    (4<<OPSHIFT)    /* right anchor -                       */
#define OANY    (5<<OPSHIFT)    /* .            -                       */
#define OANYOF  (6<<OPSHIFT)    /* [...]        set number              */
#define OBACK_  (7<<OPSHIFT)    /* begin \d     paren number            */
#define O_BACK  (8<<OPSHIFT)    /* end \d       paren number            */
#define OPLUS_  (9<<OPSHIFT)    /* + prefix     fwd to suffix           */
#define O_PLUS  (10<<OPSHIFT)   /* + suffix     back to prefix          */
#define OQUEST_ (11<<OPSHIFT)   /* ? prefix     fwd to suffix           */
#define O_QUEST (12<<OPSHIFT)   /* ? suffix     back to prefix          */
#define OLPAREN (13<<OPSHIFT)   /* (            fwd to )                */
#define ORPAREN (14<<OPSHIFT)   /* )            back to (               */
#define OCH_    (15<<OPSHIFT)   /* begin choice fwd to OOR2             */
#define OOR1    (16<<OPSHIFT)   /* | pt. 1      back to OOR1 or OCH_    */
#define OOR2    (17<<OPSHIFT)   /* | pt. 2      fwd to OOR2 or O_CH     */
#define O_CH    (18<<OPSHIFT)   /* end choice   back to OOR1            */
#define OBOW    (19<<OPSHIFT)   /* begin word   -                       */
#define OEOW    (20<<OPSHIFT)   /* end word     -                       */

/*
 * Structure for [] character-set representation.  Character sets are
 * done as bit vectors, grouped 8 to a byte vector for compactness.
 * The individual set therefore has both a pointer to the byte vector
 * and a mask to pick out the relevant bit of each byte.  A hash code
 * simplifies testing whether two sets could be identical.
 *
 * This will get trickier for multicharacter collating elements.  As
 * preliminary hooks for dealing with such things, we also carry along
 * a string of multi-character elements, and decide the size of the
 * vectors at run time.
 */
typedef struct {
        uch *ptr;               /* -> uch [csetsize] */
        uch mask;               /* bit within array */
        uch hash;               /* hash code */
        size_t smultis;
        unsigned char *multis;          /* -> char[smulti]  ab\0cd\0ef\0\0 */
} cset;
/* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
#define CHadd(cs, c)    ((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c))
#define CHsub(cs, c)    ((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c))
#define CHIN(cs, c)     ((cs)->ptr[(uch)(c)] & (cs)->mask)
#define MCadd(p, cs, cp)        mcadd(p, cs, cp)        /* regcomp() internal fns */
#define MCsub(p, cs, cp)        mcsub(p, cs, cp)
#define MCin(p, cs, cp) mcin(p, cs, cp)

/* stuff for character categories */
typedef unsigned char cat_t;

/*
 * main compiled-expression structure
 */
struct re_guts {
        int magic;
#               define  MAGIC2  ((('R'^0200)<<8)|'E')
        sop *strip;             /* malloced area for strip */
        int csetsize;           /* number of bits in a cset vector */
        int ncsets;             /* number of csets in use */
        cset *sets;             /* -> cset [ncsets] */
        uch *setbits;           /* -> uch[csetsize][ncsets/CHAR_BIT] */
        int cflags;             /* copy of regcomp() cflags argument */
        sopno nstates;          /* = number of sops */
        sopno firststate;       /* the initial OEND (normally 0) */
        sopno laststate;        /* the final OEND */
        int iflags;             /* internal flags */
#               define  USEBOL  01      /* used ^ */
#               define  USEEOL  02      /* used $ */
#               define  BAD     04      /* something wrong */
        int nbol;               /* number of ^ used */
        int neol;               /* number of $ used */
        int ncategories;        /* how many character categories */
        cat_t *categories;      /* ->catspace[-UCHAR_MIN] */
        unsigned char *must;            /* match must contain this string */
        int mlen;               /* length of must */
        size_t nsub;            /* copy of re_nsub */
        int backrefs;           /* does it use back references? */
        sopno nplus;            /* how deep does it nest +s? */
        /* catspace must be last */
        cat_t catspace[1];      /* actually [NC] */
};

/* misc utilities */
#define OUT     (UCHAR_MAX+1)   /* a non-character value */
#define ISWORD(c)       (isalnum(c) || (c) == '_')

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