/*
 * types.h - Datatypes used by BPEG
 */
#ifndef TYPES__H
#define TYPES__H

#include <sys/types.h>

enum BPEGFlag {
    BPEG_VERBOSE    = 1 << 0,
    BPEG_IGNORECASE = 1 << 1,
};

/*
 * BPEG virtual machine opcodes (these must be kept in sync with the names in vm.c)
 */
enum VMOpcode {
    VM_EMPTY = 0,
    VM_ANYCHAR = 1,
    VM_STRING,
    VM_RANGE,
    VM_NOT,
    VM_UPTO,
    VM_REPEAT,
    VM_BEFORE,
    VM_AFTER,
    VM_CAPTURE,
    VM_OTHERWISE,
    VM_CHAIN,
    VM_EQUAL,
    VM_REPLACE,
    VM_REF,
    VM_BACKREF,
    VM_NODENT,
};

/*
 * A struct reperesenting a BPEG virtual machine operation
 */
typedef struct vm_op_s {
    enum VMOpcode op;
    unsigned int multiline:1, negate:1;
    const char *start, *end;
    // Length of the match, if constant, otherwise -1
    ssize_t len;
    union {
        const char *s;
        struct {
            char low, high;
        } range;
        struct {
            ssize_t min, max;
            struct vm_op_s *sep, *repeat_pat;
        } repetitions;
        // TODO: use a linked list instead of a binary tree
        struct {
            struct vm_op_s *first, *second;
        } multiple;
        struct {
            struct vm_op_s *replace_pat;
            const char *replacement;
        } replace;
        struct {
            struct vm_op_s *capture_pat;
            char *name;
        } capture;
        void *backref;
        struct vm_op_s *pat;
    } args;
} vm_op_t;

/*
 * Pattern matching result object
 */
typedef struct match_s {
    // Where the match starts and ends (end is after the last character)
    const char *start, *end;
    unsigned int is_capture:1, is_replacement:1, is_ref:1;
    const char *name_or_replacement;
    struct match_s *child, *nextsibling;
    vm_op_t *op;
} match_t;


typedef struct {
    const char *name;
    const char *source;
    vm_op_t *op;
} def_t;

typedef struct {
    size_t defcount, defcapacity;
    def_t *definitions;

    size_t backrefcount, backrefcapacity;
    struct {
        const char *name;
        match_t *capture;
        vm_op_t *op;
    } *backrefs;
} grammar_t;

#endif
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