#ifndef __REG_CORE_H__
#define __REG_CORE_H__

/*
 * @author fenrir (https://fenrir.naruoka.org/)
 * 
 * reg_core.h 
 * 正規表現のコアとなるヘッダ。
 * 実際に使用する際はこのヘッダのみをincludeすればよい。
 */
 
#ifndef TRUE
  #define TRUE 1
#endif
#ifndef FALSE
  #define FALSE 0
#endif
 
#ifdef __cplusplus
extern "C"{
#endif

typedef unsigned char boolean;

struct reg_stack_t{
  struct reg_state_t{
    struct reg_node_t{
      void *info;
      struct reg_state_t *(*transit)(struct reg_state_t *current, struct reg_stack_t *stack);
    } *node;
    char *input_index;
  } *top;
  struct reg_state_t *bottom;
  int size;
};

typedef struct reg_state_t reg_state_t;
typedef struct reg_node_t reg_node_t;
typedef struct reg_stack_t reg_stack_t;

/**
 * 遷移表
 */
typedef struct reg_list_t{
  reg_node_t *top;
  reg_node_t *end;
  int max;
} reg_list_t;

typedef struct reg_range_t{
  char *start;
  char *end;
} reg_range_t;

typedef struct reg_submatch_t{
  reg_node_t *start;
  reg_node_t *end;
  reg_range_t range;
} reg_submatch_t;

/**
 * マッチオブジェクト
 */
typedef struct reg_match_t{
  reg_submatch_t *submatch_top;
  reg_submatch_t *submatch_end;
  int submatch_max;
} reg_match_t;

/**
 * コンパイルやマッチのときの状態を格納するオブジェクト
 */
typedef int reg_status_t;

/**
 * 正規表現オブジェクト
 */
typedef struct regexp_t{
  reg_list_t list;
  reg_match_t match_object;
  reg_status_t status;
} regexp_t;

/* コンパイル処理(reg_compile.c) */
regexp_t *reg_before_compile(regexp_t *regexp,
                             reg_node_t *node, int node_max,
                             reg_submatch_t *submatch, int submatch_max);
regexp_t *reg_compile(regexp_t *regexp, char *regexp_str);

#define reg_precompile(_regexp, _node_max, _sub_match_max) \
reg_node_t node_ ## _regexp[_node_max];\
reg_submatch_t submatch_ ## _regexp[_sub_match_max];\
reg_before_compile(&(_regexp), \
                   node_ ## _regexp, _node_max, \
                   submatch_ ## _regexp, _sub_match_max);

/* コンパイル時エラーコード */
#define REG_ERR_C_TOO_FEW_PARENTHESIS -1
#define REG_ERR_C_TOO_FEW_BRACKET -2
#define REG_ERR_C_IREGAL_LOOP_NUMBER -3
#define REG_ERR_C_IREGAL_BACKREF -4
#define REG_ERR_C_TOO_FEW_CHARACTERS -5

/* マッチ処理(reg_core.c) */
reg_match_t *reg_scan(regexp_t *regexp, char *target, int buffer_size);
reg_match_t *reg_match(regexp_t *regexp, char *target, int buffer_size);
char *reg_submatch(reg_match_t *match_object, int index, char *dist, int buffer_size);

#ifdef __cplusplus
};
#endif

#endif /* __REG_CORE_H__ */