scantab.h

PL/0源码

//////////////////////////////////////////////////////////////////////////////
//
//  scantab.h -- Definitions for interfacing with scantab.cc which is created
//               by the makescan utility.
//               NB: All variables exported by scantab.h begin with st_.
//

#ifndef SCANTAB_H
#define SCANTAB_H

#include "scanner.h"

#define    HASH_TABLE_SIZE     3001     // 3001 is prime
#define    MAX_CHAR_CODE       127
#define    MAX_CHAR_CLASS      45
#define    MAX_SCANNER_STATE   60
#define    MAX_RESERVE_WORD    50

#define    ERROR           0
#define    MOVE_APPEND     1
#define    MOVE_NO_APPEND  2
#define    HALT_APPEND     3
#define    HALT_NO_APPEND  4
#define    HALT_REUSE      5

typedef int     hash_index_t;           // 1..HASH_TABLE_SIZE
typedef char    char_class_t;           // 0..MAX_CHAR_CLASS
typedef char    scanner_state_t;    // 0..MAX_SCANNER_STATE
typedef char    scanner_act_t;          // ERROR..HALT_REUSE
typedef char    reserved_word_t;    // 1..MAX_RESERVE_WORD

struct state_vector_t  {
    scanner_act_t   action;
    scanner_state_t     next_state; // MOVE _APPEND, _NO_APPEND
    major_token_t   major;          // HALT _APPEND, _NO_APPEND, _REUSE
    minor_token_t   minor;
};
struct state_info_t  {
    bool            terminal;
    major_token_t   default_major;
    minor_token_t   default_minor;
};
struct reserve_array_t {
    major_token_t       major;
    minor_token_t       minor;
    string_number_t     text_handle;
};

extern char             st_string_space[MAX_STRING_SPACE];
extern string_number_t  st_used_strings;
extern reserve_array_t  st_reserved_words[MAX_RESERVE_WORD];
extern char_class_t     st_char_class[MAX_CHAR_CODE + 1];
extern state_vector_t   st_state_matrix[MAX_SCANNER_STATE][MAX_CHAR_CLASS];
extern state_info_t     st_state_info[MAX_SCANNER_STATE + 1];
//  Keeps track of which states are terminal, and for what

extern reserved_word_t  st_num_reserved_words;
extern major_token_t    st_end_of_file;
extern major_token_t    st_num_terminals;
extern scanner_state_t  st_start_state;
extern string_number_t  st_max_reserve_location;
extern major_token_t    st_id_major_num;
extern minor_token_t    st_id_minor_num;

#endif