Files
gw-basic-2026/include/interp.h

115 lines
2.7 KiB
C

#ifndef GW_INTERP_H
#define GW_INTERP_H
#include "types.h"
#include <stdbool.h>
/* Interpreter state - the global context */
typedef struct {
/* Text pointer (TXTPTR equivalent) */
uint8_t *text_ptr;
/* Current accumulator (FAC equivalent) */
gw_value_t fac;
/* Program state */
uint16_t cur_line_num; /* CURLIN - 65535 = direct mode */
program_line_t *prog_head; /* first line of program */
bool trace_on; /* TRON/TROFF */
/* Tokenizer buffers */
uint8_t kbuf[300]; /* crunch buffer */
char buf[256]; /* input line buffer */
/* Default variable types for A-Z (DEFTBL) */
gw_valtype_t def_type[26];
/* Variable storage */
var_entry_t vars[256];
int var_count;
array_entry_t arrays[64];
int array_count;
int option_base;
/* Control flow stacks */
#define MAX_FOR_DEPTH 16
#define MAX_GOSUB_DEPTH 24
#define MAX_WHILE_DEPTH 16
for_entry_t for_stack[MAX_FOR_DEPTH];
int for_sp;
gosub_entry_t gosub_stack[MAX_GOSUB_DEPTH];
int gosub_sp;
while_entry_t while_stack[MAX_WHILE_DEPTH];
int while_sp;
/* DEF FN */
fn_def_t fn_defs[26];
/* Run state */
program_line_t *cur_line;
bool running;
/* CONT state */
uint8_t *cont_text;
program_line_t *cont_line;
/* DATA pointer */
uint8_t *data_ptr;
program_line_t *data_line_ptr;
uint16_t data_line;
/* File I/O table (#1-#15, index 0 unused) */
file_entry_t files[16];
/* Error trapping */
uint16_t on_error_line;
bool in_error_handler;
uint8_t *err_resume_text;
program_line_t *err_resume_line;
uint16_t err_line_num;
/* AUTO mode */
bool auto_mode;
uint16_t auto_line;
uint16_t auto_inc;
/* COMMON variable list for CHAIN */
int common_count;
struct { char name[2]; gw_valtype_t type; } common_vars[64];
/* Event trapping */
timer_trap_t timer_trap;
event_trap_t key_traps[10]; /* KEY(1)-KEY(10) */
/* DEF SEG segment (for PEEK/POKE/BSAVE/BLOAD) */
uint16_t def_seg;
} interp_state_t;
extern interp_state_t gw;
/* Direct mode line number sentinel */
#define LINE_DIRECT 65535
void gw_init(void);
void gw_exec_direct(const char *line);
void gw_exec_stmt(void);
void gw_run_loop(void);
/* Program storage */
void gw_store_line(uint16_t num, uint8_t *tokens, int len);
void gw_delete_line(uint16_t num);
program_line_t *gw_find_line(uint16_t num);
void gw_free_program(void);
/* CHRGET/CHRGOT - advance/peek the text pointer */
uint8_t gw_chrget(void);
uint8_t gw_chrgot(void);
void gw_skip_spaces(void);
bool gw_is_letter(uint8_t ch);
bool gw_is_digit(uint8_t ch);
/* Expect a specific token, else syntax error */
void gw_expect(uint8_t tok);
#endif