Eremey Valetov
d8e8375366
GW-BASIC reimplementation in C11, using Microsoft's open-sourced 8088 assembly as the authoritative reference. Tokenizer (CRUNCH/LIST), expression evaluator with operator precedence, all math functions (SIN, COS, TAN, ATN, SQR, LOG, EXP, RND, etc.), string functions (LEFT$, RIGHT$, MID$, CHR$, ASC, VAL, STR$, etc.), PRINT statement with comma/semicolon zones, TAB(), SPC(). Handles integer/single/double types with correct promotion, D exponent for double-precision literals, type suffixes (%, !, #), &H hex/&O octal literals, MBF conversion routines, and GW-BASIC-compatible number formatting. Platform-independent via HAL vtable; POSIX backend included.
52 lines
1.2 KiB
C
52 lines
1.2 KiB
C
#ifndef GW_INTERP_H
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#define GW_INTERP_H
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#include "types.h"
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#include <stdbool.h>
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/* Interpreter state - the global context */
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typedef struct {
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/* Text pointer (TXTPTR equivalent) */
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uint8_t *text_ptr;
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/* Current accumulator (FAC equivalent) */
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gw_value_t fac;
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/* Program state */
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uint16_t cur_line_num; /* CURLIN - 65535 = direct mode */
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program_line_t *prog_head; /* first line of program */
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bool trace_on; /* TRON/TROFF */
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/* Tokenizer buffers */
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uint8_t kbuf[300]; /* crunch buffer */
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char buf[256]; /* input line buffer */
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/* Default variable types for A-Z (DEFTBL) */
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gw_valtype_t def_type[26];
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/* DATA pointer */
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uint8_t *data_ptr;
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uint16_t data_line;
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} interp_state_t;
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extern interp_state_t gw;
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/* Direct mode line number sentinel */
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#define LINE_DIRECT 65535
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void gw_init(void);
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void gw_exec_line(uint8_t *tokens);
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void gw_exec_direct(const char *line);
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/* CHRGET/CHRGOT - advance/peek the text pointer */
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uint8_t gw_chrget(void);
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uint8_t gw_chrgot(void);
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void gw_skip_spaces(void);
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bool gw_is_letter(uint8_t ch);
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bool gw_is_digit(uint8_t ch);
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/* Expect a specific token, else syntax error */
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void gw_expect(uint8_t tok);
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#endif
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