98 lines
3.0 KiB
C
98 lines
3.0 KiB
C
#include "forth.h"
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// Input tokenizer
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char* next_token(void) {
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if (input_ptr == NULL) return NULL;
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while (*input_ptr != '\0' && isspace((unsigned char)*input_ptr)) {
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input_ptr++;
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}
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if (*input_ptr == '\0') return NULL;
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char* start = input_ptr;
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while (*input_ptr != '\0' && !isspace((unsigned char)*input_ptr)) {
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input_ptr++;
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}
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if (*input_ptr != '\0') {
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*input_ptr = '\0';
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input_ptr++;
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}
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return start;
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}
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// Interpreter functions
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void inner_interpreter(void) {
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while (ip != NULL) {
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Cell current = *ip;
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ip++; // Move to next cell
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current.word->code(current.word);
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}
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}
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void process_token(const char* token) {
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Word* w = lookup_word(token);
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if (w != NULL) {
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if (state == 0) { // Interpret mode
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if (w->code == do_docolon) { // Colon definition
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ret_push_ip(NULL); // Return address to stop interpreter
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ip = w->body;
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inner_interpreter();
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} else { // Primitive word
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w->code(w);
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}
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} else { // Compile mode
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if (w->flags & (1 << 7)) { // Immediate word: execute now
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if (w->code == do_docolon) {
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ret_push_ip(NULL);
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ip = w->body;
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inner_interpreter();
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} else {
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w->code(w);
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}
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} else { // Normal word: compile into current definition
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if (compile_idx >= COMPILE_BUF_SIZE) {
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printf("Compile buffer full\n");
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return;
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}
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compile_buf[compile_idx++] = (Cell){.word = w};
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}
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}
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} else { // Not a known word: try to parse as number
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char* end;
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long v = strtol(token, &end, 10);
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if (end != token && *end == '\0') { // Valid integer
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if (state == 0) { // Interpret mode: push number
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data_push((int32_t)v);
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} else { // Compile mode: compile lit + number
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Word* lit_w = lookup_word_internal("lit");
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if (lit_w == NULL) {
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printf("Fatal: lit word not found\n");
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return;
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}
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if (compile_idx + 2 > COMPILE_BUF_SIZE) {
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printf("Compile buffer full\n");
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return;
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}
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compile_buf[compile_idx++] = (Cell){.word = lit_w};
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compile_buf[compile_idx++] = (Cell){.num = (int32_t)v};
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}
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} else {
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printf("Unknown word: '%s'\n", token);
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}
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}
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}
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void outer_interpreter(void) {
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while (1) {
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printf("ok ");
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fflush(stdout);
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if (fgets(input_buf, INPUT_BUF_SIZE, stdin) == NULL) {
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break; // EOF
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}
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input_ptr = input_buf;
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char* tok;
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while ((tok = next_token()) != NULL) {
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process_token(tok);
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}
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}
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printf("\n");
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}
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