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Some REPL enhancements like a history, better error messages and some Makefile enhancements.

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This commit is contained in:
Johannes Findeisen 2025-09-14 22:35:23 +02:00
commit 56289e87a2
5 changed files with 124 additions and 8 deletions
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67
src/fun.c
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@ -63,11 +63,23 @@ int main(int argc, char **argv) {
}
// REPL mode
printf("Fun REPL. Type code and press Enter. Submit an empty line to run. Type 'exit' or 'quit' to leave.\n");
printf("Fun REPL. Type code and press Enter. Submit an empty line to run.\n");
printf("Commands: :help, :reset, :dump, :quit\n");
char *buffer = NULL;
size_t bufcap = 0;
size_t buflen = 0;
#ifdef FUN_DEBUG
// Open history file for appending
const char *home = getenv("HOME");
char hist_path[1024];
FILE *hist = NULL;
if (home) {
snprintf(hist_path, sizeof(hist_path), "%s/.fun_history", home);
hist = fopen(hist_path, "a");
}
#endif
for (;;) {
fputs(buflen == 0 ? "fun> " : "... ", stdout);
fflush(stdout);
@ -78,9 +90,24 @@ int main(int argc, char **argv) {
break; // EOF
}
// Exit commands
if (buflen == 0 && (strcmp(line, "exit\n") == 0 || strcmp(line, "quit\n") == 0)) {
break;
// Single-line commands when buffer is empty
if (buflen == 0 && line[0] == ':') {
if (strncmp(line, ":quit", 5) == 0) break;
if (strncmp(line, ":help", 5) == 0) {
printf("Commands: :help, :reset, :dump, :quit\n");
continue;
}
if (strncmp(line, ":reset", 6) == 0) {
vm_reset(&vm);
printf("VM state reset.\n");
continue;
}
if (strncmp(line, ":dump", 5) == 0) {
vm_dump_globals(&vm);
continue;
}
printf("Unknown command. Use :help\n");
continue;
}
// Empty line -> compile and run accumulated buffer
@ -99,6 +126,34 @@ int main(int argc, char **argv) {
vm_print_output(&vm);
vm_clear_output(&vm);
bytecode_free(bc);
#ifdef FUN_DEBUG
if (hist) {
fprintf(hist, "%s\n", buffer);
fflush(hist);
}
#endif
} else {
// Better error message with caret
int line_no = 0, col_no = 0;
char emsg[256];
if (parser_last_error(emsg, sizeof(emsg), &line_no, &col_no)) {
printf("Parse error at %d:%d: %s\n", line_no, col_no, emsg);
// Print the offending line and caret
int cur_line = 1;
const char *p = buffer;
while (*p && cur_line < line_no) {
if (*p == '\n') cur_line++;
p++;
}
const char *line_start = p;
while (*p && *p != '\n') p++;
fwrite(line_start, 1, (size_t)(p - line_start), stdout);
printf("\n");
for (int i = 1; i < col_no; ++i) putchar(' ');
printf("^\n");
} else {
printf("Parse error.\n");
}
}
// reset buffer
buflen = 0;
@ -117,6 +172,10 @@ int main(int argc, char **argv) {
buflen += linelen;
}
#ifdef FUN_DEBUG
if (hist) fclose(hist);
#endif
free(buffer);
return 0;
}