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Struct defaults apply inside structs; exit() ends an or-block; 1e9 literals; x * 2.0 stays f32; floats print as the shortest exact text; str(x, digits)

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Also frees main's args and the message of a failing main (valgrind was not clean on two tests).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
Nexoniarz 2026-10-29 09:14:58 +01:00
commit 6142e47e71
10 changed files with 207 additions and 10 deletions
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57
runtime/finch_rt.c
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@ -12,6 +12,7 @@
#include <ctype.h>
#include <errno.h>
#include <math.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
@ -153,12 +154,50 @@ void finch_str_from_uint(FStr *out, uint64_t v) {
str_heap(out, buf, n);
}
// The shortest text that reads back as the same number (as an f32 when `single`):
// 0.1 -> "0.1", 1.0/3 -> "0.3333333333333333", 1e8 -> "100000000", 1e20 -> "1e+20".
static int fmt_float(char *buf, size_t size, double v, int single) {
if (isnan(v)) return snprintf(buf, size, "nan");
if (isinf(v)) return snprintf(buf, size, v < 0 ? "-inf" : "inf");
int p = 1;
for (; p < 17; p++) {
snprintf(buf, size, "%.*e", p - 1, v);
double back = strtod(buf, NULL);
if (single ? (float)back == (float)v : back == v) break;
}
int exp = atoi(strchr(buf, 'e') + 1);
if (exp < -5 || exp >= 17) return snprintf(buf, size, "%.*g", p, v);
int decimals = p - 1 - exp;
return snprintf(buf, size, "%.*f", decimals > 0 ? decimals : 0, v);
}
void finch_str_from_float(FStr *out, double v) {
char buf[64];
int n = snprintf(buf, sizeof buf, "%g", v);
int n = fmt_float(buf, sizeof buf, v, 0);
str_heap(out, buf, n);
}
void finch_str_from_f32(FStr *out, double v) {
char buf[64];
int n = fmt_float(buf, sizeof buf, v, 1);
str_heap(out, buf, n);
}
// str(x, 2): a fixed number of digits after the point
void finch_str_fixed(FStr *out, double v, int64_t digits) {
char buf[400];
if (digits < 0) digits = 0;
if (digits > 60) digits = 60;
int n = snprintf(buf, sizeof buf, "%.*f", (int)digits, v);
str_heap(out, buf, n);
}
void finch_print_float(double v, int32_t single) {
char buf[64];
fmt_float(buf, sizeof buf, v, single);
fputs(buf, stdout);
}
void finch_str_from_char(FStr *out, char c) { str_heap(out, &c, 1); }
void finch_str_from_bool(FStr *out, int b) { str_static(out, b ? "true" : "false"); }
@ -242,6 +281,7 @@ static void file_error(FStr *err, const char *what, const FStr *path) {
void finch_report_error(const FStr *msg) {
fflush(stdout);
fprintf(stderr, "error: %.*s\n", (int)msg->len, msg->ptr ? msg->ptr : "");
finch_str_drop((FStr *)msg);
}
void finch_str_sub(FStr *out, const FStr *s, int64_t start, int64_t end, const char *file, int64_t line) {
@ -399,7 +439,14 @@ static void buf_fmt(FStr *b, const char *fmt, ...) {
void finch_buf_int(FStr *b, int64_t v) { buf_fmt(b, "%lld", (long long)v); }
void finch_buf_uint(FStr *b, uint64_t v) { buf_fmt(b, "%llu", (unsigned long long)v); }
void finch_buf_float(FStr *b, double v) { buf_fmt(b, "%g", v); }
void finch_buf_float(FStr *b, double v) {
char t[64];
finch_buf_add(b, t, fmt_float(t, sizeof t, v, 0));
}
void finch_buf_f32(FStr *b, double v) {
char t[64];
finch_buf_add(b, t, fmt_float(t, sizeof t, v, 1));
}
void finch_buf_bool(FStr *b, int v) { finch_buf_add(b, v ? "true" : "false", v ? 4 : 5); }
void finch_buf_ptr(FStr *b, const void *p) {
if (p) buf_fmt(b, "0x%llx", (unsigned long long)(uintptr_t)p);
@ -498,6 +545,12 @@ void finch_args(FArr *out, int argc, char **argv) {
for (int i = 0; i < argc; i++) str_heap((FStr *)out->ptr + i, argv[i], (int64_t)strlen(argv[i]));
}
// after main: the arguments go
void finch_args_free(FArr *a) {
for (int64_t i = 0; i < a->len; i++) finch_str_drop((FStr *)a->ptr + i);
finch_arr_free(a);
}
// input("Name? ") prints the prompt and reads one line, without the newline.
void finch_input(FStr *out, const FStr *prompt) {
if (prompt->len) fwrite(prompt->ptr, 1, (size_t)prompt->len, stdout);