MIRROR: javascript for 🐜's, a tiny runtime with big ambitions
implement BigInt.asUintN and BigInt.asIntN methods
+81
-4
+8
examples/spec/bigint.js
+8
examples/spec/bigint.js
···
26
26
27
27
test('bigint toString', (255n).toString(16), 'ff');
28
28
29
+
test('BigInt.asUintN 0 bits', BigInt.asUintN(0, 123n), 0n);
30
+
test('BigInt.asUintN wrap', BigInt.asUintN(8, 256n), 0n);
31
+
test('BigInt.asUintN negative', BigInt.asUintN(8, -1n), 255n);
32
+
test('BigInt.asIntN 0 bits', BigInt.asIntN(0, 123n), 0n);
33
+
test('BigInt.asIntN positive', BigInt.asIntN(8, 127n), 127n);
34
+
test('BigInt.asIntN negative', BigInt.asIntN(8, 255n), -1n);
35
+
test('BigInt.asIntN sign bit', BigInt.asIntN(8, 128n), -128n);
36
+
29
37
summary();
+73
-4
src/ant.c
+73
-4
src/ant.c
···
675
675
static size_t tostr(struct js *js, jsval_t value, char *buf, size_t len);
676
676
static size_t strpromise(struct js *js, jsval_t value, char *buf, size_t len);
677
677
static size_t js_to_pcre2_pattern(const char *src, size_t src_len, char *dst, size_t dst_size);
678
+
static double js_to_number(struct js *js, jsval_t arg);
678
679
679
680
static jsval_t js_stmt_impl(struct js *js);
680
681
static jsval_t js_expr(struct js *js);
···
796
797
}
797
798
buf[len] = '\0';
798
799
return len;
800
+
}
801
+
802
+
static jsval_t bigint_from_u64(struct js *js, uint64_t value) {
803
+
char buf[32];
804
+
size_t len = uint_to_str(buf, sizeof(buf), value);
805
+
return js_mkbigint(js, buf, len, false);
799
806
}
800
807
801
808
#define MAX_STRINGIFY_DEPTH 64
···
2401
2408
return js_mkerr(js, "Cannot convert to BigInt");
2402
2409
}
2403
2410
2411
+
static jsval_t bigint_pow2(struct js *js, uint64_t bits) {
2412
+
jsval_t two = js_mkbigint(js, "2", 1, false);
2413
+
if (is_err(two)) return two;
2414
+
jsval_t exp = bigint_from_u64(js, bits);
2415
+
if (is_err(exp)) return exp;
2416
+
return bigint_exp(js, two, exp);
2417
+
}
2418
+
2419
+
static jsval_t bigint_asint_bits(struct js *js, jsval_t arg, uint64_t *bits_out) {
2420
+
double bits = js_to_number(js, arg);
2421
+
if (!isfinite(bits) || bits < 0 || bits != floor(bits)) {
2422
+
return js_mkerr_typed(js, JS_ERR_RANGE, "Invalid bits");
2423
+
}
2424
+
if (bits > 18446744073709551615.0) {
2425
+
return js_mkerr_typed(js, JS_ERR_RANGE, "Invalid bits");
2426
+
}
2427
+
*bits_out = (uint64_t)bits;
2428
+
return js_mkundef();
2429
+
}
2430
+
2404
2431
static jsval_t builtin_BigInt_asIntN(struct js *js, jsval_t *args, int nargs) {
2405
-
(void)js; (void)args; (void)nargs;
2406
-
return js_mkerr(js, "BigInt.asIntN not implemented");
2432
+
if (nargs < 2) return js_mkerr(js, "BigInt.asIntN requires 2 arguments");
2433
+
uint64_t bits = 0;
2434
+
jsval_t err = bigint_asint_bits(js, args[0], &bits);
2435
+
if (is_err(err)) return err;
2436
+
if (vtype(args[1]) != T_BIGINT) {
2437
+
return js_mkerr_typed(js, JS_ERR_TYPE, "Cannot convert to BigInt");
2438
+
}
2439
+
if (bits == 0) return js_mkbigint(js, "0", 1, false);
2440
+
2441
+
jsval_t mod = bigint_pow2(js, bits);
2442
+
if (is_err(mod)) return mod;
2443
+
jsval_t res = bigint_mod(js, args[1], mod);
2444
+
if (is_err(res)) return res;
2445
+
if (bigint_IsNegative(js, res)) {
2446
+
jsval_t adj = bigint_add(js, res, mod);
2447
+
if (is_err(adj)) return adj;
2448
+
res = adj;
2449
+
}
2450
+
2451
+
jsval_t threshold = bigint_pow2(js, bits - 1);
2452
+
if (is_err(threshold)) return threshold;
2453
+
if (bigint_compare(js, res, threshold) >= 0) {
2454
+
jsval_t adj = bigint_sub(js, res, mod);
2455
+
if (is_err(adj)) return adj;
2456
+
res = adj;
2457
+
}
2458
+
return res;
2407
2459
}
2408
2460
2409
2461
static jsval_t builtin_BigInt_asUintN(struct js *js, jsval_t *args, int nargs) {
2410
-
(void)js; (void)args; (void)nargs;
2411
-
return js_mkerr(js, "BigInt.asUintN not implemented");
2462
+
if (nargs < 2) return js_mkerr(js, "BigInt.asUintN requires 2 arguments");
2463
+
uint64_t bits = 0;
2464
+
jsval_t err = bigint_asint_bits(js, args[0], &bits);
2465
+
if (is_err(err)) return err;
2466
+
if (vtype(args[1]) != T_BIGINT) {
2467
+
return js_mkerr_typed(js, JS_ERR_TYPE, "Cannot convert to BigInt");
2468
+
}
2469
+
if (bits == 0) return js_mkbigint(js, "0", 1, false);
2470
+
2471
+
jsval_t mod = bigint_pow2(js, bits);
2472
+
if (is_err(mod)) return mod;
2473
+
jsval_t res = bigint_mod(js, args[1], mod);
2474
+
if (is_err(res)) return res;
2475
+
if (bigint_IsNegative(js, res)) {
2476
+
jsval_t adj = bigint_add(js, res, mod);
2477
+
if (is_err(adj)) return adj;
2478
+
res = adj;
2479
+
}
2480
+
return res;
2412
2481
}
2413
2482
2414
2483
static jsval_t builtin_bigint_toString(struct js *js, jsval_t *args, int nargs) {