Add custom base option to number peg combinator.

Allows parsing custom bases without needed Janet specific prefixes.

src/core/peg.c

@@ -394,12 +394,13 @@ tail:
             if (!result) return NULL;
             /* check number parsing */
             double x = 0.0;
-            if (janet_scan_number(text, (int32_t)(result - text), &x)) return NULL;
+            int32_t base = (int32_t) rule[2];
+            if (janet_scan_number_base(text, (int32_t)(result - text), base, &x)) return NULL;
             /* Specialized pushcap - avoid intermediate string creation */
             if (!s->has_backref && s->mode == PEG_MODE_ACCUMULATE) {
                 janet_buffer_push_bytes(s->scratch, text, (int32_t)(result - text));
             } else {
-                uint32_t tag = rule[2];
+                uint32_t tag = rule[3];
                 pushcap(s, janet_wrap_number(x), tag);
             }
             return result;
@@ -983,9 +984,6 @@ static void spec_cap1(Builder *b, int32_t argc, const Janet *argv, uint32_t op)
 static void spec_capture(Builder *b, int32_t argc, const Janet *argv) {
     spec_cap1(b, argc, argv, RULE_CAPTURE);
 }
-static void spec_capture_number(Builder *b, int32_t argc, const Janet *argv) {
-    spec_cap1(b, argc, argv, RULE_CAPTURE_NUM);
-}
 static void spec_accumulate(Builder *b, int32_t argc, const Janet *argv) {
     spec_cap1(b, argc, argv, RULE_ACCUMULATE);
 }
@@ -996,6 +994,25 @@ static void spec_unref(Builder *b, int32_t argc, const Janet *argv) {
     spec_cap1(b, argc, argv, RULE_UNREF);
 }
 
+static void spec_capture_number(Builder *b, int32_t argc, const Janet *argv) {
+    peg_arity(b, argc, 1, 3);
+    Reserve r = reserve(b, 4);
+    uint32_t base = 0;
+    if (argc >= 2) {
+        if (!janet_checktype(argv[1], JANET_NIL)) {
+            if (!janet_checkint(argv[1])) goto error;
+            base = (uint32_t) janet_unwrap_integer(argv[1]);
+            if (base < 2 || base > 36) goto error;
+        }
+    }
+    uint32_t tag = (argc == 3) ? emit_tag(b, argv[2]) : 0;
+    uint32_t rule = peg_compile1(b, argv[0]);
+    emit_3(r, RULE_CAPTURE_NUM, rule, base, tag);
+    return;
+error:
+    peg_panicf(b, "expected integer between 2 and 36, got %v", argv[2]);
+}
+
 static void spec_reference(Builder *b, int32_t argc, const Janet *argv) {
     peg_arity(b, argc, 1, 2);
     Reserve r = reserve(b, 3);
@@ -1441,10 +1458,15 @@ static void *peg_unmarshal(JanetMarshalContext *ctx) {
                 if (rule[1] >= clen) goto bad;
                 i += 3;
                 break;
+            case RULE_CAPTURE_NUM:
+                /* [rule, base, tag] */
+                if (rule[1] >= blen) goto bad;
+                op_flags[rule[1]] |= 0x01;
+                i += 4;
+                break;
             case RULE_ACCUMULATE:
             case RULE_GROUP:
             case RULE_CAPTURE:
-            case RULE_CAPTURE_NUM:
             case RULE_UNREF:
                 /* [rule, tag] */
                 if (rule[1] >= blen) goto bad;

src/core/strtod.c

@@ -247,14 +247,14 @@ static double convert(
 
 /* Scan a real (double) from a string. If the string cannot be converted into
  * and integer, return 0. */
-int janet_scan_number(
+int janet_scan_number_base(
     const uint8_t *str,
     int32_t len,
+    int32_t base,
     double *out) {
     const uint8_t *end = str + len;
     int seenadigit = 0;
     int ex = 0;
-    int base = 10;
     int seenpoint = 0;
     int foundexp = 0;
     int neg = 0;
@@ -278,6 +278,7 @@ int janet_scan_number(
     }
 
     /* Check for leading 0x or digit digit r */
+    if (base == 0) {
         if (str + 1 < end && str[0] == '0' && str[1] == 'x') {
             base = 16;
             str += 2;
@@ -294,6 +295,12 @@ int janet_scan_number(
             if (base < 2 || base > 36) goto error;
             str += 3;
         }
+    }
+
+    /* If still base is 0, set to default (10) */
+    if (base == 0) {
+        base = 10;
+    }
 
     /* Skip leading zeros */
     while (str < end && (*str == '0' || *str == '.')) {
@@ -376,6 +383,13 @@ error:
     return 1;
 }
 
+int janet_scan_number(
+    const uint8_t *str,
+    int32_t len,
+    double *out) {
+    return janet_scan_number_base(str, len, 0, out);
+}
+
 #ifdef JANET_INT_TYPES
 
 static int scan_uint64(

src/include/janet.h

@@ -1522,6 +1522,7 @@ JANET_API int janet_loop_fiber(JanetFiber *fiber);
 
 /* Number scanning */
 JANET_API int janet_scan_number(const uint8_t *str, int32_t len, double *out);
+JANET_API int janet_scan_number_base(const uint8_t *str, int32_t len, int32_t base, double *out);
 JANET_API int janet_scan_int64(const uint8_t *str, int32_t len, int64_t *out);
 JANET_API int janet_scan_uint64(const uint8_t *str, int32_t len, uint64_t *out);