String.length modified to be UTF-8 savvy. Added String.bytes. Unit test added.

src/runtime/gravity_core.c

@@ -2140,13 +2140,23 @@ static bool operator_string_cmp (gravity_vm *vm, gravity_value_t *args, uint16_t
     RETURN_VALUE(VALUE_FROM_INT(-1), rindex);
 }
 
+static bool string_bytes (gravity_vm *vm, gravity_value_t *args, uint16_t nargs, uint32_t rindex) {
+    #pragma unused(vm, nargs)
+    
+    DECLARE_1VARIABLE(v1, 0);
+    gravity_string_t *s1 = VALUE_AS_STRING(v1);
+    
+    RETURN_VALUE(VALUE_FROM_INT(s1->len), rindex);
+}
+
 static bool string_length (gravity_vm *vm, gravity_value_t *args, uint16_t nargs, uint32_t rindex) {
     #pragma unused(vm, nargs)
 
     DECLARE_1VARIABLE(v1, 0);
     gravity_string_t *s1 = VALUE_AS_STRING(v1);
-
-    RETURN_VALUE(VALUE_FROM_INT(s1->len), rindex);
+    uint32_t length = (s1->len) ? utf8_len(s1->s, s1->len) : 0;
+    
+    RETURN_VALUE(VALUE_FROM_INT(length), rindex);
 }
 
 static bool string_index (gravity_vm *vm, gravity_value_t *args, uint16_t nargs, uint32_t rindex) {
@@ -3192,6 +3202,8 @@ void gravity_core_init (void) {
     gravity_class_bind(gravity_class_string, GRAVITY_INTERNAL_STOREAT_NAME, NEW_CLOSURE_VALUE(string_storeat));
     closure = computed_property_create(NULL, NEW_FUNCTION(string_length), NULL);
     gravity_class_bind(gravity_class_string, "length", VALUE_FROM_OBJECT(closure));
+    closure = computed_property_create(NULL, NEW_FUNCTION(string_bytes), NULL);
+    gravity_class_bind(gravity_class_string, "bytes", VALUE_FROM_OBJECT(closure));
     gravity_class_bind(gravity_class_string, "index", NEW_CLOSURE_VALUE(string_index));
     gravity_class_bind(gravity_class_string, "contains", NEW_CLOSURE_VALUE(string_contains));
     gravity_class_bind(gravity_class_string, "replace", NEW_CLOSURE_VALUE(string_find_replace));

src/utils/gravity_utils.c

@@ -533,10 +533,10 @@ uint32_t utf8_encode(char *buffer, uint32_t value) {
 uint32_t utf8_len (const char *s, uint32_t nbytes) {
     if (nbytes == 0) nbytes = (uint32_t)strlen(s);
     
-    uint32_t pos = 1;
+    uint32_t pos = 0;
     uint32_t len = 0;
     
-    while (pos <= nbytes) {
+    while (pos < nbytes) {
         ++len;
         uint32_t n = utf8_charbytes(s, pos);
         if (n == 0) return 0; // means error

test/unittest/string_unicode_length_bytes.gravity

@@ -0,0 +1,14 @@
+#unittest {
+    name: "Unicode string length and bytes.";
+    result: 12;
+};
+
+func main() {
+    var s = "😀H😇";
+    var n1 = s.length; // 3
+    var n2 = s.bytes;  // 9
+    if (n1 != 3) return false;
+    if (n2 != 9) return false;
+    
+    return n1 + n2;
+}