+uint32_t Identifier::toUInt32(const UString& string, bool& ok)
+{
+ ok = false;
+
+ unsigned length = string.length();
+ const UChar* characters = string.characters();
+
+ // An empty string is not a number.
+ if (!length)
+ return 0;
+
+ // Get the first character, turning it into a digit.
+ uint32_t value = characters[0] - '0';
+ if (value > 9)
+ return 0;
+
+ // Check for leading zeros. If the first characher is 0, then the
+ // length of the string must be one - e.g. "042" is not equal to "42".
+ if (!value && length > 1)
+ return 0;
+
+ while (--length) {
+ // Multiply value by 10, checking for overflow out of 32 bits.
+ if (value > 0xFFFFFFFFU / 10)
+ return 0;
+ value *= 10;
+
+ // Get the next character, turning it into a digit.
+ uint32_t newValue = *(++characters) - '0';
+ if (newValue > 9)
+ return 0;
+
+ // Add in the old value, checking for overflow out of 32 bits.
+ newValue += value;
+ if (newValue < value)
+ return 0;
+ value = newValue;
+ }
+
+ ok = true;
+ return value;
+}
+
+PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const UChar* s, int length)