function scanString(): string {
let result = '',
start = pos;
while (true) {
if (pos >= len) {
result += text.substring(start, pos);
scanError = ScanError.UnexpectedEndOfString;
break;
}
if (ch === CharacterCodes.doubleQuote) {
result += text.substring(start, pos);
pos++;
break;
}
if (ch === CharacterCodes.backslash) {
result += text.substring(start, pos);