anchor.diff:                  next == $backslash) {
                 token.writeCharCode(next);
               } else {
  -              token.writeCharCode($backslash);
  -              token.writeCharCode(next);
  +              token..writeCharCode($backslash)..writeCharCode(next);
               }
             } else {
               token.writeCharCode(scanner.readChar());
  
positive.code:             // by one of the following characters when considered special:
              //
              //     $ ` " \ <newline>
              var next = scanner.readChar();
              if (next == $lf) continue;
              if (next == $dollar ||
                  next == $backquote ||
  
negative.code:   var hasToken = false;
  
    while (!scanner.isDone) {
      final next = scanner.readChar();
      switch (next) {
        case $backslash:
          // Section 2.2.1: A <backslash> that is not quoted shall preserve the
  