docs: function rootParser() {
      while (!source.isAtEnd()) {
        var token = source.first();
  
        switch (token) {
          case '@':
            cssAtSymbol();
            break;
          case '.':
            cssSelector();
            break;
          case '#':
            cssSelector();
            break;
          case '/':
            cssComment();
            break;
          case "'":
            singleQuoteString();
            break;
          case '"':
            doubleQuoteString();
            break;
          default:
            source.shift();
        }
      }
      return tokenMap;
    }