code: function () {
                      var str, j = i, e;
  
                      if (input.charAt(j) === '~') { j++, e = true } // Escaped strings
                      if (input.charAt(j) !== '"' && input.charAt(j) !== "'") return;
  
                      e && $('~');
  
                      if (str = $(/^"((?:[^"\\\r\n]|\\.)*)"|'((?:[^'\\\r\n]|\\.)*)'/)) {
                          return new(tree.Quoted)(str[0], str[1] || str[2], e);
                      }
                  }
docs: A string, which supports escaping " and '  "milky way" 'he\'s the one!'