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