code: function JSExpressionIdentifiers(lex) {
      let _identifiers_ = [];
      let model_cache = {};
  
      let IN_OBJ = false,
          CAN_BE_ID = true;
      while (!lex.END) {
          
          switch (lex.ty) {
              case lex.types.id:
                  if (!IN_OBJ || CAN_BE_ID) {
                      let id = lex.tx;
                      if (!model_cache[id]) {
                          _identifiers_.push(lex.tx);
                          model_cache[id] = true;
                      }
                  }   
                  break;
              case lex.types.op:
              case lex.types.sym:
              case lex.types.ob:
              case lex.types.cb:
                  switch (lex.ch) {
                      case "+":
                      case ">":
                      case "<":
                      case "/":
                      case "*":
                      case "-":
                          CAN_BE_ID = true;
                          break;
                      case "[":
                          IN_OBJ = false;
                          CAN_BE_ID = true;
                          break;
                      case "{":
                      case ".": //Property Getters
                          CAN_BE_ID = false;
                          IN_OBJ = true;
                          break;
                      case "]":
                      case ";":
                      case "=":
                      case "}":
                      case "(":
                          IN_OBJ = false;
                          break;
                      case ",":
                          if (IN_OBJ)
                              CAN_BE_ID = false;
                          else
                              IN_OBJ = false;
                          break;
                      case ":":
                      case "=":
                          CAN_BE_ID = true;
                  }
                  break;
          }
          lex.n;
      }
  
  
      return _identifiers_;
  }
docs: Basic JS Parser Kludge to get legitimate foreign identifiers from expressions.
  This could later be expanded into a full JS parser to generate proper JS ASTs.
  @class      JSExpressionIdentifiers
  @param      {Lexer}  lex     The lex
  @return     {Object}  { description_of_the_return_value }