maybe selector should be placed at the end of the attribute

currently:
```
host.?name
```
should be be:
```
host.name?
```

similar to regex question mark:
```
? 	The question mark indicates zero or one occurrences of the preceding element. 
```

similar to optional chaining in javascript (even though the operator is `?.`):
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining