# Path Reference Expression

A path reference expression accesses a field of an object.

```dcdl
config.host
config.feature_hoge.enable
```

## Evaluation

The expression on the left is evaluated as an object, then the named field is referenced.
The referenced field is not evaluated until needed.

Referencing a field that does not exist produces a diagnostic.
An explicit `Unknown` range does not represent a missing field, so it does not make field presence ambiguous.