pub trait Sentinel {
type Error;
}Expand description
Observes and optionally stops a change being applied to a CRDT.
This is the base trait that all Sentinels should implement. Different Sentinels may observe different changes, and different data structures may produce different changes, so we’ve split the actual behaviour into several specialized traits.
This trait should normally be paired with Visit so that the Sentinel can keep track of
which node is currently being modified in the document tree.
If Error = Infallible, the Sentinel is referred to as an Observer. If it can produce an error, it may be referred to as a Validator.