Enum WatchPredicate 

pub enum WatchPredicate {
    Changed,
    ChangedTo(Value),
    ChangedFrom(Value),
    CrossedAbove(f64),
    CrossedBelow(f64),
    BecameTrue,
    BecameFalse,
    Custom(Arc<dyn Fn(&Value, &Value) -> bool + Send + Sync>),
}

Condition under which a watcher fires, evaluated against (old, new) values.

Variants

Changed

Fires whenever the watched key’s value changed (any diff entry).

ChangedTo(Value)

Fires when the new value equals the given value.

ChangedFrom(Value)

Fires when the old value equals the given value.

CrossedAbove(f64)

Fires when old < threshold AND new >= threshold (both must be numeric).

CrossedBelow(f64)

Fires when old >= threshold AND new < threshold (both must be numeric).

BecameTrue

Fires when old != true AND new == true (JSON bool).

BecameFalse

Fires when old == true AND new != true (JSON bool).

Custom(Arc<dyn Fn(&Value, &Value) -> bool + Send + Sync>)

Fires when the custom function returns true for (old, new).

Trait Implementations

impl Debug for WatchPredicate

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.