Struct MergeReducer 

pub struct MergeReducer<S: StateSchema> { /* private fields */ }

0.22.0 C3 fix: composed merge reducer — applies every per-field reducer registered via StateGraph::set_reducer on top of the default (replace) merge.

Each field reducer (e.g. AppendMessagesReducer) merges its own field into the running result; fields without a registered reducer take the update’s values. Previously the registered reducers were dropped at compile() and every merge point used plain replace, so accumulating fields (messages / steps) were silently overwritten after each node.

Implementations

impl<S: StateSchema> MergeReducer<S>

pub fn new( fallback: Arc<dyn Reducer<S>>, fields: Vec<Arc<dyn Reducer<S>>>, ) -> Self

Composes fields (in registration order) over fallback.

Trait Implementations

impl<S: StateSchema> Reducer<S> for MergeReducer<S>

fn reduce(&self, current: &S, update: &S) -> S

Reduce current state with an update