Module reducer 

Structs

AddReducer

Add reducer: adds numeric values together.

AppendReducer

Append reducer: appends items from the update array to the current array.

FnReducer

Closure-based reducer for custom logic.

LastWriteWins

Default reducer: the new value replaces the old value.

MergeReducer

Merge reducer: deep-merges JSON objects.

Traits

Reducer

A reducer combines old and new values during state updates. Critical for correctness during parallel execution.