BloomReducerFn<S, A> typedef

BloomReducerFn<S, A> = S Function(S state, A action)

A pure state-transition function that computes the next state from the current state and an action.

Must be deterministic and free of side effects. Given the current state of type S and an incoming action of type A, it returns a new state of type S.

Used by BloomReducer and useReducer to coordinate complex state machines.

sealed class CounterAction {}
class Increment extends CounterAction { final int amount; Increment(this.amount); }
class Reset extends CounterAction {}

int counterReducer(int state, CounterAction action) => switch (action) {
  Increment(:final amount) => state + amount,
  Reset() => 0,
};

Implementation

typedef BloomReducerFn<S, A> = S Function(S state, A action);