Model.kt

class Model<ViewState, Action, Mutation, Event>(
    private val actionProcessors: Collection<ActionProcessor<Action, Mutation, Event>>,
    private val reducers: Collection<Reducer<Mutation, ViewState>>,
    private val coroutineScope: CoroutineScope,
    private val viewMutableStateFlow: MutableStateFlow<ViewState>,
    private val eventChannel: Channel<Event>,
) {
    val viewStateFlow: Flow<ViewState> = viewMutableStateFlow
    val eventFlow: Flow<ViewState> = eventChannel.receiveAsFlow()

    fun process(action: Action) {
        coroutineScope.launch {
            actionProcessors
                .map { actionProcessor -> actionProcessor(action) }
                .merge()
                .collect { value ->
                    mutation?.let(::handleMutation)
                    event?.let(eventChannel::trySend)
                }
        }
    }

    private fun handleMutation(mutation: Mutation) {
        reducers
            .asIterable()
            .forEach { reducer ->
                viewMutableStateFlow.update { currentState ->
                    reducer.invoke(mutation, currentState)
                }
            }
    }
}