although I have post it in the general, I trust your wisdom :grinning:

# arrow

[carbaj0]

although I have post it in the general, I trust your wisdom 😀

[HieiJ]

If I understand correctly, there is a conceptual error behind the compilation error. When you say that

val a: Reducer<TodosState, TodoAction>

you are saying that a will be able to handle any possible TodoAction as input parameter, while the TodoReducer you are trying to assign can't handle all the possible inputs.

[HieiJ]

What should a do when called with a GetTodo action?

[carbaj0]

In this case, the State never change due to not exist a reducer able to transform the action in a new State

[HieiJ]

Yes but you need to tell it to the compiler 😅 You can do something like this:

inline fun <P : Action, reified A : P> Reducer<TodosState, A>.asMoreGenericReducer(): Reducer<TodosState, P> =
  Reducer { state, action ->
    when(action) {
      is A -> this(state, action)
      else -> state
    }
}

val a: Reducer<TodosState, TodoAction> = TodoReducer.asMoreGenericReducer()

[carbaj0]

yes, you are right , those was my solution 😆

[carbaj0]

fun interface Reducer<S : StoreState> {
    operator fun invoke(state: S, action: Action): S
}

fun interface ReducerType<S : StoreState, A : Action> {
    operator fun S.invoke(action: A): S
}

inline fun <S : StoreState, reified A : Action> Reducer(
    reducer: ReducerType<S, A>
): Reducer<S> =
    Reducer { state, action ->
        when (action) {
            is A -> reducer.run { state(action) }
            else -> state
        }
    }

val TodoReducer: Reducer<TodosState> =
    Reducer<TodosState, TodoListAction> { action ->
        when (action) {
            is LoadTodos -> this
        }
    }

[Chris Paul]

not strictly related, but are you doing some kotlinscript? this looks so much like ngrx

[carbaj0]

I'm trying to do a Redux implementation for an Android application

[Chris Paul]

ah i see, interesting

[carbaj0]

Maybe I'll publish the final implementation. (if everything works 😆)

[Chris Paul]

seems like a lot of work, but i guess that's life when you're living on the edge

[carbaj0]

if i tell you the truth i'm on vacation 🤦 , but it's fun for me haha

[Chris Paul]

😄