Swift Functional Programming - Second Edition

Actions

Actions are structs that conform to the ActionType protocol from the Delta library. ActionType is used when we want to make modifications to the store's State. All changes to the Store object go through this type. Let's examine one example:

import Delta struct UpdateTodoAction: ActionType {     let todo: Todo     func reduce(state: State) -> State {         state.todos.value = state.todos.value.map {             todo in             guard todo == self.todo else { return todo }             return Todo(todoId: todo.todoId,                         name: self.todo.name,                         description: self.todo.description,                         notes: self.todo.notes,                         completed: self.todo.completed,                         synced: !todo.synced,                         selected: todo.selected)         }         return state     } } 

In our manager, we had a call like this:

 store.dispatch(UpdateTodoAction(todo: ...