createdynamicstore.swift

func createDiskStore(
    pathInDocs   p: String ,
    fileManager fm: FileManager = .default
) -> Store<AppState, AppState.Change>
{
    var state = loadAppStateFromStore(pathInDocuments:p,fileManager:fm) { didSet { callbacks.forEach { $0() } } }
    var callbacks: [() -> ()] = []
    return (
        state   : { state },
        change  : { state     = state.alter($0)  ; persistStore(pathInDocuments:p, state:state, fileManager:fm) },
        reset   : { state     = AppState()       ; persistStore(pathInDocuments:p, state:state, fileManager:fm) },
        updated : { callbacks = callbacks + [$0] },
        destroy : { destroyStore(pathInDocuments:p,fileManager:fm) }
    )
}