Introduce MaybeError type

src/pages/repetition_settings.rs

@@ -4,7 +4,7 @@ use crate::data_provider::card_sets::{delete_set, update_deck};
 use crate::data_provider::card_stats::{delete_stats, load_stats_of_deck};
 use crate::navigation::Page::PreviousPage;
 use crate::navigation::{NavigatedPage, Page, RootMessage};
-use crate::notification::NotificationData;
+use crate::notification::MaybeError;
 use crate::pages::repetition_settings::RepetitionSettingsMessage::*;
 use crate::styling::*;
 use crate::{push_error, push_error_task};
@@ -13,7 +13,7 @@ use iced::widget::text_input::Catalog;
 use iced::widget::{button, column, row, scrollable, space, text, text_input};
 use iced::{Element, Task};
 use iced_core::Length::Fill;
-use iced_core::{Padding, Theme, color};
+use iced_core::{color, Padding, Theme};
 use parking_lot::Mutex;
 use std::sync::Arc;
 use std::time::Duration;
@@ -179,7 +179,7 @@ impl NavigatedPage<RepetitionSettingsMessage> for RepetitionSettingsState {
     }
 }
 
-fn update_deck_stats(deck: &DeckSettings, state: &AppState) -> Result<(), NotificationData> {
+fn update_deck_stats(deck: &DeckSettings, state: &AppState) -> MaybeError {
     let mut db_stats = load_stats_of_deck(deck, &state.connection).expect("Wrong db operation");
     let filtered_words = deck.get_word_list(state);
     filtered_words.iter().for_each(|word| {