basic_usage/
basic_usage.rs

1// SPDX-FileCopyrightText: 2025 undoredo contributors
2//
3// SPDX-License-Identifier: MIT OR Apache-2.0
4
5use std::collections::HashMap;
6use undoredo::aliases::{HashMapDelta, HashMapHalfDelta};
7use undoredo::{Recorder, UndoRedo};
8
9fn main() {
10    // The recorder records the ongoing changes to the recorded container.
11    //
12    // For some containers such as `HashMap` and `HashSet`, you need
13    // to explicitly pass a half-delta type to the `Recorder` (here
14    // `HashMapHalfDelta`). For most containers, however, you don't need to do
15    // that because their half-delta is already the default, `BTreeMap`.
16    let mut recorder: Recorder<HashMap<usize, char>, HashMapHalfDelta<usize, char>> =
17        Recorder::new(HashMap::new());
18
19    // The undo-redo struct that holds and maintains the undo-redo bistack.
20    let mut undoredo: UndoRedo<HashMapDelta<usize, char>> = UndoRedo::new();
21
22    // Push elements while recording the changes in a delta.
23    recorder.insert(1, 'A');
24    recorder.insert(2, 'B');
25    recorder.insert(3, 'C');
26
27    // The pushed elements are now present in the container.
28    assert!(*recorder.container() == HashMap::from([(1, 'A'), (2, 'B'), (3, 'C')]));
29
30    // Flush the recorder and commit the recorded delta of pushing 'A', 'B', 'C'
31    // into the undo-redo bistack.
32    undoredo.commit(&mut recorder);
33
34    // Now undo the action.
35    undoredo.undo(&mut recorder);
36
37    // The container is now empty; the action of pushing elements has been undone.
38    assert!(*recorder.container() == HashMap::from([]));
39
40    // Now redo the action.
41    undoredo.redo(&mut recorder);
42
43    // The elements are back in the container; the action has been redone.
44    assert!(*recorder.container() == HashMap::from([(1, 'A'), (2, 'B'), (3, 'C')]));
45
46    // Once you are done recording, you can dissolve the recorder to regain
47    // ownership and mutability over the recorded container.
48    let (hashmap, ..) = recorder.dissolve();
49    assert!(hashmap == HashMap::from([(1, 'A'), (2, 'B'), (3, 'C')]));
50}
51
52#[test]
53fn test() {
54    main();
55}
basic_usage/basic_usage.rs

basic_usage/
basic_usage.rs
