1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
#![cfg_attr(feature = "slice", feature(slice_index_methods))]
mod traits;
pub use self::traits::*;
#[macro_use]
mod sliceable;
pub use self::sliceable::*;
#[derive(Clone)]
pub(crate) enum BacktrackingState {
Progressing,
Backtracking { position: usize },
}
use crate::BacktrackingState::*;
mod record;
pub use self::record::*;
mod copying;
pub use self::copying::*;
mod referencing;
pub use self::referencing::*;
pub mod concurrent;
#[cfg(feature = "slice")]
mod slice;
#[cfg(feature = "slice")]
pub use self::slice::*;
#[cfg(test)]
extern crate matches;
#[cfg(test)]
mod tests {
#[test]
fn basic_test() {
use crate::{Record, BacktrackingIterator};
let num_vec = vec![1_u8, 2, 3, 4, 5, 6];
let vec_iter = num_vec.into_iter();
let mut bt_rec = crate::BacktrackingRecorder::new(vec_iter);
{
let mut bt_iter = bt_rec.copying();
assert!(bt_iter.next().unwrap() == 1_u8);
assert!(bt_iter.next().unwrap() == 2_u8);
bt_iter.start_again();
assert!(bt_iter.next().unwrap() == 1_u8);
assert!(bt_iter.next().unwrap() == 2_u8);
}
bt_rec.forget();
{
let mut bt_iter = bt_rec.copying();
assert!(bt_iter.next().unwrap() == 3_u8);
assert!(bt_iter.next().unwrap() == 4_u8);
assert!(bt_iter.next().unwrap() == 5_u8);
assert!(bt_iter.next().unwrap() == 6_u8);
assert!(!bt_iter.next().is_some());
bt_iter.start_again();
assert!(bt_iter.next().unwrap() == 3_u8);
}
}
#[test]
fn backwalk_test() {
use crate::{Walkbackable};
let num_vec = vec![1_u8, 2, 3, 4, 5, 6];
let vec_iter = num_vec.into_iter();
let mut bt_rec = crate::BacktrackingRecorder::new(vec_iter);
let mut bt_iter = bt_rec.copying();
for _ in 1..=6 {
bt_iter.next();
}
let mut wb = bt_iter.walk_back();
for i in 1_u8..=6 {
assert!(wb.next().unwrap() == (7 - i));
}
}
}