ixlist 0.1.0

The “ixlist” is a linked list in a vector, or if you want a list in a pond or an arena-allocated linked index-chasing fest. Implements a queue interface and a cursor.
Documentation 
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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154

extern crate itertools as it;
extern crate ixlist;

use ixlist::{
    List,
    Seek,
};

#[test]
fn basic()
{
    let l: List<i32> = List::new();
    assert_eq!(l.len(), 0);
}

#[test]
fn push_pop()
{
    let mut l = List::new();
    assert_eq!(l.pop_front(), None);
    assert_eq!(l.pop_back(), None);

    l.push_back(1);
    l.push_back(2);
    l.push_back(3);
    assert_eq!(l.len(), 3);
    assert_eq!(l.pop_back(), Some(3));
    assert_eq!(l.pop_front(), Some(1));
    assert_eq!(l.pop_front(), Some(2));
    assert_eq!(l.pop_back(), None);
    assert_eq!(l.pop_front(), None);

    l.push_front(1);
    l.push_front(2);
    l.push_front(3);
    assert_eq!(l.len(), 3);
    assert_eq!(l.pop_back(), Some(1));
    assert_eq!(l.pop_front(), Some(3));
    assert_eq!(l.pop_front(), Some(2));
    assert_eq!(l.pop_back(), None);
    assert_eq!(l.pop_front(), None);
}

#[test]
fn iter()
{
    let mut l = List::new();
    l.push_back(2);
    l.push_front(1);
    l.push_back(3);
    assert_eq!(l.iter().count(), 3);
    assert_eq!(l.iter().rev().count(), 3);
    assert_eq!(l.iter_mut().count(), 3);
    assert_eq!(l.iter_mut().rev().count(), 3);
    it::assert_equal(l.iter(), &[1,2,3]);
    it::assert_equal(l.iter().rev(), &[3,2,1]);
    it::assert_equal(l.iter_mut(), &[1,2,3]);
    it::assert_equal(l.iter_mut().rev(), &[3,2,1]);
}

#[test]
fn cursor()
{
    let mut l = List::new();
    for index in 0..5 {
        l.push_back(index)
    }
    {
        let mut c = l.cursor();
        assert_eq!(c.next(), Some(&mut 0));
        assert_eq!(c.prev(), Some(&mut 0));
        assert_eq!(c.prev(), None);
        assert_eq!(c.prev(), Some(&mut 4));
        c.insert(77);
        assert_eq!(c.next(), Some(&mut 77));
        assert_eq!(c.next(), Some(&mut 4));
    }
    it::assert_equal(l.iter(), &[0, 1, 2, 3, 77, 4]);
    it::assert_equal(l.iter().rev(), &[4, 77, 3, 2, 1, 0]);

    {
        let mut c = l.cursor();
        c.seek(Seek::Forward(2));
        c.insert(20);
    }
    it::assert_equal(l.iter(), &[0, 1, 20, 2, 3, 77, 4]);
    it::assert_equal(l.iter().rev(), &[4, 77, 3, 2, 20, 1, 0]);

    {
        let mut c = l.cursor();
        c.seek(Seek::Forward(2));
        c.seek(Seek::Tail);
        c.insert(30);
    }
    it::assert_equal(l.iter(), &[0, 1, 20, 2, 3, 77, 4, 30]);
    it::assert_equal(l.iter().rev(), &[30, 4, 77, 3, 2, 20, 1, 0]);

    let mut l = List::new();
    {
        let mut c = l.cursor();
        c.insert(0);
        c.seek(Seek::Tail);
        c.insert(1);
        c.seek(Seek::Head);
        c.insert(2);
        c.seek(Seek::Forward(100));
        c.insert(3);
        c.seek(Seek::Backward(1));
        c.insert(4);
    }
    it::assert_equal(l.iter(), &[2, 0, 4, 1, 3]);
    it::assert_equal(l.iter().rev(), &[3, 1, 4, 0, 2]);

    l.linearize();

    it::assert_equal(l.iter(), &[2, 0, 4, 1, 3]);
    it::assert_equal(l.iter().rev(), &[3, 1, 4, 0, 2]);

    // test wrap around with .next()
    let mut l = List::new();
    {
        let mut c = l.cursor();
        c.insert(0);
        c.insert(1);
        assert!(c.next().is_some());
        assert!(c.next().is_some());
        assert!(c.next().is_none());
        assert!(c.next().is_some());
        c.insert(-1);
    }
    it::assert_equal(l.iter(), &[1, -1, 0]);
    it::assert_equal(l.iter().rev(), &[0, -1, 1]);
}

#[test]
fn extend()
{
    let mut l = List::new();
    l.push_front(1);
    l.extend(2..2);
    it::assert_equal(l.iter(), &[1]);
    it::assert_equal(l.iter().rev(), &[1]);

    l.extend(2..5);
    it::assert_equal(l.iter(), &[1, 2, 3, 4]);
    it::assert_equal(l.iter().rev(), &[4, 3, 2, 1]);
}

#[test]
fn from_iter()
{
    let l: List<_> = (0..5).collect();
    it::assert_equal(l.iter(), &[0, 1, 2, 3, 4]);
}