dsalgo 0.3.10

A package for Datastructures and Algorithms.
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

pub struct Iter<T, F, I> {
    iter: I,
    f: F,
    cur: Option<T>,
}

impl<T, F, I> Iterator for Iter<T, F, I>
where
    T: Clone,
    I: Iterator<Item = T>,
    F: Fn(T, T) -> T,
{
    type Item = T;

    fn next(&mut self) -> Option<Self::Item> {
        if self.cur.is_none() {
            return None;
        }

        let cur = self.cur.take().unwrap();

        self.cur = if let Some(next) = self.iter.next() {
            Some((self.f)(cur.clone(), next))
        } else {
            None
        };

        Some(cur)
    }
}

pub fn accumulate<T, F, I>(
    f: F,
    mut iter: I,
) -> Iter<T, F, I>
where
    T: Clone,
    F: Fn(T, T) -> T,
    I: Iterator<Item = T>,
{
    let cur = iter.next();

    Iter { iter, f, cur }
}

// TODO
#[cfg(test)]

mod tests {

    use super::*;

    #[test]

    fn test() {
        let mut iter = accumulate(|a, b| a + b, (0..4).into_iter());

        assert_eq!(iter.next(), Some(0));

        assert_eq!(iter.next(), Some(1));

        assert_eq!(iter.next(), Some(3));

        assert_eq!(iter.next(), Some(6));

        assert_eq!(iter.next(), None);
    }
}