d2_iterators/
lib.rs

1mod gen_range;
2mod combi;
3mod v4_intoiter;
4use std::ops::AddAssign;
5
6pub trait Rangeable: AddAssign + PartialOrd + Copy {}
7
8impl<T: AddAssign + PartialOrd + Copy> Rangeable for T {}
9
10pub struct GenRangeIterator<T: Rangeable> {
11    curr: T,
12    stop: T,
13    step: T,
14}
15
16impl<T: Rangeable> GenRangeIterator<T> {
17    pub fn new(start: T, stop: T, step: T) -> Self {
18        GenRangeIterator { curr: start, stop, step }
19    }
20}
21
22impl<T: Rangeable> Iterator for GenRangeIterator<T> {
23    type Item = T;
24    fn next(&mut self) -> Option<Self::Item> {
25        if self.curr >= self.stop {
26            return None;
27        }
28        let res = self.curr;
29        self.curr += self.step;
30        Some(res)
31    }
32}
33
34#[cfg(test)]
35mod tests {
36    use super::*;
37
38    #[test]
39    fn gen_test() {
40        let mut m = 0;
41        let it = GenRangeIterator::new(5, 12, 3);
42        for s in it {
43            m += s;
44        }
45
46        assert_eq!(m, 5 + 8 + 11);
47    }
48
49    #[test]
50    fn filter() {
51        let v: i32 = GenRangeIterator::new(3, 13, 3)
52            .filter(|x| x % 2 == 0)
53            .sum();
54        assert_eq!(v, 6 + 12)
55    }
56}
d2_iterators/lib.rs

d2_iterators/
lib.rs
