sort/
sort.rs

1// This is a buggy quick sort implementation, QuickCheck will find the bug for
2// you.
3
4use quickcheck::quickcheck;
5
6fn smaller_than<T: Clone + Ord>(xs: &[T], pivot: &T) -> Vec<T> {
7    xs.iter().filter(|&x| *x < *pivot).map(|x| x.clone()).collect()
8}
9
10fn larger_than<T: Clone + Ord>(xs: &[T], pivot: &T) -> Vec<T> {
11    xs.iter().filter(|&x| *x > *pivot).map(|x| x.clone()).collect()
12}
13
14fn sortk<T: Clone + Ord>(x: &T, xs: &[T]) -> Vec<T> {
15    let mut result: Vec<T> = sort(&*smaller_than(xs, x));
16    let last_part = sort(&*larger_than(xs, x));
17    result.push(x.clone());
18    result.extend(last_part.iter().map(|x| x.clone()));
19    result
20}
21
22fn sort<T: Clone + Ord>(list: &[T]) -> Vec<T> {
23    if list.is_empty() {
24        vec![]
25    } else {
26        sortk(&list[0], &list[1..])
27    }
28}
29
30fn main() {
31    fn is_sorted(xs: Vec<isize>) -> bool {
32        for win in xs.windows(2) {
33            if win[0] > win[1] {
34                return false;
35            }
36        }
37        true
38    }
39
40    fn keeps_length(xs: Vec<isize>) -> bool {
41        xs.len() == sort(&*xs).len()
42    }
43    quickcheck(keeps_length as fn(Vec<isize>) -> bool);
44
45    quickcheck(is_sorted as fn(Vec<isize>) -> bool)
46}
sort/sort.rs

sort/
sort.rs
