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// This is a buggy quick sort implementation, QuickCheck will find the bug for
// you.
extern crate quickcheck;
use quickcheck::quickcheck;
fn smaller_than<T: Clone + Ord>(xs: &[T], pivot: &T) -> Vec<T> {
return xs.iter().filter(|&x| *x < *pivot).map(|x| x.clone()).collect();
}
fn larger_than<T: Clone + Ord>(xs: &[T], pivot: &T) -> Vec<T> {
return xs.iter().filter(|&x| *x > *pivot).map(|x| x.clone()).collect();
}
fn sortk<T: Clone + Ord>(x: &T, xs: &[T]) -> Vec<T> {
let mut result : Vec<T> = sort(&*smaller_than(xs, x));
let last_part = sort(&*larger_than(xs, x));
result.push(x.clone());
result.extend(last_part.iter().map(|x| x.clone()));
result
}
fn sort<T: Clone + Ord>(list: &[T]) -> Vec<T> {
if list.is_empty() {
vec![]
} else {
sortk(&list[0], &list[1..])
}
}
fn main() {
fn is_sorted(xs: Vec<isize>) -> bool {
for win in xs.windows(2) {
if win[0] > win[1] {
return false
}
}
true
}
fn keeps_length(xs: Vec<isize>) -> bool {
xs.len() == sort(&*xs).len()
}
quickcheck(keeps_length as fn(Vec<isize>) -> bool);
quickcheck(is_sorted as fn(Vec<isize>) -> bool)
}
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