python;gutter:true;
use std::cmp::Ordering;</p>
<p>enum Fruit {
Apple(i32),
Orange(i32),
}</p>
<p>fn process_fruit(_apple_prices: &[i32], _orange_prices: &[i32]) {
// whatever we do to process fruit, does not matter
}</p>
<p>fn main() {
let mut fruit : Vec = vec![Fruit::Apple(1), Fruit::Apple(2),
Fruit::Orange(4), Fruit::Orange(3),
];</p>
<pre><code>/*
* Sort fruit by some crazy function - let's say we value oranges more
* than apples, so when we compare one to the other, we increase
* the price of oranges by 10.
*/
let fruit_comparator = |x: &Fruit, y: &Fruit| match(x, y) {
(Fruit::Apple(lhs), Fruit::Apple(rhs)) => {
lhs.cmp(rhs)
},
(Fruit::Apple(lhs), Fruit::Orange(rhs)) => {
lhs.cmp(&(*rhs + 10))
},
(Fruit::Orange(lhs), Fruit::Apple(rhs)) => {
(lhs + 10).cmp(rhs)
},
(Fruit::Orange(lhs), Fruit::Orange(rhs)) => {
lhs.cmp(rhs)
},
};
fruit.sort_by(fruit_comparator);
// apples must __only__ contain Fruit::Apple variants
let mut apple_prices : Vec = vec![];
// oranges must __only__ contain Fruit::Orange variants
let mut orange_prices : Vec = vec![];
// TODO generate fruit_grouped from an existing sorted
let fruit_sorted_by_price_grouped : Vec> = {
let mut groups = Vec::new();
let mut this_group = Vec::new();
for f in fruit {
if this_group.is_empty() || fruit_comparator(&this_group[0], &f) == Ordering::Equal {
this_group.push(f);
} else {
groups.push(this_group);
this_group = vec![f];
}
}
groups
};
for i in fruit_sorted_by_price_grouped {
for j in i {
match j {
Fruit::Apple(price) => {
apple_prices.push(price);
}
Fruit::Orange(price) => {
orange_prices.push(price);
}
};
process_fruit(&apple_prices, &orange_prices);
apple_prices = vec![];
orange_prices = vec![];
}
}
</code></pre>
<p>}
Original: https://www.cnblogs.com/pythonClub/p/16539508.html
Author: CrossPython
Title: rust sort
原创文章受到原创版权保护。转载请注明出处：https://www.johngo689.com/15772/
转载文章受原作者版权保护。转载请注明原作者出处！
