#[derive(Debug, Clone)]
struct Item {
a: i32,
b: i32,
label: String,
}
impl Item {
fn new(a: i32, b: i32, label: &str) -> Self {
Self {
a,
b,
label: label.to_string(),
}
}
fn to_string(&self) -> String {
format!("({}, {}, {})", self.a, self.b, self.label)
}
}
// Sort by a, then b
fn sort_data(items: &mut Vec<Item>) {
items.sort_by(|x, y| {
x.a.cmp(&y.a).then(x.b.cmp(&y.b))
});
}
// Print all items
fn print_data(items: &[Item]) {
for item in items {
println!("{}", item.to_string());
}
}
// Find first item by label
fn find_by_label<'a>(items: &'a [Item], label: &str) -> Option<&'a Item> {
items.iter().find(|item| item.label == label)
}
// Filter by a
fn filter_by_a(items: &[Item], value: i32) -> Vec<Item> {
items.iter()
.filter(|item| item.a == value)
.cloned()
.collect()
}
fn main() {
// data
let data = vec![
Item::new(7, 2, "python"),
Item::new(8, 3, "c"),
Item::new(3, 5, "c++"),
Item::new(4, 1, "c#"),
Item::new(3, 2, "java"),
Item::new(7, 1, "go"),
Item::new(1, 2, "rust"),
];
// Work on a copy so original stays unchanged
let mut items = data.clone();
sort_data(&mut items);
println!("Sorted data:");
print_data(&items);
println!("\nSearching for 'java':");
if let Some(found) = find_by_label(&items, "java") {
println!("{}", found.to_string());
}
println!("\nFiltering items where a == 7:");
let filtered = filter_by_a(&items, 7);
print_data(&filtered);
}
/*
run:
Sorted data:
(1, 2, rust)
(3, 2, java)
(3, 5, c++)
(4, 1, c#)
(7, 1, go)
(7, 2, python)
(8, 3, c)
Searching for 'java':
(3, 2, java)
Filtering items where a == 7:
(7, 1, go)
(7, 2, python)
*/
