Решение на упр.04 задача 2 от Димитър Колев
Резултати
- 2 точки от тестове
- 0 бонус точки
- 2 точки общо
- 4 успешни тест(а)
- 0 неуспешни тест(а)
Код
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum CompareResult {
Less,
Equal,
Greater,
}
trait Compare {
fn compare(&self, other: &Self) -> CompareResult;
}
trait Filter {
fn matches(&self, query: &str) -> bool;
}
trait Aggregate {
type Output;
fn aggregate(items: &[Self]) -> Self::Output
where
Self: Sized;
}
struct Book {
title: String,
author: String,
year: u32,
rating: f32,
}
impl Compare for Book {
fn compare(&self, other: &Self) -> CompareResult {
if self.year > other.year {
return CompareResult::Greater;
}
if self.year < other.year {
return CompareResult::Less;
}
CompareResult::Equal
}
}
impl Filter for Book {
fn matches(&self, query: &str) -> bool {
self.title.to_lowercase().contains(&query.to_lowercase())
|| self.author.to_lowercase().contains(&query.to_lowercase())
}
}
impl Aggregate for Book {
type Output = f32;
fn aggregate(items: &[Self]) -> Self::Output
where
Self: Sized,
{
if items.len() == 0 {
return 0.0;
}
items.iter().fold(0.0, |acc, x| acc + x.rating) / items.len() as f32
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum SortOrder {
Desc,
Asc,
}
fn process_items<T>(items: Vec<T>, query: &str, order: SortOrder) -> (Vec<T>, T::Output)
where
T: Compare + Filter + Aggregate,
{
use std::cmp::Ordering;
let mut items = items
.into_iter()
.filter(|x| x.matches(query))
.collect::<Vec<T>>();
items.sort_by(|x, y| match x.compare(y) {
CompareResult::Greater if order == SortOrder::Desc => Ordering::Less,
CompareResult::Greater if order == SortOrder::Asc => Ordering::Greater,
CompareResult::Less if order == SortOrder::Desc => Ordering::Greater,
CompareResult::Less if order == SortOrder::Asc => Ordering::Less,
CompareResult::Equal => Ordering::Equal,
_ => unreachable!(),
});
let aggregate = Aggregate::aggregate(&items);
(items, aggregate)
}
Лог от изпълнението
Updating crates.io index
Locking 17 packages to latest compatible versions
Compiling proc-macro2 v1.0.103
Compiling unicode-ident v1.0.22
Compiling quote v1.0.41
Compiling futures-sink v0.3.31
Compiling futures-core v0.3.31
Compiling futures-channel v0.3.31
Compiling memchr v2.7.6
Compiling syn v2.0.109
Compiling pin-project-lite v0.2.16
Compiling slab v0.4.11
Compiling pin-utils v0.1.0
Compiling futures-task v0.3.31
Compiling futures-io v0.3.31
Compiling solution v0.1.0 (/tmp/d20251106-1757769-1vhrgbt/solution)
warning: enum `CompareResult` is never used
--> src/lib.rs:2:6
|
2 | enum CompareResult {
| ^^^^^^^^^^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: trait `Compare` is never used
--> src/lib.rs:8:7
|
8 | trait Compare {
| ^^^^^^^
warning: trait `Filter` is never used
--> src/lib.rs:12:7
|
12 | trait Filter {
| ^^^^^^
warning: trait `Aggregate` is never used
--> src/lib.rs:16:7
|
16 | trait Aggregate {
| ^^^^^^^^^
warning: struct `Book` is never constructed
--> src/lib.rs:23:8
|
23 | struct Book {
| ^^^^
warning: enum `SortOrder` is never used
--> src/lib.rs:66:6
|
66 | enum SortOrder {
| ^^^^^^^^^
warning: function `process_items` is never used
--> src/lib.rs:71:4
|
71 | fn process_items<T>(items: Vec<T>, query: &str, order: SortOrder) -> (Vec<T>, T::Output)
| ^^^^^^^^^^^^^
warning: `solution` (lib) generated 7 warnings
Compiling futures-macro v0.3.31
Compiling futures-util v0.3.31
Compiling futures-executor v0.3.31
Compiling futures v0.3.31
Finished `test` profile [unoptimized + debuginfo] target(s) in 8.87s
Running tests/solution_test.rs (target/debug/deps/solution_test-8c2c5f784503f204)
running 4 tests
test solution_test::test_aggregate ... ok
test solution_test::test_compare ... ok
test solution_test::test_matches ... ok
test solution_test::test_process ... ok
test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s