Решение на упр.07 задача 1 от Илиян Копривчин
Към профила на Илиян Копривчин
Резултати
- 4 точки от тестове
- 0 бонус точки
- 4 точки общо
- 2 успешни тест(а)
- 0 неуспешни тест(а)
Код
struct Map<I, F> {
iter: I,
func: F,
}
fn iter_map<I, F, U>(iter: I, func: F) -> Map<I, F>
where
I: Iterator,
F: Fn(I::Item) -> U,
{
Map { iter, func }
}
impl<I, F, U> Iterator for Map<I, F>
where
I: Iterator,
F: Fn(I::Item) -> U,
{
type Item = U;
fn next(&mut self) -> Option<Self::Item> {
match self.iter.next() {
Some(value) => Some((self.func)(value)),
None => None,
}
}
}
struct Filter<I, F> {
iter: I,
func: F,
}
fn iter_filter<I, F>(iter: I, func: F) -> Filter<I, F>
where
I: Iterator,
F: Fn(&I::Item) -> bool,
{
Filter { iter, func }
}
impl<I, F> Iterator for Filter<I, F>
where
I: Iterator,
F: Fn(&I::Item) -> bool,
{
type Item = I::Item;
fn next(&mut self) -> Option<Self::Item> {
loop {
match self.iter.next() {
Some(v) => {
if (self.func)(&v) {
return Some(v);
}
}
None => return None,
}
}
}
}
fn iter_filter_map<I, F, U>(iter: I, func: F) -> impl Iterator<Item = U>
where
I: Iterator,
F: Fn(I::Item) -> Option<U>,
{
let mapped = iter_map(iter, func);
let filtered = iter_filter(mapped, |opt| opt.is_some());
iter_map(filtered, |opt| opt.unwrap())
}
// ----- Обяснете в коментар защо връщаме impl Iterator и ако не правехме това, какъв би бил конкретния тип на резултата.
// Връщаме impl Iterator, за да можем да върнем итератор без да се налага да изписваме
// целия му сложен конкретен тип. С impl Iterator казваме "връщам някакъв тип,
// който имплементира Iterator<Item = U>, без да ни интересува точния тип, само поведението
fn get_sum(text: &str) -> i32 {
text
.lines()
.map(|line| line.trim())
.filter(|line| !line.is_empty())
.filter_map(|line| {
match line.parse::<i32>() {
Ok(num) => Some(num),
Err(_) => None,
}
})
.sum()
}
#[derive(Debug, Eq, PartialEq)]
struct FoundWord<'a>(&'a str);
fn get_num_list(text: &str) -> Result<Vec<i32>, FoundWord<'_>> {
let parsed: Result<Vec<Option<i32>>, FoundWord> = text
.lines()
.map(|line| {
let trimmed = line.trim();
if trimmed.is_empty() {
return Ok(None);
}
match trimmed.parse::<i32>() {
Ok(num) => Ok(Some(num)),
Err(_) => Err(FoundWord(trimmed)),
}
})
.collect();
match parsed {
Ok(vec_opt) => {
let numbers = vec_opt
.into_iter()
.filter_map(|opt| opt)
.collect();
Ok(numbers)
}
Err(err) => Err(err),
}
}
fn main() {
}
Лог от изпълнението
Updating crates.io index
Locking 17 packages to latest compatible versions
Compiling proc-macro2 v1.0.103
Compiling quote v1.0.42
Compiling unicode-ident v1.0.22
Compiling futures-core v0.3.31
Compiling futures-sink v0.3.31
Compiling futures-channel v0.3.31
Compiling futures-task v0.3.31
Compiling memchr v2.7.6
Compiling syn v2.0.111
Compiling pin-project-lite v0.2.16
Compiling futures-io v0.3.31
Compiling slab v0.4.11
Compiling pin-utils v0.1.0
Compiling solution v0.1.0 (/tmp/d20251127-1757769-qck8m2/solution)
warning: struct `Map` is never constructed
--> src/lib.rs:1:8
|
1 | struct Map<I, F> {
| ^^^
|
= note: `#[warn(dead_code)]` on by default
warning: function `iter_map` is never used
--> src/lib.rs:6:4
|
6 | fn iter_map<I, F, U>(iter: I, func: F) -> Map<I, F>
| ^^^^^^^^
warning: struct `Filter` is never constructed
--> src/lib.rs:29:8
|
29 | struct Filter<I, F> {
| ^^^^^^
warning: function `iter_filter` is never used
--> src/lib.rs:34:4
|
34 | fn iter_filter<I, F>(iter: I, func: F) -> Filter<I, F>
| ^^^^^^^^^^^
warning: function `iter_filter_map` is never used
--> src/lib.rs:63:4
|
63 | fn iter_filter_map<I, F, U>(iter: I, func: F) -> impl Iterator<Item = U>
| ^^^^^^^^^^^^^^^
warning: function `get_sum` is never used
--> src/lib.rs:81:4
|
81 | fn get_sum(text: &str) -> i32 {
| ^^^^^^^
warning: struct `FoundWord` is never constructed
--> src/lib.rs:96:8
|
96 | struct FoundWord<'a>(&'a str);
| ^^^^^^^^^
warning: function `get_num_list` is never used
--> src/lib.rs:98:4
|
98 | fn get_num_list(text: &str) -> Result<Vec<i32>, FoundWord<'_>> {
| ^^^^^^^^^^^^
warning: function `main` is never used
--> src/lib.rs:128:4
|
128 | fn main() {
| ^^^^
warning: `solution` (lib) generated 9 warnings
Compiling futures-macro v0.3.31
Compiling futures-util v0.3.31
Compiling futures-executor v0.3.31
Compiling futures v0.3.31
warning: function `main` is never used
--> tests/../src/lib.rs:128:4
|
128 | fn main() {
| ^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: `solution` (test "solution_test") generated 1 warning
Finished `test` profile [unoptimized + debuginfo] target(s) in 8.41s
Running tests/solution_test.rs (target/debug/deps/solution_test-ee0783488e12dce9)
running 2 tests
test solution_test::test_adapters_ ... ok
test solution_test::test_text_parsers_ ... ok
test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s