Решение на упр.07 задача 1 от Константин Илиев
Към профила на Константин Илиев
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,
f: F,
}
fn iter_map<I, F, U>(iter: I, f: F) -> Map<I, F>
where
I: Iterator,
F: Fn(I::Item) -> U,
{
Map { iter, f }
}
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(x) => Some((self.f)(x)),
None => None,
}
}
}
struct Filter<I, F> {
iter: I,
f: F,
}
fn iter_filter<I, F>(iter: I, f: F) -> Filter<I, F>
where
I: Iterator,
F: Fn(&I::Item) -> bool,
{
Filter { iter, f }
}
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> {
while let Some(item) = self.iter.next() {
if (self.f)(&item) {
return Some(item);
}
}
None
}
}
// Типовете на ламбдите (closures) са анонимни и не можем да ги напишем директно в сигнатурата.
// Ако не използвахме impl Iterator, би трябвало да въведем още generic параметри за типовете на closures, или
// да използваме function pointers (fn(&Option<U>) -> bool и fn(Option<U>) -> U), което усложнява кода.
// impl Iterator<Item = U> ни позволява да скрием този дълбоко вложен тип и да дадем само интерфейса: “това е някакъв итератор над U“.
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: &Option<U>| opt.is_some());
iter_map(filtered, |opt: Option<U>| opt.unwrap())
}
trait IteratorExt: Iterator {
fn my_map<F, U>(self, func: F) -> Map<Self, F>
where
F: Fn(Self::Item) -> U,
Self: Sized,
{
iter_map(self, func)
}
fn my_filter<F>(self, func: F) -> Filter<Self, F>
where
F: Fn(&Self::Item) -> bool,
Self: Sized,
{
iter_filter(self, func)
}
}
impl<I> IteratorExt for I where I: Iterator {}
fn get_sum(text: &str) -> i32 {
text.lines()
.my_map(|line| line.trim())
.my_filter(|s| !s.is_empty())
.my_map(|s| s.parse::<i32>().ok())
.filter_map(|opt| opt)
.sum()
}
#[derive(Debug, Eq, PartialEq)]
struct FoundWord<'a>(&'a str);
fn get_num_list(text: &str) -> Result<Vec<i32>, FoundWord<'_>> {
text.lines()
.my_filter(|line| !line.trim().is_empty())
.my_map(|line| {
let trimmed = line.trim();
trimmed
.parse::<i32>()
.map_err(|_| FoundWord(trimmed))
})
.collect::<Result<Vec<i32>, FoundWord>>()
}
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 v1.0.42
Compiling futures-core v0.3.31
Compiling futures-sink v0.3.31
Compiling futures-channel v0.3.31
Compiling futures-io v0.3.31
Compiling memchr v2.7.6
Compiling syn v2.0.111
Compiling pin-project-lite v0.2.16
Compiling pin-utils v0.1.0
Compiling futures-task v0.3.31
Compiling slab v0.4.11
Compiling solution v0.1.0 (/tmp/d20251127-1757769-2vymhj/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, f: 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, f: F) -> Filter<I, F>
| ^^^^^^^^^^^
warning: function `iter_filter_map` is never used
--> src/lib.rs:64:4
|
64 | fn iter_filter_map<I, F, U>(iter: I, func: F) -> impl Iterator<Item = U>
| ^^^^^^^^^^^^^^^
warning: trait `IteratorExt` is never used
--> src/lib.rs:76:7
|
76 | trait IteratorExt: Iterator {
| ^^^^^^^^^^^
warning: function `get_sum` is never used
--> src/lib.rs:96:4
|
96 | fn get_sum(text: &str) -> i32 {
| ^^^^^^^
warning: struct `FoundWord` is never constructed
--> src/lib.rs:106:8
|
106 | struct FoundWord<'a>(&'a str);
| ^^^^^^^^^
warning: function `get_num_list` is never used
--> src/lib.rs:108:4
|
108 | fn get_num_list(text: &str) -> Result<Vec<i32>, FoundWord<'_>> {
| ^^^^^^^^^^^^
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
Finished `test` profile [unoptimized + debuginfo] target(s) in 8.91s
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