Решение на упр.08 задача 1 от Йоан Грозев
Код
use std::rc::Rc;
pub struct List<T>
{
head: Link<T>,
}
type Link<T> = Option<Rc<Node<T>>>;
struct Node<T>
{
elem: T,
next: Link<T>,
}
impl<T> List<T>
{
fn new() -> Self
{
List { head: None }
}
fn head(&self) -> Option<&T>
{
self.head.as_ref().map(|rc| &rc.elem)
}
fn tail(&self) -> List<T>
{
List
{
head: self.head.as_ref().and_then(|rc| rc.next.clone()),
}
}
fn prepend(&self, value: T) -> List<T>
{
List
{
head: Some(Rc::new(Node {elem: value, next: self.head.clone(),})),
}
}
fn iter(&self) -> Iter<'_, T>
{
Iter
{
next: self.head.as_deref(),
}
}
}
struct Iter<'a, T>
{
next: Option<&'a Node<T>>,
}
impl<'a, T> Iterator for Iter<'a, T>
{
type Item = &'a T;
fn next(&mut self) -> Option<Self::Item>
{
self.next.map(|node| {self.next = node.next.as_deref();&node.elem})
}
}
fn s(s: &str) -> String
{
s.to_string()
}