use std::{
clone::Clone,
convert::From,
fmt,
vec::Vec
};
#[derive(Clone)]
pub struct Stack<T: Clone>(Vec<T>);
impl<T: Clone> Stack<T> {
pub fn new() -> Self {
Stack(vec![])
}
pub fn push(&mut self, i: T) {
self.0.push(i);
}
pub fn pop(&mut self) -> Option<T> {
self.0.pop()
}
pub fn top(&self) -> Option<&T> {
self.0.last()
}
pub fn size(&self) -> usize {
self.0.len()
}
}
impl<I: Clone> From<Vec<I>> for Stack<I> {
fn from(s: Vec<I>) -> Self {
Stack(s)
}
}
impl<T: Clone + fmt::Display> fmt::Display for Stack<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.0.iter().rev().fold(Ok(()), |r, i| {
r.and_then(|_| writeln!(f, "{}", i))
})
}
}