ringstack

ringstack

[RingStack] is a tiny stack implementation which uses circular buffer.

Since [RingStack] is constructed upon a circular buffer, the oldest item automatically dropped as you [push][RingStack::push()] when the number of items has already reached its limit. (Thus [len][RingStack::len()] method saturate with that number of limit.)

And it supports [RingStack::iter()] method which returns Iterator<&T>. It provides items one by one with historical order, latest to oldest.

Though [RingStack] currently uses [Vec] as its internals, once it allocates at the timing of [new][RingStack::new()] then additional allocation never happends.

Examples

use ringstack::RingStack;

let mut s = RingStack::<i32, 3>::new();
assert_eq!(s.peek(), None);

s.push(1);
s.push(2);
assert_eq!(s.len(), 2);
assert_eq!(s.peek(), Some(&2));
assert_eq!(s.pop(), Some(2));
assert_eq!(s[0], 1);
assert_eq!(s.get(0), Some(&1));
assert_eq!(s.get(1), None);

s.push(3);
s.push(4);
let v: Vec<i32> = s.iter().map(|e| e.clone()).collect();
assert_eq!(v, vec![4, 3, 1]);

s.push(5);
let v: Vec<i32> = s.iter().map(|e| e.clone()).collect();
assert_eq!(v, vec![5, 4, 3]);

assert_eq!(s.pop(), Some(5));
assert_eq!(s.pop(), Some(4));
assert_eq!(s.pop(), Some(3));
assert_eq!(s.pop(), None);

Changelog

0.2.0

• Added [len()], [get()] methods.

• Implemented [std::ops::Index].

• Change [iter()] return type

  Changed from &Option<T> into &T and it iterates only valid elements, since it returns reference of T not Option.

0.1.1

Make RingStack [Debug] derived

0.1.0

Initial Version

License

The MIT License (MIT)

Copyright (c) 2022 msr1k