Struct PersistentStack

pub struct PersistentStack<T>(/* private fields */);

Concurrent persistent stack

Supportted operations:

• clone O(1)
• push O(1)
• pop O(1)
• iterate O(n)

use persistent_stack::PersistentStack;

let mut s1 = PersistentStack::new();
s1.push(1);
let mut s2 = s1.clone();
std::thread::spawn(move || {
    s2.push(2);
    assert_eq!(s2.iter().copied().collect::<Vec<_>>(), vec![2, 1]);
    std::thread::sleep(std::time::Duration::from_millis(20));
    s2.push(4);
    assert_eq!(s2.iter().copied().collect::<Vec<_>>(), vec![4, 2, 1]);
});
s1.push(3);
assert_eq!(s1.iter().copied().collect::<Vec<_>>(), vec![3, 1]);
std::thread::sleep(std::time::Duration::from_millis(20));
s1.push(5);
assert_eq!(s1.iter().copied().collect::<Vec<_>>(), vec![5, 3, 1]);

Implementations

impl<T> PersistentStack<T>

pub fn new() -> PersistentStack<T>

Creates new empty persistent stack

use persistent_stack::PersistentStack;

let s = PersistentStack::<i32>::new();
assert!(s.into_iter().next().is_none())

pub fn push(&mut self, data: T)

Pushes data to end of self (affects only current copy of stack)

use persistent_stack::PersistentStack;
use std::sync::Arc;

let mut s1 = PersistentStack::new();
s1.push(1);
let mut s2 = s1.clone();
s2.push(2);
assert_eq!(s1.into_iter().collect::<Vec<_>>(), [&1]);
assert_eq!(s2.into_iter().collect::<Vec<_>>(), [&2, &1]);

pub fn pop(&mut self) -> Result<T, PersistentStackPopError>

Pops value from stack and tries to return it

Returns Ok(data) if only this copy of stack owned data

Returns Err(CantUnwrap) if there are other copies, which own data

Returns Err(RootIsReached) if nothing to pop

use persistent_stack::{PersistentStack, PersistentStackPopError::*};

let mut s1 = PersistentStack::new();
s1.push(1);
s1.push(2);
let mut s2 = s1.clone();
s1.push(3);
s2.push(4);
assert_eq!(s2.pop(), Ok(4)); // only s2 owned 4
assert_eq!(s2.pop(), Err(CantUnwrap)); // s1 also owns 2
let mut s3 = s2.clone();
assert_eq!(s2.pop(), Err(CantUnwrap)); // s1 also owns 1
assert_eq!(s2.pop(), Err(RootIsReached)); // There are no elements in s2
s3.push(5);
assert_eq!(s3.iter().copied().collect::<Vec<_>>(), vec![5, 1]); // s3 is cloned, when s2 was [1]

pub fn iter(&self) -> PersistentStackIter<'_, T>

Creates iterator over self by reference

use persistent_stack::PersistentStack;

let mut s = PersistentStack::new();
s.push(1);
s.push(2);
s.push(3);
assert_eq!(s.iter().collect::<Vec<_>>(), [&3, &2, &1]);
s.push(4); // s didn't move out

Trait Implementations

impl<T> Clone for PersistentStack<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Default for PersistentStack<T>

fn default() -> PersistentStack<T>

Returns the “default value” for a type.

impl<'a, T> IntoIterator for &'a PersistentStack<T>

type IntoIter = PersistentStackIter<'a, T>

Which kind of iterator are we turning this into?

type Item = &'a T

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.