Struct TwoPhaseSet 

pub struct TwoPhaseSet<X: Clone + Eq + Hash> {
    pub added: HashSet<X>,
    pub removed: HashSet<X>,
}

A set that can add or delete values

Panics

Any attempt to del an element that one did not previously add will panic:

// this will panic
use std::collections::HashSet;
use cvrdt_exposition::{Grow, Shrink, TwoPhaseSet};
let mut x = TwoPhaseSet::new((HashSet::new(), HashSet::new()));
x.del("this will panic");

Examples

Example usage, including demonstrating some properties:

use std::collections::HashSet;
use cvrdt_exposition::{Grow, Shrink, TwoPhaseSet};
let mut x = TwoPhaseSet::new((HashSet::new(), HashSet::new()));
for c in "abc".chars() {
    x.add(c);
}
x.del('c');
assert_eq!(x.query(&'a'), true);
assert_eq!(x.query(&'z'), false);
assert_eq!(x.query(&'c'), false);
let y = TwoPhaseSet::new(("abcdef".chars().collect(), HashSet::new()));
assert_eq!(x.merge(&y).payload(), y.merge(&x).payload());
let z = TwoPhaseSet::new(("8675309abcdefg".chars().collect(), "toremove".chars().collect()));
assert_eq!(x.merge(&y.merge(&z)).payload(), x.merge(&y).merge(&z).payload());

Fields

added: HashSet<X>

The elements that have been added to this set

removed: HashSet<X>

The elements that have been removed from this set

Trait Implementations

impl<X: Clone + Clone + Eq + Hash> Clone for TwoPhaseSet<X>

fn clone(&self) -> TwoPhaseSet<X>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<X: Debug + Clone + Eq + Hash> Debug for TwoPhaseSet<X>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<X: Clone + Eq + Hash> Grow for TwoPhaseSet<X>

type Payload = (HashSet<X>, HashSet<X>)

The internal state of our CvRDT; sufficient to build a new copy via new. Required to implement Eq for testing and verification.

type Update = X

Message to update our internal state

type Query = X

Message to query the Value of our CvRDT

type Value = bool

The response to a Query

fn new(payload: Self::Payload) -> Self

Create a new version of our data structure from the given Payload

fn payload(&self) -> Self::Payload

Retrieve the Payload (internal state) of this CvRDT

fn add(&mut self, update: Self::Update)

Add an item to the data structure, mutating this CvRDT in place

fn le(&self, other: &Self) -> bool

Is this CvRDT ≤ another in the semilattice’s partial order?

fn merge(&self, other: &Self) -> Self

Merge this data structure and another into a new CvRDT

fn query(&self, query: &Self::Query) -> Self::Value

Query the data structure to get some Value

impl<X: Clone + Eq + Hash> Shrink for TwoPhaseSet<X>

fn del(&mut self, x: X)

Delete an item from the data structure, mutating this CvRDT in place