Trait differential_dataflow::lattice::Lattice

``````pub trait Lattice: PartialOrder {
fn join(&self, other: &Self) -> Self;
fn meet(&self, other: &Self) -> Self;

fn join_assign(&mut self, other: &Self)    where        Self: Sized,
{ ... }
fn meet_assign(&mut self, other: &Self)    where        Self: Sized,
{ ... }
fn advance_by(&mut self, frontier: AntichainRef<'_, Self>)    where        Self: Sized,
{ ... }
}``````
Expand description

A bounded partially ordered type supporting joins and meets.

Required Methods§

The smallest element greater than or equal to both arguments.

Examples
``````
let time1 = Product::new(3, 7);
let time2 = Product::new(4, 6);
let join = time1.join(&time2);

assert_eq!(join, Product::new(4, 7));``````

The largest element less than or equal to both arguments.

Examples
``````
let time1 = Product::new(3, 7);
let time2 = Product::new(4, 6);
let meet = time1.meet(&time2);

assert_eq!(meet, Product::new(3, 6));``````

Provided Methods§

Updates `self` to the smallest element greater than or equal to both arguments.

Examples
``````
let mut time1 = Product::new(3, 7);
let time2 = Product::new(4, 6);
time1.join_assign(&time2);

assert_eq!(time1, Product::new(4, 7));``````

Updates `self` to the largest element less than or equal to both arguments.

Examples
``````
let mut time1 = Product::new(3, 7);
let time2 = Product::new(4, 6);
time1.meet_assign(&time2);

assert_eq!(time1, Product::new(3, 6));``````

Advances self to the largest time indistinguishable under `frontier`.

This method produces the “largest” lattice element with the property that for every lattice element greater than some element of `frontier`, both the result and `self` compare identically to the lattice element. The result is the “largest” element in the sense that any other element with the same property (compares identically to times greater or equal to `frontier`) must be less or equal to the result.

When provided an empty frontier `self` is not modified.

Examples
``````
use timely::progress::frontier::{Antichain, AntichainRef};

let time = Product::new(3, 7);
let mut advanced = Product::new(3, 7);
let frontier = Antichain::from(vec![Product::new(4, 8), Product::new(5, 3)]);

// `time` and `advanced` are indistinguishable to elements >= an element of `frontier`
for i in 0 .. 10 {
for j in 0 .. 10 {
let test = Product::new(i, j);
// for `test` in the future of `frontier` ..
if frontier.less_equal(&test) {