Struct Relation 

pub struct Relation { /* private fields */ }

A set of facts sharing the same predicate.

Implementations

impl Relation

pub fn new() -> Self

Create an empty relation.

pub fn insert(&mut self, fact: Fact) -> bool

Insert a fact. Returns true if the fact was not already present.

pub fn contains(&self, fact: &Fact) -> bool

Check whether the relation contains the given fact.

pub fn len(&self) -> usize

Number of facts in this relation.

pub fn is_empty(&self) -> bool

Returns true if the relation has no facts.

pub fn iter(&self) -> impl Iterator<Item = &Fact>

Iterate over all facts.

pub fn facts(&self) -> Vec<Fact>

Return a cloned Vec of all facts.

pub fn union(&self, other: &Relation) -> Relation

Compute the union of two relations (facts from both).

pub fn difference(&self, other: &Relation) -> Relation

Compute the set-difference self − other.

Trait Implementations

impl Clone for Relation

fn clone(&self) -> Relation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Relation

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

Formats the value using the given formatter.

impl Default for Relation

fn default() -> Relation

Returns the “default value” for a type.