Trait Mapping

pub trait Mapping {
    type Dom: Eq + Clone;
    type Cod: Eq + Clone;

    // Required method
    fn apply(&self, x: &Self::Dom) -> Option<Self::Cod>;

    // Provided method
    fn is_set(&self, x: &Self::Dom) -> bool { ... }
}

A functional mapping.

A mapping sends values of type Dom to values of type Cod. Unlike a function, a mapping need not be defined on its whole domain. A mapping is thus more like a partial function, but it does not actually know its intended domain of definition. If needed, that information should be provided separately, preferably as a Set.

Neither the domain nor the codomain of the mapping are assumed to be finite.

Required Associated Types

type Dom: Eq + Clone

Type of elements in domain of mapping.

type Cod: Eq + Clone

Type of elements in codomain of mapping.

Required Methods

fn apply(&self, x: &Self::Dom) -> Option<Self::Cod>

Applies the mapping at a point possibly in the domain.

Provided Methods

fn is_set(&self, x: &Self::Dom) -> bool

Is the mapping defined at a point?

The default implementation checks whether apply returns something. Often this method can be given a more efficient implementation that avoids allocating.

Implementors

impl Mapping for SkelIndexedColumn

type Dom = usize

type Cod = usize

impl<K, V, S> Mapping for HashColumn<K, V, S>

where K: Eq + Hash + Clone, V: Eq + Clone, S: BuildHasher,

type Dom = K

type Cod = V

impl<K, V, S> Mapping for IndexedHashColumn<K, V, S>

where K: Eq + Hash + Clone, V: Eq + Hash + Clone, S: BuildHasher,

type Dom = K

type Cod = V

impl<T: Eq + Clone> Mapping for VecColumn<T>

type Dom = usize

type Cod = T

impl<T: Eq + Hash + Clone> Mapping for IndexedVecColumn<T>

type Dom = usize

type Cod = T