Trait garfield::functor::Functor

pub trait Functor: Sized {
    type Inner;
    type Wrapped<T>: Functor;

    fn rmap<B, F>(self, f: F) -> Self::Wrapped<B>
    where
        F: FnOnce(Self::Inner) -> B;
}

Functor

Required Associated Types

type Inner

Alias for the type that we are generic over.

type Wrapped<T>: Functor

The type we are generic over and it’s container.

Required Methods

fn rmap<B, F>(self, f: F) -> Self::Wrapped<B>where
    F: FnOnce(Self::Inner) -> B,

Lifts a function into the Functor context.

In Haskell speak this translates to, fmap :: a -> b -> f a -> f b

Implementations on Foreign Types

impl<A> Functor for Option<A>

type Inner = A

type Wrapped<T> = Option<T>

fn rmap<B, F: FnOnce(Self::Inner) -> B>(self, f: F) -> Self::Wrapped<B>

impl<T, E> Functor for Result<T, E>

type Inner = T

type Wrapped<U> = Result<U, E>

fn rmap<B, F: FnOnce(Self::Inner) -> B>(self, f: F) -> Self::Wrapped<B>

Implementors