Trait im::lens::Lens

pub trait Lens: PartialLens {
    fn get<R>(&self, s: R) -> Arc<Self::To>
    where
        R: AsRef<Self::From>,
    { ... }
    fn put<Convert, R>(&self, v: Convert, s: R) -> Self::From
    where
        R: AsRef<Self::From>,
        Arc<Self::To>: From<Convert>,
    { ... }
    fn chain<L, Next>(
        &self, 
        next: &L
    ) -> Compose<Self::From, Self::To, Next, Self, L>
    where
        L: Lens<From = Self::To, To = Next>,
    { ... }
}

A lens from From to To where From is guaranteed to contain the focus of the lens (ie. get and put operations cannot fail).

These must also implement PartialLens, so a default implementation is provided which will just unwrap the results of try_get and try_put.

Provided Methods

fn get<R>(&self, s: R) -> Arc<Self::To> where
    R: AsRef<Self::From>, 

Get the focus of the lens.

fn put<Convert, R>(&self, v: Convert, s: R) -> Self::From where
    R: AsRef<Self::From>,
    Arc<Self::To>: From<Convert>, 

Put a value into the lens, returning the updated From value.

fn chain<L, Next>(
    &self,
    next: &L
) -> Compose<Self::From, Self::To, Next, Self, L> where
    L: Lens<From = Self::To, To = Next>, 

Compose this lens with a lens from To to a new type Next, yielding a lens from From to Next.

Implementors

• impl<A, B, C, L, R> Lens for Compose<A, B, C, L, R> where
    L: Lens<From = A, To = B>,
    R: Lens<From = B, To = C>,