Struct AtIndex 

pub struct AtIndex { /* private fields */ }

Lens into a Vec element by index.

Panics

Panics if the index is out of bounds.

Implementations

impl AtIndex

pub fn new(index: usize) -> Self

Trait Implementations

impl<T: Clone> Lens<Vec<T>, T> for AtIndex

fn view(&self, whole: &Vec<T>) -> T

View the focused part.

fn set(&self, whole: &mut Vec<T>, part: T)

Set the focused part, mutating the whole in place.

fn over(&self, whole: &mut S, f: impl FnOnce(A) -> A)

where A: Clone,

Modify the focused part with a function.

fn then<B, L2: Lens<A, B>>(self, inner: L2) -> Composed<Self, L2, A>

where Self: Sized, A: Clone,

Compose this lens with an inner lens to focus deeper.