Struct pl_lens::ComposedLens

pub struct ComposedLens<LHS, RHS> { /* fields omitted */ }

Composes two Lenses.

In pseudocode:

    compose(Lens<A, B>, Lens<B, C>) -> Lens<A, C>

Trait Implementations

impl<LHS, RHS> Lens for ComposedLens<LHS, RHS> where
    LHS: RefLens,
    LHS::Target: 'static,
    RHS: Lens<Source = LHS::Target>, 

type Source = LHS::Source

The lens source type, i.e., the object containing the field.

type Target = RHS::Target

The lens target type, i.e., the field to be accessed or modified.

fn path(&self) -> LensPath

Returns a LensPath that describes the target of this lens relative to its source.

fn mutate<'a>(&self, source: &'a mut LHS::Source, target: RHS::Target)

fn set(&self, source: Self::Source, target: Self::Target) -> Self::Source

Sets the target of the lens and returns the new state of the source. (This consumes the source.)

impl<LHS, RHS> RefLens for ComposedLens<LHS, RHS> where
    LHS: RefLens,
    LHS::Target: 'static,
    RHS: RefLens<Source = LHS::Target>, 

fn get_ref<'a>(&self, source: &'a LHS::Source) -> &'a RHS::Target

Gets a reference to the target of the lens. (This does not consume the source.)

fn get_mut_ref<'a>(&self, source: &'a mut LHS::Source) -> &'a mut RHS::Target

fn mutate_with_fn<'a>(
    &self,
    source: &'a mut Self::Source,
    f: &dyn Fn(&Self::Target) -> Self::Target
)

Modifies the target of the lens by applying a function to the current value.

fn modify(
    &self,
    source: Self::Source,
    f: &dyn Fn(&Self::Target) -> Self::Target
) -> Self::Source

Modifies the target of the lens by applying a function to the current value. This consumes the source.

impl<LHS, RHS> ValueLens for ComposedLens<LHS, RHS> where
    LHS: RefLens,
    LHS::Target: 'static,
    RHS: ValueLens<Source = LHS::Target>, 

fn get(&self, source: &LHS::Source) -> RHS::Target

Gets a copy of the lens target. (This does not consume the source.)