Struct Iso 

pub struct Iso<S, T, A, B> { /* private fields */ }

An isomorphism witnesses that S and A are “the same” structure.

Only requires Profunctor — the weakest constraint of any optic.

S — source, T — modified source, A — focus, B — replacement.

Implementations

impl<S, T, A, B> Iso<S, T, A, B>

pub fn new(forward: fn(&S) -> A, backward: fn(B) -> T) -> Iso<S, T, A, B>

pub fn get(&self, s: &S) -> A

Extract the focus from a source.

pub fn review(&self, b: B) -> T

Construct a source from a focus value (the reverse direction).

pub fn set(&self, _s: S, b: B) -> T

Set the focus, discarding the old value.

pub fn transform<P>(&self, pab: <P as HKT2>::P<A, B>) -> <P as HKT2>::P<S, T>

where P: Profunctor, S: 'static, T: 'static, A: 'static, B: 'static,

Profunctor encoding: transform a P<A, B> into a P<S, T>.

Only requires Profunctor — no Strong or Choice needed.

pub fn to_getter(&self) -> Getter<S, A>

Convert to a Getter.

pub fn to_review(&self) -> Review<T, B>

Convert to a Review.

pub fn to_fold(&self) -> Fold<S, A>

where S: 'static, A: 'static,

Convert to a Fold (single-element).

impl<S, T, A, B> Iso<S, T, A, B>

where S: Clone,

pub fn over(&self, s: S, f: impl FnOnce(A) -> B) -> T

Modify the focus.

pub fn to_lens(&self) -> ComposedLens<S, T, A, B>

where S: 'static, T: 'static, A: 'static, B: 'static,

Convert to a ComposedLens (uses boxed closures since iso’s backward doesn’t match lens’s fn(S, B) -> T signature).

pub fn to_setter(&self) -> Setter<S, T, A, B>

where S: 'static, T: 'static, A: 'static, B: 'static,

Convert to a Setter.

pub fn to_traversal(&self) -> Traversal<S, T, A, B>

where S: 'static, T: 'static, A: 'static, B: 'static,

Convert to a Traversal (single-element).

Trait Implementations

impl<S, T, A, B> Optic for Iso<S, T, A, B>