macro-lens

macro-lens exports the lens Rust library crate for ergonomic, immutable data access and updates.

Example

use lens::{Lens, RefLens, Lenses, lens};

#[derive(Clone, Lenses)]
struct Person {
    name: String,
}

let lens = lens!(Person.name);
let person = Person {
    name: "Pop Zeus".to_string(),
};

assert_eq!(lens.get_ref(&person), "Pop Zeus");
let updated = lens.set(person, "Melisande".to_string());
assert_eq!(updated.name, "Melisande");

License

MIT.