bad-optics/src/lib.rs

127 lines
2.4 KiB
Rust

#![feature(unboxed_closures, fn_traits)]
// TODO add third_from_tuple, etc
// TODO array traversals
// TODO something for structs
// TODO something for Ok, Some, etc
// TODO make over work with changing types
/// Base trait
pub trait OpticsTrait {}
/// Wrapper type
#[derive(Clone, Copy)]
pub struct Optics<T: OpticsTrait>(pub(crate) T);
impl<L: OpticsTrait> OpticsTrait for Optics<L> {}
mod combinations;
mod fns;
pub mod lenses;
#[cfg(test)]
mod tests {
use super::lenses::*;
#[test]
fn view_first_from_tuple() {
let a = (1, 2);
assert_eq!(view(_0, a), 1);
let a = (1, 2);
assert_eq!(view(_0, &a), &1);
let mut a = (1, 2);
assert_eq!(view(_0, &mut a), &mut 1);
let a = (1, 2, 3);
assert_eq!(view(_0, a), 1);
let a = (1, 2, 3);
assert_eq!(view(_0, &a), &1);
}
#[test]
fn view_first_from_tuple_mut_works() {
let mut a = (1, 2);
*view(_0, &mut a) += 1;
assert_eq!(a, (2, 2));
}
#[test]
fn set_first_from_tuple() {
let a = (1, 2);
let a = set(_0, a, 3);
assert_eq!(a, (3, 2));
}
#[test]
fn over_first_from_tuple() {
let a = (1, 2);
let a = over(_0, a, |v| v + 1);
assert_eq!(a, (2, 2));
}
#[test]
fn over_first_from_array() {
let a = [1, 2, 3, 4];
let a = over(_0, a, |v| v + 1);
assert_eq!(a, [2, 2, 3, 4]);
}
#[test]
fn second() {
let a = (1, 2);
let a = over(_1, a, |v| v + 1);
assert_eq!(a, (1, 3));
let a = [1, 2, 3, 4];
let a = over(_1, a, |v| v + 1);
assert_eq!(a, [1, 3, 3, 4]);
}
#[test]
fn view_combination() {
let a = ((1, 2), 3);
let lens = _0 + _1;
let a = view(lens, a);
assert_eq!(a, 2);
}
#[test]
fn over_combination() {
let a = ((1, 2), 3);
let lens = _0 + _1;
let a = over(lens, a, |v| v + 1);
assert_eq!(a, ((1, 3), 3));
}
#[test]
fn call_as_funcs() {
let a = (1, 2);
assert_eq!(_0(a), 1);
let a = (1, 2);
assert_eq!(_0(a, |v| v + 1), (2, 2));
let a = ((1, 2), 3);
let res = _0(a);
assert_eq!(res, (1, 2));
let lens = _0 + _1;
let res = lens(a);
assert_eq!(res, 2);
let res = lens(a, |v| v + 1);
assert_eq!(res, ((1, 3), 3));
}
}