lending_iterator/lending_iterator/adapters/
_mod.rs

1//! [`LendingIterator`] adapters.
2//!
3//! # Example
4//!
5//! <details open class="custom"><summary><span class="summary-box"><span>Click to hide</span></span></summary>
6//!
7/*!  - ```rust
8    use ::lending_iterator::prelude::*;
9
10    let mut array = [0; 15];
11    array[1] = 1;
12    // Let's hand-roll our iterator lending `&mut` sliding windows:
13    let mut iter = {
14            // initial state:
15        ::lending_iterator::repeat_mut((&mut array, 0))
16            // main logic (lending _slices_):
17            .filter_map::<HKT!(&mut [u16]), _>(|[], (array, start)| {
18                let to_yield =
19                    array
20                        .get_mut(*start..)?
21                        .get_mut(..3)?
22                ;
23                *start += 1;
24                Some(to_yield)
25            })
26            // tiny type adaptor (lending _arrays_):
27            .map_to_mut(|[], slice| <&mut [u16; 3]>::try_from(slice).unwrap())
28        //   ⬑convenience (no need to turbofish an HKT) that is equivalent to:
29        //  .map::<HKT!(&mut [u16; 3]), _>(|[], slice| <_>::try_from(slice).unwrap())
30    };
31    while let Some(&mut [a, b, ref mut next]) = iter.next() {
32        *next = a + b;
33    }
34    assert_eq!(
35        array,
36        [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377],
37    );
38    ``` */
39//!
40//! Notice how any adapters that return a lending / dependent type (such as
41//! `&mut …` for `.{filter_,}map()`) are required to take an extra `[]`
42//! "dummy" parameter for the closure input. This is due to a technical
43//! limitation of the language, and having to add `[], ` was the least
44//! cumbersome way that I could find to work around it 😔
45//!
46//!   - See [`LendingIterator::map()`] for more info about it.
47//!
48//! </details>
49
50use super::*;
51
52match_! {(
53    filter,
54    filter_map,
55    fuse,
56    into_iter,
57    map,
58    skip,
59    take,
60) {(
61    $(
62        $(#[$attrs:meta])*
63        $module:ident
64    ),* $(,)?
65) => (
66    $(
67        $(#[$attrs])*
68        pub use self::$module::*;
69        $(#[$attrs])*
70        mod $module {
71            use super::*;
72
73            include!(concat!(stringify!($module), ".rs"));
74        }
75    )*
76)}}
lending_iterator/lending_iterator/adapters/_mod.rs

lending_iterator/lending_iterator/adapters/
_mod.rs
