hooks/
memo.rs

1use crate::utils::UninitializedHook;
2
3#[derive(Debug, Default)]
4pub struct Memo<Data, Dep> {
5    pub data: Data,
6    pub dependency: Dep,
7}
8
9impl<Data, Dep> Unpin for Memo<Data, Dep> {}
10
11impl<Data, Dep> Memo<Data, Dep> {
12    pub fn update_if_ne_and_get(
13        &mut self,
14        get_data: impl FnOnce(&Dep) -> Data,
15        new_dependency: Dep,
16    ) -> (&Data, &Dep)
17    where
18        Dep: PartialEq,
19    {
20        let Self { data, dependency } = self;
21        if *dependency != new_dependency {
22            *data = get_data(&new_dependency);
23            *dependency = new_dependency;
24        }
25        (data, dependency)
26    }
27}
28
29hooks_core::impl_hook![
30    impl<Data, Dep> Memo<Data, Dep> {
31        fn unmount() {}
32        #[inline]
33        fn poll_next_update(self) {
34            std::task::Poll::Ready(false)
35        }
36        #[inline]
37        fn use_hook(self) -> (&'hook mut Data, &'hook mut Dep) {
38            let this = self.get_mut();
39            (&mut this.data, &mut this.dependency)
40        }
41    }
42];
43
44pub struct UseMemo<Data, Dep: PartialEq, F: FnOnce(&Dep) -> Data>(pub F, pub Dep);
45pub use UseMemo as use_memo;
46
47hooks_core::impl_hook![
48    impl<Data, Dep: PartialEq, F: FnOnce(&Dep) -> Data> UseMemo<Data, Dep, F> {
49        fn into_hook(self) -> Memo<Data, Dep> {
50            Memo {
51                data: self.0(&self.1),
52                dependency: self.1,
53            }
54        }
55
56        fn update_hook(self, hook: _) {
57            let _ = hook.get_mut().update_if_ne_and_get(self.0, self.1);
58        }
59
60        fn h(self, hook: UninitializedHook<Memo<Data, Dep>>) {
61            hook.get_mut().use_into_or_update_hook(self)
62        }
63    }
64];
hooks/memo.rs

hooks/
memo.rs
