object_rainbow/
fn_fetch.rs

1use crate::*;
2
3pub struct FnFetch<F> {
4    fetch: F,
5}
6
7pub trait FetchFn: Send + Sync {
8    type T;
9    fn fetch(&self) -> impl Send + Future<Output = Result<Self::T>>;
10}
11
12impl<F: Send + Sync + Fn() -> Fut, Fut: Send + Future<Output = Result<T>>, T> FetchFn for F {
13    type T = T;
14
15    fn fetch(&self) -> impl Send + Future<Output = Result<Self::T>> {
16        self()
17    }
18}
19
20impl<F: FetchFn> FnFetch<F> {
21    pub fn new(fetch: F) -> Self {
22        Self { fetch }
23    }
24
25    pub async fn fetch(&self) -> Result<F::T> {
26        self.fetch.fetch().await
27    }
28}
29
30impl<F: FetchFn<T: Traversible>> FetchBytes for FnFetch<F> {
31    fn fetch_bytes(&'_ self) -> FailFuture<'_, ByteNode> {
32        Box::pin(async move { Ok(self.fetch().await?.byte_node()) })
33    }
34
35    fn fetch_data(&'_ self) -> FailFuture<'_, Vec<u8>> {
36        Box::pin(async move { Ok(self.fetch().await?.vec()) })
37    }
38}
39
40impl<F: FetchFn<T: Traversible>> Fetch for FnFetch<F> {
41    type T = F::T;
42
43    fn fetch(&'_ self) -> FailFuture<'_, Self::T> {
44        Box::pin(async move { self.fetch().await })
45    }
46}
47
48pub trait ClosureFn<'a, Closure: 'a>: Send + Sync + Fn(&'a Closure) -> Self::Fut {
49    type T;
50    type Fut: Send + Future<Output = Result<Self::T>>;
51    fn fetch(&'a self, closure: &'a Closure) -> Self::Fut;
52}
53
54impl<
55    'a,
56    Closure: 'a,
57    F: Send + Sync + Fn(&'a Closure) -> Fut,
58    Fut: Send + Future<Output = Result<T>>,
59    T,
60> ClosureFn<'a, Closure> for F
61{
62    type T = T;
63    type Fut = Fut;
64
65    fn fetch(&'a self, closure: &'a Closure) -> Self::Fut {
66        self(closure)
67    }
68}
69
70pub trait ClosureFetch<Closure>: Send + Sync {
71    type T;
72    fn fetch(&self, closure: &Closure) -> impl Send + Future<Output = Result<Self::T>>;
73}
74
75impl<Closure: Send + Sync, F: for<'a> ClosureFn<'a, Closure, T = T>, T> ClosureFetch<Closure>
76    for F
77{
78    type T = T;
79
80    async fn fetch(&self, closure: &Closure) -> Result<Self::T> {
81        self.fetch(closure).await
82    }
83}
84
85impl<Closure: Send + Sync, F: ClosureFetch<Closure>> FetchFn for (Closure, F) {
86    type T = F::T;
87
88    fn fetch(&self) -> impl Send + Future<Output = Result<Self::T>> {
89        self.1.fetch(&self.0)
90    }
91}
92
93pub fn closure_fetch<
94    Closure: Send + Sync,
95    F: ClosureFetch<Closure> + AsyncFn(&Closure) -> Result<F::T>,
96>(
97    closure: Closure,
98    f: F,
99) -> (Closure, F) {
100    (closure, f)
101}
object_rainbow/fn_fetch.rs

object_rainbow/
fn_fetch.rs
