spin_templates/
cancellable.rs

1pub(crate) enum Cancellable<T, E> {
2    Cancelled,
3    Err(E),
4    Ok(T),
5}
6
7impl<T, E> Cancellable<T, E> {
8    pub(crate) fn err(self) -> Result<(), E> {
9        match self {
10            Self::Ok(_) => Ok(()),
11            Self::Cancelled => Ok(()),
12            Self::Err(e) => Err(e),
13        }
14    }
15
16    pub(crate) fn and_then<U>(self, f: impl Fn(T) -> Result<U, E>) -> Cancellable<U, E> {
17        match self {
18            Self::Ok(value) => match f(value) {
19                Ok(r) => Cancellable::Ok(r),
20                Err(e) => Cancellable::Err(e),
21            },
22            Self::Cancelled => Cancellable::Cancelled,
23            Self::Err(e) => Cancellable::Err(e),
24        }
25    }
26
27    pub(crate) async fn and_then_async<U, Fut: std::future::Future<Output = Result<U, E>>>(
28        self,
29        f: impl Fn(T) -> Fut,
30    ) -> Cancellable<U, E> {
31        match self {
32            Self::Ok(value) => match f(value).await {
33                Ok(r) => Cancellable::Ok(r),
34                Err(e) => Cancellable::Err(e),
35            },
36            Self::Cancelled => Cancellable::Cancelled,
37            Self::Err(e) => Cancellable::Err(e),
38        }
39    }
40}
41
42impl<T, E> From<Result<Option<T>, E>> for Cancellable<T, E> {
43    fn from(ro: Result<Option<T>, E>) -> Self {
44        match ro {
45            Ok(Some(t)) => Self::Ok(t),
46            Ok(None) => Self::Cancelled,
47            Err(e) => Self::Err(e),
48        }
49    }
50}
spin_templates/cancellable.rs

spin_templates/
cancellable.rs
