rx_rust/operators/creating/
throw.rs

1use crate::utils::types::NecessarySendSync;
2use crate::{
3    disposable::subscription::Subscription,
4    observable::Observable,
5    observer::{Observer, Termination},
6};
7use educe::Educe;
8use std::convert::Infallible;
9
10/// Creates an Observable that emits no items and terminates with an error.
11/// See <https://reactivex.io/documentation/operators/empty-never-throw.html>
12///
13/// # Examples
14/// ```rust
15/// use rx_rust::{
16///     observable::observable_ext::ObservableExt,
17///     observer::Termination,
18///     operators::creating::throw::Throw,
19/// };
20/// use std::convert::Infallible;
21///
22/// let mut terminations = Vec::new();
23///
24/// Throw::new("boom").subscribe_with_callback(
25///     |value: Infallible| panic!("`Throw` should not emit values"),
26///     |termination| terminations.push(termination),
27/// );
28///
29/// assert_eq!(terminations, vec![Termination::Error("boom")]);
30/// ```
31#[derive(Educe)]
32#[educe(Debug, Clone)]
33pub struct Throw<E>(E);
34
35impl<E> Throw<E> {
36    pub fn new(error: E) -> Self {
37        Self(error)
38    }
39}
40
41impl<'or, 'sub, E> Observable<'or, 'sub, Infallible, E> for Throw<E> {
42    fn subscribe(
43        self,
44        observer: impl Observer<Infallible, E> + NecessarySendSync + 'or,
45    ) -> Subscription<'sub> {
46        observer.on_termination(Termination::Error(self.0));
47        Subscription::default()
48    }
49}
rx_rust/operators/creating/throw.rs

rx_rust/operators/creating/
throw.rs
