pub fn unfold<T, F, Fut, Item>(seed: T, f: F) -> Unfold<T, F, Fut> where
F: FnMut(T) -> Fut,
Fut: Future<Output = Option<(Item, T)>>,
Expand description
Creates a stream from a seed value and an async closure operating on it.
Examples
use futures_lite::stream::{self, StreamExt};
let s = stream::unfold(0, |mut n| async move {
if n < 2 {
let m = n + 1;
Some((n, m))
} else {
None
}
});
let v: Vec<i32> = s.collect().await;
assert_eq!(v, [0, 1]);