Function take_while 

pub fn take_while<T, F, Fut>(s: RS2Stream<T>, predicate: F) -> RS2Stream<T>
where
    F: FnMut(&T) -> Fut + Send + 'static,
    Fut: Future<Output = bool> + Send + 'static,
    T: Send + 'static,

Take elements from a stream while a predicate returns true

This combinator yields elements from the stream as long as the predicate returns true. It stops (and does not yield) the first element where the predicate returns false.

Examples

use rs2_stream::rs2::*;
use futures_util::stream::StreamExt;

let stream = from_iter(vec![1, 2, 3, 4, 5]);
let result = take_while(stream, |&x| async move { x < 4 }).collect::<Vec<_>>().await;
assert_eq!(result, vec![1, 2, 3]);