Function callbag::map

pub fn map<I: 'static, O: 'static, F: 'static, S>(
    f: F
) -> Box<dyn Fn(S) -> Source<O>> where
    F: Fn(I) -> O + Send + Sync + Clone,
    S: Into<Arc<Source<I>>>, 

Callbag operator that applies a transformation on data passing through it.

Works on either pullable or listenable sources.

See https://github.com/staltz/callbag-map/blob/b9d984b78bf4301d0525b21f928d896842e17a0a/readme.js#L24-L29

Examples

use crossbeam_queue::SegQueue;
use std::sync::Arc;

use callbag::{for_each, from_iter, map};

let actual = Arc::new(SegQueue::new());

let source = map(|x| (x as f64 * 0.1) as usize)(from_iter([10, 20, 30, 40]));

for_each({
    let actual = Arc::clone(&actual);
    move |x| {
        println!("{}", x);
        actual.push(x);
    }
})(source);

assert_eq!(
    &{
        let mut v = vec![];
        for _i in 0..actual.len() {
            v.push(actual.pop().unwrap());
        }
        v
    }[..],
    [1, 2, 3, 4]
);