use futures::{Async, Poll};
use actor::Actor;
use fut::ActorFuture;
#[derive(Debug)]
#[must_use = "futures do nothing unless polled"]
pub struct Map<A, F> where A: ActorFuture {
future: A,
f: Option<F>,
}
pub fn new<A, F>(future: A, f: F) -> Map<A, F>
where A: ActorFuture,
{
Map {
future: future,
f: Some(f),
}
}
impl<U, A, F> ActorFuture for Map<A, F>
where A: ActorFuture,
F: FnOnce(A::Item, &mut A::Actor, &mut <A::Actor as Actor>::Context) -> U,
{
type Item = U;
type Error = A::Error;
type Actor = A::Actor;
fn poll(&mut self,
act: &mut Self::Actor,
ctx: &mut <A::Actor as Actor>::Context) -> Poll<U, A::Error>
{
let e = match self.future.poll(act, ctx) {
Ok(Async::NotReady) => return Ok(Async::NotReady),
Ok(Async::Ready(e)) => Ok(e),
Err(e) => Err(e),
};
match e {
Ok(item) =>
Ok(Async::Ready(
self.f.take().expect("cannot poll Map twice")(item, act, ctx))),
Err(err) => Err(err)
}
}
}