Removed unused future combinators.

Author: horned-sphere

swimos_utilities/swimos_future/src/combinators/mod.rs

@@ -28,7 +28,7 @@ pub use immediate_or::{
     immediate_or_join, immediate_or_start, ImmediateOrJoin, ImmediateOrStart, SecondaryResult,
 };
 
-pub use race::{race, race3, Either3, Race2, Race3};
+pub use race::{race, Race2};
 
 /// A stream that runs another stream of [`Result`]s until it produces an error and then
 /// terminates.

swimos_utilities/swimos_future/src/combinators/race/mod.rs

@@ -59,94 +59,3 @@ where
         Poll::Pending
     }
 }
-
-#[must_use = "futures do nothing unless you `.await` or poll them"]
-#[derive(Debug)]
-pub struct Race3<L, M, R> {
-    left: L,
-    middle: M,
-    right: R,
-}
-
-impl<L, M, R> Unpin for Race3<L, M, R>
-where
-    L: Unpin,
-    M: Unpin,
-    R: Unpin,
-{
-}
-
-/// Waits for either one of three differently-typed futures to complete and then discards the other
-/// future. If all futures are ready then the left future's output is returned.
-///
-/// This function differs to Future's Select functionality where it discards the remaining futures.
-///
-/// # Cancel safety
-/// This function is not cancellation safe. If a future makes progress and another completes first,
-/// then the data may be lost in the pending future. If cancellation safety is required, then
-/// future's select may be more appropriate.
-pub fn race3<L, M, R>(left: L, middle: M, right: R) -> Race3<L, M, R>
-where
-    L: Future + Unpin,
-    R: Future + Unpin,
-{
-    Race3 {
-        left,
-        middle,
-        right,
-    }
-}
-
-pub enum Either3<L, M, R> {
-    Left(L),
-    Middle(M),
-    Right(R),
-}
-
-impl<L, M, R> Either3<L, M, R> {
-    /// Return true if the value is the left variant.
-    pub fn is_left(&self) -> bool {
-        matches!(self, Either3::Left(_))
-    }
-
-    /// Return true if the value is the middle variant.
-    pub fn is_middle(&self) -> bool {
-        matches!(self, Either3::Middle(_))
-    }
-
-    /// Return true if the value is the right variant.
-    pub fn is_right(&self) -> bool {
-        matches!(self, Either3::Right(_))
-    }
-}
-
-impl<L, M, R> Future for Race3<L, M, R>
-where
-    L: Future + Unpin,
-    M: Future + Unpin,
-    R: Future + Unpin,
-{
-    type Output = Either3<L::Output, M::Output, R::Output>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let Race3 {
-            left,
-            middle,
-            right,
-        } = self.as_mut().get_mut();
-
-        if let Poll::Ready(output) = left.poll_unpin(cx) {
-            return Poll::Ready(Either3::Left(output));
-        }
-
-        if let Poll::Ready(output) = middle.poll_unpin(cx) {
-            return Poll::Ready(Either3::Middle(output));
-        }
-
-        if let Poll::Ready(output) = right.poll_unpin(cx) {
-            return Poll::Ready(Either3::Right(output));
-        }
-
-        Poll::Pending
-    }
-}

swimos_utilities/swimos_future/src/combinators/race/tests.rs

@@ -1,4 +1,4 @@
-use crate::combinators::{race, race3, Either3};
+use crate::combinators::race;
 use futures::future::{pending, ready};
 use futures::FutureExt;
 
@@ -16,28 +16,3 @@ async fn race2_test() {
     let both_ready = race(ready(()), ready(())).await;
     assert!(both_ready.is_left());
 }
-
-#[tokio::test]
-async fn race3_test() {
-    let left_ready = race3(ready(()), pending::<()>(), pending::<()>()).await;
-    assert!(left_ready.is_left());
-
-    let middle_ready = race3(pending::<()>(), ready(()), pending::<()>()).await;
-    assert!(middle_ready.is_middle());
-
-    let right_ready = race3(pending::<()>(), pending::<()>(), ready(())).await;
-    assert!(right_ready.is_right());
-
-    let all_pending = race3(pending::<()>(), pending::<()>(), pending::<()>());
-    assert!(all_pending.now_or_never().is_none());
-
-    let both_ready = race3(ready(()), ready(()), ready(())).await;
-    assert!(both_ready.is_left());
-}
-
-#[test]
-fn either_three() {
-    assert!(Either3::<(), (), ()>::Left(()).is_left());
-    assert!(Either3::<(), (), ()>::Middle(()).is_middle());
-    assert!(Either3::<(), (), ()>::Right(()).is_right());
-}

swimos_utilities/swimos_future/src/lib.rs

@@ -17,8 +17,8 @@ mod retry_strategy;
 mod union;
 
 pub use combinators::{
-    immediate_or_join, immediate_or_start, race, race3, try_last, Either3, ImmediateOrJoin,
-    ImmediateOrStart, NotifyOnBlocked, Race2, Race3, SecondaryResult, StopAfterError,
+    immediate_or_join, immediate_or_start, race, try_last, ImmediateOrJoin, ImmediateOrStart,
+    NotifyOnBlocked, Race2, SecondaryResult, StopAfterError,
 };
 pub use retry_strategy::{ExponentialStrategy, IntervalStrategy, Quantity, RetryStrategy};
 pub use union::{UnionFuture3, UnionFuture4};