single tower

tower/src/lib.rs

@@ -0,0 +1,59 @@
+// #![allow(warnings)]
+
+pub mod balance;
+pub mod make;
+
+pub trait Sealed<T> {}
+
+/// Alias for a type-erased error type.
+pub type BoxError = Box<dyn std::error::Error + Send + Sync>;
+
+mod load {
+    pub trait Load {
+        type Metric;
+        fn load(&self) -> Self::Metric;
+    }
+}
+
+use std::future::Future;
+use std::task::Poll;
+
+use futures_core::TryStream;
+
+pub trait Discover {
+    type Key: Eq;
+    type Service;
+    type Error;
+}
+
+impl<K, S, E, D: ?Sized> Sealed<Change<(), ()>> for D
+where
+    D: TryStream<Ok = Change<K, S>, Error = E>,
+    K: Eq,
+{
+}
+
+impl<K, S, E, D: ?Sized> Discover for D
+where
+    D: TryStream<Ok = Change<K, S>, Error = E>,
+    K: Eq,
+{
+    type Key = K;
+    type Service = S;
+    type Error = E;
+}
+
+pub struct Change<K, V>(K, V);
+
+pub trait Service<Request> {
+    /// Responses given by the service.
+    type Response;
+
+    /// Errors produced by the service.
+    type Error;
+
+    /// The future response value.
+    type Future: Future<Output = Result<Self::Response, Self::Error>>;
+
+    fn poll_ready(&mut self) -> Poll<Result<(), Self::Error>>;
+}