router: replace RouterStatus with Poll

src/autorouter/autoroute.rs

@@ -2,14 +2,15 @@
 //!  routing steps. Provides access to navigation meshes, traces, ghost shapes,
 //! and obstacles encountered during routing.
 
+use core::task::Poll;
 use petgraph::graph::EdgeIndex;
 
 use crate::{
     board::mesadata::AccessMesadata,
     drawing::{band::BandTermsegIndex, graph::PrimitiveIndex},
     geometry::primitive::PrimitiveShape,
-    router::{navmesh::Navmesh, route::RouteStepper, trace::TraceStepper, Router, RouterStatus},
-    stepper::{Step, StepError},
+    router::{navmesh::Navmesh, route::RouteStepper, trace::TraceStepper, Router},
+    stepper::{PollStep, Step, StepError},
 };
 
 use super::{
@@ -107,10 +108,11 @@ impl<M: AccessMesadata> Step<Autorouter<M>, AutorouteStatus> for AutorouteExecut
             let mut router =
                 Router::new(autorouter.board.layout_mut(), self.options.router_options);
 
-            let RouterStatus::Finished(band_termseg) = route.step(&mut router)? else {
-                return Ok(AutorouteStatus::Running);
-            };
-            band_termseg
+            match route.poll_step(&mut router) {
+                Poll::Pending => return Ok(AutorouteStatus::Running),
+                Poll::Ready(Ok(band_termseg)) => band_termseg,
+                Poll::Ready(Err(err)) => return Err(err.into()),
+            }
         };
 
         let band = autorouter

src/router/route.rs

@@ -1,14 +1,18 @@
+use core::task::Poll;
+
 use crate::{
-    drawing::{dot::FixedDotIndex, graph::PrimitiveIndex, rules::AccessRules},
+    drawing::{
+        band::BandTermsegIndex, dot::FixedDotIndex, graph::PrimitiveIndex, rules::AccessRules,
+    },
     geometry::primitive::PrimitiveShape,
     router::{
         astar::{Astar, AstarError, AstarStatus},
         navmesh::{Navmesh, NavmeshError},
         trace::TraceStepper,
         tracer::Tracer,
-        Router, RouterAstarStrategy, RouterStatus,
+        Router, RouterAstarStrategy,
     },
-    stepper::{Step, StepError},
+    stepper::{PollStep, Step, StepError},
 };
 
 pub struct RouteStepper {
@@ -75,17 +79,15 @@ impl StepError for RouteStepper {
     type Error = AstarError;
 }
 
-impl<'a, R: AccessRules> Step<Router<'a, R>, RouterStatus> for RouteStepper {
-    fn step(&mut self, router: &mut Router<R>) -> Result<RouterStatus, AstarError> {
+impl<'a, R: AccessRules> PollStep<Router<'a, R>, BandTermsegIndex> for RouteStepper {
+    fn poll_step(&mut self, router: &mut Router<R>) -> Poll<Result<BandTermsegIndex, AstarError>> {
         let tracer = Tracer::new(router.layout_mut());
         let target = self.astar.graph.destination();
         let mut strategy = RouterAstarStrategy::new(tracer, &mut self.trace, target);
 
         let result = match self.astar.step(&mut strategy)? {
-            AstarStatus::Probing | AstarStatus::Probed | AstarStatus::Visited => {
-                Ok(RouterStatus::Running)
-            }
-            AstarStatus::Finished(_cost, _path, band) => Ok(RouterStatus::Finished(band)),
+            AstarStatus::Probing | AstarStatus::Probed | AstarStatus::Visited => Poll::Pending,
+            AstarStatus::Finished(_cost, _path, band) => Poll::Ready(Ok(band)),
         };
 
         self.ghosts = strategy.probe_ghosts;

src/router/router.rs

@@ -35,22 +35,6 @@ pub struct RouterOptions {
     pub squeeze_through_under_bands: bool,
 }
 
-#[derive(Debug)]
-pub enum RouterStatus {
-    Running,
-    Finished(BandTermsegIndex),
-}
-
-impl TryInto<BandTermsegIndex> for RouterStatus {
-    type Error = ();
-    fn try_into(self) -> Result<BandTermsegIndex, ()> {
-        match self {
-            RouterStatus::Running => Err(()),
-            RouterStatus::Finished(band_termseg) => Ok(band_termseg),
-        }
-    }
-}
-
 #[derive(Debug)]
 pub struct RouterAstarStrategy<'a, R: AccessRules> {
     pub tracer: Tracer<'a, R>,