router: TraceStepper is not a real stepper

Contributes towards solving #82 properly later.

src/router/router.rs

@@ -19,7 +19,6 @@ use crate::{
     },
     graph::{GetPetgraphIndex, MakeRef},
     layout::Layout,
-    stepper::{Step, StepBack},
 };
 
 use super::{

src/router/trace.rs

@@ -1,21 +1,17 @@
 use contracts::debug_ensures;
 use petgraph::data::DataMap;
 
-use crate::{
-    drawing::{
-        bend::LooseBendIndex,
-        dot::FixedDotIndex,
-        graph::PrimitiveIndex,
-        head::{BareHead, CaneHead, Head},
-        rules::AccessRules,
-    },
-    stepper::{Step, StepBack},
+use crate::drawing::{
+    bend::LooseBendIndex,
+    dot::FixedDotIndex,
+    graph::PrimitiveIndex,
+    head::{BareHead, CaneHead, Head},
+    rules::AccessRules,
 };
 
 use super::{
     draw::Draw,
     navmesh::{BinavvertexNodeIndex, Navmesh, NavvertexIndex},
-    tracer::TracerStatus,
     tracer::{Tracer, TracerException},
 };
 
@@ -104,16 +100,14 @@ pub struct TraceStepContext<'a: 'b, 'b, R: AccessRules> {
     pub width: f64,
 }
 
-impl<'a, 'b, R: AccessRules> Step<TraceStepContext<'a, 'b, R>, TracerStatus, TracerException, ()>
-    for TraceStepper
-{
+impl TraceStepper {
     #[debug_ensures(ret.is_ok() -> matches!(self.head, Head::Cane(..)))]
     #[debug_ensures(ret.is_ok() -> self.path.len() == old(self.path.len() + 1))]
     #[debug_ensures(ret.is_err() -> self.path.len() == old(self.path.len()))]
-    fn step(
+    pub fn step<'a, 'b, R: AccessRules>(
         &mut self,
         input: &mut TraceStepContext<'a, 'b, R>,
-    ) -> Result<TracerStatus, TracerException> {
+    ) -> Result<(), TracerException> {
         self.head = self
             .wrap(
                 input.tracer,
@@ -125,13 +119,14 @@ impl<'a, 'b, R: AccessRules> Step<TraceStepContext<'a, 'b, R>, TracerStatus, Tra
             .into();
         self.path.push(input.to);
 
-        Ok(TracerStatus::Running)
+        Ok(())
     }
-}
 
-impl<'a, R: AccessRules> StepBack<Tracer<'a, R>, TracerStatus, TracerException> for TraceStepper {
     #[debug_ensures(self.path.len() == old(self.path.len() - 1))]
-    fn step_back(&mut self, tracer: &mut Tracer<'a, R>) -> Result<TracerStatus, TracerException> {
+    pub fn step_back<'a, R: AccessRules>(
+        &mut self,
+        tracer: &mut Tracer<'a, R>,
+    ) -> Result<(), TracerException> {
         if let Head::Cane(head) = self.head {
             self.head = Draw::new(tracer.layout).undo_cane(head).unwrap();
         } else {
@@ -139,6 +134,6 @@ impl<'a, R: AccessRules> StepBack<Tracer<'a, R>, TracerStatus, TracerException>
         }
 
         self.path.pop();
-        Ok(TracerStatus::Running)
+        Ok(())
     }
 }

src/router/tracer.rs

@@ -4,7 +4,6 @@ use thiserror::Error;
 use crate::{
     drawing::{band::BandTermsegIndex, dot::FixedDotIndex, rules::AccessRules},
     layout::Layout,
-    stepper::{Step, StepBack},
 };
 
 use super::{
@@ -21,21 +20,6 @@ pub enum TracerException {
     CannotWrap,
 }
 
-pub enum TracerStatus {
-    Running,
-    Finished,
-}
-
-impl TryInto<()> for TracerStatus {
-    type Error = ();
-    fn try_into(self) -> Result<(), ()> {
-        match self {
-            TracerStatus::Running => Err(()),
-            TracerStatus::Finished => Ok(()),
-        }
-    }
-}
-
 #[derive(Debug)]
 pub struct Tracer<'a, R: AccessRules> {
     pub layout: &'a mut Layout<R>,