refactor(router/navcord): Make it clear that navcord is not a stepper

Rename `NavcordStepper<...>` to `Navcord<...>. Since the navcord is not
actually considered a true stepper, having the word "stepper" in its
identifier would confuse anyone new to source-diving Topola's code.

Rename Navcord's `.step(...)` to `.step_to(...)` to make it clear
that this is not just a step like in a stepper, but a step to a some
specified position.

src/autorouter/autoroute.rs

@@ -15,7 +15,7 @@ use crate::{
     geometry::primitive::PrimitiveShape,
     layout::LayoutEdit,
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
         RouteStepper, Router,
     },
@@ -169,7 +169,7 @@ impl GetMaybeNavmesh for AutorouteExecutionStepper {
 }
 
 impl GetMaybeNavcord for AutorouteExecutionStepper {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         self.route.as_ref().map(|route| route.navcord())
     }
 }

src/autorouter/compare_detours.rs

@@ -15,7 +15,7 @@ use crate::{
     geometry::{primitive::PrimitiveShape, shape::MeasureLength},
     graph::MakeRef,
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
     stepper::Step,
@@ -110,7 +110,7 @@ impl GetMaybeNavmesh for CompareDetoursExecutionStepper {
 }
 
 impl GetMaybeNavcord for CompareDetoursExecutionStepper {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         self.autoroute.maybe_navcord()
     }
 }

src/autorouter/invoker.rs

@@ -16,7 +16,7 @@ use crate::{
     drawing::graph::PrimitiveIndex,
     geometry::{edit::ApplyGeometryEdit, primitive::PrimitiveShape},
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
     stepper::Step,
@@ -42,7 +42,7 @@ pub trait GetMaybeNavmesh {
 #[enum_dispatch]
 /// Trait for getting the navcord to display it on the debug overlay.
 pub trait GetMaybeNavcord {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper>;
+    fn maybe_navcord(&self) -> Option<&Navcord>;
 }
 
 #[enum_dispatch]

src/autorouter/measure_length.rs

@@ -12,7 +12,7 @@ use crate::{
     geometry::{primitive::PrimitiveShape, shape::MeasureLength as MeasureLengthTrait},
     graph::MakeRef,
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
 };
@@ -65,7 +65,7 @@ impl GetMaybeNavmesh for MeasureLengthExecutionStepper {
 }
 
 impl GetMaybeNavcord for MeasureLengthExecutionStepper {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         None
     }
 }

src/autorouter/place_via.rs

@@ -12,7 +12,7 @@ use crate::{
     geometry::primitive::PrimitiveShape,
     layout::{via::ViaWeight, LayoutEdit},
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
 };
@@ -62,7 +62,7 @@ impl GetMaybeNavmesh for PlaceViaExecutionStepper {
 }
 
 impl GetMaybeNavcord for PlaceViaExecutionStepper {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         None
     }
 }

src/autorouter/remove_bands.rs

@@ -10,7 +10,7 @@ use crate::{
     geometry::primitive::PrimitiveShape,
     layout::LayoutEdit,
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
 };
@@ -61,7 +61,7 @@ impl GetMaybeNavmesh for RemoveBandsExecutionStepper {
 }
 
 impl GetMaybeNavcord for RemoveBandsExecutionStepper {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         None
     }
 }

src/interactor/activity.rs

@@ -21,7 +21,7 @@ use crate::{
     geometry::primitive::PrimitiveShape,
     interactor::interaction::{InteractionError, InteractionStepper},
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
     stepper::{Abort, Step},
@@ -131,7 +131,7 @@ impl GetMaybeNavmesh for ActivityStepperWithStatus {
 }
 
 impl GetMaybeNavcord for ActivityStepperWithStatus {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         self.activity.maybe_navcord()
     }
 }

src/interactor/interaction.rs

@@ -14,7 +14,7 @@ use crate::{
     drawing::graph::PrimitiveIndex,
     geometry::primitive::PrimitiveShape,
     router::{
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navmesh::{Navmesh, NavvertexIndex},
     },
     stepper::{Abort, Step},
@@ -59,7 +59,7 @@ impl GetMaybeNavmesh for InteractionStepper {
 }
 
 impl GetMaybeNavcord for InteractionStepper {
-    fn maybe_navcord(&self) -> Option<&NavcordStepper> {
+    fn maybe_navcord(&self) -> Option<&Navcord> {
         todo!()
     }
 }

src/router/navcord.rs

@@ -20,30 +20,30 @@ use super::{
     navmesh::{BinavvertexNodeIndex, Navmesh, NavvertexIndex},
 };
 
-/// The navcord (stepper) is a structure that holds the movable non-borrowing
+/// The navcord is a structure that holds the movable non-borrowing
 /// data of the currently running routing process.
 ///
 /// The name "navcord" is a shortening of "navigation cord", by analogy to
 /// "navmesh" being a shortening of "navigation mesh".
 #[derive(Debug)]
-pub struct NavcordStepper {
+pub struct Navcord {
     pub recorder: LayoutEdit,
     /// The currently attempted path.
     pub path: Vec<NavvertexIndex>,
-    /// The head of the routed band.
+    /// The head of the currently routed band.
     pub head: Head,
-    /// The width of the routed band.
+    /// The width of the currently routed band.
     pub width: f64,
 }
 
-impl NavcordStepper {
+impl Navcord {
     /// Creates a new navcord.
     pub fn new(
         recorder: LayoutEdit,
         source: FixedDotIndex,
         source_navvertex: NavvertexIndex,
         width: f64,
-    ) -> NavcordStepper {
+    ) -> Navcord {
         Self {
             recorder,
             path: vec![source_navvertex],
@@ -89,7 +89,7 @@ impl NavcordStepper {
     #[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()))]
-    pub fn step<R: AccessRules>(
+    pub fn step_to<R: AccessRules>(
         &mut self,
         layout: &mut Layout<R>,
         navmesh: &Navmesh,

src/router/navcorder.rs

@@ -12,7 +12,7 @@ use crate::{
 
 use super::{
     draw::{Draw, DrawException},
-    navcord::NavcordStepper,
+    navcord::Navcord,
     navmesh::{Navmesh, NavvertexIndex},
 };
 
@@ -31,30 +31,30 @@ pub trait Navcorder {
         source: FixedDotIndex,
         source_navvertex: NavvertexIndex,
         width: f64,
-    ) -> NavcordStepper;
+    ) -> Navcord;
 
     fn finish(
         &mut self,
         _navmesh: &Navmesh,
-        navcord: &mut NavcordStepper,
+        navcord: &mut Navcord,
         target: FixedDotIndex,
     ) -> Result<BandTermsegIndex, NavcorderException>;
 
     fn rework_path(
         &mut self,
         navmesh: &Navmesh,
-        navcord: &mut NavcordStepper,
+        navcord: &mut Navcord,
         path: &[NavvertexIndex],
     ) -> Result<(), NavcorderException>;
 
     fn path(
         &mut self,
         navmesh: &Navmesh,
-        navcord: &mut NavcordStepper,
+        navcord: &mut Navcord,
         path: &[NavvertexIndex],
     ) -> Result<(), NavcorderException>;
 
-    fn undo_path(&mut self, navcord: &mut NavcordStepper, step_count: usize);
+    fn undo_path(&mut self, navcord: &mut Navcord, step_count: usize);
 }
 
 impl<R: AccessRules> Navcorder for Layout<R> {
@@ -64,14 +64,14 @@ impl<R: AccessRules> Navcorder for Layout<R> {
         source: FixedDotIndex,
         source_navvertex: NavvertexIndex,
         width: f64,
-    ) -> NavcordStepper {
-        NavcordStepper::new(recorder, source, source_navvertex, width)
+    ) -> Navcord {
+        Navcord::new(recorder, source, source_navvertex, width)
     }
 
     fn finish(
         &mut self,
         _navmesh: &Navmesh,
-        navcord: &mut NavcordStepper,
+        navcord: &mut Navcord,
         target: FixedDotIndex,
     ) -> Result<BandTermsegIndex, NavcorderException> {
         Ok(self.finish_in_dot(&mut navcord.recorder, navcord.head, target, navcord.width)?)
@@ -82,7 +82,7 @@ impl<R: AccessRules> Navcorder for Layout<R> {
     fn rework_path(
         &mut self,
         navmesh: &Navmesh,
-        navcord: &mut NavcordStepper,
+        navcord: &mut Navcord,
         path: &[NavvertexIndex],
     ) -> Result<(), NavcorderException> {
         let prefix_length = navcord
@@ -101,11 +101,11 @@ impl<R: AccessRules> Navcorder for Layout<R> {
     fn path(
         &mut self,
         navmesh: &Navmesh,
-        navcord: &mut NavcordStepper,
+        navcord: &mut Navcord,
         path: &[NavvertexIndex],
     ) -> Result<(), NavcorderException> {
         for (i, vertex) in path.iter().enumerate() {
-            if let Err(err) = navcord.step(self, navmesh, *vertex) {
+            if let Err(err) = navcord.step_to(self, navmesh, *vertex) {
                 self.undo_path(navcord, i);
                 return Err(err);
             }
@@ -115,7 +115,7 @@ impl<R: AccessRules> Navcorder for Layout<R> {
     }
 
     #[debug_ensures(navcord.path.len() == old(navcord.path.len() - step_count))]
-    fn undo_path(&mut self, navcord: &mut NavcordStepper, step_count: usize) {
+    fn undo_path(&mut self, navcord: &mut Navcord, step_count: usize) {
         for _ in 0..step_count {
             let _ = navcord.step_back(self);
         }

src/router/route.rs

@@ -14,7 +14,7 @@ use crate::{
     layout::LayoutEdit,
     router::{
         astar::{Astar, AstarError},
-        navcord::NavcordStepper,
+        navcord::Navcord,
         navcorder::Navcorder,
         navmesh::{Navmesh, NavmeshError},
         Router, RouterAstarStrategy,
@@ -26,7 +26,7 @@ use crate::{
 pub struct RouteStepper {
     #[getter(skip)]
     astar: Astar<Navmesh, f64>,
-    navcord: NavcordStepper,
+    navcord: Navcord,
     ghosts: Vec<PrimitiveShape>,
     obstacles: Vec<PrimitiveIndex>,
 }

src/router/router.rs

@@ -28,7 +28,7 @@ use crate::{
 use super::{
     astar::{AstarStrategy, PathTracker},
     draw::DrawException,
-    navcord::NavcordStepper,
+    navcord::Navcord,
     navcorder::{Navcorder, NavcorderException},
     navmesh::{Navmesh, NavmeshEdgeReference, NavmeshError, NavvertexIndex},
     route::RouteStepper,
@@ -44,18 +44,14 @@ pub struct RouterOptions {
 #[derive(Debug)]
 pub struct RouterAstarStrategy<'a, R> {
     pub layout: &'a mut Layout<R>,
-    pub navcord: &'a mut NavcordStepper,
+    pub navcord: &'a mut Navcord,
     pub target: FixedDotIndex,
     pub probe_ghosts: Vec<PrimitiveShape>,
     pub probe_obstacles: Vec<PrimitiveIndex>,
 }
 
 impl<'a, R> RouterAstarStrategy<'a, R> {
-    pub fn new(
-        layout: &'a mut Layout<R>,
-        navcord: &'a mut NavcordStepper,
-        target: FixedDotIndex,
-    ) -> Self {
+    pub fn new(layout: &'a mut Layout<R>, navcord: &'a mut Navcord, target: FixedDotIndex) -> Self {
         Self {
             layout,
             navcord,
@@ -103,7 +99,7 @@ impl<R: AccessRules> AstarStrategy<Navmesh, f64, BandTermsegIndex> for RouterAst
         }
 
         let prev_bihead_length = self.bihead_length();
-        let result = self.navcord.step(self.layout, navmesh, edge.target());
+        let result = self.navcord.step_to(self.layout, navmesh, edge.target());
         let probe_length = self.bihead_length() - prev_bihead_length;
 
         match result {