From 9e18066ec2a5614c05e5035189231bf6051958a7 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:43:11 +0100
Subject: [PATCH 01/15] Convert `HalfEdgeBuilder` into struct

---
 .../fj-kernel/src/algorithms/approx/edge.rs   |  6 +-
 crates/fj-kernel/src/algorithms/sweep/edge.rs |  2 +-
 crates/fj-kernel/src/builder/cycle.rs         |  4 +-
 crates/fj-kernel/src/builder/edge.rs          | 56 +++++--------------
 crates/fj-operations/src/sketch.rs            |  9 +--
 5 files changed, 25 insertions(+), 52 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 80e038c42..fac854ea6 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -267,7 +267,7 @@ mod tests {
         builder::{CycleBuilder, HalfEdgeBuilder},
         geometry::{curve::GlobalPath, surface::SurfaceGeometry},
         insert::Insert,
-        objects::{HalfEdge, Surface},
+        objects::Surface,
         partial::{PartialCycle, PartialObject},
         services::Services,
     };
@@ -332,7 +332,7 @@ mod tests {
             v: [0., 0., 1.].into(),
         })
         .insert(&mut services.objects);
-        let half_edge = HalfEdge::make_line_segment(
+        let half_edge = HalfEdgeBuilder::make_line_segment(
             [[0., 1.], [TAU, 1.]],
             Some(range.boundary),
             None,
@@ -362,7 +362,7 @@ mod tests {
         let mut services = Services::new();
 
         let surface = services.objects.surfaces.xz_plane();
-        let half_edge = HalfEdge::make_circle(1., &mut services.objects);
+        let half_edge = HalfEdgeBuilder::make_circle(1., &mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index bbcdc4961..5fc50e438 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -88,7 +88,7 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
             .zip_ext(vertices)
             .zip_ext(global_edges)
             .map(|((((boundary, start), end), start_vertex), global_edge)| {
-                let half_edge = HalfEdge::make_line_segment(
+                let half_edge = HalfEdgeBuilder::make_line_segment(
                     [start, end],
                     Some(boundary),
                     Some(start_vertex),
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 77e7bff35..2a5e79361 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -63,7 +63,7 @@ impl CycleBuilder for PartialCycle {
         P: Clone + Into<Point<2>>,
     {
         points.map_with_next(|start, end| {
-            let half_edge = HalfEdge::make_line_segment(
+            let half_edge = HalfEdgeBuilder::make_line_segment(
                 [start, end],
                 None,
                 None,
@@ -86,7 +86,7 @@ impl CycleBuilder for PartialCycle {
         O: ObjectArgument<(Handle<HalfEdge>, Curve, [Point<1>; 2])>,
     {
         edges.map_with_prev(|(_, curve, boundary), (prev, _, _)| {
-            let half_edge = HalfEdge::make_half_edge(
+            let half_edge = HalfEdgeBuilder::make_half_edge(
                 curve,
                 boundary,
                 Some(prev.start_vertex().clone()),
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 1ac9e6bdc..0c8391b93 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -10,46 +10,11 @@ use crate::{
 };
 
 /// Builder API for [`HalfEdge`]
-pub trait HalfEdgeBuilder {
-    /// Create a circle
-    fn make_circle(
-        radius: impl Into<Scalar>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge>;
-
-    /// Create an arc
-    ///
-    /// # Panics
-    ///
-    /// Panics if the given angle is not within the range (-2pi, 2pi) radians.
-    fn make_arc(
-        start: impl Into<Point<2>>,
-        end: impl Into<Point<2>>,
-        angle_rad: impl Into<Scalar>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge>;
-
-    /// Create a line segment
-    fn make_line_segment(
-        points_surface: [impl Into<Point<2>>; 2],
-        boundary: Option<[Point<1>; 2]>,
-        start_vertex: Option<Handle<Vertex>>,
-        global_form: Option<Handle<GlobalEdge>>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge>;
-
-    /// Create a half-edge
-    fn make_half_edge(
-        curve: Curve,
-        boundary: [Point<1>; 2],
-        start_vertex: Option<Handle<Vertex>>,
-        global_form: Option<Handle<GlobalEdge>>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge>;
-}
+pub struct HalfEdgeBuilder {}
 
-impl HalfEdgeBuilder for HalfEdge {
-    fn make_circle(
+impl HalfEdgeBuilder {
+    /// Create a circle
+    pub fn make_circle(
         radius: impl Into<Scalar>,
         objects: &mut Service<Objects>,
     ) -> Handle<HalfEdge> {
@@ -60,7 +25,12 @@ impl HalfEdgeBuilder for HalfEdge {
         Self::make_half_edge(curve, boundary, None, None, objects)
     }
 
-    fn make_arc(
+    /// Create an arc
+    ///
+    /// # Panics
+    ///
+    /// Panics if the given angle is not within the range (-2pi, 2pi) radians.
+    pub fn make_arc(
         start: impl Into<Point<2>>,
         end: impl Into<Point<2>>,
         angle_rad: impl Into<Scalar>,
@@ -81,7 +51,8 @@ impl HalfEdgeBuilder for HalfEdge {
         Self::make_half_edge(curve, boundary, None, None, objects)
     }
 
-    fn make_line_segment(
+    /// Create a line segment
+    pub fn make_line_segment(
         points_surface: [impl Into<Point<2>>; 2],
         boundary: Option<[Point<1>; 2]>,
         start_vertex: Option<Handle<Vertex>>,
@@ -103,7 +74,8 @@ impl HalfEdgeBuilder for HalfEdge {
         )
     }
 
-    fn make_half_edge(
+    /// Create a half-edge
+    pub fn make_half_edge(
         curve: Curve,
         boundary: [Point<1>; 2],
         start_vertex: Option<Handle<Vertex>>,
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index c84cbc5fd..e889bd983 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -4,7 +4,7 @@ use fj_interop::{debug::DebugInfo, mesh::Color};
 use fj_kernel::{
     builder::{CycleBuilder, HalfEdgeBuilder},
     insert::Insert,
-    objects::{HalfEdge, Objects, Sketch},
+    objects::{Objects, Sketch},
     partial::{
         Partial, PartialCycle, PartialFace, PartialObject, PartialSketch,
     },
@@ -27,7 +27,8 @@ impl Shape for fj::Sketch {
 
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
-                let half_edge = HalfEdge::make_circle(circle.radius(), objects);
+                let half_edge =
+                    HalfEdgeBuilder::make_circle(circle.radius(), objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);
@@ -63,7 +64,7 @@ impl Shape for fj::Sketch {
                     for ((start, route), (end, _)) in segments {
                         let half_edge = match route {
                             fj::SketchSegmentRoute::Direct => {
-                                HalfEdge::make_line_segment(
+                                HalfEdgeBuilder::make_line_segment(
                                     [start, end],
                                     None,
                                     None,
@@ -72,7 +73,7 @@ impl Shape for fj::Sketch {
                                 )
                             }
                             fj::SketchSegmentRoute::Arc { angle } => {
-                                HalfEdge::make_arc(
+                                HalfEdgeBuilder::make_arc(
                                     start,
                                     end,
                                     angle.rad(),

From a9b96d1bb3aedba0da8ffb18105dec51dfaf4aef Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:44:01 +0100
Subject: [PATCH 02/15] Simplify method name to `HalfEdgeBuilder::circle`

---
 crates/fj-kernel/src/algorithms/approx/edge.rs | 2 +-
 crates/fj-kernel/src/builder/edge.rs           | 2 +-
 crates/fj-operations/src/sketch.rs             | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index fac854ea6..35cb482a5 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -362,7 +362,7 @@ mod tests {
         let mut services = Services::new();
 
         let surface = services.objects.surfaces.xz_plane();
-        let half_edge = HalfEdgeBuilder::make_circle(1., &mut services.objects);
+        let half_edge = HalfEdgeBuilder::circle(1., &mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 0c8391b93..03ef67eb5 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -14,7 +14,7 @@ pub struct HalfEdgeBuilder {}
 
 impl HalfEdgeBuilder {
     /// Create a circle
-    pub fn make_circle(
+    pub fn circle(
         radius: impl Into<Scalar>,
         objects: &mut Service<Objects>,
     ) -> Handle<HalfEdge> {
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index e889bd983..e8c703256 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -28,7 +28,7 @@ impl Shape for fj::Sketch {
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
                 let half_edge =
-                    HalfEdgeBuilder::make_circle(circle.radius(), objects);
+                    HalfEdgeBuilder::circle(circle.radius(), objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);

From 9e7c0dcfb2438dfbafd1431df374b91449ac000a Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:44:48 +0100
Subject: [PATCH 03/15] Simplify method name to `HalfEdgeBuilder::arc`

---
 crates/fj-kernel/src/builder/edge.rs | 2 +-
 crates/fj-operations/src/sketch.rs   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 03ef67eb5..93f518946 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -30,7 +30,7 @@ impl HalfEdgeBuilder {
     /// # Panics
     ///
     /// Panics if the given angle is not within the range (-2pi, 2pi) radians.
-    pub fn make_arc(
+    pub fn arc(
         start: impl Into<Point<2>>,
         end: impl Into<Point<2>>,
         angle_rad: impl Into<Scalar>,
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index e8c703256..a91fbed16 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -73,7 +73,7 @@ impl Shape for fj::Sketch {
                                 )
                             }
                             fj::SketchSegmentRoute::Arc { angle } => {
-                                HalfEdgeBuilder::make_arc(
+                                HalfEdgeBuilder::arc(
                                     start,
                                     end,
                                     angle.rad(),

From f2d403adc37a85d82ff340d7c80482dd01eb09f4 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:45:26 +0100
Subject: [PATCH 04/15] Move method to establish alphabetical ordering

---
 crates/fj-kernel/src/builder/edge.rs | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 93f518946..96bd6e0f7 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -13,18 +13,6 @@ use crate::{
 pub struct HalfEdgeBuilder {}
 
 impl HalfEdgeBuilder {
-    /// Create a circle
-    pub fn circle(
-        radius: impl Into<Scalar>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge> {
-        let curve = Curve::circle_from_radius(radius);
-        let boundary =
-            [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
-
-        Self::make_half_edge(curve, boundary, None, None, objects)
-    }
-
     /// Create an arc
     ///
     /// # Panics
@@ -51,6 +39,18 @@ impl HalfEdgeBuilder {
         Self::make_half_edge(curve, boundary, None, None, objects)
     }
 
+    /// Create a circle
+    pub fn circle(
+        radius: impl Into<Scalar>,
+        objects: &mut Service<Objects>,
+    ) -> Handle<HalfEdge> {
+        let curve = Curve::circle_from_radius(radius);
+        let boundary =
+            [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
+
+        Self::make_half_edge(curve, boundary, None, None, objects)
+    }
+
     /// Create a line segment
     pub fn make_line_segment(
         points_surface: [impl Into<Point<2>>; 2],

From d87f886f733e81f45277112b29eb71347d5f9ef8 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:46:14 +0100
Subject: [PATCH 05/15] Simplify name to `HalfEdgeBuilder::line_segment`

---
 crates/fj-kernel/src/algorithms/approx/edge.rs | 2 +-
 crates/fj-kernel/src/algorithms/sweep/edge.rs  | 2 +-
 crates/fj-kernel/src/builder/cycle.rs          | 2 +-
 crates/fj-kernel/src/builder/edge.rs           | 2 +-
 crates/fj-operations/src/sketch.rs             | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 35cb482a5..95d8cddb4 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -332,7 +332,7 @@ mod tests {
             v: [0., 0., 1.].into(),
         })
         .insert(&mut services.objects);
-        let half_edge = HalfEdgeBuilder::make_line_segment(
+        let half_edge = HalfEdgeBuilder::line_segment(
             [[0., 1.], [TAU, 1.]],
             Some(range.boundary),
             None,
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index 5fc50e438..5ce2e7020 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -88,7 +88,7 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
             .zip_ext(vertices)
             .zip_ext(global_edges)
             .map(|((((boundary, start), end), start_vertex), global_edge)| {
-                let half_edge = HalfEdgeBuilder::make_line_segment(
+                let half_edge = HalfEdgeBuilder::line_segment(
                     [start, end],
                     Some(boundary),
                     Some(start_vertex),
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 2a5e79361..4cebc67bc 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -63,7 +63,7 @@ impl CycleBuilder for PartialCycle {
         P: Clone + Into<Point<2>>,
     {
         points.map_with_next(|start, end| {
-            let half_edge = HalfEdgeBuilder::make_line_segment(
+            let half_edge = HalfEdgeBuilder::line_segment(
                 [start, end],
                 None,
                 None,
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 96bd6e0f7..c246e8d87 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -52,7 +52,7 @@ impl HalfEdgeBuilder {
     }
 
     /// Create a line segment
-    pub fn make_line_segment(
+    pub fn line_segment(
         points_surface: [impl Into<Point<2>>; 2],
         boundary: Option<[Point<1>; 2]>,
         start_vertex: Option<Handle<Vertex>>,
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index a91fbed16..2961fe065 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -64,7 +64,7 @@ impl Shape for fj::Sketch {
                     for ((start, route), (end, _)) in segments {
                         let half_edge = match route {
                             fj::SketchSegmentRoute::Direct => {
-                                HalfEdgeBuilder::make_line_segment(
+                                HalfEdgeBuilder::line_segment(
                                     [start, end],
                                     None,
                                     None,

From cf81d2f3db5e830600010ffc5dadfe97244bc4ac Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:47:18 +0100
Subject: [PATCH 06/15] Simplify method name to `HalfEdgeBuilder::build`

It doesn't quite fit right now, but it will fit once I finish
refactoring the API.
---
 crates/fj-kernel/src/builder/cycle.rs |  2 +-
 crates/fj-kernel/src/builder/edge.rs  | 14 ++++----------
 2 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 4cebc67bc..8490659c2 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -86,7 +86,7 @@ impl CycleBuilder for PartialCycle {
         O: ObjectArgument<(Handle<HalfEdge>, Curve, [Point<1>; 2])>,
     {
         edges.map_with_prev(|(_, curve, boundary), (prev, _, _)| {
-            let half_edge = HalfEdgeBuilder::make_half_edge(
+            let half_edge = HalfEdgeBuilder::build(
                 curve,
                 boundary,
                 Some(prev.start_vertex().clone()),
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index c246e8d87..1d0c109b2 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -36,7 +36,7 @@ impl HalfEdgeBuilder {
         let boundary =
             [arc.start_angle, arc.end_angle].map(|coord| Point::from([coord]));
 
-        Self::make_half_edge(curve, boundary, None, None, objects)
+        Self::build(curve, boundary, None, None, objects)
     }
 
     /// Create a circle
@@ -48,7 +48,7 @@ impl HalfEdgeBuilder {
         let boundary =
             [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
 
-        Self::make_half_edge(curve, boundary, None, None, objects)
+        Self::build(curve, boundary, None, None, objects)
     }
 
     /// Create a line segment
@@ -65,17 +65,11 @@ impl HalfEdgeBuilder {
             boundary.zip_ext(points_surface),
         );
 
-        Self::make_half_edge(
-            curve,
-            boundary,
-            start_vertex,
-            global_form,
-            objects,
-        )
+        Self::build(curve, boundary, start_vertex, global_form, objects)
     }
 
     /// Create a half-edge
-    pub fn make_half_edge(
+    pub fn build(
         curve: Curve,
         boundary: [Point<1>; 2],
         start_vertex: Option<Handle<Vertex>>,

From 2f6fbb37092726a256548711fb0d3b42d092c9b2 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:55:16 +0100
Subject: [PATCH 07/15] Separate actual build step in `HalfEdgeBuilder`

---
 .../fj-kernel/src/algorithms/approx/edge.rs   |  6 ++-
 crates/fj-kernel/src/algorithms/sweep/edge.rs |  5 +++
 crates/fj-kernel/src/builder/cycle.rs         |  7 ++--
 crates/fj-kernel/src/builder/edge.rs          | 40 ++++++++++---------
 crates/fj-operations/src/sketch.rs            |  4 +-
 5 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 95d8cddb4..5ab5ce028 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -338,7 +338,8 @@ mod tests {
             None,
             None,
             &mut services.objects,
-        );
+        )
+        .build(None, None, &mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
@@ -362,7 +363,8 @@ mod tests {
         let mut services = Services::new();
 
         let surface = services.objects.surfaces.xz_plane();
-        let half_edge = HalfEdgeBuilder::circle(1., &mut services.objects);
+        let half_edge = HalfEdgeBuilder::circle(1., &mut services.objects)
+            .build(None, None, &mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index 5ce2e7020..46eb20744 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -91,6 +91,11 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
                 let half_edge = HalfEdgeBuilder::line_segment(
                     [start, end],
                     Some(boundary),
+                    None,
+                    None,
+                    objects,
+                )
+                .build(
                     Some(start_vertex),
                     global_edge,
                     objects,
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 8490659c2..6390abb9e 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -69,7 +69,8 @@ impl CycleBuilder for PartialCycle {
                 None,
                 None,
                 objects,
-            );
+            )
+            .build(None, None, objects);
 
             self.add_half_edge(half_edge.clone());
 
@@ -86,9 +87,7 @@ impl CycleBuilder for PartialCycle {
         O: ObjectArgument<(Handle<HalfEdge>, Curve, [Point<1>; 2])>,
     {
         edges.map_with_prev(|(_, curve, boundary), (prev, _, _)| {
-            let half_edge = HalfEdgeBuilder::build(
-                curve,
-                boundary,
+            let half_edge = HalfEdgeBuilder::new(curve, boundary).build(
                 Some(prev.start_vertex().clone()),
                 None,
                 objects,
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 1d0c109b2..377975408 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -10,9 +10,17 @@ use crate::{
 };
 
 /// Builder API for [`HalfEdge`]
-pub struct HalfEdgeBuilder {}
+pub struct HalfEdgeBuilder {
+    curve: Curve,
+    boundary: [Point<1>; 2],
+}
 
 impl HalfEdgeBuilder {
+    /// Create an instance of `HalfEdgeBuilder`
+    pub fn new(curve: Curve, boundary: [Point<1>; 2]) -> Self {
+        Self { curve, boundary }
+    }
+
     /// Create an arc
     ///
     /// # Panics
@@ -22,8 +30,8 @@ impl HalfEdgeBuilder {
         start: impl Into<Point<2>>,
         end: impl Into<Point<2>>,
         angle_rad: impl Into<Scalar>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge> {
+        _: &mut Service<Objects>,
+    ) -> Self {
         let angle_rad = angle_rad.into();
         if angle_rad <= -Scalar::TAU || angle_rad >= Scalar::TAU {
             panic!("arc angle must be in the range (-2pi, 2pi) radians");
@@ -36,49 +44,45 @@ impl HalfEdgeBuilder {
         let boundary =
             [arc.start_angle, arc.end_angle].map(|coord| Point::from([coord]));
 
-        Self::build(curve, boundary, None, None, objects)
+        Self { curve, boundary }
     }
 
     /// Create a circle
-    pub fn circle(
-        radius: impl Into<Scalar>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge> {
+    pub fn circle(radius: impl Into<Scalar>, _: &mut Service<Objects>) -> Self {
         let curve = Curve::circle_from_radius(radius);
         let boundary =
             [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
 
-        Self::build(curve, boundary, None, None, objects)
+        Self { curve, boundary }
     }
 
     /// Create a line segment
     pub fn line_segment(
         points_surface: [impl Into<Point<2>>; 2],
         boundary: Option<[Point<1>; 2]>,
-        start_vertex: Option<Handle<Vertex>>,
-        global_form: Option<Handle<GlobalEdge>>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge> {
+        _: Option<Handle<Vertex>>,
+        _: Option<Handle<GlobalEdge>>,
+        _: &mut Service<Objects>,
+    ) -> Self {
         let boundary =
             boundary.unwrap_or_else(|| [[0.], [1.]].map(Point::from));
         let curve = Curve::line_from_points_with_coords(
             boundary.zip_ext(points_surface),
         );
 
-        Self::build(curve, boundary, start_vertex, global_form, objects)
+        Self { curve, boundary }
     }
 
     /// Create a half-edge
     pub fn build(
-        curve: Curve,
-        boundary: [Point<1>; 2],
+        self,
         start_vertex: Option<Handle<Vertex>>,
         global_form: Option<Handle<GlobalEdge>>,
         objects: &mut Service<Objects>,
     ) -> Handle<HalfEdge> {
         HalfEdge::new(
-            curve,
-            boundary,
+            self.curve,
+            self.boundary,
             start_vertex.unwrap_or_else(|| Vertex::new().insert(objects)),
             global_form.unwrap_or_else(|| GlobalEdge::new().insert(objects)),
         )
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index 2961fe065..a71fcfadb 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -28,7 +28,8 @@ impl Shape for fj::Sketch {
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
                 let half_edge =
-                    HalfEdgeBuilder::circle(circle.radius(), objects);
+                    HalfEdgeBuilder::circle(circle.radius(), objects)
+                        .build(None, None, objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);
@@ -82,6 +83,7 @@ impl Shape for fj::Sketch {
                             }
                         };
 
+                        let half_edge = half_edge.build(None, None, objects);
                         cycle.add_half_edge(half_edge);
                     }
 

From b640c856772efebc032c42ef9675b2fbb34582bf Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:56:25 +0100
Subject: [PATCH 08/15] Remove unused argument

---
 crates/fj-kernel/src/builder/edge.rs | 1 -
 crates/fj-operations/src/sketch.rs   | 7 +------
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 377975408..737c61e82 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -30,7 +30,6 @@ impl HalfEdgeBuilder {
         start: impl Into<Point<2>>,
         end: impl Into<Point<2>>,
         angle_rad: impl Into<Scalar>,
-        _: &mut Service<Objects>,
     ) -> Self {
         let angle_rad = angle_rad.into();
         if angle_rad <= -Scalar::TAU || angle_rad >= Scalar::TAU {
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index a71fcfadb..8c76bf6c2 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -74,12 +74,7 @@ impl Shape for fj::Sketch {
                                 )
                             }
                             fj::SketchSegmentRoute::Arc { angle } => {
-                                HalfEdgeBuilder::arc(
-                                    start,
-                                    end,
-                                    angle.rad(),
-                                    objects,
-                                )
+                                HalfEdgeBuilder::arc(start, end, angle.rad())
                             }
                         };
 

From 00906c83d01edd935022e2d4f085581db543dae7 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:57:21 +0100
Subject: [PATCH 09/15] Remove unused argument

---
 crates/fj-kernel/src/algorithms/approx/edge.rs | 7 +++++--
 crates/fj-kernel/src/builder/edge.rs           | 2 +-
 crates/fj-operations/src/sketch.rs             | 5 ++---
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 5ab5ce028..287d65e63 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -363,8 +363,11 @@ mod tests {
         let mut services = Services::new();
 
         let surface = services.objects.surfaces.xz_plane();
-        let half_edge = HalfEdgeBuilder::circle(1., &mut services.objects)
-            .build(None, None, &mut services.objects);
+        let half_edge = HalfEdgeBuilder::circle(1.).build(
+            None,
+            None,
+            &mut services.objects,
+        );
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 737c61e82..068443d9c 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -47,7 +47,7 @@ impl HalfEdgeBuilder {
     }
 
     /// Create a circle
-    pub fn circle(radius: impl Into<Scalar>, _: &mut Service<Objects>) -> Self {
+    pub fn circle(radius: impl Into<Scalar>) -> Self {
         let curve = Curve::circle_from_radius(radius);
         let boundary =
             [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index 8c76bf6c2..53736c11b 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -27,9 +27,8 @@ impl Shape for fj::Sketch {
 
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
-                let half_edge =
-                    HalfEdgeBuilder::circle(circle.radius(), objects)
-                        .build(None, None, objects);
+                let half_edge = HalfEdgeBuilder::circle(circle.radius())
+                    .build(None, None, objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);

From c1d3eae71958e73e2ac7ee3395f007a2c82229eb Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 11:58:24 +0100
Subject: [PATCH 10/15] Remove unused arguments

---
 crates/fj-kernel/src/algorithms/approx/edge.rs |  3 ---
 crates/fj-kernel/src/algorithms/sweep/edge.rs  | 15 +++------------
 crates/fj-kernel/src/builder/cycle.rs          | 10 ++--------
 crates/fj-kernel/src/builder/edge.rs           |  3 ---
 crates/fj-operations/src/sketch.rs             |  3 ---
 5 files changed, 5 insertions(+), 29 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 287d65e63..5197c7dfe 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -335,9 +335,6 @@ mod tests {
         let half_edge = HalfEdgeBuilder::line_segment(
             [[0., 1.], [TAU, 1.]],
             Some(range.boundary),
-            None,
-            None,
-            &mut services.objects,
         )
         .build(None, None, &mut services.objects);
 
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index 46eb20744..b9362a8c8 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -88,18 +88,9 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
             .zip_ext(vertices)
             .zip_ext(global_edges)
             .map(|((((boundary, start), end), start_vertex), global_edge)| {
-                let half_edge = HalfEdgeBuilder::line_segment(
-                    [start, end],
-                    Some(boundary),
-                    None,
-                    None,
-                    objects,
-                )
-                .build(
-                    Some(start_vertex),
-                    global_edge,
-                    objects,
-                );
+                let half_edge =
+                    HalfEdgeBuilder::line_segment([start, end], Some(boundary))
+                        .build(Some(start_vertex), global_edge, objects);
 
                 face.exterior.write().add_half_edge(half_edge.clone());
 
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 6390abb9e..70ed16f94 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -63,14 +63,8 @@ impl CycleBuilder for PartialCycle {
         P: Clone + Into<Point<2>>,
     {
         points.map_with_next(|start, end| {
-            let half_edge = HalfEdgeBuilder::line_segment(
-                [start, end],
-                None,
-                None,
-                None,
-                objects,
-            )
-            .build(None, None, objects);
+            let half_edge = HalfEdgeBuilder::line_segment([start, end], None)
+                .build(None, None, objects);
 
             self.add_half_edge(half_edge.clone());
 
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 068443d9c..2c57764ee 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -59,9 +59,6 @@ impl HalfEdgeBuilder {
     pub fn line_segment(
         points_surface: [impl Into<Point<2>>; 2],
         boundary: Option<[Point<1>; 2]>,
-        _: Option<Handle<Vertex>>,
-        _: Option<Handle<GlobalEdge>>,
-        _: &mut Service<Objects>,
     ) -> Self {
         let boundary =
             boundary.unwrap_or_else(|| [[0.], [1.]].map(Point::from));
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index 53736c11b..9200d0dc8 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -67,9 +67,6 @@ impl Shape for fj::Sketch {
                                 HalfEdgeBuilder::line_segment(
                                     [start, end],
                                     None,
-                                    None,
-                                    None,
-                                    objects,
                                 )
                             }
                             fj::SketchSegmentRoute::Arc { angle } => {

From b7f0919d7c12bd2b2e47bba972b2e3491669c83b Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 12:00:48 +0100
Subject: [PATCH 11/15] Refactor code to prepare for follow-on change

---
 crates/fj-kernel/src/builder/edge.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 2c57764ee..74cb85b5c 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -43,7 +43,7 @@ impl HalfEdgeBuilder {
         let boundary =
             [arc.start_angle, arc.end_angle].map(|coord| Point::from([coord]));
 
-        Self { curve, boundary }
+        Self::new(curve, boundary)
     }
 
     /// Create a circle
@@ -52,7 +52,7 @@ impl HalfEdgeBuilder {
         let boundary =
             [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
 
-        Self { curve, boundary }
+        Self::new(curve, boundary)
     }
 
     /// Create a line segment
@@ -66,7 +66,7 @@ impl HalfEdgeBuilder {
             boundary.zip_ext(points_surface),
         );
 
-        Self { curve, boundary }
+        Self::new(curve, boundary)
     }
 
     /// Create a half-edge

From a3b4a699dcedafeaabe58b0a895b0ed561413e54 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 12:11:38 +0100
Subject: [PATCH 12/15] Add `HalfEdgeBuilder::with_start_vertex`

---
 crates/fj-kernel/src/algorithms/approx/edge.rs |  9 +++------
 crates/fj-kernel/src/algorithms/sweep/edge.rs  |  3 ++-
 crates/fj-kernel/src/builder/cycle.rs          | 10 ++++------
 crates/fj-kernel/src/builder/edge.rs           | 17 ++++++++++++++---
 crates/fj-operations/src/sketch.rs             |  4 ++--
 5 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 5197c7dfe..5a9b9e38e 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -336,7 +336,7 @@ mod tests {
             [[0., 1.], [TAU, 1.]],
             Some(range.boundary),
         )
-        .build(None, None, &mut services.objects);
+        .build(None, &mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
@@ -360,11 +360,8 @@ mod tests {
         let mut services = Services::new();
 
         let surface = services.objects.surfaces.xz_plane();
-        let half_edge = HalfEdgeBuilder::circle(1.).build(
-            None,
-            None,
-            &mut services.objects,
-        );
+        let half_edge =
+            HalfEdgeBuilder::circle(1.).build(None, &mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index b9362a8c8..6e3a1bbe4 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -90,7 +90,8 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
             .map(|((((boundary, start), end), start_vertex), global_edge)| {
                 let half_edge =
                     HalfEdgeBuilder::line_segment([start, end], Some(boundary))
-                        .build(Some(start_vertex), global_edge, objects);
+                        .with_start_vertex(start_vertex)
+                        .build(global_edge, objects);
 
                 face.exterior.write().add_half_edge(half_edge.clone());
 
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 70ed16f94..2443d941d 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -64,7 +64,7 @@ impl CycleBuilder for PartialCycle {
     {
         points.map_with_next(|start, end| {
             let half_edge = HalfEdgeBuilder::line_segment([start, end], None)
-                .build(None, None, objects);
+                .build(None, objects);
 
             self.add_half_edge(half_edge.clone());
 
@@ -81,11 +81,9 @@ impl CycleBuilder for PartialCycle {
         O: ObjectArgument<(Handle<HalfEdge>, Curve, [Point<1>; 2])>,
     {
         edges.map_with_prev(|(_, curve, boundary), (prev, _, _)| {
-            let half_edge = HalfEdgeBuilder::new(curve, boundary).build(
-                Some(prev.start_vertex().clone()),
-                None,
-                objects,
-            );
+            let half_edge = HalfEdgeBuilder::new(curve, boundary)
+                .with_start_vertex(prev.start_vertex().clone())
+                .build(None, objects);
 
             self.add_half_edge(half_edge.clone());
 
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 74cb85b5c..1739748a2 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -13,12 +13,17 @@ use crate::{
 pub struct HalfEdgeBuilder {
     curve: Curve,
     boundary: [Point<1>; 2],
+    start_vertex: Option<Handle<Vertex>>,
 }
 
 impl HalfEdgeBuilder {
     /// Create an instance of `HalfEdgeBuilder`
     pub fn new(curve: Curve, boundary: [Point<1>; 2]) -> Self {
-        Self { curve, boundary }
+        Self {
+            curve,
+            boundary,
+            start_vertex: None,
+        }
     }
 
     /// Create an arc
@@ -69,17 +74,23 @@ impl HalfEdgeBuilder {
         Self::new(curve, boundary)
     }
 
+    /// Build the half-edge with a specific start vertex
+    pub fn with_start_vertex(mut self, start_vertex: Handle<Vertex>) -> Self {
+        self.start_vertex = Some(start_vertex);
+        self
+    }
+
     /// Create a half-edge
     pub fn build(
         self,
-        start_vertex: Option<Handle<Vertex>>,
         global_form: Option<Handle<GlobalEdge>>,
         objects: &mut Service<Objects>,
     ) -> Handle<HalfEdge> {
         HalfEdge::new(
             self.curve,
             self.boundary,
-            start_vertex.unwrap_or_else(|| Vertex::new().insert(objects)),
+            self.start_vertex
+                .unwrap_or_else(|| Vertex::new().insert(objects)),
             global_form.unwrap_or_else(|| GlobalEdge::new().insert(objects)),
         )
         .insert(objects)
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index 9200d0dc8..46955495d 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -28,7 +28,7 @@ impl Shape for fj::Sketch {
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
                 let half_edge = HalfEdgeBuilder::circle(circle.radius())
-                    .build(None, None, objects);
+                    .build(None, objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);
@@ -74,7 +74,7 @@ impl Shape for fj::Sketch {
                             }
                         };
 
-                        let half_edge = half_edge.build(None, None, objects);
+                        let half_edge = half_edge.build(None, objects);
                         cycle.add_half_edge(half_edge);
                     }
 

From 501f5709b85d6a0f6fa8f5d1211b621ec5925489 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 12:14:00 +0100
Subject: [PATCH 13/15] Refactor code to prepare for follow-on change

---
 crates/fj-kernel/src/algorithms/sweep/edge.rs | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index 6e3a1bbe4..ce4fa4d22 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -88,10 +88,15 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
             .zip_ext(vertices)
             .zip_ext(global_edges)
             .map(|((((boundary, start), end), start_vertex), global_edge)| {
-                let half_edge =
-                    HalfEdgeBuilder::line_segment([start, end], Some(boundary))
-                        .with_start_vertex(start_vertex)
-                        .build(global_edge, objects);
+                let half_edge = {
+                    let builder = HalfEdgeBuilder::line_segment(
+                        [start, end],
+                        Some(boundary),
+                    )
+                    .with_start_vertex(start_vertex);
+
+                    builder.build(global_edge, objects)
+                };
 
                 face.exterior.write().add_half_edge(half_edge.clone());
 

From 5c2fdde0fdab188b1e83ef9bd18a35c49fec5aeb Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 12:15:56 +0100
Subject: [PATCH 14/15] Add `HalfEdgeBuilder::with_global_form`

---
 crates/fj-kernel/src/algorithms/approx/edge.rs |  4 ++--
 crates/fj-kernel/src/algorithms/sweep/edge.rs  |  8 +++++++-
 crates/fj-kernel/src/builder/cycle.rs          |  4 ++--
 crates/fj-kernel/src/builder/edge.rs           | 17 +++++++++++------
 crates/fj-operations/src/sketch.rs             |  6 +++---
 5 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 5a9b9e38e..97e30e50f 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -336,7 +336,7 @@ mod tests {
             [[0., 1.], [TAU, 1.]],
             Some(range.boundary),
         )
-        .build(None, &mut services.objects);
+        .build(&mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
@@ -361,7 +361,7 @@ mod tests {
 
         let surface = services.objects.surfaces.xz_plane();
         let half_edge =
-            HalfEdgeBuilder::circle(1.).build(None, &mut services.objects);
+            HalfEdgeBuilder::circle(1.).build(&mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index ce4fa4d22..1558977dc 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -95,7 +95,13 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
                     )
                     .with_start_vertex(start_vertex);
 
-                    builder.build(global_edge, objects)
+                    let builder = if let Some(global_edge) = global_edge {
+                        builder.with_global_form(global_edge)
+                    } else {
+                        builder
+                    };
+
+                    builder.build(objects)
                 };
 
                 face.exterior.write().add_half_edge(half_edge.clone());
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 2443d941d..d71b9e565 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -64,7 +64,7 @@ impl CycleBuilder for PartialCycle {
     {
         points.map_with_next(|start, end| {
             let half_edge = HalfEdgeBuilder::line_segment([start, end], None)
-                .build(None, objects);
+                .build(objects);
 
             self.add_half_edge(half_edge.clone());
 
@@ -83,7 +83,7 @@ impl CycleBuilder for PartialCycle {
         edges.map_with_prev(|(_, curve, boundary), (prev, _, _)| {
             let half_edge = HalfEdgeBuilder::new(curve, boundary)
                 .with_start_vertex(prev.start_vertex().clone())
-                .build(None, objects);
+                .build(objects);
 
             self.add_half_edge(half_edge.clone());
 
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 1739748a2..834c50e3f 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -14,6 +14,7 @@ pub struct HalfEdgeBuilder {
     curve: Curve,
     boundary: [Point<1>; 2],
     start_vertex: Option<Handle<Vertex>>,
+    global_form: Option<Handle<GlobalEdge>>,
 }
 
 impl HalfEdgeBuilder {
@@ -23,6 +24,7 @@ impl HalfEdgeBuilder {
             curve,
             boundary,
             start_vertex: None,
+            global_form: None,
         }
     }
 
@@ -80,18 +82,21 @@ impl HalfEdgeBuilder {
         self
     }
 
+    /// Build the half-edge with a specific global form
+    pub fn with_global_form(mut self, global_form: Handle<GlobalEdge>) -> Self {
+        self.global_form = Some(global_form);
+        self
+    }
+
     /// Create a half-edge
-    pub fn build(
-        self,
-        global_form: Option<Handle<GlobalEdge>>,
-        objects: &mut Service<Objects>,
-    ) -> Handle<HalfEdge> {
+    pub fn build(self, objects: &mut Service<Objects>) -> Handle<HalfEdge> {
         HalfEdge::new(
             self.curve,
             self.boundary,
             self.start_vertex
                 .unwrap_or_else(|| Vertex::new().insert(objects)),
-            global_form.unwrap_or_else(|| GlobalEdge::new().insert(objects)),
+            self.global_form
+                .unwrap_or_else(|| GlobalEdge::new().insert(objects)),
         )
         .insert(objects)
     }
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index 46955495d..4b1650180 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -27,8 +27,8 @@ impl Shape for fj::Sketch {
 
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
-                let half_edge = HalfEdgeBuilder::circle(circle.radius())
-                    .build(None, objects);
+                let half_edge =
+                    HalfEdgeBuilder::circle(circle.radius()).build(objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);
@@ -74,7 +74,7 @@ impl Shape for fj::Sketch {
                             }
                         };
 
-                        let half_edge = half_edge.build(None, objects);
+                        let half_edge = half_edge.build(objects);
                         cycle.add_half_edge(half_edge);
                     }
 

From 92da422da6a9232b6f82d3b8f0e48af4d1b5e090 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 10 Mar 2023 12:18:56 +0100
Subject: [PATCH 15/15] Return `HalfEdge` from `HalfEdgeBuilder::build`

This is less convenient right now, but it makes `HalfEdgeBuilder` more
composable and future-proof.
---
 crates/fj-kernel/src/algorithms/approx/edge.rs | 8 +++++---
 crates/fj-kernel/src/algorithms/sweep/edge.rs  | 2 +-
 crates/fj-kernel/src/builder/cycle.rs          | 7 +++++--
 crates/fj-kernel/src/builder/edge.rs           | 3 +--
 crates/fj-operations/src/sketch.rs             | 8 +++++---
 5 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/approx/edge.rs b/crates/fj-kernel/src/algorithms/approx/edge.rs
index 97e30e50f..b647b7da5 100644
--- a/crates/fj-kernel/src/algorithms/approx/edge.rs
+++ b/crates/fj-kernel/src/algorithms/approx/edge.rs
@@ -336,7 +336,8 @@ mod tests {
             [[0., 1.], [TAU, 1.]],
             Some(range.boundary),
         )
-        .build(&mut services.objects);
+        .build(&mut services.objects)
+        .insert(&mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
@@ -360,8 +361,9 @@ mod tests {
         let mut services = Services::new();
 
         let surface = services.objects.surfaces.xz_plane();
-        let half_edge =
-            HalfEdgeBuilder::circle(1.).build(&mut services.objects);
+        let half_edge = HalfEdgeBuilder::circle(1.)
+            .build(&mut services.objects)
+            .insert(&mut services.objects);
 
         let tolerance = 1.;
         let approx = (&half_edge, surface.deref()).approx(tolerance);
diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index 1558977dc..656a9d6b3 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -101,7 +101,7 @@ impl Sweep for (Handle<HalfEdge>, &Handle<Vertex>, &Surface, Color) {
                         builder
                     };
 
-                    builder.build(objects)
+                    builder.build(objects).insert(objects)
                 };
 
                 face.exterior.write().add_half_edge(half_edge.clone());
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index d71b9e565..9151c671c 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -2,6 +2,7 @@ use fj_math::Point;
 
 use crate::{
     geometry::curve::Curve,
+    insert::Insert,
     objects::{HalfEdge, Objects},
     partial::PartialCycle,
     services::Service,
@@ -64,7 +65,8 @@ impl CycleBuilder for PartialCycle {
     {
         points.map_with_next(|start, end| {
             let half_edge = HalfEdgeBuilder::line_segment([start, end], None)
-                .build(objects);
+                .build(objects)
+                .insert(objects);
 
             self.add_half_edge(half_edge.clone());
 
@@ -83,7 +85,8 @@ impl CycleBuilder for PartialCycle {
         edges.map_with_prev(|(_, curve, boundary), (prev, _, _)| {
             let half_edge = HalfEdgeBuilder::new(curve, boundary)
                 .with_start_vertex(prev.start_vertex().clone())
-                .build(objects);
+                .build(objects)
+                .insert(objects);
 
             self.add_half_edge(half_edge.clone());
 
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 834c50e3f..943a48508 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -89,7 +89,7 @@ impl HalfEdgeBuilder {
     }
 
     /// Create a half-edge
-    pub fn build(self, objects: &mut Service<Objects>) -> Handle<HalfEdge> {
+    pub fn build(self, objects: &mut Service<Objects>) -> HalfEdge {
         HalfEdge::new(
             self.curve,
             self.boundary,
@@ -98,6 +98,5 @@ impl HalfEdgeBuilder {
             self.global_form
                 .unwrap_or_else(|| GlobalEdge::new().insert(objects)),
         )
-        .insert(objects)
     }
 }
diff --git a/crates/fj-operations/src/sketch.rs b/crates/fj-operations/src/sketch.rs
index 4b1650180..aefee9fa8 100644
--- a/crates/fj-operations/src/sketch.rs
+++ b/crates/fj-operations/src/sketch.rs
@@ -27,8 +27,9 @@ impl Shape for fj::Sketch {
 
         let face = match self.chain() {
             fj::Chain::Circle(circle) => {
-                let half_edge =
-                    HalfEdgeBuilder::circle(circle.radius()).build(objects);
+                let half_edge = HalfEdgeBuilder::circle(circle.radius())
+                    .build(objects)
+                    .insert(objects);
                 let exterior = {
                     let mut cycle = PartialCycle::new(objects);
                     cycle.half_edges.push(half_edge);
@@ -74,7 +75,8 @@ impl Shape for fj::Sketch {
                             }
                         };
 
-                        let half_edge = half_edge.build(objects);
+                        let half_edge =
+                            half_edge.build(objects).insert(objects);
                         cycle.add_half_edge(half_edge);
                     }