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

@@ -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);

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());

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());
 

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)
     }
 }

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);
                     }