From 5c29b41f0136c6678bc32d58af582f095944fb1b Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:11:09 +0100
Subject: [PATCH 01/21] Field fields of `PartialGlobalEdge` public

---
 crates/fj-kernel/src/partial/objects/edge.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index cbace6209..a72ab4ec8 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -149,8 +149,11 @@ impl From<&HalfEdge> for PartialHalfEdge {
 /// See [`crate::partial`] for more information.
 #[derive(Clone, Debug, Default)]
 pub struct PartialGlobalEdge {
-    curve: MaybePartial<GlobalCurve>,
-    vertices: Option<[MaybePartial<GlobalVertex>; 2]>,
+    /// The curve that the [`GlobalEdge`] is defined in
+    pub curve: MaybePartial<GlobalCurve>,
+
+    /// The vertices that bound the [`GlobalEdge`] in the curve
+    pub vertices: Option<[MaybePartial<GlobalVertex>; 2]>,
 }
 
 impl PartialGlobalEdge {

From 9301babb440da91a0452250b3fbb2b6fbab000f2 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:12:00 +0100
Subject: [PATCH 02/21] Remove `PartialGlobalEdge::curve`

---
 crates/fj-kernel/src/algorithms/transform/edge.rs | 2 +-
 crates/fj-kernel/src/partial/maybe_partial.rs     | 2 +-
 crates/fj-kernel/src/partial/objects/edge.rs      | 5 -----
 3 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index 7daf35f31..a08de13d0 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -47,7 +47,7 @@ impl TransformObject for PartialGlobalEdge {
         transform: &Transform,
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
-        let curve = self.curve().transform(transform, objects)?;
+        let curve = self.curve.clone().transform(transform, objects)?;
         let vertices = self
             .vertices()
             .map(|vertices| {
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index cad49c181..58865456b 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -168,7 +168,7 @@ impl MaybePartial<GlobalEdge> {
     pub fn curve(&self) -> MaybePartial<GlobalCurve> {
         match self {
             Self::Full(full) => full.curve().clone().into(),
-            Self::Partial(partial) => partial.curve(),
+            Self::Partial(partial) => partial.curve.clone(),
         }
     }
 
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index a72ab4ec8..ef5df3c59 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -157,11 +157,6 @@ pub struct PartialGlobalEdge {
 }
 
 impl PartialGlobalEdge {
-    /// Access the curve that the [`GlobalEdge`] is defined in
-    pub fn curve(&self) -> MaybePartial<GlobalCurve> {
-        self.curve.clone()
-    }
-
     /// Access the vertices that bound the [`GlobalEdge`] in the curve
     pub fn vertices(&self) -> Option<[MaybePartial<GlobalVertex>; 2]> {
         self.vertices.clone()

From f17c0f9db115a6b2950186fc067eaa01a7e31a4e Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:12:51 +0100
Subject: [PATCH 03/21] Remove `PartialGlobalEdge::vertices`

---
 crates/fj-kernel/src/algorithms/transform/edge.rs | 4 ++--
 crates/fj-kernel/src/partial/maybe_partial.rs     | 2 +-
 crates/fj-kernel/src/partial/objects/edge.rs      | 5 -----
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index a08de13d0..a2535c683 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -47,9 +47,9 @@ impl TransformObject for PartialGlobalEdge {
         transform: &Transform,
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
-        let curve = self.curve.clone().transform(transform, objects)?;
+        let curve = self.curve.transform(transform, objects)?;
         let vertices = self
-            .vertices()
+            .vertices
             .map(|vertices| {
                 vertices.try_map_ext(|vertex| -> Result<_, ValidationError> {
                     vertex.transform(transform, objects)
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index 58865456b..013b51123 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -178,7 +178,7 @@ impl MaybePartial<GlobalEdge> {
             Self::Full(full) => Some(
                 full.vertices().access_in_normalized_order().map(Into::into),
             ),
-            Self::Partial(partial) => partial.vertices(),
+            Self::Partial(partial) => partial.vertices.clone(),
         }
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index ef5df3c59..cbe71b5c8 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -157,11 +157,6 @@ pub struct PartialGlobalEdge {
 }
 
 impl PartialGlobalEdge {
-    /// Access the vertices that bound the [`GlobalEdge`] in the curve
-    pub fn vertices(&self) -> Option<[MaybePartial<GlobalVertex>; 2]> {
-        self.vertices.clone()
-    }
-
     /// Update the partial global edge with the given curve
     pub fn with_curve(
         mut self,

From 6b53e964fdba4105e4b585244c6c8f182d9e36c5 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:18:47 +0100
Subject: [PATCH 04/21] Remove `PartialGlobalEdge::with_curve`

---
 .../fj-kernel/src/algorithms/transform/edge.rs   | 16 ++++++++++------
 crates/fj-kernel/src/builder/edge.rs             | 10 +++++-----
 crates/fj-kernel/src/partial/objects/edge.rs     | 11 -----------
 crates/fj-kernel/src/validate/edge.rs            | 14 +++++---------
 4 files changed, 20 insertions(+), 31 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index a2535c683..efdbbfb6e 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -28,11 +28,13 @@ impl TransformObject for PartialHalfEdge {
                 Ok(vertex)
             },
         )?;
-        let global_form = self
+        let mut global_form = self
             .global_form()
             .into_partial()
-            .transform(transform, objects)?
-            .with_curve(curve.global_form());
+            .transform(transform, objects)?;
+        if let Some(curve) = curve.global_form() {
+            global_form.curve = curve;
+        }
 
         Ok(Self::default()
             .with_curve(curve)
@@ -57,8 +59,10 @@ impl TransformObject for PartialGlobalEdge {
             })
             .transpose()?;
 
-        Ok(Self::default()
-            .with_curve(Some(curve))
-            .with_vertices(vertices))
+        Ok(Self {
+            curve,
+            ..Default::default()
+        }
+        .with_vertices(vertices))
     }
 }
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 3d276c505..f2218b366 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -235,13 +235,13 @@ pub trait GlobalEdgeBuilder {
 
 impl GlobalEdgeBuilder for PartialGlobalEdge {
     fn update_from_curve_and_vertices(
-        self,
+        mut self,
         curve: &Curve,
         vertices: &[Handle<Vertex>; 2],
     ) -> Self {
-        self.with_curve(Some(curve.global_form().clone()))
-            .with_vertices(Some(
-                vertices.clone().map(|vertex| vertex.global_form().clone()),
-            ))
+        self.curve = curve.global_form().clone().into();
+        self.with_vertices(Some(
+            vertices.clone().map(|vertex| vertex.global_form().clone()),
+        ))
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index cbe71b5c8..2e8dcd86d 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -157,17 +157,6 @@ pub struct PartialGlobalEdge {
 }
 
 impl PartialGlobalEdge {
-    /// Update the partial global edge with the given curve
-    pub fn with_curve(
-        mut self,
-        curve: Option<impl Into<MaybePartial<GlobalCurve>>>,
-    ) -> Self {
-        if let Some(curve) = curve {
-            self.curve = curve.into();
-        }
-        self
-    }
-
     /// Update the partial global edge with the given vertices
     pub fn with_vertices(
         mut self,
diff --git a/crates/fj-kernel/src/validate/edge.rs b/crates/fj-kernel/src/validate/edge.rs
index 0a294d415..e7c738532 100644
--- a/crates/fj-kernel/src/validate/edge.rs
+++ b/crates/fj-kernel/src/validate/edge.rs
@@ -244,15 +244,11 @@ mod tests {
                 [[0., 0.], [1., 0.]],
             )
             .build(&objects)?;
-        let invalid = HalfEdge::new(
-            valid.vertices().clone(),
-            valid
-                .global_form()
-                .to_partial()
-                .with_curve(Some(objects.global_curves.insert(GlobalCurve)?))
-                .build(&objects)?
-                .insert(&objects)?,
-        );
+        let invalid = HalfEdge::new(valid.vertices().clone(), {
+            let mut tmp = valid.global_form().to_partial();
+            tmp.curve = objects.global_curves.insert(GlobalCurve)?.into();
+            tmp.build(&objects)?.insert(&objects)?
+        });
 
         assert!(valid.validate().is_ok());
         assert!(invalid.validate().is_err());

From 1451949426ce7ade5f0989b546fdcd29184892d2 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:38:49 +0100
Subject: [PATCH 05/21] Remove `PartialGlobalEdge::with_vertices`

---
 .../src/algorithms/transform/edge.rs          |  6 +---
 crates/fj-kernel/src/builder/edge.rs          |  9 ++++--
 crates/fj-kernel/src/partial/objects/edge.rs  | 11 --------
 crates/fj-kernel/src/validate/edge.rs         | 28 ++++++++-----------
 4 files changed, 19 insertions(+), 35 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index efdbbfb6e..6d0ce8b68 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -59,10 +59,6 @@ impl TransformObject for PartialGlobalEdge {
             })
             .transpose()?;
 
-        Ok(Self {
-            curve,
-            ..Default::default()
-        }
-        .with_vertices(vertices))
+        Ok(Self { curve, vertices })
     }
 }
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index f2218b366..49dd597de 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -240,8 +240,11 @@ impl GlobalEdgeBuilder for PartialGlobalEdge {
         vertices: &[Handle<Vertex>; 2],
     ) -> Self {
         self.curve = curve.global_form().clone().into();
-        self.with_vertices(Some(
-            vertices.clone().map(|vertex| vertex.global_form().clone()),
-        ))
+        self.vertices = Some(
+            vertices
+                .clone()
+                .map(|vertex| vertex.global_form().clone().into()),
+        );
+        self
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index 2e8dcd86d..7e50d6580 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -157,17 +157,6 @@ pub struct PartialGlobalEdge {
 }
 
 impl PartialGlobalEdge {
-    /// Update the partial global edge with the given vertices
-    pub fn with_vertices(
-        mut self,
-        vertices: Option<[impl Into<MaybePartial<GlobalVertex>>; 2]>,
-    ) -> Self {
-        if let Some(vertices) = vertices {
-            self.vertices = Some(vertices.map(Into::into));
-        }
-        self
-    }
-
     /// Build a full [`GlobalEdge`] from the partial global edge
     pub fn build(
         self,
diff --git a/crates/fj-kernel/src/validate/edge.rs b/crates/fj-kernel/src/validate/edge.rs
index e7c738532..f65f6868d 100644
--- a/crates/fj-kernel/src/validate/edge.rs
+++ b/crates/fj-kernel/src/validate/edge.rs
@@ -266,22 +266,18 @@ mod tests {
                 [[0., 0.], [1., 0.]],
             )
             .build(&objects)?;
-        let invalid = HalfEdge::new(
-            valid.vertices().clone(),
-            valid
-                .global_form()
-                .to_partial()
-                .with_vertices(Some(
-                    valid
-                        .global_form()
-                        .vertices()
-                        .access_in_normalized_order()
-                        // Creating equal but not identical vertices here.
-                        .map(|vertex| vertex.to_partial()),
-                ))
-                .build(&objects)?
-                .insert(&objects)?,
-        );
+        let invalid = HalfEdge::new(valid.vertices().clone(), {
+            let mut tmp = valid.global_form().to_partial();
+            tmp.vertices = Some(
+                valid
+                    .global_form()
+                    .vertices()
+                    .access_in_normalized_order()
+                    // Creating equal but not identical vertices here.
+                    .map(|vertex| vertex.to_partial().into()),
+            );
+            tmp.build(&objects)?.insert(&objects)?
+        });
 
         assert!(valid.validate().is_ok());
         assert!(invalid.validate().is_err());

From 3a3de92b316ae54f11dd7f04c742132934eb4b27 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:54:32 +0100
Subject: [PATCH 06/21] Rewrite partial object update using merge

---
 crates/fj-kernel/src/builder/edge.rs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 49dd597de..e307992fa 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -202,14 +202,14 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                 .collect::<[_; 2]>()
                 .map(|(vertex, global_form)| {
                     vertex.update_partial(|mut vertex| {
-                        vertex.surface_form = vertex
-                            .surface_form
-                            .update_partial(|mut surface_vertex| {
-                                if let Some(global_form) = global_form {
-                                    surface_vertex.global_form = global_form;
-                                }
-                                surface_vertex
-                            });
+                        let mut surface_form = PartialSurfaceVertex::default();
+                        if let Some(global_form) = global_form {
+                            surface_form.global_form = global_form;
+                        }
+
+                        vertex.surface_form =
+                            vertex.surface_form.merge_with(surface_form);
+
                         vertex
                     })
                 })

From b2e59169a15cdcbabee18ec74e28a63757815399 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 18:56:31 +0100
Subject: [PATCH 07/21] Simplify `vertices` field of `PartialGlobalEdge`

---
 .../src/algorithms/transform/edge.rs          | 13 +++++--------
 crates/fj-kernel/src/builder/edge.rs          |  8 +++-----
 crates/fj-kernel/src/partial/maybe_partial.rs |  2 +-
 crates/fj-kernel/src/partial/objects/edge.rs  | 19 +++++++------------
 crates/fj-kernel/src/validate/edge.rs         | 14 ++++++--------
 5 files changed, 22 insertions(+), 34 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index 6d0ce8b68..cded261d6 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -50,14 +50,11 @@ impl TransformObject for PartialGlobalEdge {
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
         let curve = self.curve.transform(transform, objects)?;
-        let vertices = self
-            .vertices
-            .map(|vertices| {
-                vertices.try_map_ext(|vertex| -> Result<_, ValidationError> {
-                    vertex.transform(transform, objects)
-                })
-            })
-            .transpose()?;
+        let vertices = self.vertices.try_map_ext(
+            |vertex| -> Result<_, ValidationError> {
+                vertex.transform(transform, objects)
+            },
+        )?;
 
         Ok(Self { curve, vertices })
     }
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index e307992fa..52d10ee37 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -240,11 +240,9 @@ impl GlobalEdgeBuilder for PartialGlobalEdge {
         vertices: &[Handle<Vertex>; 2],
     ) -> Self {
         self.curve = curve.global_form().clone().into();
-        self.vertices = Some(
-            vertices
-                .clone()
-                .map(|vertex| vertex.global_form().clone().into()),
-        );
+        self.vertices = vertices
+            .clone()
+            .map(|vertex| vertex.global_form().clone().into());
         self
     }
 }
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index 013b51123..f27939536 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -178,7 +178,7 @@ impl MaybePartial<GlobalEdge> {
             Self::Full(full) => Some(
                 full.vertices().access_in_normalized_order().map(Into::into),
             ),
-            Self::Partial(partial) => partial.vertices.clone(),
+            Self::Partial(partial) => Some(partial.vertices.clone()),
         }
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index 7e50d6580..cbc165959 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -6,7 +6,7 @@ use crate::{
         Curve, GlobalCurve, GlobalEdge, GlobalVertex, HalfEdge, Objects,
         Surface, Vertex,
     },
-    partial::{MaybePartial, MergeWith, Mergeable},
+    partial::{MaybePartial, MergeWith},
     storage::Handle,
     validate::ValidationError,
 };
@@ -153,7 +153,7 @@ pub struct PartialGlobalEdge {
     pub curve: MaybePartial<GlobalCurve>,
 
     /// The vertices that bound the [`GlobalEdge`] in the curve
-    pub vertices: Option<[MaybePartial<GlobalVertex>; 2]>,
+    pub vertices: [MaybePartial<GlobalVertex>; 2],
 }
 
 impl PartialGlobalEdge {
@@ -165,7 +165,6 @@ impl PartialGlobalEdge {
         let curve = self.curve.into_full(objects)?;
         let vertices = self
             .vertices
-            .expect("Can't build `GlobalEdge` without vertices")
             .try_map_ext(|global_vertex| global_vertex.into_full(objects))?;
 
         Ok(GlobalEdge::new(curve, vertices))
@@ -178,9 +177,7 @@ impl MergeWith for PartialGlobalEdge {
 
         Self {
             curve: self.curve.merge_with(other.curve),
-            vertices: Mergeable(self.vertices)
-                .merge_with(Mergeable(other.vertices))
-                .0,
+            vertices: self.vertices.merge_with(other.vertices),
         }
     }
 }
@@ -189,12 +186,10 @@ impl From<&GlobalEdge> for PartialGlobalEdge {
     fn from(global_edge: &GlobalEdge) -> Self {
         Self {
             curve: global_edge.curve().clone().into(),
-            vertices: Some(
-                global_edge
-                    .vertices()
-                    .access_in_normalized_order()
-                    .map(Into::into),
-            ),
+            vertices: global_edge
+                .vertices()
+                .access_in_normalized_order()
+                .map(Into::into),
         }
     }
 }
diff --git a/crates/fj-kernel/src/validate/edge.rs b/crates/fj-kernel/src/validate/edge.rs
index f65f6868d..54ee9ae74 100644
--- a/crates/fj-kernel/src/validate/edge.rs
+++ b/crates/fj-kernel/src/validate/edge.rs
@@ -268,14 +268,12 @@ mod tests {
             .build(&objects)?;
         let invalid = HalfEdge::new(valid.vertices().clone(), {
             let mut tmp = valid.global_form().to_partial();
-            tmp.vertices = Some(
-                valid
-                    .global_form()
-                    .vertices()
-                    .access_in_normalized_order()
-                    // Creating equal but not identical vertices here.
-                    .map(|vertex| vertex.to_partial().into()),
-            );
+            tmp.vertices = valid
+                .global_form()
+                .vertices()
+                .access_in_normalized_order()
+                // Creating equal but not identical vertices here.
+                .map(|vertex| vertex.to_partial().into());
             tmp.build(&objects)?.insert(&objects)?
         });
 

From a1a7b6fb449274fac2ee6a2a8d77831e25345423 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:00:31 +0100
Subject: [PATCH 08/21] Simplify return value

---
 crates/fj-kernel/src/builder/edge.rs          | 33 ++++---------------
 crates/fj-kernel/src/partial/maybe_partial.rs | 10 +++---
 2 files changed, 11 insertions(+), 32 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 52d10ee37..726139db9 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -6,14 +6,13 @@ use crate::{
     objects::{Curve, Objects, Surface, Vertex, VerticesInNormalizedOrder},
     partial::{
         MaybePartial, MergeWith, PartialCurve, PartialGlobalEdge,
-        PartialGlobalVertex, PartialHalfEdge, PartialSurfaceVertex,
-        PartialVertex,
+        PartialHalfEdge, PartialSurfaceVertex, PartialVertex,
     },
     storage::Handle,
     validate::ValidationError,
 };
 
-use super::{CurveBuilder, GlobalVertexBuilder};
+use super::CurveBuilder;
 
 /// Builder API for [`PartialHalfEdge`]
 pub trait HalfEdgeBuilder: Sized {
@@ -75,17 +74,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
         let [a_curve, b_curve] =
             [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
 
-        let global_vertex = self
-            .global_form()
-            .vertices()
-            .map(|[global_form, _]| global_form)
-            .unwrap_or_else(|| {
-                PartialGlobalVertex::from_curve_and_position(
-                    curve.clone(),
-                    a_curve,
-                )
-                .into()
-            });
+        let [global_vertex, _] = self.global_form().vertices();
 
         let surface_vertex = PartialSurfaceVertex {
             position: Some(path.point_from_path_coords(a_curve)),
@@ -181,19 +170,9 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                     must_switch_order
                 };
 
-                self.global_form()
-                    .vertices()
-                    .map(
-                        |[a, b]| {
-                            if must_switch_order {
-                                [b, a]
-                            } else {
-                                [a, b]
-                            }
-                        },
-                    )
-                    .map(|[a, b]| [Some(a), Some(b)])
-                    .unwrap_or([None, None])
+                let [a, b] = self.global_form().vertices();
+                let [a, b] = if must_switch_order { [b, a] } else { [a, b] };
+                [Some(a), Some(b)]
             };
 
             vertices
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index f27939536..dc79bafd9 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -173,12 +173,12 @@ impl MaybePartial<GlobalEdge> {
     }
 
     /// Access the vertices
-    pub fn vertices(&self) -> Option<[MaybePartial<GlobalVertex>; 2]> {
+    pub fn vertices(&self) -> [MaybePartial<GlobalVertex>; 2] {
         match self {
-            Self::Full(full) => Some(
-                full.vertices().access_in_normalized_order().map(Into::into),
-            ),
-            Self::Partial(partial) => Some(partial.vertices.clone()),
+            Self::Full(full) => {
+                full.vertices().access_in_normalized_order().map(Into::into)
+            }
+            Self::Partial(partial) => partial.vertices.clone(),
         }
     }
 }

From 78e5d0cda9fc9c0dfec4e834a8a55cade50a6b20 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:02:32 +0100
Subject: [PATCH 09/21] Refactor

---
 crates/fj-kernel/src/builder/edge.rs | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 726139db9..f888be9d3 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -171,8 +171,11 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                 };
 
                 let [a, b] = self.global_form().vertices();
-                let [a, b] = if must_switch_order { [b, a] } else { [a, b] };
-                [Some(a), Some(b)]
+                if must_switch_order {
+                    [b, a]
+                } else {
+                    [a, b]
+                }
             };
 
             vertices
@@ -181,10 +184,10 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                 .collect::<[_; 2]>()
                 .map(|(vertex, global_form)| {
                     vertex.update_partial(|mut vertex| {
-                        let mut surface_form = PartialSurfaceVertex::default();
-                        if let Some(global_form) = global_form {
-                            surface_form.global_form = global_form;
-                        }
+                        let surface_form = PartialSurfaceVertex {
+                            global_form,
+                            ..Default::default()
+                        };
 
                         vertex.surface_form =
                             vertex.surface_form.merge_with(surface_form);

From b5b19b5ae9927430c83c45b5cc12c74fda393aad Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:03:08 +0100
Subject: [PATCH 10/21] Refactor

---
 crates/fj-kernel/src/builder/edge.rs | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index f888be9d3..56c3126bc 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -184,14 +184,12 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                 .collect::<[_; 2]>()
                 .map(|(vertex, global_form)| {
                     vertex.update_partial(|mut vertex| {
-                        let surface_form = PartialSurfaceVertex {
-                            global_form,
-                            ..Default::default()
-                        };
-
-                        vertex.surface_form =
-                            vertex.surface_form.merge_with(surface_form);
-
+                        vertex.surface_form = vertex.surface_form.merge_with(
+                            PartialSurfaceVertex {
+                                global_form,
+                                ..Default::default()
+                            },
+                        );
                         vertex
                     })
                 })

From 848573814e5428b625c9c904de8e86dce10c9ad6 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:05:54 +0100
Subject: [PATCH 11/21] Make fields of `PartialHalfEdge` public

---
 crates/fj-kernel/src/partial/objects/edge.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index cbc165959..bc6597e4f 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -16,9 +16,14 @@ use crate::{
 /// See [`crate::partial`] for more information.
 #[derive(Clone, Debug, Default)]
 pub struct PartialHalfEdge {
-    curve: MaybePartial<Curve>,
-    vertices: [MaybePartial<Vertex>; 2],
-    global_form: MaybePartial<GlobalEdge>,
+    /// The curve that the [`HalfEdge`] is defined in
+    pub curve: MaybePartial<Curve>,
+
+    /// The vertices that bound the [`HalfEdge`] in the curve
+    pub vertices: [MaybePartial<Vertex>; 2],
+
+    /// The global form of the [`HalfEdge`]
+    pub global_form: MaybePartial<GlobalEdge>,
 }
 
 impl PartialHalfEdge {

From 2b99b2156b52771f698786258bbb4625c2654929 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:07:10 +0100
Subject: [PATCH 12/21] Remove `PartialHalfEdge::curve`

---
 crates/fj-kernel/src/algorithms/transform/edge.rs | 3 ++-
 crates/fj-kernel/src/builder/edge.rs              | 4 ++--
 crates/fj-kernel/src/partial/maybe_partial.rs     | 2 +-
 crates/fj-kernel/src/partial/objects/edge.rs      | 5 -----
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index cded261d6..fb1b8d294 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -16,7 +16,8 @@ impl TransformObject for PartialHalfEdge {
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
         let curve: MaybePartial<_> = self
-            .curve()
+            .curve
+            .clone()
             .into_partial()
             .transform(transform, objects)?
             .into();
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 56c3126bc..5b07d9a91 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -65,7 +65,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
         radius: impl Into<Scalar>,
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
-        let mut curve = self.curve().into_partial();
+        let mut curve = self.curve.clone().into_partial();
         curve.global_form = Some(self.extract_global_curve());
         curve.update_as_circle_from_radius(radius);
 
@@ -123,7 +123,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
             [&from, &to].map(|vertex| vertex.surface_form());
 
         let surface = self
-            .curve()
+            .curve
             .surface()
             .merge_with(from_surface.surface())
             .merge_with(to_surface.surface())
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index dc79bafd9..ccf589d14 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -188,7 +188,7 @@ impl MaybePartial<HalfEdge> {
     pub fn curve(&self) -> MaybePartial<Curve> {
         match self {
             Self::Full(full) => full.curve().clone().into(),
-            Self::Partial(partial) => partial.curve(),
+            Self::Partial(partial) => partial.curve.clone(),
         }
     }
 
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index bc6597e4f..4b036bc9d 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -27,11 +27,6 @@ pub struct PartialHalfEdge {
 }
 
 impl PartialHalfEdge {
-    /// Access the curve that the [`HalfEdge`] is defined in
-    pub fn curve(&self) -> MaybePartial<Curve> {
-        self.curve.clone()
-    }
-
     /// Access the vertices that bound this [`HalfEdge`] in the [`Curve`]
     pub fn vertices(&self) -> [MaybePartial<Vertex>; 2] {
         self.vertices.clone()

From 0bbe047570efe54de6d9a19a34ff8be75d814de4 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:09:49 +0100
Subject: [PATCH 13/21] Remove `PartialHalfEdge::vertices`

---
 crates/fj-kernel/src/algorithms/transform/edge.rs | 2 +-
 crates/fj-kernel/src/builder/edge.rs              | 6 +++---
 crates/fj-kernel/src/partial/maybe_partial.rs     | 4 ++--
 crates/fj-kernel/src/partial/objects/edge.rs      | 5 -----
 crates/fj-kernel/src/validate/cycle.rs            | 2 +-
 5 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index fb1b8d294..e91c5430c 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -21,7 +21,7 @@ impl TransformObject for PartialHalfEdge {
             .into_partial()
             .transform(transform, objects)?
             .into();
-        let vertices = self.vertices().try_map_ext(
+        let vertices = self.vertices.clone().try_map_ext(
             |vertex| -> Result<_, ValidationError> {
                 let mut vertex =
                     vertex.into_partial().transform(transform, objects)?;
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 5b07d9a91..fa016f184 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -51,12 +51,12 @@ pub trait HalfEdgeBuilder: Sized {
 
 impl HalfEdgeBuilder for PartialHalfEdge {
     fn with_back_vertex(self, back: impl Into<MaybePartial<Vertex>>) -> Self {
-        let [_, front] = self.vertices();
+        let [_, front] = self.vertices.clone();
         self.with_vertices([back.into(), front])
     }
 
     fn with_front_vertex(self, front: impl Into<MaybePartial<Vertex>>) -> Self {
-        let [back, _] = self.vertices();
+        let [back, _] = self.vertices.clone();
         self.with_vertices([back, front.into()])
     }
 
@@ -118,7 +118,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
     }
 
     fn update_as_line_segment(self) -> Self {
-        let [from, to] = self.vertices();
+        let [from, to] = self.vertices.clone();
         let [from_surface, to_surface] =
             [&from, &to].map(|vertex| vertex.surface_form());
 
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index ccf589d14..039b899a1 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -197,7 +197,7 @@ impl MaybePartial<HalfEdge> {
         match self {
             Self::Full(full) => full.front().clone().into(),
             Self::Partial(partial) => {
-                let [_, front] = &partial.vertices();
+                let [_, front] = &partial.vertices;
                 front.clone()
             }
         }
@@ -207,7 +207,7 @@ impl MaybePartial<HalfEdge> {
     pub fn vertices(&self) -> [MaybePartial<Vertex>; 2] {
         match self {
             Self::Full(full) => full.vertices().clone().map(Into::into),
-            Self::Partial(partial) => partial.vertices(),
+            Self::Partial(partial) => partial.vertices.clone(),
         }
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index 4b036bc9d..ead66724b 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -27,11 +27,6 @@ pub struct PartialHalfEdge {
 }
 
 impl PartialHalfEdge {
-    /// Access the vertices that bound this [`HalfEdge`] in the [`Curve`]
-    pub fn vertices(&self) -> [MaybePartial<Vertex>; 2] {
-        self.vertices.clone()
-    }
-
     /// Access the global form of the [`HalfEdge`]
     pub fn global_form(&self) -> MaybePartial<GlobalEdge> {
         self.global_form.clone()
diff --git a/crates/fj-kernel/src/validate/cycle.rs b/crates/fj-kernel/src/validate/cycle.rs
index b30ddaa9a..413953b54 100644
--- a/crates/fj-kernel/src/validate/cycle.rs
+++ b/crates/fj-kernel/src/validate/cycle.rs
@@ -91,7 +91,7 @@ mod tests {
                 .collect::<Vec<_>>();
 
             let first_half_edge = &mut half_edges[0];
-            let [first_vertex, _] = first_half_edge.vertices();
+            let [first_vertex, _] = first_half_edge.vertices.clone();
 
             // Sever connection between the last and first half-edge in the
             // cycle.

From cb898b1670015311abd99f2340cfde4d12643c22 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:11:04 +0100
Subject: [PATCH 14/21] Remove `PartialHalfEdge::global_form`

---
 crates/fj-kernel/src/algorithms/transform/edge.rs | 5 ++---
 crates/fj-kernel/src/builder/edge.rs              | 4 ++--
 crates/fj-kernel/src/partial/objects/edge.rs      | 5 -----
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index e91c5430c..12bb441d3 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -17,11 +17,10 @@ impl TransformObject for PartialHalfEdge {
     ) -> Result<Self, ValidationError> {
         let curve: MaybePartial<_> = self
             .curve
-            .clone()
             .into_partial()
             .transform(transform, objects)?
             .into();
-        let vertices = self.vertices.clone().try_map_ext(
+        let vertices = self.vertices.try_map_ext(
             |vertex| -> Result<_, ValidationError> {
                 let mut vertex =
                     vertex.into_partial().transform(transform, objects)?;
@@ -30,7 +29,7 @@ impl TransformObject for PartialHalfEdge {
             },
         )?;
         let mut global_form = self
-            .global_form()
+            .global_form
             .into_partial()
             .transform(transform, objects)?;
         if let Some(curve) = curve.global_form() {
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index fa016f184..4eb95d93c 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -74,7 +74,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
         let [a_curve, b_curve] =
             [Scalar::ZERO, Scalar::TAU].map(|coord| Point::from([coord]));
 
-        let [global_vertex, _] = self.global_form().vertices();
+        let [global_vertex, _] = self.global_form.vertices();
 
         let surface_vertex = PartialSurfaceVertex {
             position: Some(path.point_from_path_coords(a_curve)),
@@ -170,7 +170,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                     must_switch_order
                 };
 
-                let [a, b] = self.global_form().vertices();
+                let [a, b] = self.global_form.vertices();
                 if must_switch_order {
                     [b, a]
                 } else {
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index ead66724b..c1cc1e56b 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -27,11 +27,6 @@ pub struct PartialHalfEdge {
 }
 
 impl PartialHalfEdge {
-    /// Access the global form of the [`HalfEdge`]
-    pub fn global_form(&self) -> MaybePartial<GlobalEdge> {
-        self.global_form.clone()
-    }
-
     /// Extract the global curve from either the curve or global form
     ///
     /// If a global curve is available through both, the curve is preferred.

From 8991c0968eb309efdb2ade05d7f13e697e5c0e55 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:35:05 +0100
Subject: [PATCH 15/21] Properly merge global curves of `PartialHalfEdge`

---
 crates/fj-kernel/src/partial/objects/edge.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index c1cc1e56b..ffaa8334c 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -33,6 +33,7 @@ impl PartialHalfEdge {
     pub fn extract_global_curve(&self) -> MaybePartial<GlobalCurve> {
         self.curve
             .global_form()
+            .map(|global_form| global_form.merge_with(self.global_form.curve()))
             .unwrap_or_else(|| self.global_form.curve())
     }
 

From 385d5440c6feb5f6700cb1add03276923ee60e11 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:36:26 +0100
Subject: [PATCH 16/21] Simplify field of `PartialCurve`

---
 .../src/algorithms/transform/curve.rs         |  5 +----
 crates/fj-kernel/src/builder/edge.rs          |  4 ++--
 crates/fj-kernel/src/builder/shell.rs         | 12 +++++-----
 crates/fj-kernel/src/partial/maybe_partial.rs |  2 +-
 crates/fj-kernel/src/partial/objects/curve.rs | 22 +++++--------------
 5 files changed, 14 insertions(+), 31 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/curve.rs b/crates/fj-kernel/src/algorithms/transform/curve.rs
index a89192b7f..6b46215c5 100644
--- a/crates/fj-kernel/src/algorithms/transform/curve.rs
+++ b/crates/fj-kernel/src/algorithms/transform/curve.rs
@@ -32,10 +32,7 @@ impl TransformObject for PartialCurve {
             .surface
             .map(|surface| surface.transform(transform, objects))
             .transpose()?;
-        let global_form = self
-            .global_form
-            .map(|global_form| global_form.transform(transform, objects))
-            .transpose()?;
+        let global_form = self.global_form.transform(transform, objects)?;
 
         // Don't need to transform `self.path`, as that's defined in surface
         // coordinates, and thus transforming `surface` takes care of it.
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 4eb95d93c..43fce6871 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -66,7 +66,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
         let mut curve = self.curve.clone().into_partial();
-        curve.global_form = Some(self.extract_global_curve());
+        curve.global_form = self.extract_global_curve();
         curve.update_as_circle_from_radius(radius);
 
         let path = curve.path.expect("Expected path that was just created");
@@ -136,7 +136,7 @@ impl HalfEdgeBuilder for PartialHalfEdge {
 
         let mut curve = PartialCurve {
             surface: Some(surface),
-            global_form: Some(self.extract_global_curve()),
+            global_form: self.extract_global_curve(),
             ..Default::default()
         };
         curve.update_as_line_from_points(points);
diff --git a/crates/fj-kernel/src/builder/shell.rs b/crates/fj-kernel/src/builder/shell.rs
index 838295820..ad575271c 100644
--- a/crates/fj-kernel/src/builder/shell.rs
+++ b/crates/fj-kernel/src/builder/shell.rs
@@ -161,13 +161,11 @@ impl<'a> ShellBuilder<'a> {
                         };
 
                         let curve = PartialCurve {
-                            global_form: Some(
-                                side_up_prev
-                                    .curve()
-                                    .global_form()
-                                    .clone()
-                                    .into(),
-                            ),
+                            global_form: side_up_prev
+                                .curve()
+                                .global_form()
+                                .clone()
+                                .into(),
                             ..Default::default()
                         };
 
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index 039b899a1..a8e67d5f4 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -158,7 +158,7 @@ impl MaybePartial<Curve> {
     pub fn global_form(&self) -> Option<MaybePartial<GlobalCurve>> {
         match self {
             Self::Full(full) => Some(full.global_form().clone().into()),
-            Self::Partial(partial) => partial.global_form.clone(),
+            Self::Partial(partial) => Some(partial.global_form.clone()),
         }
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/curve.rs b/crates/fj-kernel/src/partial/objects/curve.rs
index a82a7af2f..0608dbd2e 100644
--- a/crates/fj-kernel/src/partial/objects/curve.rs
+++ b/crates/fj-kernel/src/partial/objects/curve.rs
@@ -1,7 +1,7 @@
 use crate::{
     geometry::path::SurfacePath,
     objects::{Curve, GlobalCurve, Objects, Surface},
-    partial::{MaybePartial, MergeWith, Mergeable},
+    partial::{MaybePartial, MergeWith},
     storage::Handle,
     validate::ValidationError,
 };
@@ -18,13 +18,7 @@ pub struct PartialCurve {
     pub surface: Option<Handle<Surface>>,
 
     /// The global form of the [`Curve`]
-    ///
-    /// # Implementation Note
-    ///
-    /// This can in principle be simplified to just `MaybePartial<GlobalForm`,
-    /// but as of this writing, there's still some code that relies on this
-    /// being an `Option`.
-    pub global_form: Option<MaybePartial<GlobalCurve>>,
+    pub global_form: MaybePartial<GlobalCurve>,
 }
 
 impl PartialCurve {
@@ -34,11 +28,7 @@ impl PartialCurve {
         let surface =
             self.surface.expect("Can't build `Curve` without surface");
 
-        let global_form = match self.global_form {
-            Some(global_form) => global_form,
-            None => objects.global_curves.insert(GlobalCurve)?.into(),
-        }
-        .into_full(objects)?;
+        let global_form = self.global_form.into_full(objects)?;
 
         Ok(Curve::new(surface, path, global_form))
     }
@@ -51,9 +41,7 @@ impl MergeWith for PartialCurve {
         Self {
             path: self.path.merge_with(other.path),
             surface: self.surface.merge_with(other.surface),
-            global_form: Mergeable(self.global_form)
-                .merge_with(Mergeable(other.global_form))
-                .0,
+            global_form: self.global_form.merge_with(other.global_form),
         }
     }
 }
@@ -63,7 +51,7 @@ impl From<&Curve> for PartialCurve {
         Self {
             path: Some(curve.path()),
             surface: Some(curve.surface().clone()),
-            global_form: Some(curve.global_form().clone().into()),
+            global_form: curve.global_form().clone().into(),
         }
     }
 }

From c5a4c8a9a1a5b90535f75e44816f709e9ebfc1fd Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:38:32 +0100
Subject: [PATCH 17/21] Simplify return value

---
 crates/fj-kernel/src/algorithms/transform/edge.rs | 4 +---
 crates/fj-kernel/src/partial/maybe_partial.rs     | 6 +++---
 crates/fj-kernel/src/partial/objects/edge.rs      | 3 +--
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/transform/edge.rs b/crates/fj-kernel/src/algorithms/transform/edge.rs
index 12bb441d3..27d26e8d8 100644
--- a/crates/fj-kernel/src/algorithms/transform/edge.rs
+++ b/crates/fj-kernel/src/algorithms/transform/edge.rs
@@ -32,9 +32,7 @@ impl TransformObject for PartialHalfEdge {
             .global_form
             .into_partial()
             .transform(transform, objects)?;
-        if let Some(curve) = curve.global_form() {
-            global_form.curve = curve;
-        }
+        global_form.curve = curve.global_form();
 
         Ok(Self::default()
             .with_curve(curve)
diff --git a/crates/fj-kernel/src/partial/maybe_partial.rs b/crates/fj-kernel/src/partial/maybe_partial.rs
index a8e67d5f4..dc5c32108 100644
--- a/crates/fj-kernel/src/partial/maybe_partial.rs
+++ b/crates/fj-kernel/src/partial/maybe_partial.rs
@@ -155,10 +155,10 @@ impl MaybePartial<Curve> {
     }
 
     /// Access the global form
-    pub fn global_form(&self) -> Option<MaybePartial<GlobalCurve>> {
+    pub fn global_form(&self) -> MaybePartial<GlobalCurve> {
         match self {
-            Self::Full(full) => Some(full.global_form().clone().into()),
-            Self::Partial(partial) => Some(partial.global_form.clone()),
+            Self::Full(full) => full.global_form().clone().into(),
+            Self::Partial(partial) => partial.global_form.clone(),
         }
     }
 }
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index ffaa8334c..a4c23e2ce 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -33,8 +33,7 @@ impl PartialHalfEdge {
     pub fn extract_global_curve(&self) -> MaybePartial<GlobalCurve> {
         self.curve
             .global_form()
-            .map(|global_form| global_form.merge_with(self.global_form.curve()))
-            .unwrap_or_else(|| self.global_form.curve())
+            .merge_with(self.global_form.curve())
     }
 
     /// Update the partial half-edge with the given surface

From 25c8a2cde4d57120ad762b289fb2ee597fbfb622 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:44:42 +0100
Subject: [PATCH 18/21] Refactor

---
 crates/fj-kernel/src/builder/edge.rs | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 43fce6871..dd983c725 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -5,8 +5,8 @@ use crate::{
     insert::Insert,
     objects::{Curve, Objects, Surface, Vertex, VerticesInNormalizedOrder},
     partial::{
-        MaybePartial, MergeWith, PartialCurve, PartialGlobalEdge,
-        PartialHalfEdge, PartialSurfaceVertex, PartialVertex,
+        MaybePartial, MergeWith, PartialGlobalEdge, PartialHalfEdge,
+        PartialSurfaceVertex, PartialVertex,
     },
     storage::Handle,
     validate::ValidationError,
@@ -134,11 +134,9 @@ impl HalfEdgeBuilder for PartialHalfEdge {
                 .expect("Can't infer line segment without surface position")
         });
 
-        let mut curve = PartialCurve {
-            surface: Some(surface),
-            global_form: self.extract_global_curve(),
-            ..Default::default()
-        };
+        let mut curve = self.curve.clone().into_partial();
+        curve.surface = Some(surface);
+        curve.global_form = self.extract_global_curve();
         curve.update_as_line_from_points(points);
 
         let [back, front] = {

From 6576507135edaee6f123bf889da552bc8e55a1e8 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:48:28 +0100
Subject: [PATCH 19/21] Make `PartialHalfEdge::build` smarter

---
 crates/fj-kernel/src/builder/edge.rs         |  2 --
 crates/fj-kernel/src/partial/objects/edge.rs | 21 +++++++++++++++++---
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index dd983c725..f336ed587 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -66,7 +66,6 @@ impl HalfEdgeBuilder for PartialHalfEdge {
         objects: &Objects,
     ) -> Result<Self, ValidationError> {
         let mut curve = self.curve.clone().into_partial();
-        curve.global_form = self.extract_global_curve();
         curve.update_as_circle_from_radius(radius);
 
         let path = curve.path.expect("Expected path that was just created");
@@ -136,7 +135,6 @@ impl HalfEdgeBuilder for PartialHalfEdge {
 
         let mut curve = self.curve.clone().into_partial();
         curve.surface = Some(surface);
-        curve.global_form = self.extract_global_curve();
         curve.update_as_line_from_points(points);
 
         let [back, front] = {
diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index a4c23e2ce..ff58d55d1 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -6,7 +6,7 @@ use crate::{
         Curve, GlobalCurve, GlobalEdge, GlobalVertex, HalfEdge, Objects,
         Surface, Vertex,
     },
-    partial::{MaybePartial, MergeWith},
+    partial::{MaybePartial, MergeWith, PartialCurve},
     storage::Handle,
     validate::ValidationError,
 };
@@ -87,8 +87,23 @@ impl PartialHalfEdge {
     }
 
     /// Build a full [`HalfEdge`] from the partial half-edge
-    pub fn build(self, objects: &Objects) -> Result<HalfEdge, ValidationError> {
-        let curve = self.curve.into_full(objects)?;
+    pub fn build(
+        mut self,
+        objects: &Objects,
+    ) -> Result<HalfEdge, ValidationError> {
+        let global_curve = self
+            .curve
+            .global_form()
+            .merge_with(self.global_form.curve());
+
+        let curve = {
+            self.curve = self.curve.merge_with(PartialCurve {
+                global_form: global_curve,
+                ..Default::default()
+            });
+
+            self.curve.into_full(objects)?
+        };
         let vertices = self.vertices.try_map_ext(|vertex| {
             vertex
                 .update_partial(|mut vertex| {

From b804cb10b7e811828a372c172ba1aaf52f139d7b Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:49:16 +0100
Subject: [PATCH 20/21] Remove unused method

---
 crates/fj-kernel/src/partial/objects/edge.rs | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index ff58d55d1..62b85eac1 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -27,15 +27,6 @@ pub struct PartialHalfEdge {
 }
 
 impl PartialHalfEdge {
-    /// Extract the global curve from either the curve or global form
-    ///
-    /// If a global curve is available through both, the curve is preferred.
-    pub fn extract_global_curve(&self) -> MaybePartial<GlobalCurve> {
-        self.curve
-            .global_form()
-            .merge_with(self.global_form.curve())
-    }
-
     /// Update the partial half-edge with the given surface
     pub fn with_surface(mut self, surface: Handle<Surface>) -> Self {
         self.curve = self.curve.update_partial(|mut curve| {

From ba0aaabaf5aee72b6ac6a8fc90ecdae3409af1de Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Sat, 12 Nov 2022 19:57:17 +0100
Subject: [PATCH 21/21] Refactor

---
 crates/fj-kernel/src/partial/objects/edge.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/fj-kernel/src/partial/objects/edge.rs b/crates/fj-kernel/src/partial/objects/edge.rs
index 62b85eac1..6a44d916d 100644
--- a/crates/fj-kernel/src/partial/objects/edge.rs
+++ b/crates/fj-kernel/src/partial/objects/edge.rs
@@ -6,7 +6,7 @@ use crate::{
         Curve, GlobalCurve, GlobalEdge, GlobalVertex, HalfEdge, Objects,
         Surface, Vertex,
     },
-    partial::{MaybePartial, MergeWith, PartialCurve},
+    partial::{MaybePartial, MergeWith, PartialCurve, PartialVertex},
     storage::Handle,
     validate::ValidationError,
 };
@@ -97,9 +97,9 @@ impl PartialHalfEdge {
         };
         let vertices = self.vertices.try_map_ext(|vertex| {
             vertex
-                .update_partial(|mut vertex| {
-                    vertex.curve = curve.clone().into();
-                    vertex
+                .merge_with(PartialVertex {
+                    curve: curve.clone().into(),
+                    ..Default::default()
                 })
                 .into_full(objects)
         })?;