From 63290e9665c8470d891dee5487eb703f78648950 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Tue, 12 Dec 2023 12:44:21 +0100
Subject: [PATCH 1/2] Add `SweptRegion`

---
 crates/fj-core/src/operations/sweep/mod.rs    |  2 +-
 crates/fj-core/src/operations/sweep/region.rs | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/crates/fj-core/src/operations/sweep/mod.rs b/crates/fj-core/src/operations/sweep/mod.rs
index 729307455..9ed29c1ff 100644
--- a/crates/fj-core/src/operations/sweep/mod.rs
+++ b/crates/fj-core/src/operations/sweep/mod.rs
@@ -17,7 +17,7 @@ pub use self::{
     face::SweepFace,
     half_edge::SweepHalfEdge,
     path::SweepSurfacePath,
-    region::SweepRegion,
+    region::{SweepRegion, SweptRegion},
     shell_face::SweepFaceOfShell,
     sketch::SweepSketch,
     vertex::SweepVertex,
diff --git a/crates/fj-core/src/operations/sweep/region.rs b/crates/fj-core/src/operations/sweep/region.rs
index f61a548ff..f7b9ae9b7 100644
--- a/crates/fj-core/src/operations/sweep/region.rs
+++ b/crates/fj-core/src/operations/sweep/region.rs
@@ -111,3 +111,21 @@ fn sweep_cycle(
 
     swept_cycle.top_cycle.insert(services)
 }
+
+/// The result of sweeping a [`Region`]
+///
+/// See [`SweepRegion`].
+pub struct SweptRegion {
+    /// The side faces created by the sweep
+    pub side_faces: Vec<Face>,
+
+    /// The top face created by the sweep
+    pub top_face: Face,
+}
+
+impl SweptRegion {
+    /// Return an iterator over all of the faces
+    pub fn all_faces(self) -> impl Iterator<Item = Face> {
+        self.side_faces.into_iter().chain([self.top_face])
+    }
+}

From a83b277fdde64f5793b8ea4223f97a6e22e151e4 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Tue, 12 Dec 2023 12:44:42 +0100
Subject: [PATCH 2/2] Return `SweptRegion` from region sweeping op

---
 crates/fj-core/src/operations/holes.rs            |  2 +-
 crates/fj-core/src/operations/sweep/face.rs       |  2 +-
 crates/fj-core/src/operations/sweep/region.rs     | 10 ++++++----
 crates/fj-core/src/operations/sweep/shell_face.rs |  2 +-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/crates/fj-core/src/operations/holes.rs b/crates/fj-core/src/operations/holes.rs
index 20d90a5ab..b9f9ada6e 100644
--- a/crates/fj-core/src/operations/holes.rs
+++ b/crates/fj-core/src/operations/holes.rs
@@ -50,7 +50,7 @@ impl AddHole for Shell {
                 &mut SweepCache::default(),
                 services,
             )
-            .into_iter()
+            .all_faces()
             .map(|face| face.insert(services))
             .collect::<Vec<_>>();
 
diff --git a/crates/fj-core/src/operations/sweep/face.rs b/crates/fj-core/src/operations/sweep/face.rs
index 5e4ce5c2c..212b40cbc 100644
--- a/crates/fj-core/src/operations/sweep/face.rs
+++ b/crates/fj-core/src/operations/sweep/face.rs
@@ -54,7 +54,7 @@ impl SweepFace for Handle<Face> {
         let side_faces = bottom_face
             .region()
             .sweep_region(bottom_face.surface(), path, cache, services)
-            .into_iter()
+            .all_faces()
             .map(|side_face| side_face.insert(services));
         faces.extend(side_faces);
 
diff --git a/crates/fj-core/src/operations/sweep/region.rs b/crates/fj-core/src/operations/sweep/region.rs
index f7b9ae9b7..426357a50 100644
--- a/crates/fj-core/src/operations/sweep/region.rs
+++ b/crates/fj-core/src/operations/sweep/region.rs
@@ -34,7 +34,7 @@ pub trait SweepRegion {
         path: impl Into<Vector<3>>,
         cache: &mut SweepCache,
         services: &mut Services,
-    ) -> Vec<Face>;
+    ) -> SweptRegion;
 }
 
 impl SweepRegion for Region {
@@ -44,7 +44,7 @@ impl SweepRegion for Region {
         path: impl Into<Vector<3>>,
         cache: &mut SweepCache,
         services: &mut Services,
-    ) -> Vec<Face> {
+    ) -> SweptRegion {
         let path = path.into();
 
         let mut faces = Vec::new();
@@ -84,9 +84,11 @@ impl SweepRegion for Region {
 
             Face::new(top_surface, top_region)
         };
-        faces.push(top_face);
 
-        faces
+        SweptRegion {
+            top_face,
+            side_faces: faces,
+        }
     }
 }
 
diff --git a/crates/fj-core/src/operations/sweep/shell_face.rs b/crates/fj-core/src/operations/sweep/shell_face.rs
index 5632c295e..f26b6de1c 100644
--- a/crates/fj-core/src/operations/sweep/shell_face.rs
+++ b/crates/fj-core/src/operations/sweep/shell_face.rs
@@ -57,7 +57,7 @@ impl SweepFaceOfShell for Shell {
         let region = Region::new(exterior, [], face.region().color());
         let faces = region
             .sweep_region(face.surface(), path, &mut cache, services)
-            .into_iter()
+            .all_faces()
             .map(|face| face.insert(services));
 
         self.remove_face(&face).add_faces(faces)