kernel: an assembled record is the body; its history through record::attach

Body::from_record takes the finished record as the body, so its faces and edges are the
record's and the history needs no round trip through SMLib's numbering. The edge origins
(kept edges, pieces) go to record::attach, which gives every other edge its faces' meeting.

(not built: base in progress)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017itGh5fpMEousnZ91cYcVt

crates/kernel/src/assemble.rs

@@ -3,8 +3,7 @@
 //! neighbours) starts from the body's record, takes faces away, adds faces bounded by new or
 //! existing edges, and finishes into a record in canonical order (docs/native-brep.md): pcurves
 //! from the record's one routine ([`solidcraft_geom::brep::pcurve`]) for every new use, the
-//! record's own for every use kept, edge uses, regions and shells. SMLib builds the body from
-//! that record, as from any other.
+//! record's own for every use kept, edge uses, regions and shells. The body is that record.
 //!
 //! Faces keep the record's convention as the operation gives them: each face's loops are seen
 //! from the side the material is not on (the outward side), the outer loop counter-clockwise
@@ -19,7 +18,7 @@ use solidcraft_geom::brep::{
 };
 
 use crate::body::Body;
-use crate::history::{EdgeOrigin, EdgeProv, FaceProv, History};
+use crate::history::{EdgeOrigin, FaceProv};
 use crate::{KernelError, Result};
 
 fn invalid(m: impl std::fmt::Display) -> KernelError {
@@ -426,24 +425,12 @@ fn domain_of(surface: &Surface, pcurves: &[Vec<Curve2>], kept: Option<[[f64; 2];
     Some(out)
 }
 
-/// The body SMLib builds from `record`, and whether its faces and edges are numbered as the
-/// record's (then face i of the body is face i of the record, and so for edges).
-pub(crate) fn body_of(record: &Brep) -> Result<(Body, bool)> {
-    let (brep, same) = crate::native::smlib_record_ordered(record)?;
-    let (body, kept) = crate::native::body_from_smlib_ordered(&brep)?;
-    Ok((body, same.is_some() && kept.is_some()))
-}
-
 /// The body of `finished`, built from the one operand `from`, with the history whose faces are
 /// `faces` (in the assembly's face order, taken-away faces skipped): each kept edge the operand
-/// edge it is, each new one where its two faces meet. No history where SMLib renumbered the
-/// record.
-pub(crate) fn body_with_history(finished: &Finished, assembly: &Assembly, from: &Body, faces: Vec<FaceProv>) -> Result<Body> {
-    let (body, same) = body_of(&finished.record)?;
-    let counts = crate::record::counts(&[from]);
-    if !same {
-        return Ok(body.with_checked_history(None, &counts));
-    }
+/// edge it is, each re-made one the operand edges it is a piece of, each new one where its two
+/// faces meet ([`crate::record::of_faces`]). The body is the finished record, so its faces and
+/// edges are numbered as the record's.
+pub(crate) fn body_with_history(finished: Finished, assembly: &Assembly, from: &Body, faces: Vec<FaceProv>) -> Result<Body> {
     // The provenance of each record face, from the assembly's face order.
     let mut provs: Vec<Option<FaceProv>> = vec![None; finished.record.faces.len()];
     let mut given = faces.into_iter();
@@ -451,30 +438,18 @@ pub(crate) fn body_with_history(finished: &Finished, assembly: &Assembly, from:
         let p = given.next().ok_or_else(|| invalid("history: fewer faces than the body"))?;
         *provs.get_mut(*k).ok_or_else(|| invalid("history: face"))? = Some(p);
     }
-    let mut faces: Vec<FaceProv> = provs.into_iter().collect::<Option<_>>().ok_or_else(|| invalid("history: a face without provenance"))?;
-    crate::record::mark_shared_split(&mut faces);
-    let edges = finished
-        .record
+    let faces: Option<Vec<FaceProv>> = provs.into_iter().collect();
+    let edges: Vec<Vec<EdgeOrigin>> = finished
         .edges
         .iter()
-        .zip(&finished.edges)
-        .map(|(e, a)| {
-            let mut between: Vec<usize> = e.uses.iter().map(|u| u.face as usize).collect();
-            between.sort_unstable();
-            between.dedup();
-            let origins = match assembly.edges.get(*a) {
-                Some(AEdge { source: Some(edge), .. }) => vec![EdgeOrigin::Edge { operand: 0, edge: *edge }],
-                Some(AEdge { of, .. }) if !of.is_empty() => {
-                    let mut of = of.clone();
-                    of.sort_unstable();
-                    of.into_iter().map(|edge| EdgeOrigin::Edge { operand: 0, edge }).collect()
-                }
-                _ => crate::record::meeting(&between, &faces),
-            };
-            EdgeProv { faces: between, origins }
+        .map(|a| match assembly.edges.get(*a) {
+            Some(AEdge { source: Some(edge), .. }) => crate::record::pieces_of(0, [*edge]),
+            Some(AEdge { of, .. }) => crate::record::pieces_of(0, of.iter().copied()),
+            None => Vec::new(),
         })
         .collect();
-    Ok(body.with_checked_history(Some(History { operands: 1, faces, edges }), &counts))
+    let body = Body::from_record(finished.record)?;
+    Ok(crate::record::attach(body, &crate::record::counts(&[from]), faces, &edges))
 }
 
 /// Whether the face `face` of `b` has its natural normal out of the material.

crates/kernel/src/delete_face.rs

@@ -318,7 +318,7 @@ pub fn delete_faces(body: &Body, faces: &[usize]) -> Result<Body> {
             }
         }
         let finished = asm.finish().map_err(|e| fail(format!("the neighbouring faces do not close the gap ({e})")))?;
-        crate::assemble::body_with_history(&finished, &asm, body, history)
+        crate::assemble::body_with_history(finished, &asm, body, history)
     })
 }
 

crates/kernel/src/emboss.rs

@@ -389,7 +389,7 @@ fn emboss_impl(body: &Body, anchor: Option<Vec3>, plane: &Plane, regions: &[Regi
             asm.face(f);
         }
         let finished = asm.finish()?;
-        let result = crate::assemble::body_with_history(&finished, &asm, body, history)?;
+        let result = crate::assemble::body_with_history(finished, &asm, body, history)?;
         if !result.validity().is_empty() {
             return Err(fail("rebuilt cylinder is not a closed manifold"));
         }

crates/kernel/src/lip.rs

@@ -355,7 +355,7 @@ pub fn raise_band(body: &Body, at: Vec3, width: f64, height: f64, outside: bool)
         }
         asm.face(top);
         let finished = asm.finish()?;
-        let b = crate::assemble::body_with_history(&finished, &asm, body, history)?;
+        let b = crate::assemble::body_with_history(finished, &asm, body, history)?;
         let problems = b.validity();
         if !problems.is_empty() {
             return Err(fail(&problems.join("; ")));