Store elements and regulators without keys

Since we're no longer using storage keys to refer to elements and
regulators, we don't need to store these items in keyed collections
anymore.

To keep element and regulator pointers in `BTreeSet` collections, we
implement `Ord` for `Serial` trait objects. As a bonus, this lets us
turn the element-wise regulator collections back into `BTreeSet`.

app-proto/Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "ahash"
@@ -90,7 +90,6 @@ dependencies = [
  "nalgebra",
  "readonly",
  "rustc-hash",
- "slab",
  "sycamore",
  "wasm-bindgen-test",
  "web-sys",
@@ -414,15 +413,6 @@ dependencies = [
  "wide",
 ]
 
-[[package]]
-name = "slab"
-version = "0.4.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f92a496fb766b417c996b9c5e57daf2f7ad3b0bebe1ccfca4856390e3d3bb67"
-dependencies = [
- "autocfg",
-]
-
 [[package]]
 name = "slotmap"
 version = "1.0.7"

app-proto/Cargo.toml

@@ -16,7 +16,6 @@ lazy_static = "1.5.0"
 nalgebra = "0.33.0"
 readonly = "0.2.12"
 rustc-hash = "2.0.0"
-slab = "0.4.9"
 sycamore = "0.9.0-beta.3"
 
 # The `console_error_panic_hook` crate provides better debugging of panics by

app-proto/src/assembly.rs

@@ -1,14 +1,15 @@
 use nalgebra::{DMatrix, DVector, DVectorView};
 use rustc_hash::FxHashMap;
-use slab::Slab;
 use std::{
     any::{Any, TypeId},
     cell::Cell,
+    collections::BTreeSet,
+    cmp::Ordering,
     fmt,
     fmt::{Debug, Formatter},
     hash::{Hash, Hasher},
     rc::Rc,
-    sync::atomic::{AtomicU64, Ordering}
+    sync::{atomic, atomic::AtomicU64}
 };
 use sycamore::prelude::*;
 use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
@@ -29,9 +30,6 @@ use crate::{
     specified::SpecifiedValue
 };
 
-// the types of the keys we use to access an assembly's elements
-pub type ElementKey = usize;
-
 pub type ElementColor = [f32; 3];
 
 /* KLUDGE */
@@ -53,7 +51,7 @@ pub trait Serial {
         //   https://marabos.nl/atomics/atomics.html#example-handle-overflow
         //
         NEXT_SERIAL.fetch_update(
-            Ordering::SeqCst, Ordering::SeqCst,
+            atomic::Ordering::SeqCst, atomic::Ordering::SeqCst,
             |serial| serial.checked_add(1)
         ).expect("Out of serial numbers for elements")
     }
@@ -73,6 +71,18 @@ impl PartialEq for dyn Serial {
 
 impl Eq for dyn Serial {}
 
+impl PartialOrd for dyn Serial {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for dyn Serial {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.serial().cmp(&other.serial())
+    }
+}
+
 pub trait ProblemPoser {
     fn pose(&self, problem: &mut ConstraintProblem);
 }
@@ -95,7 +105,7 @@ pub trait Element: Serial + ProblemPoser + DisplayItem {
     
     // the regulators the element is subject to. the assembly that owns the
     // element is responsible for keeping this set up to date
-    fn regulators(&self) -> Signal<Vec<Rc<dyn Regulator>>>;
+    fn regulators(&self) -> Signal<BTreeSet<Rc<dyn Regulator>>>;
     
     // the configuration matrix column index that was assigned to the element
     // last time the assembly was realized, or `None` if the element has never
@@ -128,12 +138,24 @@ impl PartialEq for dyn Element {
 
 impl Eq for dyn Element {}
 
+impl PartialOrd for dyn Element {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        <dyn Serial>::partial_cmp(self, other)
+    }
+}
+
+impl Ord for dyn Element {
+    fn cmp(&self, other: &Self) -> Ordering {
+        <dyn Serial>::cmp(self, other)
+    }
+}
+
 pub struct Sphere {
     pub id: String,
     pub label: String,
     pub color: ElementColor,
     pub representation: Signal<DVector<f64>>,
-    pub regulators: Signal<Vec<Rc<dyn Regulator>>>,
+    pub regulators: Signal<BTreeSet<Rc<dyn Regulator>>>,
     serial: u64,
     column_index: Cell<Option<usize>>
 }
@@ -152,7 +174,7 @@ impl Sphere {
             label: label,
             color: color,
             representation: create_signal(representation),
-            regulators: create_signal(Vec::new()),
+            regulators: create_signal(BTreeSet::new()),
             serial: Self::next_serial(),
             column_index: None.into()
         }
@@ -189,7 +211,7 @@ impl Element for Sphere {
         self.representation
     }
     
-    fn regulators(&self) -> Signal<Vec<Rc<dyn Regulator>>> {
+    fn regulators(&self) -> Signal<BTreeSet<Rc<dyn Regulator>>> {
         self.regulators
     }
     
@@ -223,7 +245,7 @@ pub struct Point {
     pub label: String,
     pub color: ElementColor,
     pub representation: Signal<DVector<f64>>,
-    pub regulators: Signal<Vec<Rc<dyn Regulator>>>,
+    pub regulators: Signal<BTreeSet<Rc<dyn Regulator>>>,
     serial: u64,
     column_index: Cell<Option<usize>>
 }
@@ -242,7 +264,7 @@ impl Point {
             label,
             color,
             representation: create_signal(representation),
-            regulators: create_signal(Vec::new()),
+            regulators: create_signal(BTreeSet::new()),
             serial: Self::next_serial(),
             column_index: None.into()
         }
@@ -275,7 +297,7 @@ impl Element for Point {
         self.representation
     }
     
-    fn regulators(&self) -> Signal<Vec<Rc<dyn Regulator>>> {
+    fn regulators(&self) -> Signal<BTreeSet<Rc<dyn Regulator>>> {
         self.regulators
     }
     
@@ -335,6 +357,18 @@ impl PartialEq for dyn Regulator {
 
 impl Eq for dyn Regulator {}
 
+impl PartialOrd for dyn Regulator {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        <dyn Serial>::partial_cmp(self, other)
+    }
+}
+
+impl Ord for dyn Regulator {
+    fn cmp(&self, other: &Self) -> Ordering {
+        <dyn Serial>::cmp(self, other)
+    }
+}
+
 pub struct InversiveDistanceRegulator {
     pub subjects: [Rc<dyn Element>; 2],
     pub measurement: ReadSignal<f64>,
@@ -472,8 +506,8 @@ type AssemblyMotion<'a> = Vec<ElementMotion<'a>>;
 #[derive(Clone)]
 pub struct Assembly {
     // elements and regulators
-    pub elements: Signal<Slab<Rc<dyn Element>>>,
+    pub elements: Signal<BTreeSet<Rc<dyn Element>>>,
-    pub regulators: Signal<Slab<Rc<dyn Regulator>>>,
+    pub regulators: Signal<BTreeSet<Rc<dyn Regulator>>>,
     
     // solution variety tangent space. the basis vectors are stored in
     // configuration matrix format, ordered according to the elements' column
@@ -494,8 +528,8 @@ pub struct Assembly {
 impl Assembly {
     pub fn new() -> Assembly {
         Assembly {
-            elements: create_signal(Slab::new()),
+            elements: create_signal(BTreeSet::new()),
-            regulators: create_signal(Slab::new()),
+            regulators: create_signal(BTreeSet::new()),
             tangent: create_signal(ConfigSubspace::zero(0)),
             elements_by_id: create_signal(FxHashMap::default())
         }
@@ -506,30 +540,27 @@ impl Assembly {
     // insert an element into the assembly without checking whether we already
     // have an element with the same identifier. any element that does have the
     // same identifier will get kicked out of the `elements_by_id` index
-    fn insert_element_unchecked(&self, elt: impl Element + 'static) -> ElementKey {
+    fn insert_element_unchecked(&self, elt: impl Element + 'static) {
         // insert the element
         let id = elt.id().clone();
         let elt_rc = Rc::new(elt);
-        let key = self.elements.update(|elts| elts.insert(elt_rc.clone()));
+        self.elements.update(|elts| elts.insert(elt_rc.clone()));
         self.elements_by_id.update(|elts_by_id| elts_by_id.insert(id, elt_rc.clone()));
         
         // create and insert the element's default regulators
         for reg in elt_rc.default_regulators() {
             self.insert_regulator(reg);
         }
-        
-        key
     }
     
-    pub fn try_insert_element(&self, elt: impl Element + 'static) -> Option<ElementKey> {
+    pub fn try_insert_element(&self, elt: impl Element + 'static) -> bool {
         let can_insert = self.elements_by_id.with_untracked(
             |elts_by_id| !elts_by_id.contains_key(elt.id())
         );
         if can_insert {
-            Some(self.insert_element_unchecked(elt))
+            self.insert_element_unchecked(elt);
-        } else {
-            None
         }
+        can_insert
     }
     
     pub fn insert_element_default<T: Element + 'static>(&self) {
@@ -559,7 +590,7 @@ impl Assembly {
             |subj| subj.regulators()
         ).collect();
         for regulators in subject_regulators {
-            regulators.update(|regs| regs.push(regulator.clone()));
+            regulators.update(|regs| regs.insert(regulator.clone()));
         }
         
         // update the realization when the regulator becomes a constraint, or is
@@ -581,7 +612,7 @@ impl Assembly {
         // print an updated list of regulators
         console::log_1(&JsValue::from("Regulators:"));
         self.regulators.with_untracked(|regs| {
-            for (_, reg) in regs.into_iter() {
+            for reg in regs.into_iter() {
                 console::log_1(&JsValue::from(format!(
                     "  {:?}: {}",
                     reg.subjects(),
@@ -605,7 +636,7 @@ impl Assembly {
     pub fn realize(&self) {
         // index the elements
         self.elements.update_silent(|elts| {
-            for (index, (_, elt)) in elts.into_iter().enumerate() {
+            for (index, elt) in elts.iter().enumerate() {
                 elt.set_column_index(index);
             }
         });
@@ -613,11 +644,11 @@ impl Assembly {
         // set up the constraint problem
         let problem = self.elements.with_untracked(|elts| {
             let mut problem = ConstraintProblem::new(elts.len());
-            for (_, elt) in elts {
+            for elt in elts {
                 elt.pose(&mut problem);
             }
             self.regulators.with_untracked(|regs| {
-                for (_, reg) in regs {
+                for reg in regs {
                     reg.pose(&mut problem);
                 }
             });
@@ -660,7 +691,7 @@ impl Assembly {
         
         if success {
             // read out the solution
-            for (_, elt) in self.elements.get_clone_untracked() {
+            for elt in self.elements.get_clone_untracked() {
                 elt.representation().update(
                     |rep| rep.set_column(0, &config.column(elt.column_index().unwrap()))
                 );
@@ -741,7 +772,7 @@ impl Assembly {
         // normalizations, so we restore those afterward
         /* KLUDGE */
         // for now, we only restore the normalizations of spheres
-        for (_, elt) in self.elements.get_clone_untracked() {
+        for elt in self.elements.get_clone_untracked() {
             elt.representation().update_silent(|rep| {
                 match elt.column_index() {
                     Some(column_index) => {

app-proto/src/display.rs

@@ -363,7 +363,7 @@ pub fn Display() -> View {
     let scene_changed = create_signal(true);
     create_effect(move || {
         state.assembly.elements.with(|elts| {
-            for (_, elt) in elts {
+            for elt in elts {
                 elt.representation().track();
             }
         });
@@ -616,7 +616,7 @@ pub fn Display() -> View {
                 
                 // set up the scene
                 state.assembly.elements.with_untracked(
-                    |elts| for (_, elt) in elts {
+                    |elts| for elt in elts {
                         let selected = state.selection.with(|sel| sel.contains(elt));
                         elt.show(&mut scene, selected);
                     }
@@ -851,7 +851,7 @@ pub fn Display() -> View {
                 let (dir, pixel_size) = event_dir(&event);
                 console::log_1(&JsValue::from(dir.to_string()));
                 let mut clicked: Option<(Rc<dyn Element>, f64)> = None;
-                for (_, elt) in state.assembly.elements.get_clone_untracked() {
+                for elt in state.assembly.elements.get_clone_untracked() {
                     match assembly_to_world.with(|asm_to_world| elt.cast(dir, asm_to_world, pixel_size)) {
                         Some(depth) => match clicked {
                             Some((_, best_depth)) => {

app-proto/src/outline.rs

@@ -228,11 +228,15 @@ pub fn Outline() -> View {
     let state = use_context::<AppState>();
     
     // list the elements alphabetically by ID
+    /* TO DO */
+    // this code is designed to generalize easily to other sort keys. if we only
+    // ever wanted to sort by ID, we could do that more simply using the
+    // `elements_by_id` index
     let element_list = state.assembly.elements.map(
         |elts| elts
             .clone()
             .into_iter()
-            .sorted_by_key(|(_, elt)| elt.id().clone())
+            .sorted_by_key(|elt| elt.id().clone())
             .collect()
     );
     
@@ -246,10 +250,10 @@ pub fn Outline() -> View {
         ) {
             Keyed(
                 list=element_list,
-                view=|(_, elt)| view! {
+                view=|elt| view! {
                     ElementOutlineItem(element=elt)
                 },
-                key=|(_, elt)| elt.serial()
+                key=|elt| elt.serial()
             )
         }
     }