feat(aura): surface bind-bound params in the graph model + viewer signature

A node built with `.bind(slot, value)` fixes a declared param to a structural
constant: the slot correctly leaves the tunable surface (param_space / sweep axes),
but it also vanished from the RENDERED signature, because prim_record emitted only
schema.params. The cycle-0036 `blend` (a LinComb(3) with weights[2] bound to 0.5)
rendered `LinComb[weights[0], weights[1]]` — a 2-arity signature over a 3-port box,
with the fixed 0.5 invisible. The signature misrepresented the node.

bind now ANNOTATES instead of erasing. All slots are shown; the bound one renders
`name=value`, dimmed. The blend renders:
    blend: LinComb[weights[0], weights[1], weights[2]=0.5]

Structurally a twin of cycle 0035's instance-name thread (commit 0ae8320): a
conditional field threaded engine -> model -> viewer.
- aura-core: a `BoundParam { pos, name, kind, value }` recorded by bind alongside
  the unchanged closure capture, plus a `bound_params()` accessor (twin of
  instance_name()). `pos` is the slot's ORIGINAL pre-bind position (the compressed
  index is mapped back over earlier-bound positions), so the render is faithful for
  any bind pattern, not just a trailing one.
- aura-engine: a conditional `"bound"` field in prim_record (present only when the
  node has binds, mirroring the conditional "name"), each entry [pos,"name","kind",
  "value"] via a new scalar_str helper (f64 via {:?} — keeps a decimal point so a
  bound f64 never reads as an i64).
- graph-viewer.js: adaptNodes/genDot carry `bound`; cellLabel merges free + bound
  params back into slot order by position and renders the bound slot dimmed
  (reusing the 0035 separator grey #9399b2).

Render notation settled with the user (issue #63, reconciliation comment): keep the
[...] convention and name=value (not parens, not positional value-only).

Render/debug surface only: dropped at lowering (C23 — bind still resolves the name
to a fixed position and the compilat is unchanged), model stays deterministic (C14
— the inline no-bind golden is byte-unchanged; only the sample fixture's blend node
gains "bound"). The tunable surface is untouched: the eight-param sweep pins stay
byte-identical (C12/C19). New unit tests pin the recorded original position and the
conditional model field; a new headless render guard pins the dimmed name=value
render and slot-order faithfulness for both a trailing and a non-trailing bind.

Verified: cargo build/test (0 failed) + clippy -D warnings (0) all green.

closes #63
This commit is contained in:
2026-06-13 23:23:29 +02:00
parent 4227073fce
commit 47e0e605e1
6 changed files with 241 additions and 7 deletions
+19 -4
View File
@@ -29,7 +29,7 @@ function adaptNodes(nodes) {
const n = nodes[key];
if (n.prim) {
const p = n.prim;
out[key] = { prim: { name: p.name, type: p.type, role: p.role, params: p.params, ins: adaptIns(p.ins), outs: p.outs } };
out[key] = { prim: { name: p.name, type: p.type, role: p.role, params: p.params, bound: p.bound || [], ins: adaptIns(p.ins), outs: p.outs } };
} else {
out[key] = n; // composite reference { comp }
}
@@ -69,8 +69,23 @@ function cellLabel(id, o, showTypes) {
const cell = (io, arr) => ([n, k], i) =>
`<td port="${io}${i}" id="P_${id}_${io}${i}" href="#" colspan="${span(arr.length)}" ` +
`bgcolor="${io === "i" ? "#222b33" : "#332b22"}"><font color="${col(k)}">${txt(n, k)}</font></td>`;
const sp = o.params.map(([n, k]) => `<font color="${col(k)}">${showTypes && k ? `${n}:${k}` : n}</font>`);
const sig = o.params.length ? `<font color="#9399b2">[</font>${sp.join('<font color="#9399b2">, </font>')}<font color="#9399b2">]</font>` : "";
// merge free params and bound params back into slot order by original position;
// a bound slot renders as a dimmed name=value (reuses the 0035 separator grey).
const bnd = o.bound || [];
const total = o.params.length + bnd.length;
const byPos = new Map(bnd.map(([pos, n, k, v]) => [pos, [n, k, v]]));
const slots = [];
let fi = 0;
for (let pos = 0; pos < total; pos++) {
if (byPos.has(pos)) {
const [n, , v] = byPos.get(pos);
slots.push(`<font color="#9399b2">${n}=${v}</font>`);
} else {
const [n, k] = o.params[fi++];
slots.push(`<font color="${col(k)}">${showTypes && k ? `${n}:${k}` : n}</font>`);
}
}
const sig = total ? `<font color="#9399b2">[</font>${slots.join('<font color="#9399b2">, </font>')}<font color="#9399b2">]</font>` : "";
const prefix = o.name
? `<font color="#cdd6f4">${o.name}</font><font color="#9399b2">: </font>`
: "";
@@ -108,7 +123,7 @@ function genDot(def, role, expandedSet, showTypes) {
const inst = def.nodes[key], cpath = [...path, key], cid = "n" + cpath.join("__");
if (inst.prim) {
const s = inst.prim;
block += `${cid} [label=${cellLabel(cid, { name: s.name, type: s.type, params: s.params, ins: s.ins, outs: s.outs, bodyBg: bodyBgFor(s.role), composite: false }, showTypes)}];\n`;
block += `${cid} [label=${cellLabel(cid, { name: s.name, type: s.type, params: s.params, bound: s.bound, ins: s.ins, outs: s.outs, bodyBg: bodyBgFor(s.role), composite: false }, showTypes)}];\n`;
addInfo(INFO, cid, s);
if (s.role === "source") topRank.push(cid); // sinks are placed freely (not rank-pinned)
childRes[key] = { type: "leaf", id: cid, spec: s };
+1 -1
View File
@@ -1 +1 @@
{"root":{"nodes":{"0":{"comp":"signals"},"1":{"prim":{"type":"Exposure","role":"node","params":[["scale","f64"]],"ins":[["f64","any","signal"]],"outs":[["exposure","f64"]]}},"2":{"prim":{"type":"SimBroker","role":"node","params":[],"ins":[["f64","any","exposure"],["f64","any","price"]],"outs":[["equity","f64"]]}},"3":{"prim":{"type":"Recorder","role":"sink","params":[],"ins":[["f64","any","col[0]"]],"outs":[]}},"4":{"prim":{"type":"Recorder","role":"sink","params":[],"ins":[["f64","any","col[0]"]],"outs":[]}},"src_price":{"prim":{"type":"price","role":"source","params":[],"ins":[],"outs":[["price","f64"]]}}},"edges":[["0.o0","1.i0"],["1.o0","2.i0"],["2.o0","3.i0"],["1.o0","4.i0"],["src_price.o0","0.i0"],["src_price.o0","2.i1"]]},"composites":{"signals":{"inputs":[["f64","any","price"]],"outputs":[["signal","f64"]],"nodes":{"0":{"comp":"trend"},"1":{"comp":"momentum"},"2":{"prim":{"name":"blend","type":"LinComb","role":"node","params":[["weights[0]","f64"],["weights[1]","f64"]],"ins":[["f64","any","term[0]"],["f64","any","term[1]"],["f64","any","term[2]"]],"outs":[["value","f64"]]}}},"edges":[["0.o0","2.i0"],["1.o2","2.i1"],["1.o1","2.i2"],["@price","0.i0"],["@price","1.i0"],["2.o0","#0"]]},"trend":{"inputs":[["f64","any","price"]],"outputs":[["cross","f64"]],"nodes":{"0":{"prim":{"name":"fast","type":"SMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"1":{"prim":{"name":"slow","type":"SMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"2":{"prim":{"type":"Sub","role":"node","params":[],"ins":[["f64","any","lhs"],["f64","any","rhs"]],"outs":[["value","f64"]]}}},"edges":[["0.o0","2.i0"],["1.o0","2.i1"],["@price","0.i0"],["@price","1.i0"],["2.o0","#0"]]},"momentum":{"inputs":[["f64","any","price"]],"outputs":[["macd","f64"],["signal","f64"],["histogram","f64"]],"nodes":{"0":{"prim":{"name":"fast","type":"EMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"1":{"prim":{"name":"slow","type":"EMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"2":{"prim":{"type":"Sub","role":"node","params":[],"ins":[["f64","any","lhs"],["f64","any","rhs"]],"outs":[["value","f64"]]}},"3":{"prim":{"name":"signal","type":"EMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"4":{"prim":{"type":"Sub","role":"node","params":[],"ins":[["f64","any","lhs"],["f64","any","rhs"]],"outs":[["value","f64"]]}}},"edges":[["0.o0","2.i0"],["1.o0","2.i1"],["2.o0","3.i0"],["2.o0","4.i0"],["3.o0","4.i1"],["@price","0.i0"],["@price","1.i0"],["2.o0","#0"],["3.o0","#1"],["4.o0","#2"]]}}}
{"root":{"nodes":{"0":{"comp":"signals"},"1":{"prim":{"type":"Exposure","role":"node","params":[["scale","f64"]],"ins":[["f64","any","signal"]],"outs":[["exposure","f64"]]}},"2":{"prim":{"type":"SimBroker","role":"node","params":[],"ins":[["f64","any","exposure"],["f64","any","price"]],"outs":[["equity","f64"]]}},"3":{"prim":{"type":"Recorder","role":"sink","params":[],"ins":[["f64","any","col[0]"]],"outs":[]}},"4":{"prim":{"type":"Recorder","role":"sink","params":[],"ins":[["f64","any","col[0]"]],"outs":[]}},"src_price":{"prim":{"type":"price","role":"source","params":[],"ins":[],"outs":[["price","f64"]]}}},"edges":[["0.o0","1.i0"],["1.o0","2.i0"],["2.o0","3.i0"],["1.o0","4.i0"],["src_price.o0","0.i0"],["src_price.o0","2.i1"]]},"composites":{"signals":{"inputs":[["f64","any","price"]],"outputs":[["signal","f64"]],"nodes":{"0":{"comp":"trend"},"1":{"comp":"momentum"},"2":{"prim":{"name":"blend","type":"LinComb","role":"node","params":[["weights[0]","f64"],["weights[1]","f64"]],"bound":[[2,"weights[2]","f64","0.5"]],"ins":[["f64","any","term[0]"],["f64","any","term[1]"],["f64","any","term[2]"]],"outs":[["value","f64"]]}}},"edges":[["0.o0","2.i0"],["1.o2","2.i1"],["1.o1","2.i2"],["@price","0.i0"],["@price","1.i0"],["2.o0","#0"]]},"trend":{"inputs":[["f64","any","price"]],"outputs":[["cross","f64"]],"nodes":{"0":{"prim":{"name":"fast","type":"SMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"1":{"prim":{"name":"slow","type":"SMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"2":{"prim":{"type":"Sub","role":"node","params":[],"ins":[["f64","any","lhs"],["f64","any","rhs"]],"outs":[["value","f64"]]}}},"edges":[["0.o0","2.i0"],["1.o0","2.i1"],["@price","0.i0"],["@price","1.i0"],["2.o0","#0"]]},"momentum":{"inputs":[["f64","any","price"]],"outputs":[["macd","f64"],["signal","f64"],["histogram","f64"]],"nodes":{"0":{"prim":{"name":"fast","type":"EMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"1":{"prim":{"name":"slow","type":"EMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"2":{"prim":{"type":"Sub","role":"node","params":[],"ins":[["f64","any","lhs"],["f64","any","rhs"]],"outs":[["value","f64"]]}},"3":{"prim":{"name":"signal","type":"EMA","role":"node","params":[["length","i64"]],"ins":[["f64","any","series"]],"outs":[["value","f64"]]}},"4":{"prim":{"type":"Sub","role":"node","params":[],"ins":[["f64","any","lhs"],["f64","any","rhs"]],"outs":[["value","f64"]]}}},"edges":[["0.o0","2.i0"],["1.o0","2.i1"],["2.o0","3.i0"],["2.o0","4.i0"],["3.o0","4.i1"],["@price","0.i0"],["@price","1.i0"],["2.o0","#0"],["3.o0","#1"],["4.o0","#2"]]}}}
@@ -0,0 +1,72 @@
// Headless render guard for the `aura graph` viewer (graph-viewer.js).
//
// Property protected: a bind-bound param slot renders in the node signature as a
// DIMMED `name=value`, in TRUE slot order (by original position), with the free
// slots in their type colour — never dropped. Covers a trailing bind (the
// cycle-0036 showcase shape) AND a non-trailing (middle) bind, which an
// append-after-free design would render in the wrong order.
//
// It loads the real viewer module and drives the exported pure `genDot`. `node`
// is REQUIRED: a skipped guard is not a guard.
import { createRequire } from "node:module";
import { fileURLToPath } from "node:url";
import { dirname, join } from "node:path";
const require = createRequire(import.meta.url);
const here = dirname(fileURLToPath(import.meta.url));
// Load the viewer once with an empty model; normalizeModel/genDot are pure and
// take the model/def explicitly, so each case is rendered by passing its own.
global.window = { AURA_MODEL: { root: { nodes: {}, edges: [] }, composites: {} } };
const { normalizeModel, genDot } = require(join(here, "..", "assets", "graph-viewer.js"));
const dotFor = (model) => genDot(normalizeModel(model).root, "root", new Set(), false).dot;
const fail = (msg, dot) => {
console.error(msg + "\n--- dot ---\n" + dot);
process.exit(1);
};
// --- Model A: trailing bind (the cycle-0036 showcase shape) ---
const trailing = {
root: { nodes: { "0": { prim: {
name: "blend", type: "LinComb", role: "node",
params: [["weights[0]", "f64"], ["weights[1]", "f64"]],
bound: [[2, "weights[2]", "f64", "0.5"]],
ins: [["f64", "any", "term[0]"], ["f64", "any", "term[1]"], ["f64", "any", "term[2]"]],
outs: [["value", "f64"]],
} } }, edges: [] },
composites: {},
};
const dotA = dotFor(trailing);
const BOUND = '<font color="#9399b2">weights[2]=0.5</font>';
const FREE0 = '<font color="#89b4fa">weights[0]</font>';
const FREE1 = '<font color="#89b4fa">weights[1]</font>';
if (!dotA.includes(BOUND)) fail("trailing: bound slot weights[2]=0.5 not rendered dimmed", dotA);
if (!dotA.includes(FREE0) || !dotA.includes(FREE1)) fail("trailing: a free weight slot is missing or not type-coloured", dotA);
const a0 = dotA.indexOf(FREE0), a1 = dotA.indexOf(FREE1), ab = dotA.indexOf(BOUND);
if (!(a0 < a1 && a1 < ab)) fail("trailing: slot order is not weights[0] < weights[1] < weights[2]=0.5", dotA);
// --- Model B: NON-TRAILING (middle) bind — pins slot-order faithfulness ---
const middle = {
root: { nodes: { "0": { prim: {
name: "mid", type: "Probe", role: "node",
params: [["a", "f64"], ["c", "f64"]],
bound: [[1, "b", "f64", "9.0"]],
ins: [["f64", "any", "t0"], ["f64", "any", "t1"], ["f64", "any", "t2"]],
outs: [["value", "f64"]],
} } }, edges: [] },
composites: {},
};
const dotB = dotFor(middle);
const MA = '<font color="#89b4fa">a</font>';
const MB = '<font color="#9399b2">b=9.0</font>';
const MC = '<font color="#89b4fa">c</font>';
if (!dotB.includes(MA) || !dotB.includes(MB) || !dotB.includes(MC)) fail("middle: a free or bound slot is missing", dotB);
const ba = dotB.indexOf(MA), bb = dotB.indexOf(MB), bc = dotB.indexOf(MC);
if (!(ba < bb && bb < bc)) fail("middle: bound slot b=9.0 not placed between free a and c (append-only bug)", dotB);
console.log("OK — bound slot renders dimmed name=value in true slot order (trailing + middle bind).");
process.exit(0);
@@ -0,0 +1,37 @@
//! Integration guard: the `aura graph` viewer renders a bind-bound param slot as
//! a dimmed `name=value` in true slot order (trailing + non-trailing bind).
//!
//! The property lives in JavaScript (`cellLabel` in assets/graph-viewer.js), so
//! this shells out to `node` running the headless guard
//! `tests/viewer_bound_param.mjs`, which loads the real viewer module and drives
//! the exported `genDot` over two minimal models.
//!
//! `node` is REQUIRED: if it is not on PATH this test FAILS (a skipped guard is
//! not a guard).
use std::path::PathBuf;
use std::process::Command;
#[test]
fn viewer_renders_bound_param_in_slot_order() {
let script = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
.join("tests")
.join("viewer_bound_param.mjs");
assert!(script.exists(), "guard script missing at {}", script.display());
let out = match Command::new("node").arg(&script).output() {
Ok(out) => out,
Err(e) => panic!(
"node is required for the viewer bound-param guard but could not be run \
({e}); install Node.js or ensure `node` is on PATH"
),
};
let stdout = String::from_utf8_lossy(&out.stdout);
let stderr = String::from_utf8_lossy(&out.stderr);
assert!(
out.status.success(),
"viewer bound-param guard failed (exit {:?}).\n--- node stdout ---\n{stdout}\n--- node stderr ---\n{stderr}",
out.status.code()
);
}
+64 -1
View File
@@ -66,6 +66,18 @@ pub struct ParamSpec {
pub kind: ScalarKind,
}
/// One param bound to a structural constant by [`PrimitiveBuilder::bind`] — a
/// render/debug surface only (C23), dropped at lowering. `pos` is the slot's
/// position in the node's ORIGINAL (pre-bind) param list, so the model serializer
/// and viewer can place it back into slot order regardless of bind sequence.
#[derive(Clone, Debug, PartialEq)]
pub struct BoundParam {
pub pos: usize,
pub name: String,
pub kind: ScalarKind,
pub value: Scalar,
}
/// A param-generic blueprint **primitive** recipe (C19): a node's full declared
/// signature (`NodeSchema` — inputs/output/params) plus a closure that builds a
/// sized instance through the node's own constructor (the single sizing/validation
@@ -78,6 +90,7 @@ pub struct PrimitiveBuilder {
name: &'static str,
instance_name: Option<String>,
schema: NodeSchema,
bound: Vec<BoundParam>,
// The build closure's type is exactly the recipe contract (a param slice in, a
// boxed node out); a type alias would not clarify it.
#[allow(clippy::type_complexity)]
@@ -93,7 +106,7 @@ impl PrimitiveBuilder {
schema: NodeSchema,
build: impl Fn(&[Scalar]) -> Box<dyn Node> + 'static,
) -> Self {
Self { name, instance_name: None, schema, build: Box::new(build) }
Self { name, instance_name: None, schema, bound: Vec::new(), build: Box::new(build) }
}
/// Set this node instance's explicit name. Must be non-empty: the name forms
/// a knob-address segment (`<composite>.<name>.<param>`, via `node_name()` in
@@ -120,6 +133,14 @@ impl PrimitiveBuilder {
pub fn instance_name(&self) -> Option<&str> {
self.instance_name.as_deref()
}
/// The params bound to structural constants by [`bind`](Self::bind), in
/// bind-call order, each carrying its ORIGINAL slot position. The render-
/// surface twin of [`instance_name`](Self::instance_name): the model
/// serializer reads it to show a bound slot's fixed value (the value captured
/// in the build closure is otherwise unreachable to it). Empty when no binds.
pub fn bound_params(&self) -> &[BoundParam] {
&self.bound
}
/// The full declared signature (read pre-build by `Composite::param_space`,
/// `BlueprintNode::signature`, and the renderer).
pub fn schema(&self) -> &NodeSchema {
@@ -170,6 +191,22 @@ impl PrimitiveBuilder {
self.schema.params[pos].kind,
"bind: kind mismatch for param `{slot}`",
);
// [render side] record the bound slot for the model/viewer at its ORIGINAL
// pre-bind position. `pos` indexes the already-shrunk array (earlier binds
// removed), so map it back to the full-arity index by adding one for each
// earlier-bound slot at an original position <= it. Render/debug only (C23);
// the closure capture below is what bootstrap actually reads.
let name = self.schema.params[pos].name.clone();
let kind = self.schema.params[pos].kind;
let mut orig = pos;
let mut prior: Vec<usize> = self.bound.iter().map(|b| b.pos).collect();
prior.sort_unstable();
for p in prior {
if p <= orig {
orig += 1;
}
}
self.bound.push(BoundParam { pos: orig, name, kind, value });
self.schema.params.remove(pos); // [param_space side] shrink the declared surface
let inner = self.build; // [value side] wrap the build closure
self.build = Box::new(move |open: &[Scalar]| {
@@ -407,6 +444,32 @@ mod tests {
);
}
#[test]
fn bind_records_bound_param_at_original_position() {
// middle-of-three: binding `b` records its ORIGINAL slot position (1).
let mid = probe3().bind("b", Scalar::I64(8));
assert_eq!(
mid.bound_params(),
[BoundParam { pos: 1, name: "b".into(), kind: ScalarKind::I64, value: Scalar::I64(8) }]
.as_slice(),
);
// chained reverse-order bind (b then a): each entry carries its ORIGINAL
// position regardless of the shrinking array — positions {1, 0} in call order.
let pair = probe3().bind("b", Scalar::I64(8)).bind("a", Scalar::I64(7));
assert_eq!(
pair.bound_params(),
[
BoundParam { pos: 1, name: "b".into(), kind: ScalarKind::I64, value: Scalar::I64(8) },
BoundParam { pos: 0, name: "a".into(), kind: ScalarKind::I64, value: Scalar::I64(7) },
]
.as_slice(),
);
// an unbound builder records nothing.
assert!(probe3().bound_params().is_empty());
}
#[test]
#[should_panic(expected = "no open param named")]
fn bind_unknown_slot_panics() {
+48 -1
View File
@@ -20,6 +20,20 @@ fn kind_str(k: ScalarKind) -> &'static str {
}
}
/// A scalar VALUE as a canonical, deterministic string for the model (C14). `f64`
/// uses the shortest round-trippable debug form, which keeps a decimal point on
/// whole values (`1.0`, not `1`) so a bound f64 is never mistaken for an i64 in
/// the render. The value side of `kind_str`.
fn scalar_str(s: aura_core::Scalar) -> String {
use aura_core::Scalar;
match s {
Scalar::I64(n) => n.to_string(),
Scalar::F64(f) => format!("{f:?}"),
Scalar::Bool(b) => b.to_string(),
Scalar::Ts(t) => t.0.to_string(),
}
}
/// One input port's firing policy as a model string: `"any"` or `"barrier <N>"`.
fn firing_str(f: Firing) -> String {
match f {
@@ -81,8 +95,24 @@ fn prim_record(b: &aura_core::PrimitiveBuilder) -> String {
Some(n) => format!(r#""name":{},"#, json_str(n)),
None => String::new(),
};
// bound params: present only when the node has binds (mirrors the conditional
// "name" field). each entry: [pos,"name","kind","value"].
let bound = if b.bound_params().is_empty() {
String::new()
} else {
let items = join(b.bound_params().iter().map(|bp| {
format!(
"[{},{},{},{}]",
bp.pos,
json_str(&bp.name),
json_str(kind_str(bp.kind)),
json_str(&scalar_str(bp.value)),
)
}));
format!(r#","bound":[{items}]"#)
};
format!(
r#"{{"prim":{{{name}"type":{},"role":{},"params":[{params}],"ins":[{ins}],"outs":[{outs}]}}}}"#,
r#"{{"prim":{{{name}"type":{},"role":{},"params":[{params}]{bound},"ins":[{ins}],"outs":[{outs}]}}}}"#,
json_str(&b.label()),
json_str(role),
)
@@ -393,6 +423,23 @@ mod tests {
assert!(!unnamed.contains(r#""name""#), "{unnamed}");
}
#[test]
fn prim_record_emits_bound_only_when_bound() {
// a bound i64 param → a "bound" field carrying [pos,"name","kind","value"]
let bound = prim_record(&Sma::builder().bind("length", Scalar::I64(5)));
assert!(bound.contains(r#""bound":[[0,"length","i64","5"]]"#), "{bound}");
// the bound slot also leaves the tunable "params" surface (bind's tuning side)
assert!(bound.contains(r#""params":[]"#), "{bound}");
// a bound f64 value renders canonically (shortest round-trip), e.g. 0.5
let f = prim_record(&Exposure::builder().bind("scale", Scalar::F64(0.5)));
assert!(f.contains(r#""bound":[[0,"scale","f64","0.5"]]"#), "{f}");
// an unbound builder → no "bound" field at all
let unbound = prim_record(&Sma::builder());
assert!(!unbound.contains(r#""bound""#), "{unbound}");
}
// -- Task 3: scope (index keys + synthetic sources + edges) ------------------
#[test]