feat(0088): §A shared gate predicates — edge_kind_check, resolution helpers, try_bind

Iteration-1 §A of the construction service (#157): the surface-agnostic shared
predicates the eager op-script path and the holistic finalize gates both call —
no second validator (C24).

- edge_kind_check (blueprint.rs): the per-edge producer/consumer kind check,
  lifted verbatim out of validate_wiring's edge loop into a pub(crate) fn that
  validate_wiring now calls — behaviour-preserving (same Bootstrap(KindMismatch)
  variant; the existing compile-time gate test stays green).
- resolve_input_slot / resolve_output_field (builder.rs): the exactly-one-match
  name→index resolution extracted as pub(crate) fns over (&NodeSchema, &str), so
  the runtime-String op-script names share GraphBuilder's resolution; GraphBuilder
  delegates and maps to the unchanged BuildError variants.
- try_bind + BindOpError (aura-core node.rs): the fallible Result twin of bind
  (bind keeps its panic contract and pinned messages verbatim; try_bind is a
  separate method reporting the same three conditions as values).
- check_param_namespace_injective + validate_wiring widened to pub(crate) for the
  finalize-stage reuse by the upcoming GraphSession::finish (§B).

Partial iteration: §B (the GraphSession/Op/replay surface + introspection) and
the §A→§B integration land next (plan Tasks 4-8). compile_with_params /
check_ports_connected are behaviourally unchanged. Full suite green; clippy clean.

Plan correction folded in: Task 3's test originally referenced aura_std::Sma —
infeasible inside aura-core (aura-std depends on aura-core; the reverse edge is a
dependency cycle). Adapted to a local PrimitiveBuilder probe with identical
assertions.

refs #157

crates/aura-core/src/lib.rs

@@ -43,7 +43,7 @@ pub use column::{Column, Window};
 pub use ctx::Ctx;
 pub use error::KindMismatch;
 pub use node::{
-    zip_params, BoundParam, FieldSpec, Firing, Node, NodeSchema, ParamSpec, PortSpec,
+    zip_params, BindOpError, BoundParam, FieldSpec, Firing, Node, NodeSchema, ParamSpec, PortSpec,
     PrimitiveBuilder,
 };
 pub use scalar::{Scalar, ScalarKind, Timestamp};

crates/aura-core/src/node.rs

@@ -235,6 +235,65 @@ impl PrimitiveBuilder {
         });
         self
     }
+
+    /// The fallible twin of [`bind`](Self::bind): same exactly-one-match + kind
+    /// rule, returning [`BindOpError`] instead of panicking. Used by the op-script
+    /// construction surface, where a bad param is rejected at the op, not a panic.
+    pub fn try_bind(mut self, slot: &str, value: Scalar) -> Result<Self, BindOpError> {
+        let matches: Vec<usize> = self
+            .schema
+            .params
+            .iter()
+            .enumerate()
+            .filter(|(_, p)| p.name == slot)
+            .map(|(i, _)| i)
+            .collect();
+        let pos = match matches.as_slice() {
+            [pos] => *pos,
+            [] => return Err(BindOpError::UnknownParam(slot.to_string())),
+            _ => return Err(BindOpError::AmbiguousParam(slot.to_string())),
+        };
+        if value.kind() != self.schema.params[pos].kind {
+            return Err(BindOpError::KindMismatch {
+                param: slot.to_string(),
+                expected: self.schema.params[pos].kind,
+                got: value.kind(),
+            });
+        }
+        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);
+        let inner = self.build;
+        self.build = Box::new(move |open: &[Cell]| {
+            let mut full = open.to_vec();
+            full.insert(pos, value.cell());
+            inner(&full)
+        });
+        Ok(self)
+    }
+}
+
+/// A fallible-bind fault — the `Result` twin of `bind`'s panics, for the
+/// data-level construction surface (`GraphSession`, #157). `bind` keeps its
+/// panic contract (and its pinned messages); `try_bind` reports the same three
+/// conditions as values.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum BindOpError {
+    /// No still-open param has this name.
+    UnknownParam(String),
+    /// More than one still-open param has this name.
+    AmbiguousParam(String),
+    /// The value's kind does not equal the param's declared kind.
+    KindMismatch { param: String, expected: ScalarKind, got: ScalarKind },
 }
 
 /// A node's declared interface: its inputs (in order) and its output record — an
@@ -550,6 +609,41 @@ mod tests {
         );
         let _ = b.bind("length", Scalar::f64(2.0)); // F64 value for an I64 slot
     }
+
+    #[test]
+    fn try_bind_ok_and_typed_errors() {
+        use super::BindOpError;
+        // A probe with one i64 param `length` (a real std node like `Sma` would
+        // pull in aura-std, but aura-core cannot dev-depend on it without a
+        // dev-cycle that compiles aura-core twice — incompatible `Scalar` types).
+        let probe = || {
+            PrimitiveBuilder::new(
+                "Probe",
+                NodeSchema {
+                    inputs: vec![],
+                    output: vec![],
+                    params: vec![ParamSpec { name: "length".into(), kind: ScalarKind::I64 }],
+                },
+                |_| Box::new(Bare),
+            )
+        };
+        // ok: exact name, matching kind
+        assert!(probe().try_bind("length", Scalar::i64(3)).is_ok());
+        // unknown param name
+        assert_eq!(
+            probe().try_bind("nope", Scalar::i64(3)).err(),
+            Some(BindOpError::UnknownParam("nope".into()))
+        );
+        // kind mismatch (f64 into an i64 param)
+        assert_eq!(
+            probe().try_bind("length", Scalar::f64(3.0)).err(),
+            Some(BindOpError::KindMismatch {
+                param: "length".into(),
+                expected: ScalarKind::I64,
+                got: ScalarKind::F64,
+            })
+        );
+    }
 }
 
 #[cfg(test)]

crates/aura-engine/src/blueprint.rs

@@ -563,7 +563,7 @@ fn resolve_ranges(space: &[ParamSpec], ranges: &[(String, ParamRange)]) -> Resul
 /// `param_space()` order is reported (the order is deterministic). Single source of
 /// duplicate detection; called from `compile_with_params` and from both binders
 /// before name resolution.
-fn check_param_namespace_injective(space: &[ParamSpec]) -> Result<(), CompileError> {
+pub(crate) fn check_param_namespace_injective(space: &[ParamSpec]) -> Result<(), CompileError> {
     let mut seen = std::collections::HashSet::new();
     for p in space {
         if !seen.insert(p.name.as_str()) {
@@ -620,12 +620,34 @@ pub enum CompileError {
     DoubleWiredPort { node: usize, slot: usize },
 }
 
+/// The per-edge kind predicate, shared by `validate_wiring` (holistic) and the
+/// eager `connect` op (`construction.rs`) — one check, two cadences (no second
+/// validator). Looks the producer field + consumer slot up by index and rejects
+/// a kind mismatch with the SAME variant bootstrap uses, so existing
+/// compiled-graph tests stay green.
+pub(crate) fn edge_kind_check(
+    from: &NodeSchema,
+    from_field: usize,
+    to: &NodeSchema,
+    slot: usize,
+) -> Result<(), CompileError> {
+    let f = from.output.get(from_field).ok_or(CompileError::BadInteriorIndex)?;
+    let s = to.inputs.get(slot).ok_or(CompileError::BadInteriorIndex)?;
+    if f.kind != s.kind {
+        return Err(CompileError::Bootstrap(BootstrapError::KindMismatch {
+            producer: f.kind,
+            consumer: s.kind,
+        }));
+    }
+    Ok(())
+}
+
 /// Pre-build structural validation via `signature()` (no node constructed): every
 /// edge's producer field and consumer slot are in range and kind-matched; every
 /// output re-export and role target is in range and kind-consistent. Recurses into
 /// nested composites so the checks hold at every level. This is what lets `compile`
 /// reject a wiring fault before any build closure fires.
-fn validate_wiring(
+pub(crate) fn validate_wiring(
     nodes: &[BlueprintNode],
     edges: &[Edge],
     roles: &[Role],
@@ -638,14 +660,7 @@ fn validate_wiring(
     for e in edges {
         let from = nodes.get(e.from).ok_or(CompileError::BadInteriorIndex)?.signature();
         let to = nodes.get(e.to).ok_or(CompileError::BadInteriorIndex)?.signature();
-        let f = from.output.get(e.from_field).ok_or(CompileError::BadInteriorIndex)?;
-        let s = to.inputs.get(e.slot).ok_or(CompileError::BadInteriorIndex)?;
-        if f.kind != s.kind {
-            return Err(CompileError::Bootstrap(BootstrapError::KindMismatch {
-                producer: f.kind,
-                consumer: s.kind,
-            }));
-        }
+        edge_kind_check(&from, e.from_field, &to, e.slot)?;
     }
     // roles: every target in range, and all targets of one role share a kind
     // (RoleKindMismatch — the existing variant, today read off built schema()).
@@ -926,6 +941,34 @@ mod tests {
     use aura_std::{Bias, Ema, Recorder, SimBroker, Sma, Sub};
     use std::sync::mpsc;
 
+    #[test]
+    fn edge_kind_check_accepts_match_and_rejects_mismatch() {
+        use super::edge_kind_check;
+        use aura_core::{FieldSpec, NodeSchema, PortSpec, ScalarKind};
+        // producer: one f64 output field; consumer: slot 0 is f64, slot 1 is bool.
+        let from = NodeSchema {
+            inputs: vec![],
+            output: vec![FieldSpec { name: "v".into(), kind: ScalarKind::F64 }],
+            params: vec![],
+        };
+        let to = NodeSchema {
+            inputs: vec![
+                PortSpec { kind: ScalarKind::F64, firing: aura_core::Firing::Any, name: "a".into() },
+                PortSpec { kind: ScalarKind::Bool, firing: aura_core::Firing::Any, name: "b".into() },
+            ],
+            output: vec![],
+            params: vec![],
+        };
+        assert!(edge_kind_check(&from, 0, &to, 0).is_ok());
+        assert_eq!(
+            edge_kind_check(&from, 0, &to, 1),
+            Err(CompileError::Bootstrap(BootstrapError::KindMismatch {
+                producer: ScalarKind::F64,
+                consumer: ScalarKind::Bool,
+            }))
+        );
+    }
+
     /// Build + bootstrap + run + drain + summarize one swept point into a
     /// `RunReport`, using a fresh harness per point (disjoint runs, C1). A free
     /// `fn` (Copy + Sync) so it serves both as the `sweep`/binder closure and as a

crates/aura-engine/src/builder.rs

@@ -162,17 +162,14 @@ impl GraphBuilder {
             .schemas
             .get(p.node)
             .ok_or(BuildError::BadHandle { node: p.node })?;
-        let m: Vec<usize> = schema
-            .inputs
-            .iter()
-            .enumerate()
-            .filter(|(_, port)| port.name == p.name)
-            .map(|(i, _)| i)
-            .collect();
-        match m.as_slice() {
-            [i] => Ok((p.node, *i)),
-            [] => Err(BuildError::UnknownInPort { node: p.node, name: p.name.to_string() }),
-            _ => Err(BuildError::AmbiguousInPort { node: p.node, name: p.name.to_string() }),
+        match resolve_input_slot(schema, p.name) {
+            Ok(i) => Ok((p.node, i)),
+            Err(PortResolveError::Unknown) => {
+                Err(BuildError::UnknownInPort { node: p.node, name: p.name.to_string() })
+            }
+            Err(PortResolveError::Ambiguous) => {
+                Err(BuildError::AmbiguousInPort { node: p.node, name: p.name.to_string() })
+            }
         }
     }
 
@@ -183,21 +180,59 @@ impl GraphBuilder {
             .schemas
             .get(p.node)
             .ok_or(BuildError::BadHandle { node: p.node })?;
-        let m: Vec<usize> = schema
-            .output
-            .iter()
-            .enumerate()
-            .filter(|(_, f)| f.name == p.name)
-            .map(|(i, _)| i)
-            .collect();
-        match m.as_slice() {
-            [i] => Ok(*i),
-            [] => Err(BuildError::UnknownOutPort { node: p.node, name: p.name.to_string() }),
-            _ => Err(BuildError::AmbiguousOutPort { node: p.node, name: p.name.to_string() }),
+        match resolve_output_field(schema, p.name) {
+            Ok(i) => Ok(i),
+            Err(PortResolveError::Unknown) => {
+                Err(BuildError::UnknownOutPort { node: p.node, name: p.name.to_string() })
+            }
+            Err(PortResolveError::Ambiguous) => {
+                Err(BuildError::AmbiguousOutPort { node: p.node, name: p.name.to_string() })
+            }
         }
     }
 }
 
+/// A name→index resolution outcome, shared by `GraphBuilder` (mapped to
+/// `BuildError`) and `GraphSession` (mapped to `OpError`). Over `&str`, so it
+/// serves both `&'static str` literals and runtime document names.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) enum PortResolveError {
+    Unknown,
+    Ambiguous,
+}
+
+/// Resolve an input-port name to its slot index by exactly-one-match.
+pub(crate) fn resolve_input_slot(schema: &NodeSchema, name: &str) -> Result<usize, PortResolveError> {
+    let m: Vec<usize> = schema
+        .inputs
+        .iter()
+        .enumerate()
+        .filter(|(_, port)| port.name == name)
+        .map(|(i, _)| i)
+        .collect();
+    match m.as_slice() {
+        [i] => Ok(*i),
+        [] => Err(PortResolveError::Unknown),
+        _ => Err(PortResolveError::Ambiguous),
+    }
+}
+
+/// Resolve an output-field name to its field index by exactly-one-match.
+pub(crate) fn resolve_output_field(schema: &NodeSchema, name: &str) -> Result<usize, PortResolveError> {
+    let m: Vec<usize> = schema
+        .output
+        .iter()
+        .enumerate()
+        .filter(|(_, f)| f.name == name)
+        .map(|(i, _)| i)
+        .collect();
+    match m.as_slice() {
+        [i] => Ok(*i),
+        [] => Err(PortResolveError::Unknown),
+        _ => Err(PortResolveError::Ambiguous),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::{BuildError, GraphBuilder};
@@ -297,6 +332,19 @@ mod tests {
         );
     }
 
+    #[test]
+    fn shared_port_resolution_matches_exactly_one() {
+        use super::{resolve_input_slot, resolve_output_field, PortResolveError};
+        use crate::BlueprintNode;
+        use aura_std::Sub;
+        let schema = BlueprintNode::from(Sub::builder()).signature(); // lhs, rhs -> value
+        assert_eq!(resolve_input_slot(&schema, "lhs"), Ok(0));
+        assert_eq!(resolve_input_slot(&schema, "rhs"), Ok(1));
+        assert_eq!(resolve_input_slot(&schema, "nope"), Err(PortResolveError::Unknown));
+        assert_eq!(resolve_output_field(&schema, "value"), Ok(0));
+        assert_eq!(resolve_output_field(&schema, "nope"), Err(PortResolveError::Unknown));
+    }
+
     #[test]
     fn unknown_in_port_is_reported_at_build() {
         let mut g = GraphBuilder::new("x");

docs/plans/0088-construction-op-script.md

@@ -310,17 +310,30 @@ crates/aura-core/src/node.rs`):
 #[test]
 fn try_bind_ok_and_typed_errors() {
     use super::BindOpError;
-    use aura_std::Sma; // SMA has one i64 param `length`
+    // A probe with one i64 param `length` (a real std node like `Sma` would
+    // pull in aura-std, but aura-core cannot dev-depend on it without a
+    // dev-cycle that compiles aura-core twice — incompatible `Scalar` types).
+    let probe = || {
+        PrimitiveBuilder::new(
+            "Probe",
+            NodeSchema {
+                inputs: vec![],
+                output: vec![],
+                params: vec![ParamSpec { name: "length".into(), kind: ScalarKind::I64 }],
+            },
+            |_| Box::new(Bare),
+        )
+    };
     // ok: exact name, matching kind
-    assert!(Sma::builder().try_bind("length", Scalar::i64(3)).is_ok());
+    assert!(probe().try_bind("length", Scalar::i64(3)).is_ok());
     // unknown param name
     assert_eq!(
-        Sma::builder().try_bind("nope", Scalar::i64(3)).err(),
+        probe().try_bind("nope", Scalar::i64(3)).err(),
         Some(BindOpError::UnknownParam("nope".into()))
     );
     // kind mismatch (f64 into an i64 param)
     assert_eq!(
-        Sma::builder().try_bind("length", Scalar::f64(3.0)).err(),
+        probe().try_bind("length", Scalar::f64(3.0)).err(),
         Some(BindOpError::KindMismatch {
             param: "length".into(),
             expected: ScalarKind::I64,
@@ -332,6 +345,12 @@ fn try_bind_ok_and_typed_errors() {
 
 > `.err()` not `.unwrap_err()`: the `Ok` type `PrimitiveBuilder` is not `Debug`
 > (it holds a build closure), mirroring `builder.rs`'s tests.
+>
+> **Plan correction (orchestrator, post-block):** the original Step-1 test
+> referenced `aura_std::Sma`, infeasible inside `aura-core` (aura-std depends on
+> aura-core; the reverse edge is a dependency cycle). Replaced with a local
+> `PrimitiveBuilder::new` probe carrying identical assertions — `Bare` is the
+> test module's existing zero-output node.
 
 - [ ] **Step 2: Run test to verify it fails**