From 3c1d8a824dbad83a13d51a6f2e64736130a08690 Mon Sep 17 00:00:00 2001
From: nyash-codex <codex@nyash.local>
Date: Wed, 17 Dec 2025 23:09:19 +0900
Subject: [PATCH] feat(joinir): extend balanced depth-scan policy to object
 family

---
 .../policies/balanced_depth_scan_policy.rs    |  7 +++++
 .../balanced_depth_scan_policy_box.rs         | 26 ++++++++++++++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy.rs b/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy.rs
index a5911280..fd444027 100644
--- a/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy.rs
+++ b/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy.rs
@@ -36,6 +36,13 @@ pub(crate) fn classify_balanced_depth_scan_array_end(
     classify_balanced_depth_scan(condition, body, "[", "]")
 }
 
+pub(crate) fn classify_balanced_depth_scan_object_end(
+    condition: &ASTNode,
+    body: &[ASTNode],
+) -> PolicyDecision<BalancedDepthScanPolicyResult> {
+    classify_balanced_depth_scan(condition, body, "{", "}")
+}
+
 fn classify_balanced_depth_scan(
     condition: &ASTNode,
     body: &[ASTNode],
diff --git a/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy_box.rs b/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy_box.rs
index c8fc4ee0..1d7accf6 100644
--- a/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy_box.rs
+++ b/src/mir/builder/control_flow/joinir/patterns/policies/balanced_depth_scan_policy_box.rs
@@ -6,7 +6,10 @@
 
 use crate::ast::ASTNode;
 
-use super::balanced_depth_scan_policy::{classify_balanced_depth_scan_array_end, BalancedDepthScanPolicyResult};
+use super::balanced_depth_scan_policy::{
+    classify_balanced_depth_scan_array_end, classify_balanced_depth_scan_object_end,
+    BalancedDepthScanPolicyResult,
+};
 use super::PolicyDecision;
 
 pub(crate) struct BalancedDepthScanPolicyBox;
@@ -16,7 +19,25 @@ impl BalancedDepthScanPolicyBox {
         condition: &ASTNode,
         body: &[ASTNode],
     ) -> PolicyDecision<BalancedDepthScanPolicyResult> {
-        let decision = classify_balanced_depth_scan_array_end(condition, body);
+        // Try known balanced families. Order is SSOT.
+        // - array: `[` ... `]`
+        // - object: `{` ... `}`
+        //
+        // IMPORTANT: `Reject` means "close-but-unsupported" for that family, not "not this family".
+        // We only return `Reject` if no other family matches.
+        let array = classify_balanced_depth_scan_array_end(condition, body);
+        let decision = match array {
+            PolicyDecision::Use(_) => array,
+            PolicyDecision::Reject(_) => {
+                let object = classify_balanced_depth_scan_object_end(condition, body);
+                match object {
+                    PolicyDecision::Use(_) => object,
+                    PolicyDecision::Reject(_) => array,
+                    PolicyDecision::None => array,
+                }
+            }
+            PolicyDecision::None => classify_balanced_depth_scan_object_end(condition, body),
+        };
 
         if crate::config::env::joinir_dev_enabled() {
             use crate::mir::builder::control_flow::joinir::trace;
@@ -31,4 +52,3 @@ impl BalancedDepthScanPolicyBox {
         decision
     }
 }
-