diff --git a/src/boxes/map_box.rs b/src/boxes/map_box.rs
index 23d1c637..f5f26aad 100644
--- a/src/boxes/map_box.rs
+++ b/src/boxes/map_box.rs
@@ -152,6 +152,13 @@ impl MapBox {
                 {
                     return value.share_box();
                 }
+                // Share identity for collection boxes to preserve mutability semantics
+                if value.as_any().downcast_ref::<ArrayBox>().is_some() {
+                    return value.share_box();
+                }
+                if value.as_any().downcast_ref::<MapBox>().is_some() {
+                    return value.share_box();
+                }
                 value.clone_box()
             }
             None => Box::new(StringBox::new(&format!("[map/missing] Key not found: {}", key_str))),
diff --git a/tools/hako_check/analysis_consumer.hako b/tools/hako_check/analysis_consumer.hako
index 496b8966..34529211 100644
--- a/tools/hako_check/analysis_consumer.hako
+++ b/tools/hako_check/analysis_consumer.hako
@@ -21,6 +21,7 @@ static box HakoAnalysisBuilderBox {
     ir.set("boxes", new ArrayBox())
     ir.set("methods", new ArrayBox())
     ir.set("calls", new ArrayBox())
+    ir.set("method_spans", new ArrayBox())
     ir.set("source", text)
     local eps = new ArrayBox(); eps.push("Main.main"); eps.push("main"); ir.set("entrypoints", eps)
     // debug disabled in strict environments
@@ -30,11 +31,11 @@ static box HakoAnalysisBuilderBox {
     local ast = null
     if no_ast == 0 { ast = HakoParserCoreBox.parse(text) }
     if ast != null {
-      // uses
-      local uses = ast.get("uses")
+      // uses (with fallback for backward compat)
+      local uses = ast.get("uses"); if uses == null { uses = ast.get("uses_arr") }
       if uses != null { local ui=0; while ui<uses.size() { ir.get("uses").push(uses.get(ui)); ui=ui+1 } }
       // methods (qualified: Box.method/arity)
-      local boxes_ast = ast.get("boxes")
+      local boxes_ast = ast.get("boxes"); if boxes_ast == null { boxes_ast = ast.get("boxes_arr") }
       if boxes_ast != null {
         local bi=0
         while bi<boxes_ast.size() {
@@ -45,10 +46,14 @@ static box HakoAnalysisBuilderBox {
             local mi=0
             while mi<ms.size() {
               local m = ms.get(mi)
-              ir.get("methods").push(name + "." + m.get("name") + "/" + me._itoa(m.get("arity")))
+              local qual = name + "." + m.get("name") + "/" + me._itoa(m.get("arity"))
+              local methods_arr = ir.get("methods")
+              methods_arr.push(qual)
               // capture start line spans for later source mapping
-              local spans = ir.get("method_spans"); if spans == null { spans = new ArrayBox(); ir.set("method_spans", spans) }
-              local rec = new MapBox(); rec.set("name", name + "." + m.get("name") + "/" + me._itoa(m.get("arity"))); rec.set("line", m.get("span")); spans.push(rec)
+              local spans = ir.get("method_spans")
+              if spans == null { ir.set("method_spans", new ArrayBox()); spans = ir.get("method_spans") }
+              local rec = new MapBox(); rec.set("name", qual); rec.set("line", m.get("span"))
+              spans.push(rec)
               mi = mi + 1
             }
           }
diff --git a/tools/hako_parser/parser_core.hako b/tools/hako_parser/parser_core.hako
index 05b1fe86..16407715 100644
--- a/tools/hako_parser/parser_core.hako
+++ b/tools/hako_parser/parser_core.hako
@@ -45,13 +45,19 @@ static box HakoParserCoreBox {
         // STATIC BOX IDENT LBRACE ... RBRACE
         local save = p
         p = me._advance(p, N) // STATIC
-        local tb = me._peek(toks, p, N); if me._eq(tb, "BOX") == 0 { p = save + 1; continue } p = me._advance(p, N)
-        local tn = me._peek(toks, p, N); if me._eq(tn, "IDENT") == 0 { continue }
+        local tb = me._peek(toks, p, N)
+        if me._eq(tb, "BOX") == 0 { p = save + 1; continue }
+        p = me._advance(p, N)
+        local tn = me._peek(toks, p, N)
+        if me._eq(tn, "IDENT") == 0 { continue }
         local box_name = tn.get("lexeme"); p = me._advance(p, N)
         // expect '{'
-        local tl = me._peek(toks, p, N); if me._eq(tl, "LBRACE") == 0 { continue } p = me._advance(p, N)
+        local tl = me._peek(toks, p, N)
+        if me._eq(tl, "LBRACE") == 0 { continue }
+        p = me._advance(p, N)
         // register box
-        local b = new MapBox(); b.set("name", box_name); b.set("is_static", 1); b.set("methods", new ArrayBox()); ast.get("boxes").push(b)
+        local b = new MapBox(); b.set("name", box_name); b.set("is_static", 1); b.set("methods", new ArrayBox())
+        ast.get("boxes").push(b)
         // scan until matching RBRACE (flat, tolerate nested braces count)
         local depth = 1
         while p < N && depth > 0 {