From aedb1a1648ffd1a8a2620d53e240a920c9453d43 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Tue, 28 Apr 2026 23:17:00 -0400
Subject: [PATCH] xo-object2: obj<ACollector> argument to DArray::push_back()

---
 src/expression2/DGlobalSymtab.cpp | 16 +++++++++++-----
 src/expression2/DLocalSymtab.cpp  | 13 ++++++++-----
 src/expression2/DSequenceExpr.cpp | 17 ++++++++++-------
 3 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/src/expression2/DGlobalSymtab.cpp b/src/expression2/DGlobalSymtab.cpp
index 7b6bd760..d927288a 100644
--- a/src/expression2/DGlobalSymtab.cpp
+++ b/src/expression2/DGlobalSymtab.cpp
@@ -16,6 +16,7 @@
 
 namespace xo {
     using xo::map::DArenaHashMap;
+    using xo::mm::ACollector;
     using xo::mm::AGCObject;
 
     namespace scm {
@@ -51,13 +52,13 @@ namespace xo {
             assert(var_map);
 
             /* choosing same capacity for hash, vars */
-            DArray * vars = DArray::empty(mm, var_map->capacity());
+            DArray * vars = DArray::_empty(mm, var_map->capacity());
             assert(vars);
 
             auto type_map = dp<repr_type>::make(aux_mm, type_cfg);
             assert(type_map);
 
-            DArray * types = DArray::empty(mm, type_map->capacity());
+            DArray * types = DArray::_empty(mm, type_map->capacity());
 
             void * mem = mm.alloc_for<DGlobalSymtab>();
 
@@ -110,6 +111,8 @@ namespace xo {
         {
             scope log(XO_DEBUG(false), std::string_view(*var->name()));
 
+            auto gc = mm.try_to_facet<ACollector>();
+
             // It's possible there's already a global variable
             // with the same name.
             //
@@ -165,7 +168,7 @@ namespace xo {
                 // need slot# in .map_ for this unique symbol
                 (*var_map_)[var->name()] = binding.j_slot();
 
-                vars_->push_back(obj<AGCObject,DVariable>(var));
+                vars_->push_back(gc, obj<AGCObject,DVariable>(var));
             }
         }
 
@@ -191,6 +194,8 @@ namespace xo {
             scope log(XO_DEBUG(true),
                       std::string_view(*tname->name()));
 
+            auto gc = mm.try_to_facet<ACollector>();
+
             auto ix = type_map_->find(tname->name());
 
             if (ix == type_map_->end()) {
@@ -218,12 +223,13 @@ namespace xo {
                 (*type_map_)[tname->name()] = n;
 
                 log && log("STUB: need write barrier");
-                types_->push_back(obj<AGCObject,DTypename>(tname));
+                types_->push_back(gc, obj<AGCObject,DTypename>(tname));
             } else {
                 Binding::slot_type i_slot = ix->second;
 
                 log && log("STUB: need write barrier");
-                (*types_)[i_slot] = obj<AGCObject,DTypename>(tname);
+                types_->assign_at(gc, i_slot,
+                                  obj<AGCObject,DTypename>(tname));
             }
         }
 
diff --git a/src/expression2/DLocalSymtab.cpp b/src/expression2/DLocalSymtab.cpp
index 9d85a97c..c5bf6e1e 100644
--- a/src/expression2/DLocalSymtab.cpp
+++ b/src/expression2/DLocalSymtab.cpp
@@ -13,9 +13,9 @@
 #include <xo/indentlog/scope.hpp>
 
 namespace xo {
+    using xo::mm::ACollector;
     using xo::mm::AGCObject;
     using xo::print::APrintable;
-    //using xo::facet::typeseq;
     using xo::print::ppstate;
 
     namespace scm {
@@ -34,8 +34,8 @@ namespace xo {
         {
             void * mem = mm.alloc_for<DLocalSymtab>();
 
-            DArray * vars = DArray::empty(mm, nv);
-            DArray * types = DArray::empty(mm, nt);
+            DArray * vars = DArray::_empty(mm, nv);
+            DArray * types = DArray::_empty(mm, nt);
 
             return new (mem) DLocalSymtab(p, vars, types);
         }
@@ -69,7 +69,9 @@ namespace xo {
                 Binding binding = Binding::local(vars_->size());
 
                 DVariable * var = DVariable::make(mm, name, typeref, binding);
-                vars_->push_back(obj<AGCObject,DVariable>(var));
+
+                auto gc = mm.try_to_facet<ACollector>();
+                vars_->push_back(gc, obj<AGCObject,DVariable>(var));
 
                 return binding;
             }
@@ -87,7 +89,8 @@ namespace xo {
             } else {
                 obj<AGCObject> tname = DTypename::make(mm, name, type);
 
-                types_->push_back(tname);
+                auto gc = mm.try_to_facet<ACollector>();
+                types_->push_back(gc, tname);
             }
         }
 
diff --git a/src/expression2/DSequenceExpr.cpp b/src/expression2/DSequenceExpr.cpp
index 8fdfcf9b..bfece9e6 100644
--- a/src/expression2/DSequenceExpr.cpp
+++ b/src/expression2/DSequenceExpr.cpp
@@ -15,6 +15,7 @@
 #include <xo/reflectutil/typeseq.hpp>
 
 namespace xo {
+    using xo::mm::ACollector;
     using xo::mm::AGCObject;
     using xo::print::APrintable;
     using xo::facet::FacetRegistry;
@@ -47,8 +48,8 @@ namespace xo {
             /** allocate 2nd, so it comes after DSequenceExpr in
              *  memory.  This may later allow realloc
              **/
-            DArray * expr_v = DArray::empty(mm,
-                                            c_hint_capacity);
+            DArray * expr_v = DArray::_empty(mm,
+                                             c_hint_capacity);
 
             expr->expr_v_ = expr_v;
 
@@ -73,23 +74,25 @@ namespace xo {
         DSequenceExpr::push_back(obj<AAllocator> mm,
                                  obj<AExpression> expr)
         {
+            // null gc -> no write barrier
+            obj<ACollector> gc = mm.try_to_facet<ACollector>();
+
             if (expr_v_->size() == expr_v_->capacity()) {
                 /* reallocate+expand */
 
                 DArray * expr_2x_v
-                    = DArray::empty(mm, 2 * expr_v_->capacity());
+                    = DArray::_empty(mm, 2 * expr_v_->capacity());
 
                 for (size_type i = 0, z = expr_v_->size(); i < z; ++i) {
-                    expr_2x_v->push_back((*expr_2x_v)[i]);
+                    expr_2x_v->push_back(gc, (*expr_2x_v)[i]);
                 }
 
                 this->expr_v_ = expr_2x_v;
             }
 
-            obj<AGCObject> expr_gco
-                = FacetRegistry::instance().variant<AGCObject,AExpression>(expr);
+            obj<AGCObject> expr_gco = expr.to_facet<AGCObject>();
 
-            this->expr_v_->push_back(expr_gco);
+            this->expr_v_->push_back(gc, expr_gco);
         }
 
         void