git subrepo clone git@github.com:Rconybea/xo-expression2.git xo-expression2

subrepo:
  subdir:   "xo-expression2"
  merged:   "9823ce36"
upstream:
  origin:   "git@github.com:Rconybea/xo-expression2.git"
  branch:   "main"
  commit:   "9823ce36"
git-subrepo:
  version:  "0.4.9"
  origin:   "???"
  commit:   "???"

xo-expression2/src/expression2/Binding.cpp

@@ -0,0 +1,41 @@
+/** @file Binding.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "Binding.hpp"
+#include <cassert>
+
+namespace xo {
+    namespace scm {
+
+        Binding
+        Binding::relative(int32_t i_link, Binding def)
+        {
+            if (def.i_link_ == Binding::c_link_global) {
+                // for globally defined vars, i_link always -1
+                return def;
+            } else if (def.i_link_ >= 0) {
+                return Binding(i_link + def.i_link_, def.j_slot_);
+            } else {
+                assert(false);
+                return Binding();
+            }
+        }
+
+        void
+        Binding::print(std::ostream & os) const
+        {
+            if (i_link_ == c_link_global) {
+                os << "{path:global:" << j_slot_ << "}";
+            } else if (i_link_ == c_link_sentinel) {
+                os << "{path}";
+            } else {
+                os << "{path:" << i_link_ << ":" << j_slot_ << "}";
+            }
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end Binding.cpp */