xo-expression: + binding_path + assoc w/ each Variable

src/expression/LocalEnv.cpp

@@ -0,0 +1,31 @@
+/* file LocalEnv.cpp
+ *
+ * author: Roland Conybeare
+ */
+
+#include "LocalEnv.hpp"
+
+namespace xo {
+    namespace ast {
+        binding_path
+        LocalEnv::lookup_binding(const std::string & vname) const
+        {
+            int j_slot = 0;
+            for (const auto & arg : argv_) {
+                if (arg->name() == vname)
+                    return { 0 /*i_link*/, j_slot };
+                ++j_slot;
+            }
+
+            auto tmp = parent_env_->lookup_binding(vname);
+
+            if (tmp.i_link_ == -1)
+                return tmp;
+            else
+                return { tmp.i_link_ + 1, tmp.j_slot_ };
+        } /*lookup_binding*/
+    } /*namespace ast*/
+} /*namespace xo*/
+
+
+/* end LocalEnv.cpp */