Add 'xo-expression/' from commit '5ac3c03a0c'

git-subtree-dir: xo-expression
git-subtree-mainline: d0f5ccc1ce
git-subtree-split: 5ac3c03a0c

xo-expression/src/expression/Variable.cpp

@@ -0,0 +1,32 @@
+/* @file Variable.cpp */
+
+#include "Variable.hpp"
+#include "Environment.hpp"
+
+namespace xo {
+    namespace ast {
+        void
+        Variable::attach_envs(ref::brw<Environment> e) {
+            /** e makes accessible all enclosing lexical scopes **/
+            if (this->path_.i_link_ == -2 /*sentinel*/) {
+                this->path_ = e->lookup_binding(this->name_);
+            } else {
+                /* have already established binding for this Variable */
+            }
+        } /*attach_envs*/
+
+        void
+        Variable::display(std::ostream & os) const {
+            os << "<Variable"
+               << xtag("name", name_);
+            if (this->valuetype())
+                os << xtag("type", this->valuetype()->short_name());
+            else
+                os << xtag("type", "nullptr");
+            os << ">";
+        } /*display*/
+    } /*namespace ast*/
+} /*namespace xo*/
+
+
+/* end Variable.cpp */