+ xo-interpreter2 scaffold for constant expression [WIP]

include/xo/interpreter2/VsmOpcode.hpp

@@ -0,0 +1,29 @@
+/** @file VsmOpcode.hpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include <cstdint>
+
+namespace xo {
+    namespace scm {
+        /** Opcode for a virtual schematika expression;
+         *  exeucted by VirtualSchematikaMachine
+         **/
+        enum class vsm_opcode {
+            /** Immediately halt virtual schematika machine. **/
+            halt,
+            /** Evaluate expression in expr register **/
+            eval,
+
+            /** sentinel, counts number of opcodes **/
+            N,
+        };
+
+        static constexpr uint32_t n_opcode = static_cast<uint32_t>(vsm_opcode::N);
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end VsmOpcode.hpp */