Add move command for moving (leaf)list instances

Change-Id: I0bff25209f74601a450c12a810200b3c124d65f2
diff --git a/src/interpreter.hpp b/src/interpreter.hpp
index 0dfe2b6..bd90a60 100644
--- a/src/interpreter.hpp
+++ b/src/interpreter.hpp
@@ -26,6 +26,7 @@
     void operator()(const discard_&) const;
     void operator()(const help_&) const;
     void operator()(const copy_& copy) const;
+    void operator()(const move_& move) const;
 
 private:
     template <typename T>