+ xo-interpreter2 scaffold for constant expression [WIP]

src/expression2/DConstant.cpp

@@ -0,0 +1,53 @@
+/** @file DConstant.cpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#include "DConstant.hpp"
+#include "TypeDescr.hpp"
+#include <xo/object2/DFloat.hpp>
+#include <xo/object2/DInteger.hpp>
+#include <xo/reflect/Reflect.hpp>
+#include <xo/reflectutil/typeseq.hpp>
+
+namespace xo {
+    using xo::scm::DFloat;
+    using xo::scm::DInteger;
+    using xo::reflect::Reflect;
+    using xo::reflect::TypeDescr;
+    using xo::reflect::typeseq;
+
+    namespace scm {
+        DConstant::DConstant(obj<AGCObject> value) noexcept
+            :
+            //typeref_{TypeRef::resolved(td)},
+              value_{value}
+        {
+            // todo: use ObjectConverter here
+
+            auto tseq = value_._typeseq();
+
+            TypeDescr td = this->_lookup_td(tseq);
+
+            if (td) {
+                typeref_ = TypeRef::resolved(td);
+            }
+        }
+
+        TypeDescr
+        DConstant::_lookup_td(typeseq tseq)
+        {
+            if (tseq == typeseq::id<DFloat>()) {
+                /* double */
+                return Reflect::require<DFloat::value_type>();
+            } else if (tseq == typeseq::id<DInteger>()) {
+                /* long */
+                return Reflect::require<DInteger::value_type>();
+            }
+
+            return nullptr;
+        }
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end DConstant.cpp */