xo-objectd2 xo-printable xo-facet: pp working for List(Integer)

Also streamline facet switching

src/object2/DInteger.cpp

@@ -0,0 +1,32 @@
+/** @file DInteger.cpp
+*
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#include "DInteger.hpp"
+#include <xo/indentlog/print/pretty.hpp>
+
+namespace xo {
+    using xo::facet::typeseq;
+    using xo::print::ppdetail_atomic;
+
+    namespace scm {
+        DInteger *
+        DInteger::make(obj<AAllocator> mm,
+                       long x)
+        {
+            void * mem = mm.alloc(typeseq::id<DInteger>(),
+                                  sizeof(DInteger));
+
+            return new (mem) DInteger(x);
+        }
+
+        bool
+        DInteger::pretty(const ppindentinfo & ppii) const
+        {
+            return ppdetail_atomic<long>::print_pretty(ppii, value_);
+        }
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end DInteger.cpp */