Change the creation/deletion of tangibles so that the tangible database is never really deleted.

luprex/cpp/core/luastack.hpp

@@ -222,9 +222,8 @@ int LuaTypeTagValue(lua_State *L) { return 0; }
 #define LUA_TT_GLOBALENV     18
 #define LUA_TT_TANGIBLE      19
 #define LUA_TT_TANGIBLEMETA  20
-#define LUA_TT_DEADTANGIBLE  21
-#define LUA_TT_GLOBALDB      22
-#define LUA_TT_CLASS         23
+#define LUA_TT_GLOBALDB      21
+#define LUA_TT_CLASS         22
 
 // World types enum.
 
@@ -458,8 +457,16 @@ public:
     void makeclass(LuaSlot tab, LuaSlot name) const;
     void makeclass(LuaSlot tab, std::string_view name) const;
 
-    // Get the ID of a tangible.  It's a little weird to put this in
-    // this module.
+    // Create a tangible, or look up an existing tangible.
+    // This doesn't do the entire process of tangible creation.  It
+    // just creates an empty table, marks it as a tangible, creates
+    // the metatable, stores the tangible ID, and stores it in the tangible table.
+    void maketan(LuaSlot tab, int64_t id) const;
+
+    // Return true if a tangible is empty (deleted or not yet created).
+    bool tanblank(LuaSlot tab) const;
+
+    // Get the ID of a tangible.
     int64_t tanid(LuaSlot tab) const;
 
     // Return true if the value is a sortable key (string, number, or boolean).