better implementation of `lua_ref' (much better...)

lref.h

@@ -1,5 +1,5 @@
 /*
-** $Id: $
+** $Id: lref.h,v 1.1 1999/10/04 17:50:24 roberto Exp roberto $
 ** REF mechanism
 ** See Copyright Notice in lua.h
 */
@@ -9,6 +9,19 @@
 
 #include "lobject.h"
 
+
+#define NONEXT          -1      /* to end the free list */
+#define HOLD            -2
+#define COLLECTED       -3
+#define LOCK            -4
+
+
+struct ref {
+  TObject o;
+  int st;  /* can be LOCK, HOLD, COLLECTED, or next (for free list) */
+};
+
+
 int luaR_ref (const TObject *o, int lock);
 const TObject *luaR_getref (int ref);
 void luaR_invalidaterefs (void);