first implementation of long strings

llimits.h

@@ -1,5 +1,5 @@
 /*
-** $Id: llimits.h,v 1.94 2011/11/29 15:39:48 roberto Exp roberto $
+** $Id: llimits.h,v 1.95 2011/12/06 16:58:36 roberto Exp roberto $
 ** Limits, basic types, and some other `installation-dependent' definitions
 ** See Copyright Notice in lua.h
 */
@@ -124,6 +124,15 @@ typedef LUAI_UACNUMBER l_uacNumber;
 #define MAXUPVAL	UCHAR_MAX
 
 
+/*
+** maximum length for short strings, that is, strings that are
+** internalized. (Cannot be smaller than reserved words or tags
+** for metamethods; #"function" = 8, #"__newindex" = 10; should
+** not be larger than 255, to allow future changes)
+*/
+#define LUA_MAXSHORTLEN		(8 * sizeof(void*))
+
+
 /*
 ** type for virtual-machine instructions
 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)