New macro 'makevariant' to codify variant tags
diff --git a/lobject.h b/lobject.h
index a529ceb..62e4d05 100644
--- a/lobject.h
+++ b/lobject.h
@@ -36,6 +36,9 @@
** bit 6: whether value is collectable
*/
+/* add variant bits to a type */
+#define makevariant(t,v) ((t) | ((v) << 4))
+
/*
@@ -165,13 +168,13 @@
** Variant tag, used only in tables to signal an empty slot
** (which might be different from a slot containing nil)
*/
-#define LUA_TEMPTY (LUA_TNIL | (1 << 4))
+#define LUA_TEMPTY makevariant(LUA_TNIL, 1)
/*
** Variant used only in the value returned for a key not found in a
** table (absent key).
*/
-#define LUA_TABSTKEY (LUA_TNIL | (2 << 4))
+#define LUA_TABSTKEY makevariant(LUA_TNIL, 2)
#define isabstkey(v) checktag((v), LUA_TABSTKEY)
@@ -210,8 +213,8 @@
*/
-#define LUA_TFALSE (LUA_TBOOLEAN | (1 << 4))
-#define LUA_TTRUE (LUA_TBOOLEAN | (2 << 4))
+#define LUA_TFALSE makevariant(LUA_TBOOLEAN, 1)
+#define LUA_TTRUE makevariant(LUA_TBOOLEAN, 2)
#define ttisboolean(o) checktype((o), LUA_TBOOLEAN)
#define ttisfalse(o) checktag((o), LUA_TFALSE)
@@ -292,8 +295,8 @@
*/
/* Variant tags for numbers */
-#define LUA_TNUMFLT (LUA_TNUMBER | (1 << 4)) /* float numbers */
-#define LUA_TNUMINT (LUA_TNUMBER | (2 << 4)) /* integer numbers */
+#define LUA_TNUMINT makevariant(LUA_TNUMBER, 1) /* integer numbers */
+#define LUA_TNUMFLT makevariant(LUA_TNUMBER, 2) /* float numbers */
#define ttisnumber(o) checktype((o), LUA_TNUMBER)
#define ttisfloat(o) checktag((o), LUA_TNUMFLT)
@@ -329,8 +332,8 @@
*/
/* Variant tags for strings */
-#define LUA_TSHRSTR (LUA_TSTRING | (1 << 4)) /* short strings */
-#define LUA_TLNGSTR (LUA_TSTRING | (2 << 4)) /* long strings */
+#define LUA_TSHRSTR makevariant(LUA_TSTRING, 1) /* short strings */
+#define LUA_TLNGSTR makevariant(LUA_TSTRING, 2) /* long strings */
#define ttisstring(o) checktype((o), LUA_TSTRING)
#define ttisshrstring(o) checktag((o), ctb(LUA_TSHRSTR))
@@ -546,9 +549,9 @@
*/
/* Variant tags for functions */
-#define LUA_TLCL (LUA_TFUNCTION | (1 << 4)) /* Lua closure */
-#define LUA_TLCF (LUA_TFUNCTION | (2 << 4)) /* light C function */
-#define LUA_TCCL (LUA_TFUNCTION | (3 << 4)) /* C closure */
+#define LUA_TLCL makevariant(LUA_TFUNCTION, 1) /* Lua closure */
+#define LUA_TLCF makevariant(LUA_TFUNCTION, 2) /* light C function */
+#define LUA_TCCL makevariant(LUA_TFUNCTION, 3) /* C closure */
#define ttisfunction(o) checktype(o, LUA_TFUNCTION)
#define ttisclosure(o) ((rawtt(o) & 0x1F) == LUA_TLCL)
