explicit stack control in the API

lauxlib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.c,v 1.31 2000/08/28 17:57:04 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.32 2000/08/29 14:33:31 roberto Exp roberto $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -49,6 +49,12 @@ static void type_error (lua_State *L, int narg, const char *type_name) {
 }
 
 
+void luaL_checkstack (lua_State *L, int space, const char *mes) {
+  if (space > lua_stackspace(L))
+    luaL_verror(L, "stack overflow (%.30s)", mes);
+}
+
+
 /*
 ** use the 3rd letter of type names for testing:
 ** nuMber, niL, stRing, fuNction, usErdata, taBle, anY