diff --git a/lapi.c b/lapi.c
index 9d7a07ce..86e20807 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 1.86 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: lapi.c,v 1.87 2000/08/14 19:10:14 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -16,7 +16,6 @@
 #include "lgc.h"
 #include "lmem.h"
 #include "lobject.h"
-#include "lref.h"
 #include "lstate.h"
 #include "lstring.h"
 #include "ltable.h"
@@ -29,246 +28,148 @@ const char lua_ident[] = "$Lua: " LUA_VERSION " " LUA_COPYRIGHT " $\n"
 
 
 
-void luaA_checkCargs (lua_State *L, int nargs) {
-  if (nargs > L->top-L->Cstack.base)
-    luaL_verror(L, "Lua API error - "
-                   "expected at least %d arguments in C2lua stack", nargs);
+#define Index(L,i)	((i) >= 0 ? (L->Cbase+((i)-1)) : (L->top+(i)))
+
+#define api_incr_top(L)	(++L->top)
+
+
+
+
+TObject *luaA_index (lua_State *L, int index) {
+  return Index(L, index);
 }
 
 
-lua_Object luaA_putluaObject (lua_State *L, const TObject *o) {
-  luaD_openstack(L, L->Cstack.base);
-  *L->Cstack.base++ = *o;
-  return L->Cstack.base-1;
-}
-
-
-static void top2LC (lua_State *L, int n) {
-  /* Put the `n' elements on the top as the Lua2C contents */
-  L->Cstack.base = L->top;  /* new base */
-  L->Cstack.lua2C = L->Cstack.base-n;  /* position of the new results */
-  L->Cstack.num = n;  /* number of results */
-}
-
-
-lua_Object lua_pop (lua_State *L) {
-  luaA_checkCargs(L, 1);
-  if (L->Cstack.base != L->top-1) {
-    luaD_openstack(L, L->Cstack.base);
-    *L->Cstack.base = *(--L->top);
-  }
-  return L->Cstack.base++;
-}
-
-
-void lua_pushglobals (lua_State *L) {
-  hvalue(L->top) = L->gt;
-  ttype(L->top) = TAG_TABLE;
+void luaA_pushobject (lua_State *L, const TObject *o) {
+  *L->top = *o;
   incr_top;
 }
 
 
-void lua_setglobals (lua_State *L, lua_Object newtable) {
-  if (lua_type(L, newtable)[0] != 't')  /* type == "table"? */
-    lua_error(L, "Lua API error - invalid value for global table");
-  L->gt = hvalue(newtable);
+
+/*
+** basic stack manipulation
+*/
+
+
+int lua_gettop (lua_State *L) {
+  return (L->top - L->Cbase);
 }
 
 
+void lua_settop (lua_State *L, int index) {
+  if (index >= 0)
+    luaD_adjusttop(L, L->Cbase, index);
+  else
+    L->top += index;  /* index is negative */
+}
+
+
+void lua_pushobject (lua_State *L, int index) {
+  *L->top = *Index(L, index);
+  api_incr_top(L);
+}
+
+
+
 /*
-** Get a parameter, returning the object handle or LUA_NOOBJECT on error.
-** `number' must be 1 to get the first parameter.
+** access functions (stack -> C)
 */
-lua_Object lua_lua2C (lua_State *L, int number) {
-  if (number <= 0 || number > L->Cstack.num) return LUA_NOOBJECT;
-  return L->Cstack.lua2C+number-1;
+
+
+#define btest(L,i,value,default)	{ \
+  StkId o; \
+  if ((i) >= 0) { \
+    o = L->Cbase+((i)-1); \
+    if (o >= L->top) return (default); \
+  } \
+  else o = L->top+(i); \
+  return (value); }
+
+
+#define access(L,i,test,default,value)	{ \
+  StkId o; \
+  if ((i) >= 0) { \
+    o = L->Cbase+((i)-1); \
+    if (o >= L->top) return (default); \
+  } \
+  else o = L->top+(i); \
+  return ((test) ? (value) : (default)); }
+
+
+const char *lua_type (lua_State *L, int index) {
+  btest(L, index, luaO_typename(o), "NO VALUE");
+}
+
+int lua_iscfunction (lua_State *L, int index) {
+  btest(L, index, (ttype(o) == TAG_CCLOSURE), 0);
+}
+
+int lua_isnumber (lua_State *L, int index) {
+  btest(L, index, (tonumber(Index(L, index)) == 0), 0);
+}
+
+int lua_tag (lua_State *L, int index) {
+  btest(L, index, 
+   ((ttype(o) == TAG_USERDATA) ? tsvalue(o)->u.d.tag : luaT_effectivetag(L, o)),
+   -1);
+}
+
+int lua_equal(lua_State *L, int index1, int index2) {
+  return luaO_equalObj(Index(L, index1), Index(L, index2));
 }
 
 
-int lua_callfunction (lua_State *L, lua_Object function) {
-  if (function == LUA_NOOBJECT)
-    return 1;
-  else {
-    luaD_openstack(L, L->Cstack.base);
-    *L->Cstack.base = *function;
-    return luaD_protectedrun(L);
-  }
+
+double lua_tonumber (lua_State *L, int index) {
+  access(L, index, (tonumber(o) == 0), 0.0, nvalue(o));
 }
 
-
-lua_Object lua_gettagmethod (lua_State *L, int tag, const char *event) {
-  return luaA_putluaObject(L, luaT_gettagmethod(L, tag, event));
-}
-
-
-lua_Object lua_settagmethod (lua_State *L, int tag, const char *event) {
-  TObject *method;
-  luaA_checkCargs(L, 1);
-  method = L->top-1;
-  if ((ttype(method) != TAG_NIL) && (*lua_type(L, method) != 'f'))
-    lua_error(L, "Lua API error - tag method must be a function or nil");
-  luaT_settagmethod(L, tag, event, method);
-  return lua_pop(L);
-}
-
-
-lua_Object lua_gettable (lua_State *L) {
-  luaA_checkCargs(L, 2);
-  luaV_gettable(L, L->top--);
-  return lua_pop(L);
-}
-
-
-lua_Object lua_rawget (lua_State *L) {
-  lua_Object res;
-  luaA_checkCargs(L, 2);
-  if (ttype(L->top-2) != TAG_TABLE)
-    lua_error(L, "indexed expression not a table");
-  res = luaA_putluaObject(L, luaH_get(L, hvalue(L->top-2), L->top-1));
-  L->top -= 2;
-  return res;
-}
-
-
-void lua_settable (lua_State *L) {
-  StkId top;
-  luaA_checkCargs(L, 3);
-  top = L->top;
-  luaV_settable(L, top-3, top);
-  L->top = top-3;  /* pop table, index, and value */
-}
-
-
-void lua_rawset (lua_State *L) {
-  luaA_checkCargs(L, 3);
-  if (ttype(L->top-3) != TAG_TABLE)
-    lua_error(L, "indexed expression not a table");
-  *luaH_set(L, hvalue(L->top-3), L->top-2) = *(L->top-1);
-  L->top -= 3;
-}
-
-
-lua_Object lua_createtable (lua_State *L) {
-  TObject o;
-  luaC_checkGC(L);
-  hvalue(&o) = luaH_new(L, 0);
-  ttype(&o) = TAG_TABLE;
-  return luaA_putluaObject(L, &o);
-}
-
-
-lua_Object lua_getglobal (lua_State *L, const char *name) {
-  luaV_getglobal(L, luaS_new(L, name), L->top++);
-  return lua_pop(L);
-}
-
-
-void lua_setglobal (lua_State *L, const char *name) {
-  luaA_checkCargs(L, 1);
-  luaV_setglobal(L, luaS_new(L, name), L->top--);
-}
-
-
-const char *lua_type (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o == LUA_NOOBJECT) ? "NOOBJECT" : luaO_typename(o);
-}
-
-int lua_isnil (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o != LUA_NOOBJECT) && (ttype(o) == TAG_NIL);
-}
-
-int lua_istable (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o != LUA_NOOBJECT) && (ttype(o) == TAG_TABLE);
-}
-
-int lua_isuserdata (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o != LUA_NOOBJECT) && (ttype(o) == TAG_USERDATA);
-}
-
-int lua_iscfunction (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o != LUA_NOOBJECT) && (ttype(o) == TAG_CCLOSURE);
-}
-
-int lua_isnumber (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o != LUA_NOOBJECT) && (tonumber(o) == 0);
-}
-
-int lua_isstring (lua_State *L, lua_Object o) {
-  UNUSED(L);
-  return (o != LUA_NOOBJECT && (ttype(o) == TAG_STRING ||
-                                ttype(o) == TAG_NUMBER));
-}
-
-int lua_isfunction (lua_State *L, lua_Object o) {
-  return *lua_type(L, o) == 'f';
-}
-
-int lua_equal(lua_State *L, lua_Object o1, lua_Object o2) {
-  UNUSED(L);
-  if (o1 == LUA_NOOBJECT || o2 == LUA_NOOBJECT)
-    return (o1 == o2);
-  else return luaO_equalObj(o1, o2);
-}
-
-
-double lua_getnumber (lua_State *L, lua_Object obj) {
-  UNUSED(L);
-  if (obj == LUA_NOOBJECT  || tonumber(obj))
-     return 0.0;
-  else return (nvalue(obj));
-}
-
-const char *lua_getstring (lua_State *L, lua_Object obj) {
+const char *lua_tostring (lua_State *L, int index) {
   luaC_checkGC(L);  /* `tostring' may create a new string */
-  if (obj == LUA_NOOBJECT || tostring(L, obj))
-    return NULL;
-  else return (svalue(obj));
+  access(L, index, (tostring(L, o) == 0), NULL, svalue(o));
 }
 
-size_t lua_strlen (lua_State *L, lua_Object obj) {
-  if (obj == LUA_NOOBJECT || tostring(L, obj))
-    return 0L;
-  else return (tsvalue(obj)->u.s.len);
+size_t lua_strlen (lua_State *L, int index) {
+  access(L, index, (tostring(L, o) == 0), 0, tsvalue(o)->u.s.len);
 }
 
-void *lua_getuserdata (lua_State *L, lua_Object obj) {
-  UNUSED(L);
-  if (obj == LUA_NOOBJECT || ttype(obj) != TAG_USERDATA)
-    return NULL;
-  else return tsvalue(obj)->u.d.value;
+lua_CFunction lua_tocfunction (lua_State *L, int index) {
+  access(L, index, (ttype(o) == TAG_CCLOSURE), NULL, clvalue(o)->f.c);
 }
 
-lua_CFunction lua_getcfunction (lua_State *L, lua_Object obj) {
-  if (!lua_iscfunction(L, obj))
-    return NULL;
-  else return clvalue(obj)->f.c;
+void *lua_touserdata (lua_State *L, int index) {
+  access(L, index, (ttype(o) == TAG_USERDATA), NULL, tsvalue(o)->u.d.value);
 }
 
 
+
+/*
+** push functions (C -> stack)
+*/
+
+
 void lua_pushnil (lua_State *L) {
   ttype(L->top) = TAG_NIL;
-  incr_top;
+  api_incr_top(L);
 }
 
+
 void lua_pushnumber (lua_State *L, double n) {
   ttype(L->top) = TAG_NUMBER;
   nvalue(L->top) = n;
-  incr_top;
+  api_incr_top(L);
 }
 
+
 void lua_pushlstring (lua_State *L, const char *s, size_t len) {
+  luaC_checkGC(L);
   tsvalue(L->top) = luaS_newlstr(L, s, len);
   ttype(L->top) = TAG_STRING;
-  incr_top;
-  luaC_checkGC(L);
+  api_incr_top(L);
 }
 
+
 void lua_pushstring (lua_State *L, const char *s) {
   if (s == NULL)
     lua_pushnil(L);
@@ -276,48 +177,154 @@ void lua_pushstring (lua_State *L, const char *s) {
     lua_pushlstring(L, s, strlen(s));
 }
 
+
 void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
-  if (fn == NULL)
-    lua_error(L, "Lua API error - attempt to push a NULL Cfunction");
-  luaA_checkCargs(L, n);
-  luaV_Cclosure(L, fn, n);
   luaC_checkGC(L);
+  luaV_Cclosure(L, fn, n);
 }
 
+
 void lua_pushusertag (lua_State *L, void *u, int tag) {  /* ORDER LUA_T */
+  luaC_checkGC(L);
   if (tag != LUA_ANYTAG && tag != TAG_USERDATA && tag < NUM_TAGS)
     luaL_verror(L, "invalid tag for a userdata (%d)", tag);
   tsvalue(L->top) = luaS_createudata(L, u, tag);
   ttype(L->top) = TAG_USERDATA;
-  incr_top;
-  luaC_checkGC(L);
-}
-
-void luaA_pushobject (lua_State *L, const TObject *o) {
-  *L->top = *o;
-  incr_top;
-}
-
-void lua_pushobject (lua_State *L, lua_Object o) {
-  if (o == LUA_NOOBJECT)
-    lua_error(L, "Lua API error - attempt to push a NOOBJECT");
-  *L->top = *o;
-  incr_top;
+  api_incr_top(L);
 }
 
 
-int lua_tag (lua_State *L, lua_Object o) {
-  if (o == LUA_NOOBJECT)
-    return TAG_NIL;
-  else if (ttype(o) == TAG_USERDATA)  /* to allow `old' tags (deprecated) */
-    return tsvalue(o)->u.d.tag;
+
+/*
+** get functions (Lua -> stack)
+*/
+
+
+void lua_getglobal (lua_State *L, const char *name) {
+  luaV_getglobal(L, luaS_new(L, name), L->top++);
+}
+
+
+void lua_gettable (lua_State *L) {
+  luaV_gettable(L, L->top--);
+}
+
+
+void lua_rawget (lua_State *L) {
+  if (ttype(L->top - 2) != TAG_TABLE)
+    lua_error(L, "indexed expression not a table");
+  *(L->top - 2) = *luaH_get(L, hvalue(L->top - 2), L->top - 1);
+  L->top--;
+}
+
+
+void lua_getglobals (lua_State *L) {
+  hvalue(L->top) = L->gt;
+  ttype(L->top) = TAG_TABLE;
+  api_incr_top(L);
+}
+
+
+void lua_gettagmethod (lua_State *L, int tag, const char *event) {
+  *L->top = *luaT_gettagmethod(L, tag, event);
+  api_incr_top(L);
+}
+
+
+int lua_getref (lua_State *L, int ref) {
+  if (ref == LUA_REFNIL)
+    ttype(L->top) = TAG_NIL;
+  else if (0 <= ref && ref < L->refSize &&
+          (L->refArray[ref].st == LOCK || L->refArray[ref].st == HOLD))
+    *L->top = L->refArray[ref].o;
   else
-    return luaT_effectivetag(L, o);
+    return 0;
+  api_incr_top(L);
+  return 1;
 }
 
 
+void lua_newtable (lua_State *L) {
+  luaC_checkGC(L);
+  hvalue(L->top) = luaH_new(L, 0);
+  ttype(L->top) = TAG_TABLE;
+  api_incr_top(L);
+}
+
+
+
+/*
+** set functions (stack -> Lua)
+*/
+
+
+void lua_setglobal (lua_State *L, const char *name) {
+  luaV_setglobal(L, luaS_new(L, name), L->top--);
+}
+
+
+void lua_settable (lua_State *L) {
+  StkId top = L->top;
+  luaV_settable(L, top-3, top);
+  L->top = top-3;  /* pop table, index, and value */
+}
+
+
+void lua_rawset (lua_State *L) {
+  if (ttype(L->top-3) != TAG_TABLE)
+    lua_error(L, "indexed expression not a table");
+  *luaH_set(L, hvalue(L->top-3), L->top-2) = *(L->top-1);
+  L->top -= 3;
+}
+
+
+void lua_setglobals (lua_State *L) {
+  TObject *newtable = --L->top;
+  if (ttype(newtable) != TAG_TABLE)
+    lua_error(L, "Lua API error - invalid value for global table");
+  L->gt = hvalue(newtable);
+}
+
+
+void lua_settagmethod (lua_State *L, int tag, const char *event) {
+  TObject *method = L->top - 1;
+  if (ttype(method) != TAG_NIL &&
+      ttype(method) != TAG_CCLOSURE &&
+      ttype(method) != TAG_LCLOSURE)
+    lua_error(L, "Lua API error - tag method must be a function or nil");
+  luaT_settagmethod(L, tag, event, method);
+}
+
+
+int lua_ref (lua_State *L,  int lock) {
+  int ref;
+  if (ttype(L->top-1) == TAG_NIL)
+    ref = LUA_REFNIL;
+  else {
+    if (L->refFree != NONEXT) {  /* is there a free place? */
+      ref = L->refFree;
+      L->refFree = L->refArray[ref].st;
+    }
+    else {  /* no more free places */
+      luaM_growvector(L, L->refArray, L->refSize, 1, struct Ref,
+                      "reference table overflow", MAX_INT);
+      ref = L->refSize++;
+    }
+    L->refArray[ref].o = *(L->top-1);
+    L->refArray[ref].st = lock ? LOCK : HOLD;
+  }
+  L->top--;
+  return ref;
+}
+
+
+
+/*
+** miscelaneous functions
+*/
+
+
 void lua_settag (lua_State *L, int tag) {
-  luaA_checkCargs(L, 1);
   luaT_realtag(L, tag);
   switch (ttype(L->top-1)) {
     case TAG_TABLE:
@@ -334,6 +341,17 @@ void lua_settag (lua_State *L, int tag) {
 }
 
 
+void lua_unref (lua_State *L, int ref) {
+  if (ref >= 0) {
+    if (ref >= L->refSize || L->refArray[ref].st >= 0)
+      lua_error(L, "Lua API error - "
+                   "invalid argument for function `lua_unref'");
+    L->refArray[ref].st = L->refFree;
+    L->refFree = ref;
+  }
+}
+
+
 int luaA_next (lua_State *L, const Hash *t, int i) {
   int tsize = t->size;
   for (; i<tsize; i++) {
@@ -348,38 +366,10 @@ int luaA_next (lua_State *L, const Hash *t, int i) {
 }
 
 
-int lua_next (lua_State *L, lua_Object t, int i) {
+int lua_next (lua_State *L, int index, int i) {
+  const TObject *t = Index(L, index);
   if (ttype(t) != TAG_TABLE)
     lua_error(L, "Lua API error - object is not a table in `lua_next'"); 
-  i = luaA_next(L, hvalue(t), i);
-  top2LC(L, (i==0) ? 0 : 2);
-  return i;
+  return luaA_next(L, hvalue(t), i);
 }
 
-
-
-#if LUA_DEPRECATETFUNCS
-
-/*
-** obsolete functions
-*/
-
-lua_Object lua_rawgetglobal (lua_State *L, const char *name) {
-  lua_pushglobals(L);
-  lua_pushstring(L, name);
-  return lua_rawget(L);
-}
-
-
-void lua_rawsetglobal (lua_State *L, const char *name) {
-  lua_Object value;
-  lua_beginblock(L);
-  value = lua_pop(L);
-  lua_pushglobals(L);
-  lua_pushstring(L, name);
-  lua_pushobject(L, value);
-  lua_rawset(L);
-  lua_endblock(L);
-}
-
-#endif
diff --git a/lapi.h b/lapi.h
index 05153d6d..e8c66393 100644
--- a/lapi.h
+++ b/lapi.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.h,v 1.17 2000/05/08 19:32:53 roberto Exp roberto $
+** $Id: lapi.h,v 1.18 2000/05/08 20:49:05 roberto Exp roberto $
 ** Auxiliary functions from Lua API
 ** See Copyright Notice in lua.h
 */
@@ -11,9 +11,8 @@
 #include "lobject.h"
 
 
-void luaA_checkCargs (lua_State *L, int nargs);
+TObject *luaA_index (lua_State *L, int index);
 void luaA_pushobject (lua_State *L, const TObject *o);
 int luaA_next (lua_State *L, const Hash *t, int i);
-lua_Object luaA_putluaObject (lua_State *L, const TObject *o);
 
 #endif
diff --git a/lauxlib.c b/lauxlib.c
index a657c2c0..2234934b 100644
--- a/lauxlib.c
+++ b/lauxlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.c,v 1.29 2000/06/12 13:52:05 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.30 2000/08/09 19:16:57 roberto Exp roberto $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -41,72 +41,61 @@ void luaL_argerror (lua_State *L, int narg, const char *extramsg) {
 }
 
 
-static void type_error (lua_State *L, int narg, const char *type_name,
-                        lua_Object o) {
+static void type_error (lua_State *L, int narg, const char *type_name) {
   char buff[100];
-  const char *otype = (o == LUA_NOOBJECT) ? "no value" : lua_type(L, o);
-  sprintf(buff, "%.10s expected, got %.10s", type_name, otype);
+  const char *rt = lua_type(L, narg);
+  if (*rt == 'N') rt = "no value";
+  sprintf(buff, "%.10s expected, got %.10s", type_name, rt);
   luaL_argerror(L, narg, buff);
 }
 
 
-static const char *checkstr (lua_State *L, lua_Object o, int narg,
-                             size_t *len) {
-  const char *s = lua_getstring(L, o);
-  if (!s) type_error(L, narg, "string", o);
-  if (len) *len = lua_strlen(L, o);
+/*
+** use the 3rd letter of type names for testing:
+** nuMber, niL, stRing, fuNction, usErdata, taBle, anY
+*/
+void luaL_checktype(lua_State *L, int narg, const char *tname) {
+  const char *rt = lua_type(L, narg);
+  if (!(*rt != 'N' && (tname[2] == 'y' || tname[2] == rt[2])))
+    type_error(L, narg, tname);
+}
+
+
+static const char *checkstr (lua_State *L, int narg, size_t *len) {
+  const char *s = lua_tostring(L, narg);
+  if (!s) type_error(L, narg, "string");
+  if (len) *len = lua_strlen(L, narg);
   return s;
 }
 
 const char *luaL_check_lstr (lua_State *L, int narg, size_t *len) {
-  return checkstr(L, lua_getparam(L, narg), narg, len);
+  return checkstr(L, narg, len);
 }
 
 const char *luaL_opt_lstr (lua_State *L, int narg, const char *def,
                            size_t *len) {
-  lua_Object o = lua_getparam(L, narg);
-  if (o == LUA_NOOBJECT) {
+  if (lua_isnull(L, narg)) {
     if (len) *len = def ? strlen(def) : 0;
     return def;
   }
-  else return checkstr(L, o, narg, len);
+  else return checkstr(L, narg, len);
 }
 
 double luaL_check_number (lua_State *L, int narg) {
-  lua_Object o = lua_getparam(L, narg);
-  if (!lua_isnumber(L, o)) type_error(L, narg, "number", o);
-  return lua_getnumber(L, o);
+  if (!lua_isnumber(L, narg)) type_error(L, narg, "number");
+  return lua_tonumber(L, narg);
 }
 
 
 double luaL_opt_number (lua_State *L, int narg, double def) {
-  lua_Object o = lua_getparam(L, narg);
-  if (o == LUA_NOOBJECT) return def;
+  if (lua_isnull(L, narg)) return def;
   else {
-    if (!lua_isnumber(L, o)) type_error(L, narg, "number", o);
-    return lua_getnumber(L, o);
+    if (!lua_isnumber(L, narg)) type_error(L, narg, "number");
+    return lua_tonumber(L, narg);
   }
 }
 
 
-lua_Object luaL_tablearg (lua_State *L, int narg) {
-  lua_Object o = lua_getparam(L, narg);
-  if (!lua_istable(L, o)) type_error(L, narg, "table", o);
-  return o;
-}
-
-lua_Object luaL_functionarg (lua_State *L, int narg) {
-  lua_Object o = lua_getparam(L, narg);
-  if (!lua_isfunction(L, o)) type_error(L, narg, "function", o);
-  return o;
-}
-
-lua_Object luaL_nonnullarg (lua_State *L, int narg) {
-  lua_Object o = lua_getparam(L, narg);
-  luaL_arg_check(L, o != LUA_NOOBJECT, narg, "value expected");
-  return o;
-}
-
 void luaL_openlib (lua_State *L, const struct luaL_reg *l, int n) {
   int i;
   for (i=0; i<n; i++)
@@ -150,3 +139,4 @@ void luaL_filesource (char *out, const char *filename, int len) {
   if (filename == NULL) filename = "(stdin)";
   sprintf(out, "@%.*s", len-2, filename);  /* -2 for '@' and '\0' */
 }
+
diff --git a/lauxlib.h b/lauxlib.h
index 1898e95e..25dbc1f9 100644
--- a/lauxlib.h
+++ b/lauxlib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.h,v 1.18 2000/05/24 13:54:49 roberto Exp roberto $
+** $Id: lauxlib.h,v 1.19 2000/08/09 19:16:57 roberto Exp roberto $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -27,14 +27,15 @@ const char *luaL_opt_lstr (lua_State *L, int numArg, const char *def,
                            size_t *len);
 double luaL_check_number (lua_State *L, int numArg);
 double luaL_opt_number (lua_State *L, int numArg, double def);
-lua_Object luaL_functionarg (lua_State *L, int arg);
-lua_Object luaL_tablearg (lua_State *L, int arg);
-lua_Object luaL_nonnullarg (lua_State *L, int numArg);
+
+void luaL_checktype(lua_State *L, int narg, const char *tname);
+
 void luaL_verror (lua_State *L, const char *fmt, ...);
 int luaL_findstring (const char *name, const char *const list[]);
 void luaL_chunkid (char *out, const char *source, int len);
 void luaL_filesource (char *out, const char *filename, int len);
 
+
 char *luaL_openspace (lua_State *L, size_t size);
 void luaL_resetbuffer (lua_State *L);
 void luaL_addchar (lua_State *L, int c);
@@ -91,9 +92,6 @@ char *luaL_buffer (lua_State *L);
 				(luaL_opt_lstr)(lua_state,numArg,def,len)
 #define luaL_check_number(numArg)	(luaL_check_number)(lua_state,numArg)
 #define luaL_opt_number(numArg,def)	(luaL_opt_number)(lua_state,numArg,def)
-#define luaL_functionarg(arg)	(luaL_functionarg)(lua_state,arg)
-#define luaL_tablearg(arg)	(luaL_tablearg)(lua_state,arg)
-#define luaL_nonnullarg(numArg)	(luaL_nonnullarg)(lua_state,numArg)
 #define luaL_openspace(size)	(luaL_openspace)(lua_state,size)
 #define luaL_resetbuffer()	(luaL_resetbuffer)(lua_state)
 #define luaL_addchar(c)		(luaL_addchar)(lua_state,c)
diff --git a/lbuiltin.c b/lbuiltin.c
index 6bcfad4b..d7180f2d 100644
--- a/lbuiltin.c
+++ b/lbuiltin.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbuiltin.c,v 1.120 2000/08/14 19:10:14 roberto Exp roberto $
+** $Id: lbuiltin.c,v 1.121 2000/08/15 18:28:48 roberto Exp roberto $
 ** Built-in functions
 ** See Copyright Notice in lua.h
 */
@@ -50,7 +50,6 @@ void luaB_opentests (lua_State *L);
 ** =======================================================
 */
 
-
 static Number getsize (const Hash *h) {
   Number max = 0;
   int i = h->size;
@@ -73,7 +72,8 @@ static Number getnarg (lua_State *L, const Hash *a) {
 
 
 static Hash *gettable (lua_State *L, int arg) {
-  return hvalue(luaL_tablearg(L, arg));
+  luaL_checktype(L, arg, "table");
+  return hvalue(luaA_index(L, arg));
 }
 
 /* }====================================================== */
@@ -90,8 +90,9 @@ static Hash *gettable (lua_State *L, int arg) {
 ** If your system does not support `stderr', redefine this function, or
 ** redefine _ERRORMESSAGE so that it won't need _ALERT.
 */
-void luaB__ALERT (lua_State *L) {
+int luaB__ALERT (lua_State *L) {
   fputs(luaL_check_string(L, 1), stderr);
+  return 0;
 }
 
 
@@ -99,18 +100,19 @@ void luaB__ALERT (lua_State *L) {
 ** Standard implementation of _ERRORMESSAGE.
 ** The library `liolib' redefines _ERRORMESSAGE for better error information.
 */
-void luaB__ERRORMESSAGE (lua_State *L) {
-  lua_Object al;
-  lua_pushglobals(L);
+int luaB__ERRORMESSAGE (lua_State *L) {
+  lua_getglobals(L);
   lua_pushstring(L, LUA_ALERT);
-  al = lua_rawget(L);
-  if (lua_isfunction(L, al)) {  /* avoid error loop if _ALERT is not defined */
+  lua_rawget(L);
+  if (lua_isfunction(L, -1)) {  /* avoid error loop if _ALERT is not defined */
     const char *s = luaL_check_string(L, 1);
     char *buff = luaL_openspace(L, strlen(s)+sizeof("error: \n"));
     strcpy(buff, "error: "); strcat(buff, s); strcat(buff, "\n");
+    lua_pushobject(L, -1);  /* function to be called */
     lua_pushstring(L, buff);
-    lua_callfunction(L, al);
+    lua_call(L, 1, 0);
   }
+  return 0;
 }
 
 
@@ -120,36 +122,35 @@ void luaB__ERRORMESSAGE (lua_State *L) {
 ** model but changing `fputs' to put the strings at a proper place
 ** (a console window or a log file, for instance).
 */
-void luaB_print (lua_State *L) {
-  lua_Object args[MAXPRINT];
-  lua_Object obj;
-  int n = 0;
+int luaB_print (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
   int i;
-  while ((obj = lua_getparam(L, n+1)) != LUA_NOOBJECT) {
-    luaL_arg_check(L, n < MAXPRINT, n+1, "too many arguments");
-    args[n++] = obj;
-  }
-  for (i=0; i<n; i++) {
-    lua_pushobject(L, args[i]);
-    if (lua_call(L, "tostring"))
+  lua_getglobal(L, "tostring");
+  for (i=1; i<=n; i++) {
+    const char *s;
+    lua_pushobject(L, -1);  /* function to be called */
+    lua_pushobject(L, i);
+    if (lua_call(L, 1, 1) != 0)
       lua_error(L, "error in `tostring' called by `print'");
-    obj = lua_getresult(L, 1);
-    if (!lua_isstring(L, obj))
+    s = lua_tostring(L, -1);  /* get result */
+    if (s == NULL)
       lua_error(L, "`tostring' must return a string to `print'");
-    if (i>0) fputs("\t", stdout);
-    fputs(lua_getstring(L, obj), stdout);
+    if (i>1) fputs("\t", stdout);
+    fputs(s, stdout);
+    lua_settop(L, -1);  /* pop result */
   }
   fputs("\n", stdout);
+  return 0;
 }
 
 
-void luaB_tonumber (lua_State *L) {
+int luaB_tonumber (lua_State *L) {
   int base = luaL_opt_int(L, 2, 10);
   if (base == 10) {  /* standard conversion */
-    lua_Object o = luaL_nonnullarg(L, 1);
-    if (lua_isnumber(L, o)) {
-      lua_pushnumber(L, lua_getnumber(L, o));
-      return;
+    luaL_checktype(L, 1, "any");
+    if (lua_isnumber(L, 1)) {
+      lua_pushnumber(L, lua_tonumber(L, 1));
+      return 1;
     }
   }
   else {
@@ -162,94 +163,108 @@ void luaB_tonumber (lua_State *L) {
       while (isspace((unsigned char)*s2)) s2++;  /* skip trailing spaces */
       if (*s2 == '\0') {  /* no invalid trailing characters? */
         lua_pushnumber(L, n);
-        return;
+        return 1;
       }
     }
   }
   lua_pushnil(L);  /* else not a number */
+  return 1;
 }
 
 
-void luaB_error (lua_State *L) {
+int luaB_error (lua_State *L) {
   lua_error(L, luaL_opt_string(L, 1, NULL));
+  return 0;  /* to avoid errors */
 }
 
-void luaB_setglobal (lua_State *L) {
-  const char *name = luaL_check_string(L, 1);
-  lua_Object value = luaL_nonnullarg(L, 2);
-  lua_pushobject(L, value);
-  lua_setglobal(L, name);
+int luaB_setglobal (lua_State *L) {
+  luaL_checktype(L, 2, "any");
+  lua_setglobal(L, luaL_check_string(L, 1));
+  return 0;
 }
 
-void luaB_getglobal (lua_State *L) {
-  lua_pushobject(L, lua_getglobal(L, luaL_check_string(L, 1)));
+int luaB_getglobal (lua_State *L) {
+  lua_getglobal(L, luaL_check_string(L, 1));
+  return 1;
 }
 
-void luaB_tag (lua_State *L) {
-  lua_pushnumber(L, lua_tag(L, luaL_nonnullarg(L, 1)));
+int luaB_tag (lua_State *L) {
+  luaL_checktype(L, 1, "any");
+  lua_pushnumber(L, lua_tag(L, 1));
+  return 1;
 }
 
-void luaB_settag (lua_State *L) {
-  lua_Object o = luaL_tablearg(L, 1);
-  lua_pushobject(L, o);
+int luaB_settag (lua_State *L) {
+  luaL_checktype(L, 1, "table");
+  lua_pushobject(L, 1);  /* push table */
   lua_settag(L, luaL_check_int(L, 2));
-  lua_pushobject(L, o);  /* return first argument */
+  lua_pushobject(L, 1);  /* return first argument */
+  return 1;
 }
 
-void luaB_newtag (lua_State *L) {
+int luaB_newtag (lua_State *L) {
   lua_pushnumber(L, lua_newtag(L));
+  return 1;
 }
 
-void luaB_copytagmethods (lua_State *L) {
+int luaB_copytagmethods (lua_State *L) {
   lua_pushnumber(L, lua_copytagmethods(L, luaL_check_int(L, 1),
                                           luaL_check_int(L, 2)));
+  return 1;
 }
 
-void luaB_globals (lua_State *L) {
-  lua_pushglobals(L);
-  if (lua_getparam(L, 1) != LUA_NOOBJECT)
-    lua_setglobals(L, luaL_tablearg(L, 1));
+int luaB_globals (lua_State *L) {
+  lua_getglobals(L);  /* value to be returned */
+  if (!lua_isnull(L, 1)) {
+    luaL_checktype(L, 1, "table");
+    lua_pushobject(L, 1);  /* new table of globals */
+    lua_setglobals(L);
+  }
+  return 1;
 }
 
-void luaB_rawget (lua_State *L) {
-  lua_pushobject(L, luaL_nonnullarg(L, 1));
-  lua_pushobject(L, luaL_nonnullarg(L, 2));
-  lua_pushobject(L, lua_rawget(L));
+int luaB_rawget (lua_State *L) {
+  luaL_checktype(L, 1, "table");
+  luaL_checktype(L, 2, "any");
+  lua_rawget(L);
+  return 1;
 }
 
-void luaB_rawset (lua_State *L) {
-  lua_pushobject(L, luaL_nonnullarg(L, 1));
-  lua_pushobject(L, luaL_nonnullarg(L, 2));
-  lua_pushobject(L, luaL_nonnullarg(L, 3));
+int luaB_rawset (lua_State *L) {
+  luaL_checktype(L, 1, "table");
+  luaL_checktype(L, 2, "any");
+  luaL_checktype(L, 3, "any");
   lua_rawset(L);
+  return 1;
 }
 
-void luaB_settagmethod (lua_State *L) {
-  int tag = luaL_check_int(L, 1);
+int luaB_settagmethod (lua_State *L) {
+  int tag = (int)luaL_check_int(L, 1);
   const char *event = luaL_check_string(L, 2);
-  lua_Object nf = luaL_nonnullarg(L, 3);
-  luaL_arg_check(L, lua_isnil(L, nf) || lua_isfunction(L, nf), 3,
+  luaL_arg_check(L, lua_isfunction(L, 3) || lua_isnil(L, 3), 3,
                  "function or nil expected");
   if (strcmp(event, "gc") == 0 && tag != TAG_NIL)
     lua_error(L, "deprecated use: cannot set the `gc' tag method from Lua");
-  lua_pushobject(L, nf);
-  lua_pushobject(L, lua_settagmethod(L, tag, event));
+  lua_settagmethod(L, tag, event);
+  return 1;
 }
 
-void luaB_gettagmethod (lua_State *L) {
-  lua_pushobject(L, lua_gettagmethod(L, luaL_check_int(L, 1),
-                                        luaL_check_string(L, 2)));
+int luaB_gettagmethod (lua_State *L) {
+  lua_gettagmethod(L, luaL_check_int(L, 1), luaL_check_string(L, 2));
+  return 1;
 }
 
 
-void luaB_collectgarbage (lua_State *L) {
+int luaB_collectgarbage (lua_State *L) {
   lua_pushnumber(L, lua_collectgarbage(L, luaL_opt_int(L, 1, 0)));
+  return 1;
 }
 
 
-void luaB_type (lua_State *L) {
-  lua_Object o = luaL_nonnullarg(L, 1);
-  lua_pushstring(L, lua_type(L, o));
+int luaB_type (lua_State *L) {
+  luaL_checktype(L, 1, "any");
+  lua_pushstring(L, lua_type(L, 1));
+  return 1;
 }
 
 /* }====================================================== */
@@ -263,99 +278,115 @@ void luaB_type (lua_State *L) {
 */
 
 
-static void passresults (lua_State *L) {
-  L->Cstack.base = L->Cstack.lua2C;  /* position of first result */
-  if (L->Cstack.num == 0)
-    lua_pushuserdata(L, NULL);  /* at least one result to signal no errors */
+static int passresults (lua_State *L, int status, int oldtop) {
+  if (status == 0) {
+    int nresults = lua_gettop(L) - oldtop;
+    if (nresults > 0)
+      return nresults;  /* results are already on the stack */
+    else {
+      lua_pushuserdata(L, NULL);  /* at least one result to signal no errors */
+      return 1;
+    }
+  }
+  else {  /* error */
+    lua_pushnil(L);
+    lua_pushnumber(L, status);  /* error code */
+    return 2;
+  }
 }
 
-void luaB_dostring (lua_State *L) {
+int luaB_dostring (lua_State *L) {
+  int oldtop = lua_gettop(L);
   size_t l;
   const char *s = luaL_check_lstr(L, 1, &l);
   if (*s == ID_CHUNK)
     lua_error(L, "`dostring' cannot run pre-compiled code");
-  if (lua_dobuffer(L, s, l, luaL_opt_string(L, 2, s)) == 0)
-    passresults(L);
-  else
-    lua_pushnil(L);
+  return passresults(L, lua_dobuffer(L, s, l, luaL_opt_string(L, 2, s)), oldtop);
 }
 
 
-void luaB_dofile (lua_State *L) {
+int luaB_dofile (lua_State *L) {
+  int oldtop = lua_gettop(L);
   const char *fname = luaL_opt_string(L, 1, NULL);
-  if (lua_dofile(L, fname) == 0)
-    passresults(L);
-  else
-    lua_pushnil(L);
+  return passresults(L, lua_dofile(L, fname), oldtop);
 }
 
 
-void luaB_call (lua_State *L) {
-  lua_Object f = luaL_nonnullarg(L, 1);
+int luaB_call (lua_State *L) {
+  int oldtop;
   const Hash *arg = gettable(L, 2);
   const char *options = luaL_opt_string(L, 3, "");
-  lua_Object err = lua_getparam(L, 4);
-  int narg = (int)getnarg(L, arg);
+  int err = 0;  /* index of old error method */
+  int n = (int)getnarg(L, arg);
   int i, status;
-  if (err != LUA_NOOBJECT) {  /* set new error method */
-    lua_Object oldem = lua_getglobal(L, LUA_ERRORMESSAGE);
-    lua_pushobject(L, err);
+  if (!lua_isnull(L, 4)) {  /* set new error method */
+    lua_getglobal(L, LUA_ERRORMESSAGE);
+    err = lua_gettop(L);  /* get index */
+    lua_pushobject(L, 4);
     lua_setglobal(L, LUA_ERRORMESSAGE);
-    err = oldem;
   }
+  oldtop = lua_gettop(L);  /* top before function-call preparation */
+  /* push function */
+  lua_pushobject(L, 1);
   /* push arg[1...n] */
-  luaD_checkstack(L, narg);
-  for (i=0; i<narg; i++)
+  luaD_checkstack(L, n);
+  for (i=0; i<n; i++)
     *(L->top++) = *luaH_getnum(arg, i+1);
-  status = lua_callfunction(L, f);
-  if (err != LUA_NOOBJECT) {  /* restore old error method */
+  status = lua_call(L, n, LUA_MULTRET);
+  n = lua_gettop(L) - oldtop;  /* number of results */
+  if (err != 0) {  /* restore old error method */
     lua_pushobject(L, err);
     lua_setglobal(L, LUA_ERRORMESSAGE);
   }
   if (status != 0) {  /* error in call? */
-    if (strchr(options, 'x')) {
-      lua_pushnil(L);
-      return;  /* return nil to signal the error */
-    }
+    if (strchr(options, 'x'))
+      lua_pushnil(L);  /* return nil to signal the error */
     else
       lua_error(L, NULL);  /* propagate error without additional messages */
+    return 1;
   }
   else {  /* no errors */
     if (strchr(options, 'p')) {  /* pack results? */
-      luaV_pack(L, L->Cstack.lua2C, L->Cstack.num, L->top);
+      luaV_pack(L, luaA_index(L, oldtop+1), n, L->top);
       incr_top;
+      return 1;  /* only table is returned */
     }
     else
-      L->Cstack.base = L->Cstack.lua2C;  /* position of first result */
+      return n;  /* results are already on the stack */
   }
 }
 
 
-void luaB_next (lua_State *L) {
+int luaB_next (lua_State *L) {
   const Hash *a = gettable(L, 1);
-  lua_Object k = lua_getparam(L, 2);
   int i;  /* `luaA_next' gets first element after `i' */
-  if (k == LUA_NOOBJECT || ttype(k) == TAG_NIL)
+  if (lua_isnull(L, 2) || lua_isnil(L, 2))  /* no index or nil index? */
     i = 0;  /* get first */
   else {
-    i = luaH_pos(L, a, k)+1;
+    i = luaH_pos(L, a, luaA_index(L, 2))+1;
     luaL_arg_check(L, i != 0, 2, "key not found");
   }
-  if (luaA_next(L, a, i) == 0)
+  if (luaA_next(L, a, i) != 0)
+    return 2;  /* `luaA_next' left them on the stack */
+  else {
     lua_pushnil(L);
+    return 1;
+  }
 }
 
 
-void luaB_tostring (lua_State *L) {
-  lua_Object o = luaL_nonnullarg(L, 1);
+int luaB_tostring (lua_State *L) {
   char buff[64];
+  const TObject *o;
+  luaL_checktype(L, 1, "any");
+  o = luaA_index(L, 1);
   switch (ttype(o)) {
     case TAG_NUMBER:
-      lua_pushstring(L, lua_getstring(L, o));
-      return;
+      lua_pushstring(L, lua_tostring(L, 1));
+      return 1;
     case TAG_STRING:
-      lua_pushobject(L, o);
-      return;
+      lua_pushobject(L, 1);
+      return 1;
     case TAG_TABLE:
       sprintf(buff, "table: %p", hvalue(o));
       break;
@@ -368,11 +399,12 @@ void luaB_tostring (lua_State *L) {
       break;
     case TAG_NIL:
       lua_pushstring(L, "nil");
-      return;
+      return 1;
     default:
       LUA_INTERNALERROR("invalid type");
   }
   lua_pushstring(L, buff);
+  return 1;
 }
 
 /* }====================================================== */
@@ -389,15 +421,17 @@ void luaB_tostring (lua_State *L) {
 ** =======================================================
 */
 
-void luaB_assert (lua_State *L) {
-  lua_Object p = luaL_nonnullarg(L, 1);
-  if (lua_isnil(L, p))
+int luaB_assert (lua_State *L) {
+  luaL_checktype(L, 1, "any");
+  if (lua_isnil(L, 1))
     luaL_verror(L, "assertion failed!  %.90s", luaL_opt_string(L, 2, ""));
+  return 0;
 }
 
 
-void luaB_getn (lua_State *L) {
+int luaB_getn (lua_State *L) {
   lua_pushnumber(L, getnarg(L, gettable(L, 1)));
+  return 1;
 }
 
 
@@ -408,72 +442,72 @@ static void t_move (lua_State *L, Hash *t, int from, int to) {
 }
 
 
-void luaB_tinsert (lua_State *L) {
+int luaB_tinsert (lua_State *L) {
   Hash *a = gettable(L, 1);
-  lua_Object v = lua_getparam(L, 3);
   int n = (int)getnarg(L, a);
+  int v = lua_gettop(L);  /* last argument: to be inserted */
   int pos;
-  if (v != LUA_NOOBJECT)
-    pos = luaL_check_int(L, 2);
-  else {  /* called with only 2 arguments */
-    v = luaL_nonnullarg(L, 2);
+  if (v == 2)  /* called with only 2 arguments */
     pos = n+1;
-  }
+  else
+    pos = luaL_check_int(L, 2);  /* 2nd argument is the position */
   luaH_setstrnum(L, a, luaS_new(L, "n"), n+1);  /* a.n = n+1 */
   for (; n>=pos; n--)
     t_move(L, a, n, n+1);  /* a[n+1] = a[n] */
-  *luaH_setint(L, a, pos) = *v;  /* a[pos] = v */
+  *luaH_setint(L, a, pos) = *luaA_index(L, v);  /* a[pos] = v */
+  return 0;
 }
 
 
-void luaB_tremove (lua_State *L) {
+int luaB_tremove (lua_State *L) {
   Hash *a = gettable(L, 1);
   int n = (int)getnarg(L, a);
   int pos = luaL_opt_int(L, 2, n);
-  if (n <= 0) return;  /* table is "empty" */
+  if (n <= 0) return 0;  /* table is "empty" */
   luaA_pushobject(L, luaH_getnum(a, pos));  /* result = a[pos] */
   for ( ;pos<n; pos++)
     t_move(L, a, pos+1, pos);  /* a[pos] = a[pos+1] */
   luaH_setstrnum(L, a, luaS_new(L, "n"), n-1);  /* a.n = n-1 */
   ttype(luaH_setint(L, a, n)) = TAG_NIL;  /* a[n] = nil */
+  return 1;
 }
 
 
-static void luaB_foreachi (lua_State *L) {
+static int luaB_foreachi (lua_State *L) {
   const Hash *t = gettable(L, 1);
   int n = (int)getnarg(L, t);
   int i;
-  lua_Object f = luaL_functionarg(L, 2);
-  luaD_checkstack(L, 3);  /* for f, key, and val */
+  luaL_checktype(L, 2, "function");
   for (i=1; i<=n; i++) {
-    *(L->top++) = *f;
+    lua_pushobject(L, 2);
     ttype(L->top) = TAG_NUMBER; nvalue(L->top++) = i;
     *(L->top++) = *luaH_getnum(t, i);
     luaD_call(L, L->top-3, 1);
     if (ttype(L->top-1) != TAG_NIL)
-      return;
+      return 1;
     L->top--;  /* remove nil result */
   }
+  return 0;
 }
 
 
-static void luaB_foreach (lua_State *L) {
+static int luaB_foreach (lua_State *L) {
   const Hash *a = gettable(L, 1);
-  lua_Object f = luaL_functionarg(L, 2);
   int i;
-  luaD_checkstack(L, 3);  /* for f, key, and val */
+  luaL_checktype(L, 2, "function");
   for (i=0; i<a->size; i++) {
     const Node *nd = &(a->node[i]);
     if (ttype(val(nd)) != TAG_NIL) {
-      *(L->top++) = *f;
+      lua_pushobject(L, 2);
       *(L->top++) = *key(nd);
       *(L->top++) = *val(nd);
       luaD_call(L, L->top-3, 1);
       if (ttype(L->top-1) != TAG_NIL)
-        return;
+        return 1;
       L->top--;  /* remove result */
     }
   }
+  return 0;
 }
 
 
@@ -492,10 +526,10 @@ static void swap (lua_State *L, Hash *a, int i, int j) {
   *luaH_setint(L, a, j) = temp;
 }
 
-static int sort_comp (lua_State *L, lua_Object f, const TObject *a,
-                                                  const TObject *b) {
+static int sort_comp (lua_State *L, const TObject *f, const TObject *a,
+                                                      const TObject *b) {
   /* WARNING: the caller (auxsort) must ensure stack space */
-  if (f != LUA_NOOBJECT) {
+  if (f != NULL) {
     *(L->top) = *f;
     *(L->top+1) = *a;
     *(L->top+2) = *b;
@@ -508,7 +542,7 @@ static int sort_comp (lua_State *L, lua_Object f, const TObject *a,
     return luaV_lessthan(L, a, b, L->top);
 }
 
-static void auxsort (lua_State *L, Hash *a, int l, int u, lua_Object f) {
+static void auxsort (lua_State *L, Hash *a, int l, int u, const TObject *f) {
   StkId P = L->top++;  /* temporary place for pivot */
   ttype(P) = TAG_NIL;
   while (l < u) {  /* for tail recursion */
@@ -552,14 +586,16 @@ static void auxsort (lua_State *L, Hash *a, int l, int u, lua_Object f) {
   L->top--;  /* remove pivot from stack */
 }
 
-void luaB_sort (lua_State *L) {
+int luaB_sort (lua_State *L) {
   Hash *a = gettable(L, 1);
   int n = (int)getnarg(L, a);
-  lua_Object func = lua_getparam(L, 2);
-  luaL_arg_check(L, func == LUA_NOOBJECT || lua_isfunction(L, func), 2,
-                 "function expected");
-  luaD_checkstack(L, 4);  /* for pivot, f, a, b (sort_comp) */
+  const TObject *func = NULL;
+  if (!lua_isnull(L, 2)) {  /* is there a 2nd argument? */
+    luaL_checktype(L, 2, "function");
+    func = luaA_index(L, 2);
+  }
   auxsort(L, a, 1, n, func);
+  return 0;
 }
 
 /* }====================================================== */
@@ -615,8 +651,9 @@ static void deprecated_funcs (lua_State *L) {
 /*
 ** gives an explicit error in any attempt to call a deprecated function
 */
-static void deprecated_func (lua_State *L) {
+static int deprecated_func (lua_State *L) {
   luaL_verror(L, "function `%.20s' is deprecated", luaL_check_string(L, 1));
+  return 0;  /* to avoid warnings */
 }
 
 
diff --git a/lbuiltin.h b/lbuiltin.h
index 213f3f3d..7d8a2236 100644
--- a/lbuiltin.h
+++ b/lbuiltin.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lbuiltin.h,v 1.8 2000/05/08 19:32:53 roberto Exp roberto $
+** $Id: lbuiltin.h,v 1.9 2000/05/26 19:17:57 roberto Exp roberto $
 ** Built-in functions
 ** See Copyright Notice in lua.h
 */
@@ -9,34 +9,34 @@
 
 #include "lua.h"
 
-void luaB__ALERT (lua_State *L);
-void luaB__ERRORMESSAGE (lua_State *L);
-void luaB_assert (lua_State *L);
-void luaB_call (lua_State *L);
-void luaB_collectgarbage (lua_State *L);
-void luaB_copytagmethods (lua_State *L);
-void luaB_dofile (lua_State *L);
-void luaB_dostring (lua_State *L);
-void luaB_error (lua_State *L);
-void luaB_getglobal (lua_State *L);
-void luaB_getn (lua_State *L);
-void luaB_gettagmethod (lua_State *L);
-void luaB_globals (lua_State *L);
-void luaB_newtag (lua_State *L);
-void luaB_next (lua_State *L);
-void luaB_print (lua_State *L);
-void luaB_rawget (lua_State *L);
-void luaB_rawset (lua_State *L);
-void luaB_setglobal (lua_State *L);
-void luaB_settag (lua_State *L);
-void luaB_settagmethod (lua_State *L);
-void luaB_sort (lua_State *L);
-void luaB_tag (lua_State *L);
-void luaB_tinsert (lua_State *L);
-void luaB_tonumber (lua_State *L);
-void luaB_tostring (lua_State *L);
-void luaB_tremove (lua_State *L);
-void luaB_type (lua_State *L);
+int luaB__ALERT (lua_State *L);
+int luaB__ERRORMESSAGE (lua_State *L);
+int luaB_assert (lua_State *L);
+int luaB_call (lua_State *L);
+int luaB_collectgarbage (lua_State *L);
+int luaB_copytagmethods (lua_State *L);
+int luaB_dofile (lua_State *L);
+int luaB_dostring (lua_State *L);
+int luaB_error (lua_State *L);
+int luaB_getglobal (lua_State *L);
+int luaB_getn (lua_State *L);
+int luaB_gettagmethod (lua_State *L);
+int luaB_globals (lua_State *L);
+int luaB_newtag (lua_State *L);
+int luaB_next (lua_State *L);
+int luaB_print (lua_State *L);
+int luaB_rawget (lua_State *L);
+int luaB_rawset (lua_State *L);
+int luaB_setglobal (lua_State *L);
+int luaB_settag (lua_State *L);
+int luaB_settagmethod (lua_State *L);
+int luaB_sort (lua_State *L);
+int luaB_tag (lua_State *L);
+int luaB_tinsert (lua_State *L);
+int luaB_tonumber (lua_State *L);
+int luaB_tostring (lua_State *L);
+int luaB_tremove (lua_State *L);
+int luaB_type (lua_State *L);
 
 void luaB_predefine (lua_State *L);
 
diff --git a/ldblib.c b/ldblib.c
index 45edc8c2..17edcda5 100644
--- a/ldblib.c
+++ b/ldblib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldblib.c,v 1.17 2000/06/12 13:52:05 roberto Exp roberto $
+** $Id: ldblib.c,v 1.18 2000/08/09 19:16:57 roberto Exp roberto $
 ** Interface from Lua to its debug API
 ** See Copyright Notice in lua.h
 */
@@ -17,102 +17,96 @@
 
 
 
-static void settabss (lua_State *L, lua_Object t, const char *i, const char *v) {
-  lua_pushobject(L, t);
+static void settabss (lua_State *L, const char *i, const char *v) {
+  lua_pushobject(L, -1);
   lua_pushstring(L, i);
   lua_pushstring(L, v);
   lua_settable(L);
 }
 
 
-static void settabsi (lua_State *L, lua_Object t, const char *i, int v) {
-  lua_pushobject(L, t);
+static void settabsi (lua_State *L, const char *i, int v) {
+  lua_pushobject(L, -1);
   lua_pushstring(L, i);
   lua_pushnumber(L, v);
   lua_settable(L);
 }
 
 
-static void settabso (lua_State *L, lua_Object t, const char *i, lua_Object v) {
-  lua_pushobject(L, t);
-  lua_pushstring(L, i);
-  lua_pushobject(L, v);
-  lua_settable(L);
-}
-
-
-static void getinfo (lua_State *L) {
+static int getinfo (lua_State *L) {
   lua_Debug ar;
-  lua_Object res;
-  lua_Object func = lua_getparam(L, 1);
   const char *options = luaL_opt_string(L, 2, "flnSu");
   char buff[20];
-  if (lua_isnumber(L, func)) {
-    if (!lua_getstack(L, (int)lua_getnumber(L, func), &ar)) {
+  if (lua_isnumber(L, 1)) {
+    if (!lua_getstack(L, (int)lua_tonumber(L, 1), &ar)) {
       lua_pushnil(L);  /* level out of range */
-      return;
+      return 1;
     }
   }
-  else if (lua_isfunction(L, func)) {
-    ar.func = func;
+  else if (lua_isfunction(L, 1)) {
+    lua_pushobject(L, 1);
     sprintf(buff, ">%.10s", options);
     options = buff;
   }
   else
     luaL_argerror(L, 1, "function or level expected");
-  res = lua_createtable(L);
   if (!lua_getinfo(L, options, &ar))
     luaL_argerror(L, 2, "invalid option");
+  lua_newtable(L);
   for (; *options; options++) {
     switch (*options) {
       case 'S':
-        settabss(L, res, "source", ar.source);
-        settabsi(L, res, "linedefined", ar.linedefined);
-        settabss(L, res, "what", ar.what);
+        settabss(L, "source", ar.source);
+        settabsi(L, "linedefined", ar.linedefined);
+        settabss(L, "what", ar.what);
         break;
       case 'l':
-        settabsi(L, res, "currentline", ar.currentline);
+        settabsi(L, "currentline", ar.currentline);
         break;
       case 'u':
-        settabsi(L, res, "nups", ar.nups);
+        settabsi(L, "nups", ar.nups);
         break;
       case 'n':
-        settabss(L, res, "name", ar.name);
-        settabss(L, res, "namewhat", ar.namewhat);
+        settabss(L, "name", ar.name);
+        settabss(L, "namewhat", ar.namewhat);
         break;
       case 'f':
-        settabso(L, res, "func", ar.func);
+        lua_pushobject(L, -1);
+        lua_pushstring(L, "func");
+        lua_pushobject(L, -4);
+        lua_settable(L);
         break;
     }
   }
-  lua_pushobject(L, res);
+  return 1;  /* return table */
 }
     
 
-static void getlocal (lua_State *L) {
+static int getlocal (lua_State *L) {
   lua_Debug ar;
-  lua_Localvar lvar;
+  const char *name;
   if (!lua_getstack(L, luaL_check_int(L, 1), &ar))  /* level out of range? */
     luaL_argerror(L, 1, "level out of range");
-  lvar.index = luaL_check_int(L, 2);
-  if (lua_getlocal(L, &ar, &lvar)) {
-    lua_pushstring(L, lvar.name);
-    lua_pushobject(L, lvar.value);
+  name = lua_getlocal(L, &ar, luaL_check_int(L, 2));
+  if (name) {
+    lua_pushstring(L, name);
+    lua_pushobject(L, -2);
+    return 2;
+  }
+  else {
+    lua_pushnil(L);
+    return 1;
   }
-  else lua_pushnil(L);
 }
 
 
-static void setlocal (lua_State *L) {
+static int setlocal (lua_State *L) {
   lua_Debug ar;
-  lua_Localvar lvar;
   if (!lua_getstack(L, luaL_check_int(L, 1), &ar))  /* level out of range? */
     luaL_argerror(L, 1, "level out of range");
-  lvar.index = luaL_check_int(L, 2);
-  lvar.value = luaL_nonnullarg(L, 3);
-  if (lua_setlocal(L, &ar, &lvar))
-    lua_pushstring(L, lvar.name);
-  else lua_pushnil(L);
+  luaL_checktype(L, 3, "any");
+  lua_pushstring(L, lua_setlocal(L, &ar, luaL_check_int(L, 2)));
+  return 1;
 }
 
 
@@ -128,47 +122,47 @@ static int callhook = LUA_NOREF;  /* Lua reference to call hook function */
 
 static void linef (lua_State *L, lua_Debug *ar) {
   if (linehook != LUA_NOREF) {
+    lua_getref(L, linehook);
     lua_pushnumber(L, ar->currentline);
-    lua_callfunction(L, lua_getref(L, linehook));
+    lua_call(L, 1, 0);
   }
 }
 
 
 static void callf (lua_State *L, lua_Debug *ar) {
   if (callhook != LUA_NOREF) {
+    lua_getref(L, callhook);
     lua_pushstring(L, ar->event);
-    lua_callfunction(L, lua_getref(L, callhook));
+    lua_call(L, 1, 0);
   }
 }
 
 
-static void setcallhook (lua_State *L) {
-  lua_Object f = lua_getparam(L, 1);
+static int setcallhook (lua_State *L) {
   lua_unref(L, callhook);
-  if (f == LUA_NOOBJECT) {
+  if (lua_isnull(L, 1)) {
     callhook = LUA_NOREF;
     lua_setcallhook(L, NULL);
   }
   else {
-    lua_pushobject(L, f);
     callhook = lua_ref(L, 1);
     lua_setcallhook(L, callf);
   }
+  return 0;
 }
 
 
-static void setlinehook (lua_State *L) {
-  lua_Object f = lua_getparam(L, 1);
+static int setlinehook (lua_State *L) {
   lua_unref(L, linehook);
-  if (f == LUA_NOOBJECT) {
+  if (lua_isnull(L, 1)) {
     linehook = LUA_NOREF;
     lua_setlinehook(L, NULL);
   }
   else {
-    lua_pushobject(L, f);
     linehook = lua_ref(L, 1);
     lua_setlinehook(L, linef);
   }
+  return 0;
 }
 
 
diff --git a/ldebug.c b/ldebug.c
index 2e851c1b..56bf6ddb 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 1.35 2000/08/14 17:59:20 roberto Exp roberto $
+** $Id: ldebug.c,v 1.36 2000/08/15 18:28:48 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -144,26 +144,28 @@ static Proto *getluaproto (StkId f) {
 }
 
 
-int lua_getlocal (lua_State *L, const lua_Debug *ar, lua_Localvar *v) {
+const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int localnum) {
+  const char *name;
   StkId f = ar->_func;
   Proto *fp = getluaproto(f);
-  if (!fp) return 0;  /* `f' is not a Lua function? */
-  v->name = luaF_getlocalname(fp, v->index, lua_currentpc(f));
-  if (!v->name) return 0;
-  v->value = luaA_putluaObject(L, (f+1)+(v->index-1));
-  return 1;
+  if (!fp) return NULL;  /* `f' is not a Lua function? */
+  name = luaF_getlocalname(fp, localnum, lua_currentpc(f));
+  if (!name) return NULL;
+  luaA_pushobject(L, (f+1)+(localnum-1));  /* push value */
+  return name;
 }
 
 
-int lua_setlocal (lua_State *L, const lua_Debug *ar, lua_Localvar *v) {
+const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int localnum) {
+  const char *name;
   StkId f = ar->_func;
   Proto *fp = getluaproto(f);
   UNUSED(L);
-  if (!fp) return 0;  /* `f' is not a Lua function? */
-  v->name = luaF_getlocalname(fp, v->index, lua_currentpc(f));
-  if (!v->name || v->name[0] == '*') return 0;  /* `*' starts private locals */
-  *((f+1)+(v->index-1)) = *v->value;
-  return 1;
+  if (!fp) return NULL;  /* `f' is not a Lua function? */
+  name = luaF_getlocalname(fp, localnum, lua_currentpc(f));
+  if (!name || name[0] == '*') return NULL;  /* `*' starts private locals */
+  *((f+1)+(localnum-1)) = *(--L->top);
+  return name;
 }
 
 
@@ -236,7 +238,7 @@ int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
     func = ar->_func;
   else {
     what++;  /* skip the '>' */
-    func = ar->func;
+    func = L->top - 1;
   }
   for (; *what; what++) {
     switch (*what) {
@@ -260,13 +262,13 @@ int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
       }
       case 'f': {
         setnormalized(L->top, func);
-        incr_top;
-        ar->func = lua_pop(L);
+        incr_top;  /* push function */
         break;
       }
       default: return 0;  /* invalid option */
     }
   }
+  if (!isactive) L->top--;  /* pop function */
   return 1;
 }
 
@@ -420,7 +422,7 @@ static const char *getfuncname (lua_State *L, StkId f, const char **name) {
 void luaG_typeerror (lua_State *L, StkId o, const char *op) {
   const char *name;
   const char *kind = getobjname(L, o, &name);
-  const char *t = lua_type(L, o);
+  const char *t = luaO_typename(o);
   if (kind)
     luaL_verror(L, "attempt to %.30s %.20s `%.40s' (a %.10s value)",
                 op, kind, name, t);
@@ -437,8 +439,8 @@ void luaG_binerror (lua_State *L, StkId p1, lua_Type t, const char *op) {
 
 
 void luaG_ordererror (lua_State *L, StkId top) {
-  const char *t1 = lua_type(L, top-2);
-  const char *t2 = lua_type(L, top-1);
+  const char *t1 = luaO_typename(top-2);
+  const char *t2 = luaO_typename(top-1);
   if (t1[2] == t2[2])
     luaL_verror(L, "attempt to compare two %.10s values", t1);
   else
diff --git a/ldo.c b/ldo.c
index 06eb0d2d..074638c3 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 1.84 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: ldo.c,v 1.85 2000/08/10 19:50:47 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -41,8 +41,7 @@ void luaD_init (lua_State *L, int stacksize) {
   L->stack = luaM_newvector(L, stacksize+EXTRA_STACK, TObject);
   L->stack_last = L->stack+(stacksize-1);
   L->stacksize = stacksize;
-  L->Cstack.base = L->Cstack.lua2C = L->top = L->stack;
-  L->Cstack.num = 0;
+  L->Cbase = L->top = L->stack;
 }
 
 
@@ -68,8 +67,8 @@ void luaD_checkstack (lua_State *L, int n) {
 
 
 static void restore_stack_limit (lua_State *L) {
-  if (L->top-L->stack < L->stacksize-1)
-    L->stack_last = L->stack+(L->stacksize-1);
+  if (L->top - L->stack < L->stacksize - 1)
+    L->stack_last = L->stack + (L->stacksize-1);
 }
 
 
@@ -103,9 +102,8 @@ void luaD_openstack (lua_State *L, StkId pos) {
 void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook) {
   if (L->allowhooks) {
     lua_Debug ar;
-    struct C_Lua_Stack oldCLS = L->Cstack;
-    StkId old_top = L->Cstack.lua2C = L->Cstack.base = L->top;
-    L->Cstack.num = 0;
+    StkId old_Cbase = L->Cbase;
+    StkId old_top = L->Cbase = L->top;
     ar._func = func;
     ar.event = "line";
     ar.currentline = line;
@@ -113,7 +111,7 @@ void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook) {
     (*linehook)(L, &ar);
     L->allowhooks = 1;
     L->top = old_top;
-    L->Cstack = oldCLS;
+    L->Cbase = old_Cbase;
   }
 }
 
@@ -122,42 +120,36 @@ static void luaD_callHook (lua_State *L, StkId func, lua_Hook callhook,
                     const char *event) {
   if (L->allowhooks) {
     lua_Debug ar;
-    struct C_Lua_Stack oldCLS = L->Cstack;
-    StkId old_top = L->Cstack.lua2C = L->Cstack.base = L->top;
-    L->Cstack.num = 0;
+    StkId old_Cbase = L->Cbase;
+    StkId old_top = L->Cbase = L->top;
     ar._func = func;
     ar.event = event;
     L->allowhooks = 0;  /* cannot call hooks inside a hook */
     callhook(L, &ar);
     L->allowhooks = 1;
     L->top = old_top;
-    L->Cstack = oldCLS;
+    L->Cbase = old_Cbase;
   }
 }
 
 
 static StkId callCclosure (lua_State *L, const struct Closure *cl, StkId base) {
   int nup = cl->nupvalues;  /* number of upvalues */
-  int numarg = L->top-base;
-  struct C_Lua_Stack oldCLS = L->Cstack;
-  StkId firstResult;
+  StkId old_Cbase = L->Cbase;
+  int nres;  /* number of results */
   if (nup > 0) {
-    int n = numarg;
+    int n = L->top - base;  /* number of arguments */
     luaD_checkstack(L, nup);
     /* open space for upvalues as extra arguments */
     while (n--) *(base+nup+n) = *(base+n);
     L->top += nup;
-    numarg += nup;
     /* copy upvalues into stack */
     while (nup--) *(base+nup) = cl->upvalue[nup];
   }
-  L->Cstack.num = numarg;
-  L->Cstack.lua2C = base;
-  L->Cstack.base = L->top;
-  (*cl->f.c)(L);  /* do the actual call */
-  firstResult = L->Cstack.base;
-  L->Cstack = oldCLS;
-  return firstResult;
+  L->Cbase = base;       /* new base for C function */
+  nres = (*cl->f.c)(L);  /* do the actual call */
+  L->Cbase = old_Cbase;  /* restore old C base */
+  return L->top - nres;  /* return index of first result */
 }
 
 
@@ -257,42 +249,36 @@ void lua_error (lua_State *L, const char *s) {
 
 
 static void chain_longjmp (lua_State *L, struct lua_longjmp *lj) {
-  lj->base = L->Cstack.base;
-  lj->numCblocks = L->numCblocks;
+  lj->status = 0;
+  lj->base = L->Cbase;
   lj->previous = L->errorJmp;
   L->errorJmp = lj;
 }
 
 
-static void restore_longjmp (lua_State *L, struct lua_longjmp *lj) {
-  L->Cstack.num = 0;  /* no results */
-  L->top = L->Cstack.base = L->Cstack.lua2C = lj->base;
-  L->numCblocks = lj->numCblocks;
+static int restore_longjmp (lua_State *L, struct lua_longjmp *lj) {
+  L->Cbase = lj->base;
   L->errorJmp = lj->previous;
+  return lj->status;
 }
 
 
 /*
-** Execute a protected call. Assumes that function is at Cstack.base and
-** parameters are on top of it.
+** Execute a protected call.
 */
-int luaD_protectedrun (lua_State *L) {
+int lua_call (lua_State *L, int nargs, int nresults) {
+  StkId func = L->top - (nargs+1);  /* function to be called */
   struct lua_longjmp myErrorJmp;
   chain_longjmp(L, &myErrorJmp);
+  if (nresults == LUA_MULTRET) nresults = MULT_RET;  /* internal code */
   if (setjmp(myErrorJmp.b) == 0) {
-    StkId base = L->Cstack.base;
-    luaD_call(L, base, MULT_RET);
-    L->Cstack.lua2C = base;  /* position of the new results */
-    L->Cstack.num = L->top - base;
-    L->Cstack.base = base + L->Cstack.num;  /* incorporate results on stack */
-    L->errorJmp = myErrorJmp.previous;
-    return 0;
+    luaD_call(L, func, nresults);
   }
-  else {  /* an error occurred: restore the stack */
-    restore_longjmp(L, &myErrorJmp);
+  else {  /* an error occurred: restore the state */
+    L->top = func;  /* remove garbage from the stack */
     restore_stack_limit(L);
-    return myErrorJmp.status;
   }
+  return restore_longjmp(L, &myErrorJmp);
 }
 
 
@@ -302,20 +288,17 @@ int luaD_protectedrun (lua_State *L) {
 static int protectedparser (lua_State *L, ZIO *z, int bin) {
   struct lua_longjmp myErrorJmp;
   chain_longjmp(L, &myErrorJmp);
-  L->top = L->Cstack.base;   /* clear C2Lua */
   if (setjmp(myErrorJmp.b) == 0) {
     Proto *tf = bin ? luaU_undump1(L, z) : luaY_parser(L, z);
-    L->errorJmp = myErrorJmp.previous;
-    if (tf == NULL) return -1;  /* `natural' end */
+    if (tf == NULL)
+      myErrorJmp.status = -1;  /* `natural' end */
     luaV_Lclosure(L, tf, 0);
-    return 0;
   }
-  else {  /* an error occurred */
-    restore_longjmp(L, &myErrorJmp);
+  else {  /* an error occurred: correct error code */
     if (myErrorJmp.status == LUA_ERRRUN)
       myErrorJmp.status = LUA_ERRSYNTAX;
-    return myErrorJmp.status;  /* error code */
   }
+  return restore_longjmp(L, &myErrorJmp);  /* error code */
 }
 
 
@@ -331,7 +314,7 @@ static int do_main (lua_State *L, ZIO *z, int bin) {
     else {
       unsigned long newelems2 = 2*(L->nblocks-old_blocks);
       L->GCthreshold += newelems2;
-      status = luaD_protectedrun(L);
+      status = lua_call(L, 0, LUA_MULTRET);
       L->GCthreshold -= newelems2;
     }
   } while (bin && status == 0);
diff --git a/ldo.h b/ldo.h
index 0e91c7c8..ba168ccb 100644
--- a/ldo.h
+++ b/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 1.21 2000/06/28 20:21:06 roberto Exp roberto $
+** $Id: ldo.h,v 1.22 2000/08/07 18:39:16 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -26,7 +26,6 @@ void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook);
 void luaD_call (lua_State *L, StkId func, int nResults);
 void luaD_callTM (lua_State *L, const TObject *f, int nParams, int nResults);
 void luaD_breakrun (lua_State *L, int errcode);
-int luaD_protectedrun (lua_State *L);
 void luaD_checkstack (lua_State *L, int n);
 
 
diff --git a/lgc.c b/lgc.c
index 1e26ed51..f6768dd2 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 1.62 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: lgc.c,v 1.63 2000/08/22 17:44:17 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -11,7 +11,6 @@
 #include "lgc.h"
 #include "lmem.h"
 #include "lobject.h"
-#include "lref.h"
 #include "lstate.h"
 #include "lstring.h"
 #include "ltable.h"
@@ -145,6 +144,43 @@ static void markall (lua_State *L) {
 }
 
 
+static int hasmark (const TObject *o) {
+  /* valid only for locked objects */
+  switch (o->ttype) {
+    case TAG_STRING: case TAG_USERDATA:
+      return tsvalue(o)->marked;
+    case TAG_TABLE:
+      return ismarked(hvalue(o));
+    case TAG_LCLOSURE:  case TAG_CCLOSURE:
+      return ismarked(clvalue(o)->mark);
+    default:  /* number */
+      return 1;
+  }
+}
+
+
+/* macro for internal debugging; check if a link of free refs is valid */
+#define VALIDLINK(L, st,n)      (NONEXT <= (st) && (st) < (n))
+
+static void invalidaterefs (lua_State *L) {
+  int n = L->refSize;
+  int i;
+  for (i=0; i<n; i++) {
+    struct Ref *r = &L->refArray[i];
+    if (r->st == HOLD && !hasmark(&r->o))
+      r->st = COLLECTED;
+    LUA_ASSERT((r->st == LOCK && hasmark(&r->o)) ||
+               (r->st == HOLD && hasmark(&r->o)) ||
+                r->st == COLLECTED ||
+                r->st == NONEXT ||
+               (r->st < n && VALIDLINK(L, L->refArray[r->st].st, n)),
+               "inconsistent ref table");
+  }
+  LUA_ASSERT(VALIDLINK(L, L->refFree, n), "inconsistent ref table");
+}
+
+
+
 static void collectproto (lua_State *L) {
   Proto **p = &L->rootproto;
   Proto *next;
@@ -300,7 +336,7 @@ void luaC_collect (lua_State *L, int all) {
 long lua_collectgarbage (lua_State *L, long limit) {
   unsigned long recovered = L->nblocks;  /* to subtract `nblocks' after gc */
   markall(L);
-  luaR_invalidaterefs(L);
+  invalidaterefs(L);
   luaC_collect(L, 0);
   recovered = recovered - L->nblocks;
   L->GCthreshold = (limit == 0) ? 2*L->nblocks : L->nblocks+limit;
diff --git a/liolib.c b/liolib.c
index dc432b40..b73bd359 100644
--- a/liolib.c
+++ b/liolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: liolib.c,v 1.70 2000/08/14 19:10:14 roberto Exp roberto $
+** $Id: liolib.c,v 1.71 2000/08/22 17:47:17 roberto Exp roberto $
 ** Standard I/O (and system) library
 ** See Copyright Notice in lua.h
 */
@@ -61,13 +61,16 @@ typedef struct IOCtrl {
 static const char *const filenames[] = {"_INPUT", "_OUTPUT"};
 
 
-static void pushresult (lua_State *L, int i) {
-  if (i)
+static int pushresult (lua_State *L, int i) {
+  if (i) {
     lua_pushuserdata(L, NULL);
+    return 1;
+  }
   else {
     lua_pushnil(L);
     lua_pushstring(L, strerror(errno));
     lua_pushnumber(L, errno);
+    return 3;;
   }
 }
 
@@ -79,8 +82,8 @@ static void pushresult (lua_State *L, int i) {
 */
 
 
-static FILE *gethandle (lua_State *L, IOCtrl *ctrl, lua_Object f) {
-  void *p = lua_getuserdata(L, f);
+static FILE *gethandle (lua_State *L, IOCtrl *ctrl, int f) {
+  void *p = lua_touserdata(L, f);
   if (p != NULL) {  /* is `f' a userdata ? */
     int ftag = lua_tag(L, f);
     if (ftag == ctrl->iotag)  /* does it have the correct tag? */
@@ -94,7 +97,7 @@ static FILE *gethandle (lua_State *L, IOCtrl *ctrl, lua_Object f) {
 
 
 static FILE *getnonullfile (lua_State *L, IOCtrl *ctrl, int arg) {
-  FILE *f = gethandle(L, ctrl, lua_getparam(L, arg));
+  FILE *f = gethandle(L, ctrl, arg);
   luaL_arg_check(L, f, arg, "invalid file handle");
   return f;
 }
@@ -102,9 +105,11 @@ static FILE *getnonullfile (lua_State *L, IOCtrl *ctrl, int arg) {
 
 static FILE *getfilebyref (lua_State *L, IOCtrl *ctrl, int inout) {
   FILE *f;
-  lua_pushglobals(L);
-  lua_pushref(L, ctrl->ref[inout]);
-  f = gethandle(L, ctrl, lua_rawget(L));
+  lua_getglobals(L);
+  lua_getref(L, ctrl->ref[inout]);
+  lua_rawget(L);
+  f = gethandle(L, ctrl, -1);
+  lua_settop(L, -1);  /* remove global */
   if (f == NULL)
     luaL_verror(L, "global variable `%.10s' is not a file handle",
                 filenames[inout]);
@@ -122,12 +127,13 @@ static void setfilebyname (lua_State *L, IOCtrl *ctrl, FILE *f,
 #define setfile(L,ctrl,f,inout)	(setfilebyname(L,ctrl,f,filenames[inout]))
 
 
-static void setreturn (lua_State *L, IOCtrl *ctrl, FILE *f, int inout) {
+static int setreturn (lua_State *L, IOCtrl *ctrl, FILE *f, int inout) {
   if (f == NULL)
-    pushresult(L, 0);
+    return pushresult(L, 0);
   else {
     setfile(L, ctrl, f, inout);
     lua_pushusertag(L, f, ctrl->iotag);
+    return 1;
   }
 }
 
@@ -143,15 +149,15 @@ static int closefile (lua_State *L, IOCtrl *ctrl, FILE *f) {
 }
 
 
-static void io_close (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
-  pushresult(L, closefile(L, ctrl, getnonullfile(L, ctrl, 2)));
+static int io_close (lua_State *L) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
+  return pushresult(L, closefile(L, ctrl, getnonullfile(L, ctrl, 2)));
 }
 
 
-static void file_collect (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
-  if (ctrl == (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 2))) {
+static int file_collect (lua_State *L) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
+  if (ctrl == (IOCtrl *)lua_touserdata(L, 2)) {
     /* collectig `ctrl' itself */
     lua_unref(L, ctrl->ref[INFILE]);
     lua_unref(L, ctrl->ref[OUTFILE]);
@@ -162,50 +168,54 @@ static void file_collect (lua_State *L) {
     if (f != stdin && f != stdout && f != stderr)
       CLOSEFILE(L, f);
   }
+  return 0;
 }
 
 
-static void io_open (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
+static int io_open (lua_State *L) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
   FILE *f = fopen(luaL_check_string(L, 2), luaL_check_string(L, 3));
-  if (f) lua_pushusertag(L, f, ctrl->iotag);
-  else pushresult(L, 0);
+  if (f) {
+    lua_pushusertag(L, f, ctrl->iotag);
+    return 1;
+  }
+  else
+    return pushresult(L, 0);
 }
 
 
 
-static void io_fromto (lua_State *L, int inout, const char *mode) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
-  lua_Object f = lua_getparam(L, 2);
+static int io_fromto (lua_State *L, int inout, const char *mode) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
   FILE *current;
-  if (f == LUA_NOOBJECT) {
+  if (lua_isnull(L, 2)) {
     closefile(L, ctrl, getfilebyref(L, ctrl, inout));
     current = (inout == 0) ? stdin : stdout;    
   }
-  else if (lua_tag(L, f) == ctrl->iotag)  /* deprecated option */
-    current = (FILE *)lua_getuserdata(L, f);
+  else if (lua_tag(L, 2) == ctrl->iotag)  /* deprecated option */
+    current = (FILE *)lua_touserdata(L, 2);
   else {
     const char *s = luaL_check_string(L, 2);
     current = (*s == '|') ? popen(s+1, mode) : fopen(s, mode);
   }
-  setreturn(L, ctrl, current, inout);
+  return setreturn(L, ctrl, current, inout);
 }
 
 
-static void io_readfrom (lua_State *L) {
-  io_fromto(L, INFILE, "r");
+static int io_readfrom (lua_State *L) {
+  return io_fromto(L, INFILE, "r");
 }
 
 
-static void io_writeto (lua_State *L) {
-  io_fromto(L, OUTFILE, "w");
+static int io_writeto (lua_State *L) {
+  return io_fromto(L, OUTFILE, "w");
 }
 
 
-static void io_appendto (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
+static int io_appendto (lua_State *L) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
   FILE *current = fopen(luaL_check_string(L, 2), "a");
-  setreturn(L, ctrl, current, OUTFILE);
+  return setreturn(L, ctrl, current, OUTFILE);
 }
 
 
@@ -342,28 +352,29 @@ static int read_chars (lua_State *L, FILE *f, size_t n) {
 }
 
 
-static void io_read (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
-  int arg = 2;
-  lua_Object op;
-  FILE *f = gethandle(L, ctrl, lua_getparam(L, arg));
-  if (f) arg++;
+static int io_read (lua_State *L) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
+  int lastarg = lua_gettop(L);
+  int firstarg = 2;
+  FILE *f = gethandle(L, ctrl, firstarg);
+  int n = 0;
+  if (f) firstarg++;
   else f = getfilebyref(L, ctrl, INFILE);  /* get _INPUT */
-  op = lua_getparam(L, arg);
   do {  /* repeat for each part */
     size_t l;
     int success;
     luaL_resetbuffer(L);
-    if (lua_isnumber(L, op))
-      success = read_chars(L, f, (size_t)lua_getnumber(L, op));
+    if (lua_isnumber(L, firstarg+n))
+      success = read_chars(L, f, (size_t)lua_tonumber(L, firstarg+n));
     else {
-      const char *p = luaL_opt_string(L, arg, "*l");
+      const char *p = luaL_opt_string(L, firstarg+n, "*l");
       if (p[0] != '*')
         success = read_pattern(L, f, p);  /* deprecated! */
       else {
         switch (p[1]) {
           case 'n':  /* number */
-            if (!read_number(L, f)) return;  /* read fails */
+            if (!read_number(L, f)) return n;  /* read fails */
+            n++;
             continue;  /* number is already pushed; avoid the "pushstring" */
           case 'l':  /* line */
             success = read_line(L, f);
@@ -377,66 +388,69 @@ static void io_read (lua_State *L) {
             success = 0;  /* must read something to succeed */
             break;
           default:
-            luaL_argerror(L, arg, "invalid format");
+            luaL_argerror(L, firstarg+n, "invalid format");
             success = 0;  /* to avoid warnings */
         }
       }
     }
     l = luaL_getsize(L);
-    if (!success && l==0) return;  /* read fails */
+    if (!success && l==0) return n;  /* read fails */
     lua_pushlstring(L, luaL_buffer(L), l);
-  } while ((op = lua_getparam(L, ++arg)) != LUA_NOOBJECT);
+    n++;
+  } while (firstarg+n <= lastarg);
+  return n;
 }
 
 /* }====================================================== */
 
 
-static void io_write (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
+static int io_write (lua_State *L) {
+  int lastarg = lua_gettop(L);
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
   int arg = 2;
   int status = 1;
-  lua_Object o;
-  FILE *f = gethandle(L, ctrl, lua_getparam(L, arg));
+  FILE *f = gethandle(L, ctrl, arg);
   if (f) arg++;
   else f = getfilebyref(L, ctrl, OUTFILE);  /* get _OUTPUT */
-  while ((o = lua_getparam(L, arg)) != LUA_NOOBJECT) {
-    if (lua_type(L, o)[2] == 'm') {  /* nuMber? */  /* LUA_NUMBER */
+  for (; arg <=  lastarg; arg++) {
+    if (lua_type(L, arg)[2] == 'm') {  /* nuMber? */  /* LUA_NUMBER */
       /* optimization: could be done exactly as for strings */
-      status = status && fprintf(f, "%.16g", lua_getnumber(L, o)) > 0;
+      status = status && fprintf(f, "%.16g", lua_tonumber(L, arg)) > 0;
     }
     else {
       size_t l;
       const char *s = luaL_check_lstr(L, arg, &l);
       status = status && (fwrite(s, sizeof(char), l, f) == l);
     }
-    arg++;
   }
   pushresult(L, status);
+  return 1;
 }
 
 
-static void io_seek (lua_State *L) {
+static int io_seek (lua_State *L) {
   static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
   static const char *const modenames[] = {"set", "cur", "end", NULL};
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
   FILE *f = getnonullfile(L, ctrl, 2);
   int op = luaL_findstring(luaL_opt_string(L, 3, "cur"), modenames);
   long offset = luaL_opt_long(L, 4, 0);
   luaL_arg_check(L, op != -1, 3, "invalid mode");
   op = fseek(f, offset, mode[op]);
   if (op)
-    pushresult(L, 0);  /* error */
-  else
+    return pushresult(L, 0);  /* error */
+  else {
     lua_pushnumber(L, ftell(f));
+    return 1;
+  }
 }
 
 
-static void io_flush (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_getuserdata(L, lua_getparam(L, 1));
-  lua_Object of = lua_getparam(L, 2);
-  FILE *f = gethandle(L, ctrl, of);
-  luaL_arg_check(L, f || of == LUA_NOOBJECT, 2, "invalid file handle");
-  pushresult(L, fflush(f) == 0);
+static int io_flush (lua_State *L) {
+  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, 1);
+  FILE *f = gethandle(L, ctrl, 2);
+  luaL_arg_check(L, f || lua_isnull(L, 2), 2, "invalid file handle");
+  return pushresult(L, fflush(f) == 0);
 }
 
 /* }====================================================== */
@@ -448,39 +462,43 @@ static void io_flush (lua_State *L) {
 ** =======================================================
 */
 
-static void io_execute (lua_State *L) {
+static int io_execute (lua_State *L) {
   lua_pushnumber(L, system(luaL_check_string(L, 1)));
+  return 1;
 }
 
 
-static void io_remove (lua_State *L) {
-  pushresult(L, remove(luaL_check_string(L, 1)) == 0);
+static int io_remove (lua_State *L) {
+  return pushresult(L, remove(luaL_check_string(L, 1)) == 0);
 }
 
 
-static void io_rename (lua_State *L) {
-  pushresult(L, rename(luaL_check_string(L, 1),
+static int io_rename (lua_State *L) {
+  return pushresult(L, rename(luaL_check_string(L, 1),
                     luaL_check_string(L, 2)) == 0);
 }
 
 
-static void io_tmpname (lua_State *L) {
+static int io_tmpname (lua_State *L) {
   lua_pushstring(L, tmpnam(NULL));
+  return 1;
 }
 
 
 
-static void io_getenv (lua_State *L) {
+static int io_getenv (lua_State *L) {
   lua_pushstring(L, getenv(luaL_check_string(L, 1)));  /* if NULL push nil */
+  return 1;
 }
 
 
-static void io_clock (lua_State *L) {
+static int io_clock (lua_State *L) {
   lua_pushnumber(L, ((double)clock())/CLOCKS_PER_SEC);
+  return 1;
 }
 
 
-static void io_date (lua_State *L) {
+static int io_date (lua_State *L) {
   char b[256];
   const char *s = luaL_opt_string(L, 1, "%c");
   struct tm *stm;
@@ -490,10 +508,11 @@ static void io_date (lua_State *L) {
     lua_pushstring(L, b);
   else
     lua_error(L, "invalid `date' format");
+  return 1;
 }
 
 
-static void setloc (lua_State *L) {
+static int setloc (lua_State *L) {
   static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY,
                       LC_NUMERIC, LC_TIME};
   static const char *const catnames[] = {"all", "collate", "ctype", "monetary",
@@ -501,25 +520,28 @@ static void setloc (lua_State *L) {
   int op = luaL_findstring(luaL_opt_string(L, 2, "all"), catnames);
   luaL_arg_check(L, op != -1, 2, "invalid option");
   lua_pushstring(L, setlocale(cat[op], luaL_check_string(L, 1)));
+  return 1;
 }
 
 
-static void io_exit (lua_State *L) {
+static int io_exit (lua_State *L) {
   exit(luaL_opt_int(L, 1, EXIT_SUCCESS));
+  return 0;  /* to avoid warnings */
 }
 
 /* }====================================================== */
 
 
 
-static void io_debug (lua_State *L) {
+static int io_debug (lua_State *L) {
   for (;;) {
     char buffer[250];
     fprintf(stderr, "lua_debug> ");
     if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
         strcmp(buffer, "cont\n") == 0)
-      return;
+      return 0;
     lua_dostring(L, buffer);
+    lua_settop(L, 0);  /* remove eventual returns */
   }
 }
 
@@ -529,12 +551,11 @@ static void io_debug (lua_State *L) {
 #define MAXMESSAGE (MESSAGESIZE*10)
 
 
-static void errorfb (lua_State *L) {
+static int errorfb (lua_State *L) {
   char buff[MAXMESSAGE];
   int level = 1;  /* skip level 0 (it's this function) */
   lua_Debug ar;
-  lua_Object alertfunc;
-  sprintf(buff, "error: %.200s\n", lua_getstring(L, lua_getparam(L, 1)));
+  sprintf(buff, "error: %.200s\n", lua_tostring(L, 1));
   while (lua_getstack(L, level++, &ar)) {
     char buffchunk[60];
     lua_getinfo(L, "Snl", &ar);
@@ -572,13 +593,14 @@ static void errorfb (lua_State *L) {
       sprintf(buff+strlen(buff), " [%.70s]", buffchunk);
     strcat(buff, "\n");
   }
-  lua_pushglobals(L);
+  lua_getglobals(L);
   lua_pushstring(L, LUA_ALERT);
-  alertfunc = lua_rawget(L);
-  if (lua_isfunction(L, alertfunc)) {  /* avoid loop if _ALERT is not defined */
+  lua_rawget(L);
+  if (lua_isfunction(L, -1)) {  /* avoid loop if _ALERT is not defined */
     lua_pushstring(L, buff);
-    lua_callfunction(L, alertfunc);
+    lua_call(L, 1, 0);
   }
+  return 0;
 }
 
 
diff --git a/llimits.h b/llimits.h
index f7412acf..c716b0dd 100644
--- a/llimits.h
+++ b/llimits.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llimits.h,v 1.11 2000/06/28 17:03:32 roberto Exp roberto $
+** $Id: llimits.h,v 1.12 2000/08/15 18:28:48 roberto Exp roberto $
 ** Limits, basic types, and some other "installation-dependent" definitions
 ** See Copyright Notice in lua.h
 */
@@ -197,12 +197,6 @@ typedef unsigned long Instruction;
 #define RFIELDS_PER_FLUSH	(LFIELDS_PER_FLUSH/2)
 
 
-/* maximum number of values printed in one call to `print' */
-#ifndef MAXPRINT
-#define MAXPRINT        40	/* arbitrary limit */
-#endif
-
-
 /* maximum lookback to find a real constant (for code generation) */
 #ifndef LOOKBACKNUMS
 #define LOOKBACKNUMS    20      /* arbitrary constant */
diff --git a/lmathlib.c b/lmathlib.c
index 86850cc9..d6957e76 100644
--- a/lmathlib.c
+++ b/lmathlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmathlib.c,v 1.25 2000/06/12 13:52:05 roberto Exp roberto $
+** $Id: lmathlib.c,v 1.26 2000/08/09 19:16:57 roberto Exp roberto $
 ** Standard mathematical library
 ** See Copyright Notice in lua.h
 */
@@ -33,138 +33,169 @@
 #endif
 
 
-static void math_abs (lua_State *L) {
+static int math_abs (lua_State *L) {
   lua_pushnumber(L, fabs(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_sin (lua_State *L) {
+static int math_sin (lua_State *L) {
   lua_pushnumber(L, sin(TORAD(luaL_check_number(L, 1))));
+  return 1;
 }
 
-static void math_cos (lua_State *L) {
+static int math_cos (lua_State *L) {
   lua_pushnumber(L, cos(TORAD(luaL_check_number(L, 1))));
+  return 1;
 }
 
-static void math_tan (lua_State *L) {
+static int math_tan (lua_State *L) {
   lua_pushnumber(L, tan(TORAD(luaL_check_number(L, 1))));
+  return 1;
 }
 
-static void math_asin (lua_State *L) {
+static int math_asin (lua_State *L) {
   lua_pushnumber(L, FROMRAD(asin(luaL_check_number(L, 1))));
+  return 1;
 }
 
-static void math_acos (lua_State *L) {
+static int math_acos (lua_State *L) {
   lua_pushnumber(L, FROMRAD(acos(luaL_check_number(L, 1))));
+  return 1;
 }
 
-static void math_atan (lua_State *L) {
+static int math_atan (lua_State *L) {
   lua_pushnumber(L, FROMRAD(atan(luaL_check_number(L, 1))));
+  return 1;
 }
 
-static void math_atan2 (lua_State *L) {
+static int math_atan2 (lua_State *L) {
   lua_pushnumber(L, FROMRAD(atan2(luaL_check_number(L, 1), luaL_check_number(L, 2))));
+  return 1;
 }
 
-static void math_ceil (lua_State *L) {
+static int math_ceil (lua_State *L) {
   lua_pushnumber(L, ceil(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_floor (lua_State *L) {
+static int math_floor (lua_State *L) {
   lua_pushnumber(L, floor(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_mod (lua_State *L) {
+static int math_mod (lua_State *L) {
   lua_pushnumber(L, fmod(luaL_check_number(L, 1), luaL_check_number(L, 2)));
+  return 1;
 }
 
-static void math_sqrt (lua_State *L) {
+static int math_sqrt (lua_State *L) {
   lua_pushnumber(L, sqrt(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_pow (lua_State *L) {
+static int math_pow (lua_State *L) {
   lua_pushnumber(L, pow(luaL_check_number(L, 1), luaL_check_number(L, 2)));
+  return 1;
 }
 
-static void math_log (lua_State *L) {
+static int math_log (lua_State *L) {
   lua_pushnumber(L, log(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_log10 (lua_State *L) {
+static int math_log10 (lua_State *L) {
   lua_pushnumber(L, log10(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_exp (lua_State *L) {
+static int math_exp (lua_State *L) {
   lua_pushnumber(L, exp(luaL_check_number(L, 1)));
+  return 1;
 }
 
-static void math_deg (lua_State *L) {
+static int math_deg (lua_State *L) {
   lua_pushnumber(L, luaL_check_number(L, 1)/RADIANS_PER_DEGREE);
+  return 1;
 }
 
-static void math_rad (lua_State *L) {
+static int math_rad (lua_State *L) {
   lua_pushnumber(L, luaL_check_number(L, 1)*RADIANS_PER_DEGREE);
+  return 1;
 }
 
-static void math_frexp (lua_State *L) {
+static int math_frexp (lua_State *L) {
   int e;
   lua_pushnumber(L, frexp(luaL_check_number(L, 1), &e));
   lua_pushnumber(L, e);
+  return 2;
 }
 
-static void math_ldexp (lua_State *L) {
+static int math_ldexp (lua_State *L) {
   lua_pushnumber(L, ldexp(luaL_check_number(L, 1), luaL_check_int(L, 2)));
+  return 1;
 }
 
 
 
-static void math_min (lua_State *L) {
-  int i = 1;
-  double dmin = luaL_check_number(L, i);
-  while (lua_getparam(L, ++i) != LUA_NOOBJECT) {
+static int math_min (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  double dmin = luaL_check_number(L, 1);
+  int i;
+  for (i=2; i<=n; i++) {
     double d = luaL_check_number(L, i);
     if (d < dmin)
       dmin = d;
   }
   lua_pushnumber(L, dmin);
+  return 1;
 }
 
 
-static void math_max (lua_State *L) {
-  int i = 1;
-  double dmax = luaL_check_number(L, i);
-  while (lua_getparam(L, ++i) != LUA_NOOBJECT) {
+static int math_max (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  double dmax = luaL_check_number(L, 1);
+  int i;
+  for (i=2; i<=n; i++) {
     double d = luaL_check_number(L, i);
     if (d > dmax)
       dmax = d;
   }
   lua_pushnumber(L, dmax);
+  return 1;
 }
 
 
-static void math_random (lua_State *L) {
+static int math_random (lua_State *L) {
   /* the '%' avoids the (rare) case of r==1, and is needed also because on
      some systems (SunOS!) "rand()" may return a value larger than RAND_MAX */
   double r = (double)(rand()%RAND_MAX) / (double)RAND_MAX;
-  if (lua_getparam(L, 1) == LUA_NOOBJECT)  /* no arguments? */
-    lua_pushnumber(L, r);  /* Number between 0 and 1 */
-  else {
-    int l, u;  /* lower & upper limits */
-    if (lua_getparam(L, 2) == LUA_NOOBJECT) {  /* only one argument? */
-      l = 1;
-      u = luaL_check_int(L, 1);
+  switch (lua_gettop(L)) {  /* check number of arguments */
+    case 0: {  /* no arguments */
+      lua_pushnumber(L, r);  /* Number between 0 and 1 */
+      break;
     }
-    else {  /* two arguments */
-      l = luaL_check_int(L, 1);
-      u = luaL_check_int(L, 2);
+    case 1: {  /* only upper limit */
+      int u = luaL_check_int(L, 1);
+      luaL_arg_check(L, 1<=u, 1, "interval is empty");
+      lua_pushnumber(L, (int)(r*u)+1);  /* integer between 1 and `u' */
+      break;
     }
-    luaL_arg_check(L, l<=u, 1, "interval is empty");
-    lua_pushnumber(L, (int)(r*(u-l+1))+l);  /* integer between `l' and `u' */
+    case 2: {  /* lower and upper limits */
+      int l = luaL_check_int(L, 1);
+      int u = luaL_check_int(L, 2);
+      luaL_arg_check(L, l<=u, 2, "interval is empty");
+      lua_pushnumber(L, (int)(r*(u-l+1))+l);  /* integer between `l' and `u' */
+      break;
+    }
+    default: lua_error(L, "wrong number of arguments");
   }
+  return 1;
 }
 
 
-static void math_randomseed (lua_State *L) {
+static int math_randomseed (lua_State *L) {
   srand(luaL_check_int(L, 1));
+  return 0;
 }
 
 
@@ -199,9 +230,10 @@ static const struct luaL_reg mathlib[] = {
 */
 void lua_mathlibopen (lua_State *L) {
   luaL_openl(L, mathlib);
-  lua_pushcfunction(L, math_pow);
   lua_pushnumber(L, 0);  /* to get its tag */
-  lua_settagmethod(L, lua_tag(L, lua_pop(L)), "pow");
+  lua_pushcfunction(L, math_pow);
+  lua_settagmethod(L, lua_tag(L, -2), "pow");
+  lua_settop(L, -1);  /* remove number */
   lua_pushnumber(L, PI); lua_setglobal(L, "PI");
 }
 
diff --git a/lref.c b/lref.c
deleted file mode 100644
index c3fc57af..00000000
--- a/lref.c
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
-** $Id: lref.c,v 1.17 2000/08/09 19:16:57 roberto Exp roberto $
-** reference mechanism
-** See Copyright Notice in lua.h
-*/
-
-
-#include "lua.h"
-
-#include "lapi.h"
-#include "ldo.h"
-#include "lmem.h"
-#include "lref.h"
-#include "lstate.h"
-
-
-int lua_ref (lua_State *L,  int lock) {
-  int ref;
-  luaA_checkCargs(L, 1);
-  if (ttype(L->top-1) == TAG_NIL)
-    ref = LUA_REFNIL;
-  else {
-    if (L->refFree != NONEXT) {  /* is there a free place? */
-      ref = L->refFree;
-      L->refFree = L->refArray[ref].st;
-    }
-    else {  /* no more free places */
-      luaM_growvector(L, L->refArray, L->refSize, 1, struct Ref,
-                      "reference table overflow", MAX_INT);
-      ref = L->refSize++;
-    }
-    L->refArray[ref].o = *(L->top-1);
-    L->refArray[ref].st = lock ? LOCK : HOLD;
-  }
-  L->top--;
-  return ref;
-}
-
-
-void lua_unref (lua_State *L, int ref) {
-  if (ref >= 0) {
-    if (ref >= L->refSize || L->refArray[ref].st >= 0)
-      lua_error(L, "Lua API error - "
-                   "invalid argument for function `lua_unref'");
-    L->refArray[ref].st = L->refFree;
-    L->refFree = ref;
-  }
-}
-
-
-int lua_pushref (lua_State *L, int ref) {
-  if (ref == LUA_REFNIL)
-    ttype(L->top) = TAG_NIL;
-  else if (0 <= ref && ref < L->refSize &&
-          (L->refArray[ref].st == LOCK || L->refArray[ref].st == HOLD))
-    *L->top = L->refArray[ref].o;
-  else
-    return 0;
-  incr_top;
-  return 1;
-}
-
-
-void lua_beginblock (lua_State *L) {
-  luaM_growvector(L, L->Cblocks, L->numCblocks, 1, struct C_Lua_Stack,
-                  "too many nested blocks", L->stacksize);
-  L->Cblocks[L->numCblocks] = L->Cstack;
-  L->numCblocks++;
-}
-
-
-void lua_endblock (lua_State *L) {
-  if (L->numCblocks <= 0)
-    lua_error(L, "Lua API error - no block to end");
-  --L->numCblocks;
-  L->Cstack = L->Cblocks[L->numCblocks];
-  L->top = L->Cstack.base;
-}
-
-
-
-
-
-
-static int hasmark (const TObject *o) {
-  /* valid only for locked objects */
-  switch (o->ttype) {
-    case TAG_STRING: case TAG_USERDATA:
-      return tsvalue(o)->marked;
-    case TAG_TABLE:
-      return ismarked(hvalue(o));
-    case TAG_LCLOSURE:  case TAG_CCLOSURE:
-      return ismarked(clvalue(o)->mark);
-    default:  /* number */
-      return 1;
-  }
-}
-
-
-/* for internal debugging only; check if a link of free refs is valid */
-#define VALIDLINK(L, st,n)	(NONEXT <= (st) && (st) < (n))
-
-void luaR_invalidaterefs (lua_State *L) {
-  int n = L->refSize;
-  int i;
-  for (i=0; i<n; i++) {
-    struct Ref *r = &L->refArray[i];
-    if (r->st == HOLD && !hasmark(&r->o))
-      r->st = COLLECTED;
-    LUA_ASSERT((r->st == LOCK && hasmark(&r->o)) ||
-                r->st == COLLECTED ||
-                r->st == NONEXT ||
-               (r->st < n && VALIDLINK(L, L->refArray[r->st].st, n)),
-               "inconsistent ref table");
-  }
-  LUA_ASSERT(VALIDLINK(L, L->refFree, n), "inconsistent ref table");
-}
-
diff --git a/lref.h b/lref.h
deleted file mode 100644
index 4aec948d..00000000
--- a/lref.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
-** $Id: lref.h,v 1.5 1999/12/27 17:33:22 roberto Exp roberto $
-** reference mechanism
-** See Copyright Notice in lua.h
-*/
-
-#ifndef lref_h
-#define lref_h
-
-#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) */
-};
-
-
-void luaR_invalidaterefs (lua_State *L);
-
-#endif
diff --git a/lstate.c b/lstate.c
index a50252bc..d3d045f0 100644
--- a/lstate.c
+++ b/lstate.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.c,v 1.32 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: lstate.c,v 1.33 2000/08/14 17:46:07 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -9,13 +9,11 @@
 
 #include "lua.h"
 
-#include "lauxlib.h"
 #include "lbuiltin.h"
 #include "ldo.h"
 #include "lgc.h"
 #include "llex.h"
 #include "lmem.h"
-#include "lref.h"
 #include "lstate.h"
 #include "lstring.h"
 #include "ltable.h"
@@ -35,8 +33,6 @@ lua_State *lua_newstate (int stacksize, int put_builtin) {
   L->Mbuffbase = 0;
   L->Mbuffsize = 0;
   L->Mbuffnext = 0;
-  L->Cblocks = NULL;
-  L->numCblocks = 0;
   L->rootproto = NULL;
   L->rootcl = NULL;
   L->roottable = NULL;
@@ -84,8 +80,6 @@ void lua_close (lua_State *L) {
   luaM_free(L, L->IMtable);
   luaM_free(L, L->refArray);
   luaM_free(L, L->Mbuffer);
-  luaM_free(L, L->Cblocks);
-  LUA_ASSERT(L->numCblocks == 0, "Cblocks still open");
   LUA_ASSERT(L->nblocks == 0, "wrong count for nblocks");
   luaM_free(L, L);
   LUA_ASSERT(L != lua_state || memdebug_numblocks == 0, "memory leak!");
diff --git a/lstate.h b/lstate.h
index d177c3a6..65e4c6ef 100644
--- a/lstate.h
+++ b/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 1.35 2000/08/07 18:39:16 roberto Exp roberto $
+** $Id: lstate.h,v 1.36 2000/08/08 20:42:07 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -18,6 +18,21 @@
 typedef TObject *StkId;  /* index to stack elements */
 
 
+/*
+** marks for Reference array
+*/
+#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) */
+};
+
+
 /*
 ** chain list of long jumps
 */
@@ -26,20 +41,6 @@ struct lua_longjmp {
   struct lua_longjmp *previous;
   volatile int status;  /* error code */
   StkId base;
-  int numCblocks;
-};
-
-
-/*
-** stack layout for C point of view:
-** [lua2C, lua2C+num) - `array' lua2C
-** [lua2C+num, base)  - space for extra lua_Objects (limbo)
-** [base, L->top)     - `stack' C2Lua
-*/
-struct C_Lua_Stack {
-  StkId base;
-  StkId lua2C;
-  int num;
 };
 
 
@@ -57,14 +58,12 @@ struct lua_State {
   StkId stack;  /* stack base */
   StkId stack_last;  /* last free slot in the stack */
   int stacksize;
-  struct C_Lua_Stack Cstack;  /* C2lua struct */
+  StkId Cbase;  /* base for current C function */
   struct lua_longjmp *errorJmp;  /* current error recover point */
   char *Mbuffer;  /* global buffer */
   size_t Mbuffbase;  /* current first position of Mbuffer */
   size_t Mbuffsize;  /* size of Mbuffer */
   size_t Mbuffnext;  /* next position to fill in Mbuffer */
-  struct C_Lua_Stack *Cblocks;
-  int numCblocks;  /* number of nested Cblocks */
   /* global state */
   Proto *rootproto;  /* list of all prototypes */
   Closure *rootcl;  /* list of all closures */
diff --git a/lstrlib.c b/lstrlib.c
index 16066499..c380359b 100644
--- a/lstrlib.c
+++ b/lstrlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstrlib.c,v 1.45 2000/06/12 14:37:18 roberto Exp roberto $
+** $Id: lstrlib.c,v 1.46 2000/08/09 19:16:57 roberto Exp roberto $
 ** Standard library for string operations and pattern-matching
 ** See Copyright Notice in lua.h
 */
@@ -25,10 +25,11 @@ static void addnchar (lua_State *L, const char *s, size_t n) {
 }
 
 
-static void str_len (lua_State *L) {
+static int str_len (lua_State *L) {
   size_t l;
   luaL_check_lstr(L, 1, &l);
   lua_pushnumber(L, l);
+  return 1;
 }
 
 
@@ -43,7 +44,7 @@ static long posrelat (long pos, size_t len) {
 }
 
 
-static void str_sub (lua_State *L) {
+static int str_sub (lua_State *L) {
   size_t l;
   const char *s = luaL_check_lstr(L, 1, &l);
   long start = posrelat(luaL_check_long(L, 2), l);
@@ -53,10 +54,11 @@ static void str_sub (lua_State *L) {
   if (start <= end)
     lua_pushlstring(L, s+start-1, end-start+1);
   else lua_pushstring(L, "");
+  return 1;
 }
 
 
-static void str_lower (lua_State *L) {
+static int str_lower (lua_State *L) {
   size_t l;
   size_t i;
   const char *s = luaL_check_lstr(L, 1, &l);
@@ -64,10 +66,11 @@ static void str_lower (lua_State *L) {
   for (i=0; i<l; i++)
     luaL_addchar(L, tolower((unsigned char)(s[i])));
   closeandpush(L);
+  return 1;
 }
 
 
-static void str_upper (lua_State *L) {
+static int str_upper (lua_State *L) {
   size_t l;
   size_t i;
   const char *s = luaL_check_lstr(L, 1, &l);
@@ -75,9 +78,10 @@ static void str_upper (lua_State *L) {
   for (i=0; i<l; i++)
     luaL_addchar(L, toupper((unsigned char)(s[i])));
   closeandpush(L);
+  return 1;
 }
 
-static void str_rep (lua_State *L) {
+static int str_rep (lua_State *L) {
   size_t l;
   const char *s = luaL_check_lstr(L, 1, &l);
   int n = luaL_check_int(L, 2);
@@ -85,27 +89,31 @@ static void str_rep (lua_State *L) {
   while (n-- > 0)
     addnchar(L, s, l);
   closeandpush(L);
+  return 1;
 }
 
 
-static void str_byte (lua_State *L) {
+static int str_byte (lua_State *L) {
   size_t l;
   const char *s = luaL_check_lstr(L, 1, &l);
   long pos = posrelat(luaL_opt_long(L, 2, 1), l);
   luaL_arg_check(L, 0<pos && (size_t)pos<=l, 2,  "out of range");
   lua_pushnumber(L, (unsigned char)s[pos-1]);
+  return 1;
 }
 
 
-static void str_char (lua_State *L) {
-  int i = 0;
+static int str_char (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  int i;
   luaL_resetbuffer(L);
-  while (lua_getparam(L, ++i) != LUA_NOOBJECT) {
+  for (i=1; i<=n; i++) {
     int c = luaL_check_int(L, i);
     luaL_arg_check(L, (unsigned char)c == c, i, "invalid value");
     luaL_addchar(L, (unsigned char)c);
   }
   closeandpush(L);
+  return 1;
 }
 
 
@@ -135,16 +143,6 @@ struct Capture {
 #define SPECIALS	"^$*+?.([%-"
 
 
-static void push_captures (lua_State *L, struct Capture *cap) {
-  int i;
-  for (i=0; i<cap->level; i++) {
-    int l = cap->capture[i].len;
-    if (l == -1) lua_error(L, "unfinished capture");
-    lua_pushlstring(L, cap->capture[i].init, l);
-  }
-}
-
-
 static int check_capture (lua_State *L, int l, struct Capture *cap) {
   l -= '1';
   if (!(0 <= l && l < cap->level && cap->capture[l].len != -1))
@@ -400,20 +398,31 @@ static const char *lmemfind (const char *s1, size_t l1,
 }
 
 
-static void str_find (lua_State *L) {
+static int push_captures (lua_State *L, struct Capture *cap) {
+  int i;
+  for (i=0; i<cap->level; i++) {
+    int l = cap->capture[i].len;
+    if (l == -1) lua_error(L, "unfinished capture");
+    lua_pushlstring(L, cap->capture[i].init, l);
+  }
+  return cap->level;  /* number of strings pushed */
+}
+
+
+static int str_find (lua_State *L) {
   size_t l1, l2;
   const char *s = luaL_check_lstr(L, 1, &l1);
   const char *p = luaL_check_lstr(L, 2, &l2);
   long init = posrelat(luaL_opt_long(L, 3, 1), l1) - 1;
   struct Capture cap;
   luaL_arg_check(L, 0 <= init && (size_t)init <= l1, 3, "out of range");
-  if (lua_getparam(L, 4) != LUA_NOOBJECT ||
-      strpbrk(p, SPECIALS) == NULL) {  /* no special characters? */
+  if (lua_gettop(L) > 3 ||  /* extra argument? */
+      strpbrk(p, SPECIALS) == NULL) {  /* or no special characters? */
     const char *s2 = lmemfind(s+init, l1-init, p, l2);
     if (s2) {
       lua_pushnumber(L, s2-s+1);
       lua_pushnumber(L, s2-s+l2);
-      return;
+      return 2;
     }
   }
   else {
@@ -426,19 +435,19 @@ static void str_find (lua_State *L) {
       if ((res=match(L, s1, p, &cap)) != NULL) {
         lua_pushnumber(L, s1-s+1);  /* start */
         lua_pushnumber(L, res-s);   /* end */
-        push_captures(L, &cap);
-        return;
+        return push_captures(L, &cap) + 2;
       }
     } while (s1++<cap.src_end && !anchor);
   }
   lua_pushnil(L);  /* not found */
+  return 1;
 }
 
 
-static void add_s (lua_State *L, lua_Object newp, struct Capture *cap) {
-  if (lua_isstring(L, newp)) {
-    const char *news = lua_getstring(L, newp);
-    size_t l = lua_strlen(L, newp);
+static void add_s (lua_State *L, struct Capture *cap) {
+  if (lua_isstring(L, 3)) {
+    const char *news = lua_tostring(L, 3);
+    size_t l = lua_strlen(L, 3);
     size_t i;
     for (i=0; i<l; i++) {
       if (news[i] != ESC)
@@ -455,39 +464,38 @@ static void add_s (lua_State *L, lua_Object newp, struct Capture *cap) {
     }
   }
   else {  /* is a function */
-    lua_Object res;
     int status;
     size_t oldbuff;
-    lua_beginblock(L);
-    push_captures(L, cap);
+    int n;
+    const char *s;
+    lua_pushobject(L, 3);
+    n = push_captures(L, cap);
     /* function may use buffer, so save it and create a new one */
     oldbuff = luaL_newbuffer(L, 0);
-    status = lua_callfunction(L, newp);
+    status = lua_call(L, n, 1);
     /* restore old buffer */
     luaL_oldbuffer(L, oldbuff);
-    if (status != 0) {
-      lua_endblock(L);
+    if (status != 0)
       lua_error(L, NULL);
-    }
-    res = lua_getresult(L, 1);
-    if (lua_isstring(L, res))
-      addnchar(L, lua_getstring(L, res), lua_strlen(L, res));
-    lua_endblock(L);
+    s = lua_tostring(L, -1);
+    if (s)
+      addnchar(L, lua_tostring(L, -1), lua_strlen(L, -1));
+    lua_settop(L, -1);  /* pop function result */
   }
 }
 
 
-static void str_gsub (lua_State *L) {
+static int str_gsub (lua_State *L) {
   size_t srcl;
   const char *src = luaL_check_lstr(L, 1, &srcl);
   const char *p = luaL_check_string(L, 2);
-  lua_Object newp = lua_getparam(L, 3);
   int max_s = luaL_opt_int(L, 4, srcl+1);
   int anchor = (*p == '^') ? (p++, 1) : 0;
   int n = 0;
   struct Capture cap;
-  luaL_arg_check(L, lua_isstring(L, newp) || lua_isfunction(L, newp), 3,
-                 "string or function expected");
+  luaL_arg_check(L,
+    lua_gettop(L) >= 3 && (lua_isstring(L, 3) || lua_isfunction(L, 3)),
+    3, "string or function expected");
   luaL_resetbuffer(L);
   cap.src_end = src+srcl;
   while (n < max_s) {
@@ -496,7 +504,7 @@ static void str_gsub (lua_State *L) {
     e = match(L, src, p, &cap);
     if (e) {
       n++;
-      add_s(L, newp, &cap);
+      add_s(L, &cap);
     }
     if (e && e>src) /* non empty match? */
       src = e;  /* skip it */
@@ -508,6 +516,7 @@ static void str_gsub (lua_State *L) {
   addnchar(L, src, cap.src_end-src);
   closeandpush(L);
   lua_pushnumber(L, n);  /* number of substitutions */
+  return 2;
 }
 
 /* }====================================================== */
@@ -534,7 +543,7 @@ static void luaI_addquoted (lua_State *L, int arg) {
 /* maximum size of each format specification (such as '%-099.99d') */
 #define MAX_FORMAT 20  /* arbitrary limit */
 
-static void str_format (lua_State *L) {
+static int str_format (lua_State *L) {
   int arg = 1;
   const char *strfrmt = luaL_check_string(L, arg);
   luaL_resetbuffer(L);
@@ -597,6 +606,7 @@ static void str_format (lua_State *L) {
     }
   }
   closeandpush(L);  /* push the result */
+  return 1;
 }
 
 
diff --git a/ltests.c b/ltests.c
index b0f38e7c..0d83f011 100644
--- a/ltests.c
+++ b/ltests.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltests.c,v 1.33 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: ltests.c,v 1.34 2000/08/15 20:14:27 roberto Exp roberto $
 ** Internal Module for Debugging of the Lua Implementation
 ** See Copyright Notice in lua.h
 */
@@ -10,7 +10,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#define LUA_SINGLESTATE
 
 #include "lua.h"
 
@@ -38,11 +37,11 @@ void luaB_opentests (lua_State *L);
 
 
 
-static void setnameval (lua_Object t, const char *name, int val) {
-  lua_pushobject(t);
-  lua_pushstring(name);
-  lua_pushnumber(val);
-  lua_settable();
+static void setnameval (lua_State *L, const char *name, int val) {
+  lua_pushobject(L, -1);
+  lua_pushstring(L, name);
+  lua_pushnumber(L, val);
+  lua_settable(L);
 }
 
 
@@ -65,7 +64,7 @@ static const char *const instrname[NUM_OPCODES] = {
 };
 
 
-static int pushop (Proto *p, int pc) {
+static int pushop (lua_State *L, Proto *p, int pc) {
   char buff[100];
   Instruction i = p->code[pc];
   OpCode o = GET_OPCODE(i);
@@ -85,146 +84,161 @@ static int pushop (Proto *p, int pc) {
       sprintf(buff+8, "%-12s%4d %4d", name, GETARG_A(i), GETARG_B(i));
       break;
   }
-  lua_pushstring(buff);
+  lua_pushstring(L, buff);
   return (o != OP_END);
 }
 
 
-static void listcode (void) {
-  lua_Object o = luaL_nonnullarg(1);
-  lua_Object t = lua_createtable();
+static int listcode (lua_State *L) {
   int pc;
   Proto *p;
   int res;
-  luaL_arg_check(ttype(o) == TAG_LCLOSURE, 1, "Lua function expected");
-  p = clvalue(o)->f.l;
-  setnameval(t, "maxstack", p->maxstacksize);
-  setnameval(t, "numparams", p->numparams);
+  luaL_arg_check(L, lua_tag(L, 1) == TAG_LCLOSURE, 1, "Lua function expected");
+  p = clvalue(luaA_index(L, 1))->f.l;
+  lua_newtable(L);
+  setnameval(L, "maxstack", p->maxstacksize);
+  setnameval(L, "numparams", p->numparams);
   pc = 0;
   do {
-    lua_pushobject(t);
-    lua_pushnumber(pc+1);
-    res = pushop(p, pc++);
-    lua_settable();
+    lua_pushobject(L, -1);
+    lua_pushnumber(L, pc+1);
+    res = pushop(L, p, pc++);
+    lua_settable(L);
   } while (res);
-  lua_pushobject(t);
+  return 1;
 }
 
 
-static void liststrings (void) {
-  lua_Object o = luaL_nonnullarg(1);
-  lua_Object t = lua_createtable();
+static int liststrings (lua_State *L) {
   Proto *p;
   int i;
-  luaL_arg_check(ttype(o) == TAG_LCLOSURE, 1, "Lua function expected");
-  p = clvalue(o)->f.l;
+  luaL_arg_check(L, lua_tag(L, 1) == TAG_LCLOSURE, 1, "Lua function expected");
+  p = clvalue(luaA_index(L, 1))->f.l;
+  lua_newtable(L);
   for (i=0; i<p->nkstr; i++) {
-    lua_pushobject(t);
-    lua_pushnumber(i+1);
-    lua_pushstring(p->kstr[i]->str);
-    lua_settable();
+    lua_pushobject(L, -1);
+    lua_pushnumber(L, i+1);
+    lua_pushstring(L, p->kstr[i]->str);
+    lua_settable(L);
   }
-  lua_pushobject(t);
+  return 1;
 }
 
 
-static void listlocals (void) {
-  lua_Object o = luaL_nonnullarg(1);
+static int listlocals (lua_State *L) {
   Proto *p;
-  int pc = luaL_check_int(2) - 1;
-  int i = 1;
+  int pc = luaL_check_int(L, 2) - 1;
+  int i = 0;
   const char *name;
-  luaL_arg_check(ttype(o) == TAG_LCLOSURE, 1, "Lua function expected");
-  p = clvalue(o)->f.l;
-  while ((name = luaF_getlocalname(p, i++, pc)) != NULL)
-    lua_pushstring(name);
+  luaL_arg_check(L, lua_tag(L, 1) == TAG_LCLOSURE, 1, "Lua function expected");
+  p = clvalue(luaA_index(L, 1))->f.l;
+  while ((name = luaF_getlocalname(p, ++i, pc)) != NULL)
+    lua_pushstring(L, name);
+  return i-1;
 }
 
 /* }====================================================== */
 
 
 
-static void get_limits (void) {
-  lua_Object t = lua_createtable();
-  setnameval(t, "BITS_INT", BITS_INT);
-  setnameval(t, "LFPF", LFIELDS_PER_FLUSH);
-  setnameval(t, "MAXARG_A", MAXARG_A);
-  setnameval(t, "MAXARG_B", MAXARG_B);
-  setnameval(t, "MAXARG_S", MAXARG_S);
-  setnameval(t, "MAXARG_U", MAXARG_U);
-  setnameval(t, "MAXLOCALS", MAXLOCALS);
-  setnameval(t, "MAXPARAMS", MAXPARAMS);
-  setnameval(t, "MAXSTACK", MAXSTACK);
-  setnameval(t, "MAXUPVALUES", MAXUPVALUES);
-  setnameval(t, "MAXVARSLH", MAXVARSLH);
-  setnameval(t, "RFPF", RFIELDS_PER_FLUSH);
-  setnameval(t, "SIZE_A", SIZE_A);
-  setnameval(t, "SIZE_B", SIZE_B);
-  setnameval(t, "SIZE_OP", SIZE_OP);
-  setnameval(t, "SIZE_U", SIZE_U);
-  lua_pushobject(t);
+static int get_limits (lua_State *L) {
+  lua_newtable(L);
+  setnameval(L, "BITS_INT", BITS_INT);
+  setnameval(L, "LFPF", LFIELDS_PER_FLUSH);
+  setnameval(L, "MAXARG_A", MAXARG_A);
+  setnameval(L, "MAXARG_B", MAXARG_B);
+  setnameval(L, "MAXARG_S", MAXARG_S);
+  setnameval(L, "MAXARG_U", MAXARG_U);
+  setnameval(L, "MAXLOCALS", MAXLOCALS);
+  setnameval(L, "MAXPARAMS", MAXPARAMS);
+  setnameval(L, "MAXSTACK", MAXSTACK);
+  setnameval(L, "MAXUPVALUES", MAXUPVALUES);
+  setnameval(L, "MAXVARSLH", MAXVARSLH);
+  setnameval(L, "RFPF", RFIELDS_PER_FLUSH);
+  setnameval(L, "SIZE_A", SIZE_A);
+  setnameval(L, "SIZE_B", SIZE_B);
+  setnameval(L, "SIZE_OP", SIZE_OP);
+  setnameval(L, "SIZE_U", SIZE_U);
+  return 1;
 }
 
 
-static void mem_query (void) {
-  lua_Object arg = lua_getparam(1);
-  if (arg == LUA_NOOBJECT) {
-    lua_pushnumber(memdebug_total);
-    lua_pushnumber(memdebug_numblocks);
-    lua_pushnumber(memdebug_maxmem);
-  }
-  else
-    memdebug_memlimit = luaL_check_int(1);
-}
-
-
-static void hash_query (void) {
-  lua_Object o = luaL_nonnullarg(1);
-  if (lua_getparam(2) == LUA_NOOBJECT) {
-    luaL_arg_check(ttype(o) == TAG_STRING, 1, "string expected");
-    lua_pushnumber(tsvalue(o)->u.s.hash);
+static int mem_query (lua_State *L) {
+  if (lua_isnull(L, 1)) {
+    lua_pushnumber(L, memdebug_total);
+    lua_pushnumber(L, memdebug_numblocks);
+    lua_pushnumber(L, memdebug_maxmem);
+    return 3;
   }
   else {
-    const Hash *t = hvalue(luaL_tablearg(2));
-    lua_pushnumber(luaH_mainposition(t, o) - t->node);
+    memdebug_memlimit = luaL_check_int(L, 1);
+    return 0;
   }
 }
 
 
-static void table_query (void) {
-  const Hash *t = hvalue(luaL_tablearg(1));
-  int i = luaL_opt_int(2, -1);
+static int hash_query (lua_State *L) {
+  if (lua_isnull(L, 2)) {
+    luaL_arg_check(L, lua_tag(L, 1) == TAG_STRING, 1, "string expected");
+    lua_pushnumber(L, tsvalue(luaA_index(L, 1))->u.s.hash);
+  }
+  else {
+    Hash *t;
+    luaL_checktype(L, 2, "table");
+    t = hvalue(luaA_index(L, 2));
+    lua_pushnumber(L, luaH_mainposition(t, luaA_index(L, 1)) - t->node);
+  }
+  return 1;
+}
+
+
+static int table_query (lua_State *L) {
+  const Hash *t;
+  int i = luaL_opt_int(L, 2, -1);
+  luaL_checktype(L, 1, "table");
+  t = hvalue(luaA_index(L, 1));
   if (i == -1) {
-    lua_pushnumber(t->size);
-    lua_pushnumber(t->firstfree - t->node);
+    lua_pushnumber(L, t->size);
+    lua_pushnumber(L, t->firstfree - t->node);
+    return 2;
   }
   else if (i < t->size) {
-    luaA_pushobject(lua_state, &t->node[i].key);
-    luaA_pushobject(lua_state, &t->node[i].val);
-    if (t->node[i].next)
-      lua_pushnumber(t->node[i].next - t->node);
+    luaA_pushobject(L, &t->node[i].key);
+    luaA_pushobject(L, &t->node[i].val);
+    if (t->node[i].next) {
+      lua_pushnumber(L, t->node[i].next - t->node);
+      return 3;
+    }
+    else
+      return 2;
   }
+  return 0;
 }
 
 
-static void string_query (void) {
-  lua_State *L = lua_state;
-  stringtable *tb = (*luaL_check_string(1) == 's') ? &L->strt : &L->udt;
-  int s = luaL_opt_int(2, 0) - 1;
+static int string_query (lua_State *L) {
+  stringtable *tb = (*luaL_check_string(L, 1) == 's') ? &L->strt : &L->udt;
+  int s = luaL_opt_int(L, 2, 0) - 1;
   if (s==-1) {
-    lua_pushnumber(tb->nuse);
-    lua_pushnumber(tb->size);
+    lua_pushnumber(L ,tb->nuse);
+    lua_pushnumber(L ,tb->size);
+    return 2;
   }
   else if (s < tb->size) {
     TString *ts;
+    int n = 0;
     for (ts = tb->hash[s]; ts; ts = ts->nexthash) {
       ttype(L->top) = TAG_STRING;
       tsvalue(L->top) = ts;
       incr_top;
+      n++;
     }
+    return n;
   }
+  return 0;
 }
 
+
 /*
 ** {======================================================
 ** function to test the API with C. It interprets a kind of "assembler"
@@ -238,21 +252,33 @@ static void skip (const char **pc) {
   while (**pc != '\0' && strchr(delimits, **pc)) (*pc)++;
 }
 
-static int getnum (const char **pc) {
+static int getnum (const char **pc, int *reg) {
   int res = 0;
+  int sig = 1;
+  int ref = 0;
   skip(pc);
+  if (**pc == 'r') {
+    ref = 1;
+    (*pc)++;
+  }
+  else if (**pc == '-') {
+    sig = -1;
+    (*pc)++;
+  }
   while (isdigit(**pc)) res = res*10 + (*(*pc)++) - '0';
-  return res;
+  if (!ref)
+    return sig*res;
+  else
+    return reg[res];
 }
   
 static int getreg (const char **pc) {
   skip(pc);
-  if (*(*pc)++ != 'r') lua_error("`testC' expecting a register");
-  return getnum(pc);
+  (*pc)++;  /* skip the `r' */
+  return getnum(pc, NULL);
 }
 
-static const char *getname (const char **pc) {
-  static char buff[30];
+static const char *getname (char *buff, const char **pc) {
   int i = 0;
   skip(pc);
   while (**pc != '\0' && !strchr(delimits, **pc))
@@ -264,159 +290,148 @@ static const char *getname (const char **pc) {
 
 #define EQ(s1)	(strcmp(s1, inst) == 0)
 
+#define getnum	((getnum)(&pc, reg))
+#define getreg	((getreg)(&pc))
+#define getname	((getname)(buff, &pc))
 
-static void testC (void) {
-  lua_Object reg[10];
-  const char *pc = luaL_check_string(1);
+
+static int testC (lua_State *L) {
+  char buff[30];
+  int reg[10];
+  const char *pc = luaL_check_string(L, 1);
   for (;;) {
-    const char *inst = getname(&pc);
-    if EQ("") return;
-    else if EQ("pushnum") {
-      lua_pushnumber(getnum(&pc));
+    const char *inst = getname;
+    if EQ("") return 0;
+    else if EQ("return") {
+      return getnum;
     }
-    else if EQ("createtable") {
-      reg[getreg(&pc)] = lua_createtable();
+    else if EQ("retall") {
+      return lua_gettop(L) - 1;
+    }
+    else if EQ("gettop") {
+      reg[getreg] = lua_gettop(L);
+    }
+    else if EQ("settop") {
+      lua_settop(L, getnum);
+    }
+    else if EQ("setreg") {
+      int n = getreg;
+      reg[n] = lua_tonumber(L, getnum);
+    }
+    else if EQ("pushnum") {
+      lua_pushnumber(L, getnum);
+    }
+    else if EQ("newtable") {
+      lua_newtable(L);
     }
     else if EQ("closure") {
-      lua_CFunction f = lua_getcfunction(lua_getglobal(getname(&pc)));
-      lua_pushcclosure(f, getnum(&pc));
+      lua_CFunction f;
+      lua_getglobal(L, getname);
+      f = lua_tocfunction(L, -1);
+      lua_settop(L, -1);
+      lua_pushcclosure(L, f, getnum);
     }
-    else if EQ("pop") {
-      reg[getreg(&pc)] = lua_pop();
+    else if EQ("pushobject") {
+      lua_pushobject(L, getnum);
     }
     else if EQ("getglobal") {
-      int n = getreg(&pc);
-      reg[n] = lua_getglobal(getname(&pc));
+      lua_getglobal(L, getname);
     }
     else if EQ("ref") {
-      lua_pushnumber(lua_ref(0));
-      reg[getreg(&pc)] = lua_pop();
+      reg[getreg] = lua_ref(L, 0);
     }
     else if EQ("reflock") {
-      lua_pushnumber(lua_ref(1));
-      reg[getreg(&pc)] = lua_pop();
+      reg[getreg] = lua_ref(L, 1);
     }
     else if EQ("getref") {
-      int n = getreg(&pc);
-      reg[n] = lua_getref((int)lua_getnumber(reg[getreg(&pc)]));
+      int n = getreg;
+      reg[n] = lua_getref(L, getnum);
     }
     else if EQ("unref") {
-      lua_unref((int)lua_getnumber(reg[getreg(&pc)]));
-    }
-    else if EQ("getparam") {
-      int n = getreg(&pc);
-      reg[n] = lua_getparam(getnum(&pc)+1);  /* skips the command itself */
-    }
-    else if EQ("getresult") {
-      int n = getreg(&pc);
-      reg[n] = lua_getparam(getnum(&pc));
+      lua_unref(L, getnum);
     }
     else if EQ("setglobal") {
-      lua_setglobal(getname(&pc));
-    }
-    else if EQ("pushglobals") {
-      lua_pushglobals();
+      lua_setglobal(L, getname);
     }
     else if EQ("pushstring") {
-      lua_pushstring(getname(&pc));
-    }
-    else if EQ("pushreg") {
-      lua_pushobject(reg[getreg(&pc)]);
+      lua_pushstring(L, getname);
     }
     else if EQ("call") {
-      if (lua_call(getname(&pc))) lua_error(NULL);
+      int narg = getnum;
+      int nres = getnum;
+      if (lua_call(L, narg, nres)) lua_error(L, NULL);
     }
     else if EQ("gettable") {
-      reg[getreg(&pc)] = lua_gettable();
+      lua_gettable(L);
     }
     else if EQ("rawget") {
-      reg[getreg(&pc)] = lua_rawget();
+      lua_rawget(L);
     }
     else if EQ("settable") {
-      lua_settable();
+      lua_settable(L);
     }
     else if EQ("rawset") {
-      lua_rawset();
+      lua_rawset(L);
     }
     else if EQ("tag") {
-      lua_pushnumber(lua_tag(reg[getreg(&pc)]));
+      int n = getreg;
+      reg[n] = lua_tag(L, getnum);
     }
     else if EQ("type") {
-      lua_pushstring(lua_type(reg[getreg(&pc)]));
-    }
-    else if EQ("next") {
-      int n = getreg(&pc);
-      n = lua_next(reg[n], (int)lua_getnumber(reg[getreg(&pc)]));
-      lua_pushnumber(n);
+      lua_pushstring(L, lua_type(L, getnum));
     }
     else if EQ("equal") {
-      int n1 = getreg(&pc);
-      int n2 = getreg(&pc);
-      lua_pushnumber(lua_equal(reg[n1], reg[n2]));
+      int n1 = getreg;
+      int n2 = getnum;
+      int n3 = getnum;
+      reg[n1] = lua_equal(L, n2, n3);
     }
     else if EQ("pushusertag") {
-      int val = getreg(&pc);
-      int tag = getreg(&pc);
-      lua_pushusertag((void *)(int)lua_getnumber(reg[val]),
-                         (int)lua_getnumber(reg[tag]));
+      int val = getnum;
+      int tag = getnum;
+      lua_pushusertag(L, (void *)val, tag);
     }
     else if EQ("udataval") {
-      int n = getreg(&pc);
-      lua_pushnumber((int)lua_getuserdata(reg[getreg(&pc)]));
-      reg[n] = lua_pop();
+      int n = getreg;
+      reg[n] = (int)lua_touserdata(L, getnum);
     }
     else if EQ("settagmethod") {
-      int n = getreg(&pc);
-      lua_settagmethod((int)lua_getnumber(reg[n]), getname(&pc));
-    }
-    else if EQ("beginblock") {
-      lua_beginblock();
-    }
-    else if EQ("endblock") {
-      lua_endblock();
+      int n = getnum;
+      lua_settagmethod(L, n, getname);
     }
     else if EQ("newstate") {
-      int stacksize = getnum(&pc);
-      lua_State *L1 = lua_newstate(stacksize, getnum(&pc));
+      int stacksize = getnum;
+      lua_State *L1 = lua_newstate(stacksize, getnum);
       if (L1)
-        lua_pushuserdata(L1);
+        lua_pushuserdata(L, L1);
       else
-        lua_pushnil();
+        lua_pushnil(L);
     }
     else if EQ("closestate") {
-      (lua_close)((lua_State *)lua_getuserdata(reg[getreg(&pc)]));
+      (lua_close)((lua_State *)lua_touserdata(L, getnum));
     }
     else if EQ("doremote") {
-      lua_Object ol1 = reg[getreg(&pc)];
-      lua_Object str = reg[getreg(&pc)];
+      int ol1 = getnum;
+      int str = getnum;
       lua_State *L1;
-      lua_Object temp;
       int status;
-      if (!lua_isuserdata(ol1) || !lua_isstring(str))
-        lua_error("bad arguments for `doremote'");
-      L1 = (lua_State *)lua_getuserdata(ol1);
-      status = (lua_dostring)(L1, lua_getstring(str));
+      if (!lua_isuserdata(L, ol1) || !lua_isstring(L, str))
+        lua_error(L, "bad arguments for `doremote'");
+      L1 = (lua_State *)lua_touserdata(L, ol1);
+      status = lua_dostring(L1, lua_tostring(L, str));
       if (status != 0) {
-        lua_pushnil();
-        lua_pushnumber(status);
+        lua_pushnil(L);
+        lua_pushnumber(L, status);
       }
       else {
-        int i = 1;
-        while ((temp = (lua_getresult)(L1, i++)) != LUA_NOOBJECT)
-          lua_pushstring((lua_getstring)(L1, temp));
+        int i = 0;
+        while (!lua_isnull(L, ++i))
+          lua_pushstring(L, lua_tostring(L1, i));
       }
     }
-#if LUA_DEPRECATETFUNCS
-    else if EQ("rawsetglobal") {
-      lua_rawsetglobal(getname(&pc));
-    }
-    else if EQ("rawgetglobal") {
-      int n = getreg(&pc);
-      reg[n] = lua_rawgetglobal(getname(&pc));
-    }
-#endif
-    else luaL_verror(lua_state, "unknown command in `testC': %.20s", inst);
+    else luaL_verror(L, "unknown instruction %.30s", buff);
   }
+  return 0;
 }
 
 /* }====================================================== */
@@ -424,22 +439,20 @@ static void testC (void) {
 
 
 static const struct luaL_reg tests_funcs[] = {
-  {"hash", (lua_CFunction)hash_query},
-  {"limits", (lua_CFunction)get_limits},
-  {"listcode", (lua_CFunction)listcode},
-  {"liststrings", (lua_CFunction)liststrings},
-  {"listlocals", (lua_CFunction)listlocals},
-  {"querystr", (lua_CFunction)string_query},
-  {"querytab", (lua_CFunction)table_query},
-  {"testC", (lua_CFunction)testC},
-  {"totalmem", (lua_CFunction)mem_query}
+  {"hash", hash_query},
+  {"limits", get_limits},
+  {"listcode", listcode},
+  {"liststrings", liststrings},
+  {"listlocals", listlocals},
+  {"querystr", string_query},
+  {"querytab", table_query},
+  {"testC", testC},
+  {"totalmem", mem_query}
 };
 
 
 void luaB_opentests (lua_State *L) {
-  if (lua_state != NULL) return;  /* do not open tests for auxiliar states */
-  lua_state = L;
-  luaL_openl(tests_funcs);
+  luaL_openl(L, tests_funcs);
 }
 
 #endif
diff --git a/lua.c b/lua.c
index b3b8e6ea..3a50ceb2 100644
--- a/lua.c
+++ b/lua.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.c,v 1.44 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: lua.c,v 1.45 2000/08/14 17:45:59 roberto Exp roberto $
 ** Lua stand-alone interpreter
 ** See Copyright Notice in lua.h
 */
@@ -10,14 +10,14 @@
 #include <stdlib.h>
 #include <string.h>
 
-#define LUA_SINGLESTATE
-
 #include "lua.h"
 
 #include "luadebug.h"
 #include "lualib.h"
 
+
 lua_State *lua_state = NULL;
+#define L	lua_state
 
 
 #ifndef PROMPT
@@ -54,10 +54,10 @@ extern void USERINIT (void);
 #else
 #define USERINIT	userinit
 static void userinit (void) {
-  lua_iolibopen();
-  lua_strlibopen();
-  lua_mathlibopen();
-  lua_dblibopen();
+  lua_iolibopen(L);
+  lua_strlibopen(L);
+  lua_mathlibopen(L);
+  lua_dblibopen(L);
 }
 #endif
 
@@ -68,10 +68,10 @@ static handler lreset (void) {
 
 
 static void lstop (void) {
-  lua_setlinehook(lua_state, old_linehook);
-  lua_setcallhook(lua_state, old_callhook);
+  lua_setlinehook(L, old_linehook);
+  lua_setcallhook(L, old_callhook);
   lreset();
-  lua_error("interrupted!");
+  lua_error(L, "interrupted!");
 }
 
 
@@ -79,15 +79,15 @@ static void laction (int i) {
   (void)i;  /* to avoid warnings */
   signal(SIGINT, SIG_DFL); /* if another SIGINT happens before lstop,
                               terminate process (default action) */
-  old_linehook = lua_setlinehook(lua_state, (lua_Hook)lstop);
-  old_callhook = lua_setcallhook(lua_state, (lua_Hook)lstop);
+  old_linehook = lua_setlinehook(L, (lua_Hook)lstop);
+  old_callhook = lua_setcallhook(L, (lua_Hook)lstop);
 }
 
 
-static int ldo (int (*f)(lua_State *L, const char *), const char *name) {
+static int ldo (int (*f)(lua_State *l, const char *), const char *name) {
   int res;
   handler h = lreset();
-  res = f(lua_state, name);  /* dostring | dofile */
+  res = f(L, name);  /* dostring | dofile */
   signal(SIGINT, h);  /* restore old action */
   if (res == LUA_ERRMEM) {
     /* Lua gives no message in such case, so lua.c provides one */
@@ -122,29 +122,29 @@ static void print_version (void) {
 static void assign (char *arg) {
   char *eq = strchr(arg, '=');
   *eq = '\0';  /* spilt `arg' in two strings (name & value) */
-  lua_pushstring(eq+1);
-  lua_setglobal(arg);
+  lua_pushstring(L, eq+1);
+  lua_setglobal(L, arg);
 }
 
 
-static lua_Object getargs (char *argv[]) {
-  lua_Object args = lua_createtable();
+static void getargs (char *argv[]) {
   int i;
+  lua_newtable(L);
   for (i=0; argv[i]; i++) {
     /* arg[i] = argv[i] */
-    lua_pushobject(args); lua_pushnumber(i);
-    lua_pushstring(argv[i]); lua_settable();
+    lua_pushobject(L, -1); lua_pushnumber(L, i);
+    lua_pushstring(L, argv[i]); lua_settable(L);
   }
   /* arg.n = maximum index in table `arg' */
-  lua_pushobject(args); lua_pushstring("n");
-  lua_pushnumber(i-1); lua_settable();
-  return args;
+  lua_pushobject(L, -1); lua_pushstring(L, "n");
+  lua_pushnumber(L, i-1); lua_settable(L);
 }
 
 
-static void l_getargs (void) {
-  char **argv = (char **)lua_getuserdata(lua_getparam(1));
-  lua_pushobject(getargs(argv));
+static int l_getargs (lua_State *l) {
+  char **argv = (char **)lua_touserdata(l, 1);
+  getargs(argv);
+  return 1;
 }
 
 
@@ -173,9 +173,11 @@ static void manual_input (int version, int prompt) {
   while (cont) {
     char buffer[MAXINPUT];
     int i = 0;
-    lua_beginblock();
     if (prompt) {
-      const char *s = lua_getstring(lua_getglobal("_PROMPT"));
+      const char *s;
+      lua_getglobal(L, "_PROMPT");
+      s = lua_tostring(L, -1);
+      lua_settop(L, -1);  /* remove global */
       if (!s) s = PROMPT;
       fputs(s, stdout);
     }
@@ -198,7 +200,7 @@ static void manual_input (int version, int prompt) {
     }
     buffer[i] = '\0';
     ldo(lua_dostring, buffer);
-    lua_endblock();
+    lua_settop(L, 0);  /* remove eventual results */
   }
   printf("\n");
 }
@@ -262,8 +264,8 @@ static int handle_argv (char *argv[], struct Options *opt) {
               print_message();
               return EXIT_FAILURE;
             }
-            lua_pushobject(getargs(argv+i));  /* collect remaining arguments */
-            lua_setglobal("arg");
+            getargs(argv+i);  /* collect remaining arguments */
+            lua_setglobal(L, "arg");
             return file_input(argv[i]);  /* stop scanning arguments */
           }
           case 's': {
@@ -296,9 +298,9 @@ static void getstacksize (int argc, char *argv[], struct Options *opt) {
 
 
 static void register_getargs (char *argv[]) {
-  lua_pushuserdata(argv);
-  lua_pushcclosure(l_getargs, 1);
-  lua_setglobal("getargs");
+  lua_pushuserdata(L, argv);
+  lua_pushcclosure(L, l_getargs, 1);
+  lua_setglobal(L, "getargs");
 }
 
 
@@ -307,12 +309,12 @@ int main (int argc, char *argv[]) {
   int status;
   opt.toclose = 0;
   getstacksize(argc, argv, &opt);  /* handle option `-s' */
-  lua_state = lua_newstate(opt.stacksize, 1);  /* create state */
+  L = lua_newstate(opt.stacksize, 1);  /* create state */
   USERINIT();  /* open libraries */
   register_getargs(argv);  /* create `getargs' function */
   status = handle_argv(argv+1, &opt);
   if (opt.toclose)
-    lua_close();
+    lua_close(L);
   return status;
 }
 
diff --git a/lua.h b/lua.h
index 96f3597a..43459a4d 100644
--- a/lua.h
+++ b/lua.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.h,v 1.58 2000/08/14 19:10:14 roberto Exp roberto $
+** $Id: lua.h,v 1.59 2000/08/17 13:18:01 roberto Exp roberto $
 ** Lua - An Extensible Extension Language
 ** TeCGraf: Grupo de Tecnologia em Computacao Grafica, PUC-Rio, Brazil
 ** e-mail: lua@tecgraf.puc-rio.br
@@ -30,8 +30,10 @@
 
 #define LUA_ANYTAG	(-1)
 
+#define LUA_MULTRET	(-1)
 
-/* error code for lua_do* */
+
+/* error codes for lua_do* */
 #define LUA_ERRFILE	2
 #define LUA_ERRSYNTAX	3
 #define LUA_ERRRUN	1
@@ -40,95 +42,103 @@
 
 typedef struct lua_State lua_State;
 
-typedef void (*lua_CFunction) (lua_State *L);
-
-typedef struct lua_TObject *lua_Object;
-
-#define LUA_NOOBJECT	((lua_Object)0)
+typedef int (*lua_CFunction) (lua_State *L);
 
 
+/*
+** state manipulation
+*/
 lua_State     *lua_newstate (int stacksize, int builtin);
 void           lua_close (lua_State *L);
 
-lua_Object     lua_settagmethod (lua_State *L, int tag, const char *event);
-                                                       /* In: new method */
-lua_Object     lua_gettagmethod (lua_State *L, int tag, const char *event);
 
-int            lua_newtag (lua_State *L);
-int            lua_copytagmethods (lua_State *L, int tagto, int tagfrom);
-void           lua_settag (lua_State *L, int tag); /* In: object */
-
-void           lua_error (lua_State *L, const char *s);
-int            lua_dofile (lua_State *L, const char *filename);
-                                                        /* Out: returns */
-int            lua_dostring (lua_State *L, const char *str);
-                                                        /* Out: returns */
-int            lua_dobuffer (lua_State *L, const char *buff, size_t size,
-                             const char *name);         /* Out: returns */
-int            lua_callfunction (lua_State *L, lua_Object f);
-					  /* In: arguments; Out: returns */
-
-void	       lua_beginblock (lua_State *L);
-void	       lua_endblock (lua_State *L);
-
-void           lua_pushglobals (lua_State *L);
-void           lua_setglobals (lua_State *L, lua_Object newtable);
-
-lua_Object     lua_lua2C (lua_State *L, int number);
-#define	       lua_getparam		lua_lua2C
-#define	       lua_getresult		lua_lua2C
-
-const char    *lua_type (lua_State *L, lua_Object obj);
-
-int            lua_isnil (lua_State *L, lua_Object obj);
-int            lua_istable (lua_State *L, lua_Object obj);
-int            lua_isuserdata (lua_State *L, lua_Object obj);
-int            lua_iscfunction (lua_State *L, lua_Object obj);
-int            lua_isnumber (lua_State *L, lua_Object obj);
-int            lua_isstring (lua_State *L, lua_Object obj);
-int            lua_isfunction (lua_State *L, lua_Object obj);
-
-int            lua_equal (lua_State *L, lua_Object o1, lua_Object o2);
-
-double         lua_getnumber (lua_State *L, lua_Object obj);
-const char    *lua_getstring (lua_State *L, lua_Object obj);
-size_t         lua_strlen (lua_State *L, lua_Object obj);
-lua_CFunction  lua_getcfunction (lua_State *L, lua_Object obj);
-void	      *lua_getuserdata (lua_State *L, lua_Object obj);
+/*
+** basic stack manipulation
+*/
+int            lua_gettop (lua_State *L);
+void           lua_settop (lua_State *L, int index);
+void           lua_pushobject (lua_State *L, int index);
 
 
-void 	       lua_pushnil (lua_State *L);
+/*
+** access functions (stack -> C)
+*/
+
+const char    *lua_type (lua_State *L, int index);
+int            lua_isnumber (lua_State *L, int index);
+int            lua_iscfunction (lua_State *L, int index);
+int            lua_tag (lua_State *L, int index);
+
+int            lua_equal (lua_State *L, int index1, int index2);
+
+double         lua_tonumber (lua_State *L, int index);
+const char    *lua_tostring (lua_State *L, int index);
+size_t         lua_strlen (lua_State *L, int index);
+lua_CFunction  lua_tocfunction (lua_State *L, int index);
+void	      *lua_touserdata (lua_State *L, int index);
+
+
+/*
+** push functions (C -> stack)
+*/
+void           lua_pushnil (lua_State *L);
 void           lua_pushnumber (lua_State *L, double n);
 void           lua_pushlstring (lua_State *L, const char *s, size_t len);
 void           lua_pushstring (lua_State *L, const char *s);
 void           lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);
 void           lua_pushusertag (lua_State *L, void *u, int tag);
-void           lua_pushobject (lua_State *L, lua_Object obj);
 
-lua_Object     lua_pop (lua_State *L);
 
-lua_Object     lua_getglobal (lua_State *L, const char *name);
-void           lua_setglobal (lua_State *L, const char *name); /* In: value */
+/*
+** get functions (Lua -> stack)
+*/
+void           lua_getglobal (lua_State *L, const char *name);
+void           lua_gettable (lua_State *L);
+void           lua_rawget (lua_State *L);
+void           lua_getglobals (lua_State *L);
+void           lua_gettagmethod (lua_State *L, int tag, const char *event);
 
-void           lua_settable (lua_State *L); /* In: table, index, value */
-lua_Object     lua_gettable (lua_State *L); /* In: table, index */
+int            lua_getref (lua_State *L, int ref);
 
-void           lua_rawset (lua_State *L); /* In: table, index, value */
-lua_Object     lua_rawget (lua_State *L); /* In: table, index */
+void           lua_newtable (lua_State *L);
 
-int            lua_tag (lua_State *L, lua_Object obj);
 
-int            lua_next (lua_State *L, lua_Object o, int i);
-						/* Out: index, value */ 
+/*
+** set functions (stack -> Lua)
+*/
+void           lua_setglobal (lua_State *L, const char *name);
+void           lua_settable (lua_State *L);
+void           lua_rawset (lua_State *L);
+void           lua_setglobals (lua_State *L);
+void           lua_settagmethod (lua_State *L, int tag, const char *event);
+int            lua_ref (lua_State *L, int lock);
+
+
+/*
+** "do" functions (run Lua code)
+*/
+int            lua_call (lua_State *L, int nargs, int nresults);
+int            lua_dofile (lua_State *L, const char *filename);
+int            lua_dostring (lua_State *L, const char *str);
+int            lua_dobuffer (lua_State *L, const char *buff, size_t size,
+                             const char *name);
+
+
+/*
+** miscelaneous functions
+*/
+int            lua_newtag (lua_State *L);
+int            lua_copytagmethods (lua_State *L, int tagto, int tagfrom);
+void           lua_settag (lua_State *L, int tag);
+
+void           lua_error (lua_State *L, const char *s);
 
-int            lua_ref (lua_State *L, int lock); /* In: value */
-int            lua_pushref (lua_State *L, int ref);  /* Out: value */
 void	       lua_unref (lua_State *L, int ref);
 
-lua_Object     lua_createtable (lua_State *L);
-
 long	       lua_collectgarbage (lua_State *L, long limit);
 
+int            lua_next (lua_State *L, int index, int i);
+
 
 
 /* 
@@ -137,122 +147,17 @@ long	       lua_collectgarbage (lua_State *L, long limit);
 ** ===============================================================
 */
 
-#ifndef LUA_SINGLESTATE
-
-#define lua_call(L,name)	lua_callfunction(L, lua_getglobal(L, name))
-#define lua_getref(L, ref)  (lua_pushref(L, ref) ? lua_pop(L) : LUA_NOOBJECT)
-#define lua_refobject(L,o,l)	(lua_pushobject(L, o), lua_ref(L, l))
 #define lua_register(L,n,f)	(lua_pushcfunction(L, f), lua_setglobal(L, n))
 #define lua_pushuserdata(L,u)	lua_pushusertag(L, u, 0)
 #define lua_pushcfunction(L,f)	lua_pushcclosure(L, f, 0)
 #define lua_clonetag(L,t)	lua_copytagmethods(L, lua_newtag(L), (t))
 
-#else
-
-#define lua_call(name)		lua_callfunction(lua_getglobal(name))
-#define lua_getref(ref)		(lua_pushref(ref) ? lua_pop() : LUA_NOOBJECT)
-#define lua_refobject(o,l)	(lua_pushobject(o), lua_ref(l))
-#define lua_register(n,f)	(lua_pushcfunction(f), lua_setglobal(n))
-#define lua_pushuserdata(u)	lua_pushusertag(u, 0)
-#define lua_pushcfunction(f)	lua_pushcclosure(f, 0)
-#define lua_clonetag(t)		lua_copytagmethods(lua_newtag(), (t))
-
-#endif
-
-
-
-#ifdef LUA_SINGLESTATE
-/* 
-** {==============================================================
-** Macros for single-state use
-** ===============================================================
-*/
-
-extern lua_State *lua_state;
-
-#define lua_open()	((void)(lua_state?0:(lua_state=lua_newstate(0, 1))))
-
-#define lua_close()		(lua_close)(lua_state)
-#define lua_settagmethod(tag,event)	(lua_settagmethod)(lua_state, tag,event)
-#define lua_gettagmethod(tag,event)	(lua_gettagmethod)(lua_state, tag,event)
-#define lua_newtag()		(lua_newtag)(lua_state)
-#define lua_copytagmethods(tagto,tagfrom)	\
-		(lua_copytagmethods)(lua_state, tagto,tagfrom)
-#define lua_settag(tag)		(lua_settag)(lua_state, tag)
-#define lua_error(s)		(lua_error)(lua_state, s)
-#define lua_dofile(filename)	(lua_dofile)(lua_state, filename)
-#define lua_dostring(str)	(lua_dostring)(lua_state, str)
-#define lua_dobuffer(b,s,n)	(lua_dobuffer)(lua_state, b,s,n)
-#define lua_callfunction(f)	(lua_callfunction)(lua_state, f)
-#define lua_beginblock()	(lua_beginblock)(lua_state)
-#define lua_endblock()		(lua_endblock)(lua_state)
-#define lua_pushglobals()	(lua_pushglobals)(lua_state)
-#define lua_setglobals(t)	(lua_setglobals)(lua_state, t)
-#define lua_lua2C(number)	(lua_lua2C)(lua_state, number)
-#define lua_type(obj)		(lua_type)(lua_state, obj)
-#define lua_isnil(obj)		(lua_isnil)(lua_state, obj)
-#define lua_istable(obj)	(lua_istable)(lua_state, obj)
-#define lua_isuserdata(obj)	(lua_isuserdata)(lua_state, obj)
-#define lua_iscfunction(obj)	(lua_iscfunction)(lua_state, obj)
-#define lua_isnumber(obj)	(lua_isnumber)(lua_state, obj)
-#define lua_isstring(obj)	(lua_isstring)(lua_state, obj)
-#define lua_isfunction(obj)	(lua_isfunction)(lua_state, obj)
-#define lua_equal(o1,o2)	(lua_equal)(lua_state, o1,o2)
-#define lua_getnumber(obj)	(lua_getnumber)(lua_state, obj)
-#define lua_getstring(obj)	(lua_getstring)(lua_state, obj)
-#define lua_strlen(obj)		(lua_strlen)(lua_state, obj)
-#define lua_getcfunction(obj)	(lua_getcfunction)(lua_state, obj)
-#define lua_getuserdata(obj)	(lua_getuserdata)(lua_state, obj)
-#define lua_pushnil()		(lua_pushnil)(lua_state)
-#define lua_pushnumber(n)	(lua_pushnumber)(lua_state, n)
-#define lua_pushlstring(s,len)	(lua_pushlstring)(lua_state, s,len)
-#define lua_pushstring(s)	(lua_pushstring)(lua_state, s)
-#define lua_pushusertag(u,tag)	(lua_pushusertag)(lua_state, u,tag)
-#define lua_pushobject(obj)	(lua_pushobject)(lua_state, obj)
-#define lua_pop()		(lua_pop)(lua_state)
-#define lua_getglobal(name)	(lua_getglobal)(lua_state, name)
-#define lua_setglobal(name)	(lua_setglobal)(lua_state, name)
-#define lua_settable()		(lua_settable)(lua_state)
-#define lua_gettable()		(lua_gettable)(lua_state)
-#define lua_rawset()		(lua_rawset)(lua_state)
-#define lua_rawget()		(lua_rawget)(lua_state)
-#define lua_tag(obj)		(lua_tag)(lua_state, obj)
-#define lua_next(o,i)		(lua_next)(lua_state, o,i)
-#define lua_ref(lock)		(lua_ref)(lua_state, lock)
-#define lua_pushref(ref)	(lua_pushref)(lua_state, ref)
-#define lua_unref(ref)		(lua_unref)(lua_state, ref)
-#define lua_createtable()	(lua_createtable)(lua_state)
-#define lua_collectgarbage(limit)	(lua_collectgarbage)(lua_state, limit)
-/*
-** the following typecast is a little dirty, but we know of no other
-** way to keep compatibility with old definition of `lua_CFunction'
-*/
-#define lua_pushcclosure(fn,n) \
-		(lua_pushcclosure)(lua_state, (lua_CFunction)(fn), n)
-
-
-/*
-** }==============================================================
-*/
-#endif
-
-/*
-** compatibility with 3.2
-** these functions are only available when Lua is compiled with 
-** the option LUA_DEPRECATETFUNCS
-*/
-
-#define lua_rawsettable		lua_rawset
-#define lua_rawgettable		lua_rawget
-
-lua_Object     lua_rawgetglobal (lua_State *L, const char *name);
-void           lua_rawsetglobal (lua_State *L, const char *name);/* In: value */
-
-#ifdef LUA_SINGLESTATE
-#define lua_rawgetglobal(name)	(lua_rawgetglobal(lua_state, name))
-#define lua_rawsetglobal(name)	(lua_rawsetglobal(lua_state, name))
-#endif
-
+#define lua_isfunction(L,n)	(*lua_type(L,n) == 'f')
+#define lua_isstring(L,n)	(lua_tostring(L,n))
+#define lua_istable(L,n)	(*lua_type(L,n) == 't')
+#define lua_isuserdata(L,n)	(*lua_type(L,n) == 'u')
+#define lua_isnil(L,n)		(lua_type(L,n)[2] == 'l')
+#define lua_isnull(L,n)		(*lua_type(L,n) == 'N')
 
 #endif
 
diff --git a/luadebug.h b/luadebug.h
index 6944cc17..67472ad9 100644
--- a/luadebug.h
+++ b/luadebug.h
@@ -1,5 +1,5 @@
 /*
-** $Id: luadebug.h,v 1.11 2000/08/08 20:42:07 roberto Exp roberto $
+** $Id: luadebug.h,v 1.12 2000/08/11 16:17:28 roberto Exp roberto $
 ** Debugging API
 ** See Copyright Notice in lua.h
 */
@@ -19,8 +19,8 @@ typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
 
 int lua_getstack (lua_State *L, int level, lua_Debug *ar);
 int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);
-int lua_getlocal (lua_State *L, const lua_Debug *ar, lua_Localvar *v);
-int lua_setlocal (lua_State *L, const lua_Debug *ar, lua_Localvar *v);
+const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int localnum);
+const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int localnum);
 
 lua_Hook lua_setcallhook (lua_State *L, lua_Hook func);
 lua_Hook lua_setlinehook (lua_State *L, lua_Hook func);
@@ -36,16 +36,8 @@ struct lua_Debug {
   const char *name;      /* (n) */
   const char *namewhat;  /* (n) `global', `tag method', `local', `field' */
   int nups;              /* (u) number of upvalues */
-  lua_Object func;       /* (f) function being executed */
   /* private part */
-  lua_Object _func;  /* active function */
-};
-
-
-struct lua_Localvar {
-  int index;
-  const char *name;
-  lua_Object value;
+  struct lua_TObject *_func;  /* active function */
 };
 
 
diff --git a/lundump.c b/lundump.c
index 386bebc9..2e3478ad 100644
--- a/lundump.c
+++ b/lundump.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.c,v 1.24 2000/08/09 19:16:57 roberto Exp roberto $
+** $Id: lundump.c,v 1.25 2000/08/24 14:19:39 roberto Exp roberto $
 ** load bytecodes from files
 ** See Copyright Notice in lua.h
 */
@@ -130,7 +130,7 @@ static void LoadCode (lua_State* L, Proto* tf, ZIO* Z)
 }
 
 static void LoadLocals (lua_State* L, Proto* tf, ZIO* Z)
-{
+{ 
 }
 
 static Proto* LoadFunction (lua_State* L, ZIO* Z, int native);