8 files changed, 146 insertions, 157 deletions

diff --git a/auxlib.c b/auxlib.c
new file mode 100644
index 00000000..0bee6430
--- /dev/null
+++ b/auxlib.c
@@ -0,0 +1,47 @@
+char *rcs_auxlib="$Id: $";
+
+#include <stdio.h>
+
+#include "lua.h"
+
+
+void luaL_arg_check(int cond, char *funcname, int numarg, char *extramsg)
+{
+  if (!cond) {
+    char buff[100];
+    if (extramsg == NULL)
+      sprintf(buff, "bad argument #%d to function `%s'", numarg, funcname);
+    else
+      sprintf(buff, "bad argument #%d to function `%s' (%s)",
+                      numarg, funcname, extramsg);
+    lua_error(buff);
+  }
+}
+
+char *luaL_check_string (int numArg, char *funcname)
+{
+  lua_Object o = lua_getparam(numArg);
+  luaL_arg_check(lua_isstring(o), funcname, numArg, "string expected");
+  return lua_getstring(o);
+}
+
+char *luaL_opt_string (int numArg, char *def, char *funcname)
+{
+  return (lua_getparam(numArg) == LUA_NOOBJECT) ? def :
+                              luaL_check_string(numArg, funcname);
+}
+
+double luaL_check_number (int numArg, char *funcname)
+{
+  lua_Object o = lua_getparam(numArg);
+  luaL_arg_check(lua_isnumber(o), funcname, numArg, "number expected");
+  return lua_getnumber(o);
+}
+
+
+double luaL_opt_number (int numArg, double def, char *funcname)
+{
+  return (lua_getparam(numArg) == LUA_NOOBJECT) ? def :
+                              luaL_check_number(numArg, funcname);
+}
+
diff --git a/inout.c b/inout.c
index cfe0e78e..b0b3d2c3 100644
--- a/inout.c
+++ b/inout.c
@@ -5,7 +5,7 @@
 ** Also provides some predefined lua functions.
 */
 
-char *rcs_inout="$Id: inout.c,v 2.44 1997/02/26 17:38:41 roberto Unstable roberto $";
+char *rcs_inout="$Id: inout.c,v 2.45 1997/03/11 18:44:28 roberto Exp roberto $";
 
 #include <stdio.h>
 #include <string.h>
@@ -101,32 +101,6 @@ void lua_closestring (void)
 }
 
 
-static void check_arg (int cond, char *func)
-{
-  if (!cond)
-  {
-    char buff[100];
-    sprintf(buff, "incorrect argument to function `%s'", func);
-    lua_error(buff);
-  }
-}
-
-static char *check_string (int numArg, char *funcname)
-{
-  lua_Object o = lua_getparam(numArg);
-  check_arg(lua_isstring(o), funcname);
-  return lua_getstring(o);
-}
-
-static int check_number (int numArg, char *funcname)
-{
-  lua_Object o = lua_getparam(numArg);
-  check_arg(lua_isnumber(o), funcname);
-  return (int)lua_getnumber(o);
-}
-
-
-
 static int passresults (void)
 {
   int arg = 0;
@@ -141,7 +115,7 @@ static int passresults (void)
 */
 static void lua_internaldostring (void)
 {
-  if (lua_dostring(check_string(1, "dostring")) == 0)
+  if (lua_dostring(luaL_check_string(1, "dostring")) == 0)
     if (passresults() == 0)
       lua_pushuserdata(NULL);  /* at least one result to signal no errors */
 }
@@ -151,13 +125,7 @@ static void lua_internaldostring (void)
 */
 static void lua_internaldofile (void)
 {
- lua_Object obj = lua_getparam (1);
- char *fname = NULL;
- if (lua_isstring(obj))
-   fname = lua_getstring(obj);
- else if (obj != LUA_NOOBJECT)
-   lua_error("invalid argument to function `dofile'");
- /* else fname = NULL */
+ char *fname = luaL_opt_string(1, NULL, "dofile");
  if (lua_dofile(fname) == 0)
     if (passresults() == 0)
       lua_pushuserdata(NULL);  /* at least one result to signal no errors */
@@ -247,15 +215,15 @@ static void luaI_assert (void)
 static void luaI_setglobal (void)
 {
   lua_Object value = lua_getparam(2);
-  check_arg(value != LUA_NOOBJECT, "setglobal");
+  luaL_arg_check(value != LUA_NOOBJECT, "setglobal", 2, NULL);
   lua_pushobject(value);
-  lua_storeglobal(check_string(1, "setglobal"));
+  lua_storeglobal(luaL_check_string(1, "setglobal"));
   lua_pushobject(value);  /* return given value */
 }
 
 static void luaI_getglobal (void)
 {
-  lua_pushobject(lua_getglobal(check_string(1, "getglobal")));
+  lua_pushobject(lua_getglobal(luaL_check_string(1, "getglobal")));
 }
 
 #define MAXPARAMS       256
@@ -265,8 +233,8 @@ static void luaI_call (void)
   lua_Object arg = lua_getparam(2);
   lua_Object temp, params[MAXPARAMS];
   int narg, i;
-  check_arg(lua_istable(arg), "call");
-  check_arg(lua_isfunction(f), "call");
+  luaL_arg_check(lua_isfunction(f), "call", 1, "function expected");
+  luaL_arg_check(lua_istable(arg), "call", 2, "table expected");
   /* narg = arg.n */
   lua_pushobject(arg);
   lua_pushstring("n");
@@ -296,21 +264,22 @@ static void luaI_call (void)
 static void luaIl_settag (void)
 {
   lua_Object o = lua_getparam(1);
-  check_arg(o != LUA_NOOBJECT, "settag");
+  luaL_arg_check(o != LUA_NOOBJECT, "settag", 1, NULL);
   lua_pushobject(o);
-  lua_settag(check_number(2, "settag"));
+  lua_settag(luaL_check_number(2, "settag"));
 }
 
 static void luaIl_newtag (void)
 {
-  lua_pushnumber(lua_newtag(check_string(1, "newtag")));
+  lua_pushnumber(lua_newtag(luaL_check_string(1, "newtag")));
 }
 
 static void basicindex (void)
 {
   lua_Object t = lua_getparam(1);
   lua_Object i = lua_getparam(2);
-  check_arg(t != LUA_NOOBJECT && i != LUA_NOOBJECT, "basicindex");
+  luaL_arg_check(t != LUA_NOOBJECT, "basicindex", 1, NULL);
+  luaL_arg_check(i != LUA_NOOBJECT, "basicindex", 2, NULL);
   lua_pushobject(t);
   lua_pushobject(i);
   lua_pushobject(lua_basicindex());
@@ -321,8 +290,8 @@ static void basicstoreindex (void)
   lua_Object t = lua_getparam(1);
   lua_Object i = lua_getparam(2);
   lua_Object v = lua_getparam(3);
-  check_arg(t != LUA_NOOBJECT && i != LUA_NOOBJECT && v != LUA_NOOBJECT,
-            "basicindex");
+  luaL_arg_check(t != LUA_NOOBJECT && i != LUA_NOOBJECT && v != LUA_NOOBJECT,
+            "basicindex", 0, NULL);
   lua_pushobject(t);
   lua_pushobject(i);
   lua_pushobject(v);
diff --git a/iolib.c b/iolib.c
index bb352009..8315707f 100644
--- a/iolib.c
+++ b/iolib.c
@@ -58,7 +58,7 @@ static void io_readfrom (void)
   else if (lua_isuserdata(f))
     lua_infile = lua_getuserdata(f);
   else {
-    char *s = lua_check_string(1, "readfrom");
+    char *s = luaL_check_string(1, "readfrom");
     FILE *fp = (*s == '|') ? popen(s+1, "r") : fopen(s, "r");
     if (fp)
       lua_infile = fp;
@@ -79,7 +79,7 @@ static void io_writeto (void)
   else if (lua_isuserdata(f))
     lua_outfile = lua_getuserdata(f);
   else {
-    char *s = lua_check_string(1, "writeto");
+    char *s = luaL_check_string(1, "writeto");
     FILE *fp = (*s == '|') ? popen(s+1,"w") : fopen(s,"w");
     if (fp)
       lua_outfile = fp;
@@ -94,7 +94,7 @@ static void io_writeto (void)
 
 static void io_appendto (void)
 {
-  char *s = lua_check_string(1, "appendto");
+  char *s = luaL_check_string(1, "appendto");
   FILE *fp = fopen (s, "a");
   if (fp != NULL) {
     lua_outfile = fp;
@@ -110,7 +110,7 @@ static void io_appendto (void)
 static void io_read (void)
 {
   char *buff;
-  char *p = lua_opt_string(1, "[^\n]*{\n}", "read");
+  char *p = luaL_opt_string(1, "[^\n]*{\n}", "read");
   int inskip = 0;  /* to control {skips} */
   int c = NEED_OTHER;
   luaI_addchar(0);
@@ -161,7 +161,7 @@ static void io_write (void)
   int arg = 1;
   int status = 1;
   char *s;
-  while ((s = lua_opt_string(arg++, NULL, "write")) != NULL)
+  while ((s = luaL_opt_string(arg++, NULL, "write")) != NULL)
     status = status && (fputs(s, lua_outfile) != EOF);
   pushresult(status);
 }
@@ -169,20 +169,20 @@ static void io_write (void)
 
 static void io_execute (void)
 {
-  lua_pushnumber(system(lua_check_string(1, "execute")));
+  lua_pushnumber(system(luaL_check_string(1, "execute")));
 }
 
 
 static void io_remove  (void)
 {
-  pushresult(remove(lua_check_string(1, "remove")) == 0);
+  pushresult(remove(luaL_check_string(1, "remove")) == 0);
 }
 
 
 static void io_rename (void)
 {
-  pushresult(rename(lua_check_string(1, "rename"),
-                    lua_check_string(2, "rename")) == 0);
+  pushresult(rename(luaL_check_string(1, "rename"),
+                    luaL_check_string(2, "rename")) == 0);
 }
 
 
@@ -195,7 +195,7 @@ static void io_tmpname (void)
 
 static void io_getenv (void)
 {
-  lua_pushstring(getenv(lua_check_string(1, "getenv"))); /* if NULL push nil */
+  lua_pushstring(getenv(luaL_check_string(1, "getenv"))); /* if NULL push nil */
 }
 
 
@@ -203,7 +203,7 @@ static void io_date (void)
 {
   time_t t;
   struct tm *tm;
-  char *s = lua_opt_string(1, "%c", "date");
+  char *s = luaL_opt_string(1, "%c", "date");
   char b[BUFSIZ];
   time(&t); tm = localtime(&t);
   if (strftime(b,sizeof(b),s,tm))
@@ -269,7 +269,7 @@ static void lua_printstack (FILE *f)
 
 static void errorfb (void)
 {
-  char *s = lua_opt_string(1, "(no messsage)", NULL);
+  char *s = luaL_opt_string(1, "(no messsage)", NULL);
   fprintf(stderr, "lua: %s\n", s);
   lua_printstack(stderr);
 }
diff --git a/lua.h b/lua.h
index 623465e1..2aeb9981 100644
--- a/lua.h
+++ b/lua.h
@@ -2,7 +2,7 @@
 ** LUA - Linguagem para Usuarios de Aplicacao
 ** Grupo de Tecnologia em Computacao Grafica
 ** TeCGraf - PUC-Rio
-** $Id: lua.h,v 3.34 1997/02/20 15:51:14 roberto Exp roberto $
+** $Id: lua.h,v 3.35 1997/02/26 17:38:41 roberto Unstable roberto $
 */
 
 
@@ -80,6 +80,7 @@ void	       lua_unref		(int ref);
 lua_Object     lua_createtable          (void);
 
 
+/* =============================================================== */
 /* some useful macros */
 
 #define lua_refobject(o,l)      (lua_pushobject(o), lua_ref(l))
@@ -89,7 +90,17 @@ lua_Object     lua_createtable		(void);
 #define lua_pushuserdata(u)     lua_pushusertag(u, 0)
 
 
+/* =============================================================== */
+/* Auxiliar functions for libraries */
 
+void luaL_arg_check(int cond, char *funcname, int numarg, char *extramsg);
+char *luaL_check_string (int numArg, char *funcname);
+char *luaL_opt_string (int numArg, char *def, char *funcname);
+double luaL_check_number (int numArg, char *funcname);
+double luaL_opt_number (int numArg, double def, char *funcname);
+
+
+/* =============================================================== */
 /* for compatibility with old versions. Avoid using these macros */
 
 #define lua_type(o)             (lua_tag(o))
diff --git a/lualib.h b/lualib.h
index ba2d108d..6deb9e97 100644
--- a/lualib.h
+++ b/lualib.h
@@ -2,7 +2,7 @@
 ** Libraries to be used in LUA programs
 ** Grupo de Tecnologia em Computacao Grafica
 ** TeCGraf - PUC-Rio
-** $Id: lualib.h,v 1.9 1996/08/01 14:55:33 roberto Exp roberto $
+** $Id: lualib.h,v 1.10 1996/08/05 20:55:24 roberto Exp roberto $
 */
 
 #ifndef lualib_h
@@ -23,11 +23,6 @@ struct lua_reg {
 };
 
 void luaI_openlib (struct lua_reg *l, int n);
-void lua_arg_check(int cond, char *funcname);
-char *lua_check_string (int numArg, char *funcname);
-char *lua_opt_string (int numArg, char *def, char *funcname);
-double lua_check_number (int numArg, char *funcname);
-long lua_opt_number (int numArg, long def, char *funcname);
 char *luaI_addchar (int c);
 void luaI_addquoted (char *s);
 
diff --git a/makefile b/makefile
index 2f65498e..8e23fcdd 100644
--- a/makefile
+++ b/makefile
@@ -1,4 +1,4 @@
-# $Id: makefile,v 1.27 1996/11/06 20:48:03 roberto Exp roberto $
+# $Id: makefile,v 1.28 1997/03/05 13:37:04 roberto Exp roberto $
 
 #configuration
 
@@ -30,7 +30,8 @@ LUAOBJS = \
         fallback.o \
         mem.o \
         func.o \
-        undump.o
+        undump.o \
+        auxlib.o
 
 LIBOBJS =       \
         iolib.o \
@@ -75,6 +76,7 @@ clear	:
         co $@
 
 
+auxlib.o: auxlib.c lua.h
 fallback.o: fallback.c mem.h fallback.h lua.h opcode.h types.h tree.h \
  func.h table.h hash.h
 func.o: func.c luadebug.h lua.h table.h tree.h types.h opcode.h func.h \
@@ -97,6 +99,6 @@ strlib.o: strlib.c lua.h lualib.h
 table.o: table.c mem.h opcode.h lua.h types.h tree.h func.h hash.h \
  table.h inout.h fallback.h luadebug.h
 tree.o: tree.c mem.h lua.h tree.h types.h lex.h hash.h opcode.h func.h \
- table.h
+ table.h fallback.h
 undump.o: undump.c opcode.h lua.h types.h tree.h func.h mem.h table.h \
  undump.h
diff --git a/mathlib.c b/mathlib.c
index 896ec1f5..0ed1a9a6 100644
--- a/mathlib.c
+++ b/mathlib.c
@@ -3,7 +3,7 @@
 ** Mathematics library to LUA
 */
 
-char *rcs_mathlib="$Id: mathlib.c,v 1.17 1996/04/30 21:13:55 roberto Exp roberto $";
+char *rcs_mathlib="$Id: mathlib.c,v 1.18 1996/08/01 14:55:33 roberto Exp roberto $";
 
 #include <stdlib.h>
 #include <math.h>
@@ -19,7 +19,7 @@ char *rcs_mathlib="$Id: mathlib.c,v 1.17 1996/04/30 21:13:55 roberto Exp roberto
 
 static void math_abs (void)
 {
- double d = lua_check_number(1, "abs"); 
+ double d = luaL_check_number(1, "abs"); 
  if (d < 0) d = -d;
  lua_pushnumber (d);
 }
@@ -27,7 +27,7 @@ static void math_abs (void)
 
 static void math_sin (void)
 {
- double d = lua_check_number(1, "sin");
+ double d = luaL_check_number(1, "sin");
  lua_pushnumber (sin(TORAD(d)));
 }
 
@@ -35,7 +35,7 @@ static void math_sin (void)
 
 static void math_cos (void)
 {
- double d = lua_check_number(1, "cos");
+ double d = luaL_check_number(1, "cos");
  lua_pushnumber (cos(TORAD(d)));
 }
 
@@ -43,64 +43,64 @@ static void math_cos (void)
 
 static void math_tan (void)
 {
- double d = lua_check_number(1, "tan");
+ double d = luaL_check_number(1, "tan");
  lua_pushnumber (tan(TORAD(d)));
 }
 
 
 static void math_asin (void)
 {
- double d = lua_check_number(1, "asin");
+ double d = luaL_check_number(1, "asin");
  lua_pushnumber (TODEGREE(asin(d)));
 }
 
 
 static void math_acos (void)
 {
- double d = lua_check_number(1, "acos");
+ double d = luaL_check_number(1, "acos");
  lua_pushnumber (TODEGREE(acos(d)));
 }
 
 
 static void math_atan (void)
 {
- double d = lua_check_number(1, "atan");
+ double d = luaL_check_number(1, "atan");
  lua_pushnumber (TODEGREE(atan(d)));
 }
 
 
 static void math_atan2 (void)
 {
- double d1 = lua_check_number(1, "atan2");
- double d2 = lua_check_number(2, "atan2");
+ double d1 = luaL_check_number(1, "atan2");
+ double d2 = luaL_check_number(2, "atan2");
  lua_pushnumber (TODEGREE(atan2(d1, d2)));
 }
 
 
 static void math_ceil (void)
 {
- double d = lua_check_number(1, "ceil");
+ double d = luaL_check_number(1, "ceil");
  lua_pushnumber (ceil(d));
 }
 
 
 static void math_floor (void)
 {
- double d = lua_check_number(1, "floor");
+ double d = luaL_check_number(1, "floor");
  lua_pushnumber (floor(d));
 }
 
 static void math_mod (void)
 {
-  float x = lua_check_number(1, "mod");
-  float y = lua_check_number(2, "mod");
+  float x = luaL_check_number(1, "mod");
+  float y = luaL_check_number(2, "mod");
   lua_pushnumber(fmod(x, y));
 }
 
 
 static void math_sqrt (void)
 {
- double d = lua_check_number(1, "sqrt");
+ double d = luaL_check_number(1, "sqrt");
  lua_pushnumber (sqrt(d));
 }
 
@@ -131,10 +131,10 @@ static void math_pow (void)
 static void math_min (void)
 {
  int i=1;
- double dmin = lua_check_number(i, "min");
+ double dmin = luaL_check_number(i, "min");
  while (lua_getparam(++i) != LUA_NOOBJECT)
  {
-  double d = lua_check_number(i, "min");
+  double d = luaL_check_number(i, "min");
   if (d < dmin) dmin = d;
  }
  lua_pushnumber (dmin);
@@ -143,10 +143,10 @@ static void math_min (void)
 static void math_max (void)
 {
  int i=1;
- double dmax = lua_check_number(i, "max");
+ double dmax = luaL_check_number(i, "max");
  while (lua_getparam(++i) != LUA_NOOBJECT)
  {
-  double d = lua_check_number(i, "max");
+  double d = luaL_check_number(i, "max");
   if (d > dmax) dmax = d;
  }
  lua_pushnumber (dmax);
@@ -154,33 +154,33 @@ static void math_max (void)
 
 static void math_log (void)
 {
- double d = lua_check_number(1, "log");
+ double d = luaL_check_number(1, "log");
  lua_pushnumber (log(d));
 }
 
 
 static void math_log10 (void)
 {
- double d = lua_check_number(1, "log10");
+ double d = luaL_check_number(1, "log10");
  lua_pushnumber (log10(d));
 }
 
 
 static void math_exp (void)
 {
- double d = lua_check_number(1, "exp");
+ double d = luaL_check_number(1, "exp");
  lua_pushnumber (exp(d));
 }
 
 static void math_deg (void)
 {
- float d = lua_check_number(1, "deg");
+ float d = luaL_check_number(1, "deg");
  lua_pushnumber (d*180./PI);
 }
 
 static void math_rad (void)
 {
- float d = lua_check_number(1, "rad");
+ float d = luaL_check_number(1, "rad");
  lua_pushnumber (d/180.*PI);
 }
 
@@ -191,7 +191,7 @@ static void math_random (void)
 
 static void math_randomseed (void)
 {
-  srand(lua_check_number(1, "randomseed"));
+  srand(luaL_check_number(1, "randomseed"));
 }
 
 
diff --git a/strlib.c b/strlib.c
index fef0e1ef..3db67936 100644
--- a/strlib.c
+++ b/strlib.c
@@ -3,7 +3,7 @@
 ** String library to LUA
 */
 
-char *rcs_strlib="$Id: strlib.c,v 1.34 1996/11/22 13:08:02 roberto Exp roberto $";
+char *rcs_strlib="$Id: strlib.c,v 1.35 1997/02/21 15:21:34 roberto Exp roberto $";
 
 #include <string.h>
 #include <stdio.h>
@@ -42,41 +42,6 @@ static char *openspace (unsigned long size)
   return buff+lbuffer.size;
 }
 
-void lua_arg_check(int cond, char *funcname)
-{
-  if (!cond) {
-    char buff[100];
-    sprintf(buff, "incorrect argument to function `%s'", funcname);
-    lua_error(buff);
-  }
-}
-
-char *lua_check_string (int numArg, char *funcname)
-{
-  lua_Object o = lua_getparam(numArg);
-  lua_arg_check(lua_isstring(o), funcname);
-  return lua_getstring(o);
-}
-
-char *lua_opt_string (int numArg, char *def, char *funcname)
-{
-  return (lua_getparam(numArg) == LUA_NOOBJECT) ? def :
-                              lua_check_string(numArg, funcname);
-}
-
-double lua_check_number (int numArg, char *funcname)
-{
-  lua_Object o = lua_getparam(numArg);
-  lua_arg_check(lua_isnumber(o), funcname);
-  return lua_getnumber(o);
-}
-
-long lua_opt_number (int numArg, long def, char *funcname)
-{
-  return (lua_getparam(numArg) == LUA_NOOBJECT) ? def :
-                              (long)lua_check_number(numArg, funcname);
-}
-
 char *luaI_addchar (int c)
 {
   if (lbuffer.size >= lbuffer.max)
@@ -104,8 +69,8 @@ static void addstr (char *s)
 */
 static void str_tok (void)
 {
-  char *s1 = lua_check_string(1, "strtok");
-  char *del = lua_check_string(2, "strtok");
+  char *s1 = luaL_check_string(1, "strtok");
+  char *del = luaL_check_string(2, "strtok");
   lua_Object t = lua_createtable();
   int i = 1;
   /* As strtok changes s1, and s1 is "constant",  make a copy of it */
@@ -127,7 +92,7 @@ static void str_tok (void)
 */
 static void str_len (void)
 {
- lua_pushnumber(strlen(lua_check_string(1, "strlen")));
+ lua_pushnumber(strlen(luaL_check_string(1, "strlen")));
 }
 
 /*
@@ -135,9 +100,9 @@ static void str_len (void)
 */
 static void str_sub (void)
 {
-  char *s = lua_check_string(1, "strsub");
-  long start = (long)lua_check_number(2, "strsub");
-  long end = lua_opt_number(3, strlen(s), "strsub");
+  char *s = luaL_check_string(1, "strsub");
+  long start = (long)luaL_check_number(2, "strsub");
+  long end = (long)luaL_opt_number(3, strlen(s), "strsub");
   if (1 <= start && start <= end && end <= strlen(s)) {
     luaI_addchar(0);
     addnchar(s+start-1, end-start+1);
@@ -151,7 +116,7 @@ static void str_sub (void)
 */
 static void str_lower (void)
 {
-  char *s = lua_check_string(1, "strlower");
+  char *s = luaL_check_string(1, "strlower");
   luaI_addchar(0);
   while (*s)
     luaI_addchar(tolower((unsigned char)*s++));
@@ -163,7 +128,7 @@ static void str_lower (void)
 */
 static void str_upper (void)
 {
-  char *s = lua_check_string(1, "strupper");
+  char *s = luaL_check_string(1, "strupper");
   luaI_addchar(0);
   while (*s)
     luaI_addchar(toupper((unsigned char)*s++));
@@ -172,8 +137,8 @@ static void str_upper (void)
 
 static void str_rep (void)
 {
-  char *s = lua_check_string(1, "strrep");
-  int n = (int)lua_check_number(2, "strrep");
+  char *s = luaL_check_string(1, "strrep");
+  int n = (int)luaL_check_number(2, "strrep");
   luaI_addchar(0);
   while (n-- > 0)
     addstr(s);
@@ -185,9 +150,9 @@ static void str_rep (void)
 */
 static void str_ascii (void)
 {
-  char *s = lua_check_string(1, "ascii");
-  long pos = lua_opt_number(2, 1, "ascii") - 1;
-  lua_arg_check(0<=pos && pos<strlen(s), "ascii");
+  char *s = luaL_check_string(1, "ascii");
+  long pos = (long)luaL_opt_number(2, 1, "ascii") - 1;
+  luaL_arg_check(0<=pos && pos<strlen(s), "ascii", 2,  "out of range");
   lua_pushnumber((unsigned char)s[pos]);
 }
 
@@ -394,10 +359,10 @@ static char *match (char *s, char *p, int level)
 
 static void str_find (void)
 {
-  char *s = lua_check_string(1, "strfind");
-  char *p = lua_check_string(2, "strfind");
-  long init = lua_opt_number(3, 1, "strfind") - 1;
-  lua_arg_check(0 <= init && init <= strlen(s), "strfind");
+  char *s = luaL_check_string(1, "strfind");
+  char *p = luaL_check_string(2, "strfind");
+  long init = (long)luaL_opt_number(3, 1, "strfind") - 1;
+  luaL_arg_check(0 <= init && init <= strlen(s), "strfind", 3, "out of range");
   if (lua_getparam(4) != LUA_NOOBJECT || 
       strpbrk(p, SPECIALS) == NULL) {  /* no special caracters? */
     char *s2 = strstr(s+init, p);
@@ -450,15 +415,15 @@ static void add_s (lua_Object newp)
     addstr(lua_isstring(res) ? lua_getstring(res) : "");
     lua_endblock();
   }
-  else lua_arg_check(0, "gsub");
+  else luaL_arg_check(0, "gsub", 3, NULL);
 }
 
 static void str_gsub (void)
 {
-  char *src = lua_check_string(1, "gsub");
-  char *p = lua_check_string(2, "gsub");
+  char *src = luaL_check_string(1, "gsub");
+  char *p = luaL_check_string(2, "gsub");
   lua_Object newp = lua_getparam(3);
-  int max_s = lua_opt_number(4, strlen(src)+1, "gsub");
+  int max_s = (int)luaL_opt_number(4, strlen(src)+1, "gsub");
   int anchor = (*p == '^') ? (p++, 1) : 0;
   int n = 0;
   luaI_addchar(0);
@@ -482,9 +447,9 @@ static void str_gsub (void)
 
 static void str_set (void)
 {
-  char *item = lua_check_string(1, "strset");
+  char *item = luaL_check_string(1, "strset");
   int i;
-  lua_arg_check(*item_end(item) == 0, "strset");
+  luaL_arg_check(*item_end(item) == 0, "strset", 1, "wrong format");
   luaI_addchar(0);
   for (i=1; i<256; i++)  /* 0 cannot be part of a set */
     if (singlematch(i, item))
@@ -509,7 +474,7 @@ void luaI_addquoted (char *s)
 static void str_format (void)
 {
   int arg = 1;
-  char *strfrmt = lua_check_string(arg++, "format");
+  char *strfrmt = luaL_check_string(arg++, "format");
   luaI_addchar(0);  /* initialize */
   while (*strfrmt) {
     if (*strfrmt != '%')
@@ -528,20 +493,20 @@ static void str_format (void)
       buff = openspace(1000);  /* to store the formated value */
       switch (*strfrmt++) {
         case 'q':
-          luaI_addquoted(lua_check_string(arg++, "format"));
+          luaI_addquoted(luaL_check_string(arg++, "format"));
           continue;
         case 's': {
-          char *s = lua_check_string(arg++, "format");
+          char *s = luaL_check_string(arg++, "format");
           buff = openspace(strlen(s));
           sprintf(buff, form, s);
           break;
         }
         case 'c':  case 'd':  case 'i': case 'o':
         case 'u':  case 'x':  case 'X':
-          sprintf(buff, form, (int)lua_check_number(arg++, "format"));
+          sprintf(buff, form, (int)luaL_check_number(arg++, "format"));
           break;
         case 'e':  case 'E': case 'f': case 'g':
-          sprintf(buff, form, lua_check_number(arg++, "format"));
+          sprintf(buff, form, luaL_check_number(arg++, "format"));
           break;
         default:  /* also treat cases 'pnLlh' */
           lua_error("invalid format option in function `format'");