/*** $Id: lauxlib.c,v 1.159 2006/03/21 19:31:09 roberto Exp $** Auxiliary functions for building Lua libraries** See Copyright Notice in lua.h*/#include <ctype.h>#include <errno.h>#include <stdarg.h>#include <stdio.h>#include <stdlib.h>#include <string.h>/* This file uses only the official API of Lua.** Any function declared here could be written as an application function.*/#define lauxlib_c#define LUA_LIB#include "lua.h"#include "lauxlib.h"#define FREELIST_REF	0	/* free list of references *//* convert a stack index to positive */#define abs_index(L, i)		((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \					lua_gettop(L) + (i) + 1)/*** {======================================================** Error-report functions** =======================================================*/LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {  lua_Debug ar;  if (!lua_getstack(L, 0, &ar))  /* no stack frame? */    return luaL_error(L, "bad argument #%d (%s)", narg, extramsg);  lua_getinfo(L, "n", &ar);  if (strcmp(ar.namewhat, "method") == 0) {    narg--;  /* do not count `self' */    if (narg == 0)  /* error is in the self argument itself? */      return luaL_error(L, "calling " LUA_QS " on bad self (%s)",                           ar.name, extramsg);  }  if (ar.name == NULL)    ar.name = "?";  return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)",                        narg, ar.name, extramsg);}LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname) {  const char *msg = lua_pushfstring(L, "%s expected, got %s",                                    tname, luaL_typename(L, narg));  return luaL_argerror(L, narg, msg);}static void tag_error (lua_State *L, int narg, int tag) {  luaL_typerror(L, narg, lua_typename(L, tag));}LUALIB_API void luaL_where (lua_State *L, int level) {  lua_Debug ar;  if (lua_getstack(L, level, &ar)) {  /* check function at level */    lua_getinfo(L, "Sl", &ar);  /* get info about it */    if (ar.currentline > 0) {  /* is there info? */      lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);      return;    }  }  lua_pushliteral(L, "");  /* else, no information available... */}LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {  va_list argp;  va_start(argp, fmt);  luaL_where(L, 1);  lua_pushvfstring(L, fmt, argp);  va_end(argp);  lua_concat(L, 2);  return lua_error(L);}/* }====================================================== */LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def,                                 const char *const lst[]) {  const char *name = (def) ? luaL_optstring(L, narg, def) :                             luaL_checkstring(L, narg);  int i;  for (i=0; lst[i]; i++)    if (strcmp(lst[i], name) == 0)      return i;  return luaL_argerror(L, narg,                       lua_pushfstring(L, "invalid option " LUA_QS, name));}LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {  lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get registry.name */  if (!lua_isnil(L, -1))  /* name already in use? */    return 0;  /* leave previous value on top, but return 0 */  lua_pop(L, 1);  lua_newtable(L);  /* create metatable */  lua_pushvalue(L, -1);  lua_setfield(L, LUA_REGISTRYINDEX, tname);  /* registry.name = metatable */  return 1;}LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {  void *p = lua_touserdata(L, ud);  if (p != NULL) {  /* value is a userdata? */    if (lua_getmetatable(L, ud)) {  /* does it have a metatable? */      lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get correct metatable */      if (lua_rawequal(L, -1, -2)) {  /* does it have the correct mt? */        lua_pop(L, 2);  /* remove both metatables */        return p;      }    }  }  luaL_typerror(L, ud, tname);  /* else error */  return NULL;  /* to avoid warnings */}LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) {  if (!lua_checkstack(L, space))    luaL_error(L, "stack overflow (%s)", mes);}LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) {  if (lua_type(L, narg) != t)    tag_error(L, narg, t);}LUALIB_API void luaL_checkany (lua_State *L, int narg) {  if (lua_type(L, narg) == LUA_TNONE)    luaL_argerror(L, narg, "value expected");}LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) {  const char *s = lua_tolstring(L, narg, len);  if (!s) tag_error(L, narg, LUA_TSTRING);  return s;}LUALIB_API const char *luaL_optlstring (lua_State *L, int narg,                                        const char *def, size_t *len) {  if (lua_isnoneornil(L, narg)) {    if (len)      *len = (def ? strlen(def) : 0);    return def;  }  else return luaL_checklstring(L, narg, len);}LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) {  lua_Number d = lua_tonumber(L, narg);  if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */    tag_error(L, narg, LUA_TNUMBER);  return d;}LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {  return luaL_opt(L, luaL_checknumber, narg, def);}LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) {  lua_Integer d = lua_tointeger(L, narg);  if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */    tag_error(L, narg, LUA_TNUMBER);  return d;}LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,                                                      lua_Integer def) {  return luaL_opt(L, luaL_checkinteger, narg, def);}LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {  if (!lua_getmetatable(L, obj))  /* no metatable? */    return 0;  lua_pushstring(L, event);  lua_rawget(L, -2);  if (lua_isnil(L, -1)) {    lua_pop(L, 2);  /* remove metatable and metafield */    return 0;  }  else {    lua_remove(L, -2);  /* remove only metatable */    return 1;  }}LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {  obj = abs_index(L, obj);  if (!luaL_getmetafield(L, obj, event))  /* no metafield? */    return 0;  lua_pushvalue(L, obj);  lua_call(L, 1, 1);  return 1;}LUALIB_API void (luaL_register) (lua_State *L, const char *libname,                                const luaL_Reg *l) {  luaI_openlib(L, libname, l, 0);}static int libsize (const luaL_Reg *l) {  int size = 0;  for (; l->name; l++) size++;  return size;}LUALIB_API void luaI_openlib (lua_State *L, const char *libname,                              const luaL_Reg *l, int nup) {  if (libname) {    int size = libsize(l);    /* check whether lib already exists */    luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", size);    lua_getfield(L, -1, libname);  /* get _LOADED[libname] */    if (!lua_istable(L, -1)) {  /* not found? */      lua_pop(L, 1);  /* remove previous result */      /* try global variable (and create one if it does not exist) */      if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)        luaL_error(L, "name conflict for module " LUA_QS, libname);      lua_pushvalue(L, -1);      lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */    }    lua_remove(L, -2);  /* remove _LOADED table */    lua_insert(L, -(nup+1));  /* move library table to below upvalues */  }  for (; l->name; l++) {    int i;    for (i=0; i<nup; i++)  /* copy upvalues to the top */      lua_pushvalue(L, -nup);    lua_pushcclosure(L, l->func, nup);    lua_setfield(L, -(nup+2), l->name);  }  lua_pop(L, nup);  /* remove upvalues */}/*** {======================================================** getn-setn: size for arrays** =======================================================*/#if defined(LUA_COMPAT_GETN)static int checkint (lua_State *L, int topop) {  int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;  lua_pop(L, topop);  return n;}static void getsizes (lua_State *L) {  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  if (lua_isnil(L, -1)) {  /* no `size' table? */    lua_pop(L, 1);  /* remove nil */    lua_newtable(L);  /* create it */    lua_pushvalue(L, -1);  /* `size' will be its own metatable */    lua_setmetatable(L, -2);    lua_pushliteral(L, "kv");    lua_setfield(L, -2, "__mode");  /* metatable(N).__mode = "kv" */    lua_pushvalue(L, -1);    lua_setfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  /* store in register */  }}LUALIB_API void luaL_setn (lua_State *L, int t, int n) {  t = abs_index(L, t);  lua_pushliteral(L, "n");  lua_rawget(L, t);  if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */    lua_pushliteral(L, "n");  /* use it */    lua_pushinteger(L, n);    lua_rawset(L, t);  }  else {  /* use `sizes' */    getsizes(L);    lua_pushvalue(L, t);    lua_pushinteger(L, n);    lua_rawset(L, -3);  /* sizes[t] = n */    lua_pop(L, 1);  /* remove `sizes' */  }}LUALIB_API int luaL_getn (lua_State *L, int t) {  int n;  t = abs_index(L, t);  lua_pushliteral(L, "n");  /* try t.n */  lua_rawget(L, t);  if ((n = checkint(L, 1)) >= 0) return n;  getsizes(L);  /* else try sizes[t] */