#define lauxlib_c

#define LUA_LIB

#include "lprefix.h"

#include <errno.h>

#include <stdarg.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "lua.h"

#include "lauxlib.h"

#include "llimits.h"

#define LEVELS1 10 /* size of the first part of the stack */

#define LEVELS2 11 /* size of the second part of the stack */

static int findfield (lua_State *L, int objidx, int level) {

if (level == 0 || !lua_istable(L, -1))

return 0; /* not found */

lua_pushnil(L); /* start 'next' loop */

while (lua_next(L, -2)) { /* for each pair in table */

if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */

if (lua_rawequal(L, objidx, -1)) { /* found object? */

lua_pop(L, 1); /* remove value (but keep name) */

return 1;

}

else if (findfield(L, objidx, level - 1)) { /* try recursively */

/* stack: lib_name, lib_table, field_name (top) */

lua_pushliteral(L, "."); /* place '.' between the two names */

lua_replace(L, -3); /* (in the slot occupied by table) */

lua_concat(L, 3); /* lib_name.field_name */

return 1;

}

}

lua_pop(L, 1); /* remove value */

}

return 0; /* not found */

}

static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {

int top = lua_gettop(L);

lua_getinfo(L, "f", ar); /* push function */

lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);

luaL_checkstack(L, 6, "not enough stack"); /* slots for 'findfield' */

if (findfield(L, top + 1, 2)) {

const char *name = lua_tostring(L, -1);

if (strncmp(name, LUA_GNAME ".", 3) == 0) { /* name start with '_G.'? */

lua_pushstring(L, name + 3); /* push name without prefix */

lua_remove(L, -2); /* remove original name */

}

lua_copy(L, -1, top + 1); /* copy name to proper place */

lua_settop(L, top + 1); /* remove table "loaded" and name copy */

return 1;

}

else {

lua_settop(L, top); /* remove function and global table */

return 0;

}

}

static void pushfuncname (lua_State *L, lua_Debug *ar) {

if (*ar->namewhat != '\0') /* is there a name from code? */

lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name); /* use it */

else if (*ar->what == 'm') /* main? */

lua_pushliteral(L, "main chunk");

else if (pushglobalfuncname(L, ar)) { /* try a global name */

lua_pushfstring(L, "function '%s'", lua_tostring(L, -1));

lua_remove(L, -2); /* remove name */

}

else if (*ar->what != 'C') /* for Lua functions, use <file:line> */

lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);

else /* nothing left... */

lua_pushliteral(L, "?");

}

static int lastlevel (lua_State *L) {

lua_Debug ar;

int li = 1, le = 1;

/* find an upper bound */

while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }

/* do a binary search */

while (li < le) {

int m = (li + le)/2;

if (lua_getstack(L, m, &ar)) li = m + 1;

else le = m;

}

return le - 1;

}

LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,

const char *msg, int level) {

luaL_Buffer b;

lua_Debug ar;

int last = lastlevel(L1);

int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;

luaL_buffinit(L, &b);

if (msg) {

luaL_addstring(&b, msg);

luaL_addchar(&b, '\n');

}

luaL_addstring(&b, "stack traceback:");

while (lua_getstack(L1, level++, &ar)) {

if (limit2show-- == 0) { /* too many levels? */

int n = last - level - LEVELS2 + 1; /* number of levels to skip */

lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n);

luaL_addvalue(&b); /* add warning about skip */

level += n; /* and skip to last levels */

}

else {

lua_getinfo(L1, "Slnt", &ar);

if (ar.currentline <= 0)

lua_pushfstring(L, "\n\t%s: in ", ar.short_src);

else

lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline);

luaL_addvalue(&b);

pushfuncname(L, &ar);

luaL_addvalue(&b);

if (ar.istailcall)

luaL_addstring(&b, "\n\t(...tail calls...)");

}

}

luaL_pushresult(&b);

}

LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {

lua_Debug ar;

const char *argword;

if (!lua_getstack(L, 0, &ar)) /* no stack frame? */

return luaL_error(L, "bad argument #%d (%s)", arg, extramsg);

lua_getinfo(L, "nt", &ar);

if (arg <= ar.extraargs) /* error in an extra argument? */

argword = "extra argument";

else {

arg -= ar.extraargs; /* do not count extra arguments */

if (strcmp(ar.namewhat, "method") == 0) { /* colon syntax? */

arg--; /* do not count (extra) self argument */

if (arg == 0) /* error in self argument? */

return luaL_error(L, "calling '%s' on bad self (%s)",

ar.name, extramsg);

/* else go through; error in a regular argument */

}

argword = "argument";

}

if (ar.name == NULL)

ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?";

return luaL_error(L, "bad %s #%d to '%s' (%s)",

argword, arg, ar.name, extramsg);

}

LUALIB_API int luaL_typeerror (lua_State *L, int arg, const char *tname) {

const char *msg;

const char *typearg; /* name for the type of the actual argument */

if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)

typearg = lua_tostring(L, -1); /* use the given type name */

else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA)

typearg = "light userdata"; /* special name for messages */

else

typearg = luaL_typename(L, arg); /* standard name */

msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg);

return luaL_argerror(L, arg, msg);

}

static void tag_error (lua_State *L, int arg, int tag) {

luaL_typeerror(L, arg, 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_pushfstring(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_fileresult (lua_State *L, int stat, const char *fname) {

int en = errno; /* calls to Lua API may change this value */

if (stat) {

lua_pushboolean(L, 1);

return 1;

}

else {

const char *msg;

luaL_pushfail(L);

msg = (en != 0) ? strerror(en) : "(no extra info)";

if (fname)

lua_pushfstring(L, "%s: %s", fname, msg);

else

lua_pushstring(L, msg);

lua_pushinteger(L, en);

return 3;

}

}

#if !defined(l_inspectstat) /* { */

#if defined(LUA_USE_POSIX)

#include <sys/wait.h>

#define l_inspectstat(stat,what) \

if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \

else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }

#define l_inspectstat(stat,what) /* no op */

#endif /* } */

LUALIB_API int luaL_execresult (lua_State *L, int stat) {

if (stat != 0 && errno != 0) /* error with an 'errno'? */

return luaL_fileresult(L, 0, NULL);

else {

const char *what = "exit"; /* type of termination */

l_inspectstat(stat, what); /* interpret result */

if (*what == 'e' && stat == 0) /* successful termination? */

lua_pushboolean(L, 1);

else

luaL_pushfail(L);

lua_pushstring(L, what);

lua_pushinteger(L, stat);

return 3; /* return true/fail,what,code */

}

}

LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {

if (luaL_getmetatable(L, tname) != LUA_TNIL) /* name already in use? */

return 0; /* leave previous value on top, but return 0 */

lua_pop(L, 1);

lua_createtable(L, 0, 2); /* create metatable */

lua_pushstring(L, tname);

lua_setfield(L, -2, "__name"); /* metatable.__name = tname */

lua_pushvalue(L, -1);

lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */

return 1;

}

LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) {

luaL_getmetatable(L, tname);

lua_setmetatable(L, -2);

}

LUALIB_API void *luaL_testudata (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? */

luaL_getmetatable(L, tname); /* get correct metatable */

if (!lua_rawequal(L, -1, -2)) /* not the same? */

p = NULL; /* value is a userdata with wrong metatable */

lua_pop(L, 2); /* remove both metatables */

return p;

}

}

return NULL; /* value is not a userdata with a metatable */

}

LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {

void *p = luaL_testudata(L, ud, tname);

luaL_argexpected(L, p != NULL, ud, tname);

return p;

}

LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,

const char *const lst[]) {

const char *name = (def) ? luaL_optstring(L, arg, def) :

luaL_checkstring(L, arg);

int i;

for (i=0; lst[i]; i++)

if (strcmp(lst[i], name) == 0)

return i;

return luaL_argerror(L, arg,

lua_pushfstring(L, "invalid option '%s'", name));

}

LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {

if (l_unlikely(!lua_checkstack(L, space))) {

if (msg)

luaL_error(L, "stack overflow (%s)", msg);

else

luaL_error(L, "stack overflow");

}

}

LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) {

if (l_unlikely(lua_type(L, arg) != t))

tag_error(L, arg, t);

}

LUALIB_API void luaL_checkany (lua_State *L, int arg) {

if (l_unlikely(lua_type(L, arg) == LUA_TNONE))

luaL_argerror(L, arg, "value expected");

}

LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) {

const char *s = lua_tolstring(L, arg, len);

if (l_unlikely(!s)) tag_error(L, arg, LUA_TSTRING);

return s;

}

LUALIB_API const char *luaL_optlstring (lua_State *L, int arg,

const char *def, size_t *len) {

if (lua_isnoneornil(L, arg)) {

if (len)

*len = (def ? strlen(def) : 0);

return def;

}

else return luaL_checklstring(L, arg, len);

}

LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) {

int isnum;

lua_Number d = lua_tonumberx(L, arg, &isnum);

if (l_unlikely(!isnum))

tag_error(L, arg, LUA_TNUMBER);

return d;

}

LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) {

return luaL_opt(L, luaL_checknumber, arg, def);

}

static void interror (lua_State *L, int arg) {

if (lua_isnumber(L, arg))

luaL_argerror(L, arg, "number has no integer representation");

else

tag_error(L, arg, LUA_TNUMBER);

}

LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) {

int isnum;

lua_Integer d = lua_tointegerx(L, arg, &isnum);

if (l_unlikely(!isnum)) {

interror(L, arg);

}

return d;

}

LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg,

lua_Integer def) {

return luaL_opt(L, luaL_checkinteger, arg, def);

}

typedef struct UBox {

void *box;

size_t bsize;

} UBox;

static void *resizebox (lua_State *L, int idx, size_t newsize) {

UBox *box = (UBox *)lua_touserdata(L, idx);

if (box->bsize == newsize) /* not changing size? */

return box->box; /* keep the buffer */

else {

void *ud;

lua_Alloc allocf = lua_getallocf(L, &ud);

void *temp = allocf(ud, box->box, box->bsize, newsize);

if (l_unlikely(temp == NULL && newsize > 0)) { /* allocation error? */

lua_pushliteral(L, "not enough memory");

lua_error(L); /* raise a memory error */

}

box->box = temp;

box->bsize = newsize;

return temp;

}

}

static int boxgc (lua_State *L) {

resizebox(L, 1, 0);

return 0;

}

static const luaL_Reg boxmt[] = { /* box metamethods */

{"__gc", boxgc},

{"__close", boxgc},

{NULL, NULL}

};

static void newbox (lua_State *L) {

UBox *box = (UBox *)lua_newuserdatauv(L, sizeof(UBox), 0);

box->box = NULL;

box->bsize = 0;

if (luaL_newmetatable(L, "_UBOX*")) /* creating metatable? */

luaL_setfuncs(L, boxmt, 0); /* set its metamethods */

lua_setmetatable(L, -2);

}

#define buffonstack(B) ((B)->b != (B)->init.b)

#define checkbufferlevel(B,idx) \

lua_assert(buffonstack(B) ? lua_touserdata(B->L, idx) != NULL \

: lua_touserdata(B->L, idx) == (void*)B)

static size_t newbuffsize (luaL_Buffer *B, size_t sz) {

size_t newsize = B->size;

if (l_unlikely(sz >= MAX_SIZE - B->n))

return cast_sizet(luaL_error(B->L, "resulting string too large"));

/* else B->n + sz + 1 <= MAX_SIZE */

if (newsize <= MAX_SIZE/3 * 2) /* no overflow? */

newsize += (newsize >> 1); /* new size *= 1.5 */

if (newsize < B->n + sz + 1) /* not big enough? */

newsize = B->n + sz + 1;

return newsize;

}

static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {

checkbufferlevel(B, boxidx);

if (B->size - B->n >= sz) /* enough space? */

return B->b + B->n;

else {

lua_State *L = B->L;

char *newbuff;

size_t newsize = newbuffsize(B, sz);

/* create larger buffer */

if (buffonstack(B)) /* buffer already has a box? */

newbuff = (char *)resizebox(L, boxidx, newsize); /* resize it */

else { /* no box yet */

lua_remove(L, boxidx); /* remove placeholder */

newbox(L); /* create a new box */

lua_insert(L, boxidx); /* move box to its intended position */

lua_toclose(L, boxidx);

newbuff = (char *)resizebox(L, boxidx, newsize);

memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */

}

B->b = newbuff;

B->size = newsize;

return newbuff + B->n;

}

}

LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {

return prepbuffsize(B, sz, -1);

}

LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {

if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */

char *b = prepbuffsize(B, l, -1);

memcpy(b, s, l * sizeof(char));

luaL_addsize(B, l);

}

}

LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {

luaL_addlstring(B, s, strlen(s));

}

LUALIB_API void luaL_pushresult (luaL_Buffer *B) {

lua_State *L = B->L;

checkbufferlevel(B, -1);

if (!buffonstack(B)) /* using static buffer? */

lua_pushlstring(L, B->b, B->n); /* save result as regular string */

else { /* reuse buffer already allocated */

UBox *box = (UBox *)lua_touserdata(L, -1);

void *ud;

lua_Alloc allocf = lua_getallocf(L, &ud); /* function to free buffer */

size_t len = B->n; /* final string length */

char *s;

resizebox(L, -1, len + 1); /* adjust box size to content size */

s = (char*)box->box; /* final buffer address */

s[len] = '\0'; /* add ending zero */

/* clear box, as Lua will take control of the buffer */

box->bsize = 0; box->box = NULL;

lua_pushexternalstring(L, s, len, allocf, ud);

lua_closeslot(L, -2); /* close the box */

lua_gc(L, LUA_GCSTEP, len);

}

lua_remove(L, -2); /* remove box or placeholder from the stack */

}

LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {

luaL_addsize(B, sz);

luaL_pushresult(B);

}

LUALIB_API void luaL_addvalue (luaL_Buffer *B) {

lua_State *L = B->L;

size_t len;

const char *s = lua_tolstring(L, -1, &len);

char *b = prepbuffsize(B, len, -2);

memcpy(b, s, len * sizeof(char));

luaL_addsize(B, len);

lua_pop(L, 1); /* pop string */

}

LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {

B->L = L;

B->b = B->init.b;

B->n = 0;

B->size = LUAL_BUFFERSIZE;

lua_pushlightuserdata(L, (void*)B); /* push placeholder */

}

LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {

luaL_buffinit(L, B);

return prepbuffsize(B, sz, -1);

}

LUALIB_API int luaL_ref (lua_State *L, int t) {

int ref;

if (lua_isnil(L, -1)) {

lua_pop(L, 1); /* remove from stack */

return LUA_REFNIL; /* 'nil' has a unique fixed reference */

}

t = lua_absindex(L, t);

if (lua_rawgeti(L, t, 1) == LUA_TNUMBER) /* already initialized? */

ref = (int)lua_tointeger(L, -1); /* ref = t[1] */

else { /* first access */

lua_assert(!lua_toboolean(L, -1)); /* must be nil or false */

ref = 0; /* list is empty */

lua_pushinteger(L, 0); /* initialize as an empty list */

lua_rawseti(L, t, 1); /* ref = t[1] = 0 */

}

lua_pop(L, 1); /* remove element from stack */

if (ref != 0) { /* any free element? */

lua_rawgeti(L, t, ref); /* remove it from list */

lua_rawseti(L, t, 1); /* (t[1] = t[ref]) */

}

else /* no free elements */

ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */

lua_rawseti(L, t, ref);

return ref;

}

LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {

if (ref >= 0) {

t = lua_absindex(L, t);

lua_rawgeti(L, t, 1);

lua_assert(lua_isinteger(L, -1));

lua_rawseti(L, t, ref); /* t[ref] = t[1] */

lua_pushinteger(L, ref);

lua_rawseti(L, t, 1); /* t[1] = ref */

}

}

typedef struct LoadF {

} LoadF;

static const char *getF (lua_State *L, void *ud, size_t *size) {

LoadF *lf = (LoadF *)ud;

UNUSED(L);

if (lf->n > 0) { /* are there pre-read characters to be read? */

*size = lf->n; /* return them (chars already in buffer) */

lf->n = 0; /* no more pre-read characters */

}

else { /* read a block from file */

/* 'fread' can return > 0 *and* set the EOF flag. If next call to

if (feof(lf->f)) return NULL;

*size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */

}

return lf->buff;

}

static int errfile (lua_State *L, const char *what, int fnameindex) {

int err = errno;

const char *filename = lua_tostring(L, fnameindex) + 1;

if (err != 0)

lua_pushfstring(L, "cannot %s %s: %s", what, filename, strerror(err));

else

lua_pushfstring(L, "cannot %s %s", what, filename);

lua_remove(L, fnameindex);

return LUA_ERRFILE;

}

static int skipBOM (FILE *f) {

int c = getc(f); /* read first character */

if (c == 0xEF && getc(f) == 0xBB && getc(f) == 0xBF) /* correct BOM? */

return getc(f); /* ignore BOM and return next char */

else /* no (valid) BOM */

return c; /* return first character */

}

static int skipcomment (FILE *f, int *cp) {

int c = *cp = skipBOM(f);

if (c == '#') { /* first line is a comment (Unix exec. file)? */

do { /* skip first line */

c = getc(f);

} while (c != EOF && c != '\n');

*cp = getc(f); /* next character after comment, if present */

return 1; /* there was a comment */

}

else return 0; /* no comment */

}

LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,

const char *mode) {

LoadF lf;

int status, readstatus;

int c;

int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */

if (filename == NULL) {

lua_pushliteral(L, "=stdin");

lf.f = stdin;

}

else {

lua_pushfstring(L, "@%s", filename);

errno = 0;

lf.f = fopen(filename, "r");

if (lf.f == NULL) return errfile(L, "open", fnameindex);

}

lf.n = 0;

if (skipcomment(lf.f, &c)) /* read initial portion */

lf.buff[lf.n++] = '\n'; /* add newline to correct line numbers */

if (c == LUA_SIGNATURE[0]) { /* binary file? */

lf.n = 0; /* remove possible newline */

if (filename) { /* "real" file? */

errno = 0;

lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */

if (lf.f == NULL) return errfile(L, "reopen", fnameindex);

skipcomment(lf.f, &c); /* re-read initial portion */

}

}

if (c != EOF)

lf.buff[lf.n++] = cast_char(c); /* 'c' is the first character */

status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);

readstatus = ferror(lf.f);

errno = 0; /* no useful error number until here */

if (filename) fclose(lf.f); /* close file (even in case of errors) */

if (readstatus) {

lua_settop(L, fnameindex); /* ignore results from 'lua_load' */

return errfile(L, "read", fnameindex);

}

lua_remove(L, fnameindex);

return status;

}

typedef struct LoadS {

const char *s;

size_t size;

} LoadS;

static const char *getS (lua_State *L, void *ud, size_t *size) {

LoadS *ls = (LoadS *)ud;

UNUSED(L);

if (ls->size == 0) return NULL;

*size = ls->size;

ls->size = 0;

return ls->s;

}

LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size,

const char *name, const char *mode) {

LoadS ls;

ls.s = buff;

ls.size = size;

return lua_load(L, getS, &ls, name, mode);

}

LUALIB_API int luaL_loadstring (lua_State *L, const char *s) {

return luaL_loadbuffer(L, s, strlen(s), s);

}

LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {

if (!lua_getmetatable(L, obj)) /* no metatable? */

return LUA_TNIL;

else {

int tt;

lua_pushstring(L, event);

tt = lua_rawget(L, -2);

if (tt == LUA_TNIL) /* is metafield nil? */

lua_pop(L, 2); /* remove metatable and metafield */

else

lua_remove(L, -2); /* remove only metatable */

return tt; /* return metafield type */

}

}

LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {

obj = lua_absindex(L, obj);

if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */

return 0;

lua_pushvalue(L, obj);

lua_call(L, 1, 1);

return 1;

}

LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {

lua_Integer l;

int isnum;

lua_len(L, idx);

l = lua_tointegerx(L, -1, &isnum);

if (l_unlikely(!isnum))

luaL_error(L, "object length is not an integer");

lua_pop(L, 1); /* remove object */

return l;

}

LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {

idx = lua_absindex(L,idx);

if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */

if (!lua_isstring(L, -1))

luaL_error(L, "'__tostring' must return a string");

}

else {

switch (lua_type(L, idx)) {

case LUA_TNUMBER: {

char buff[LUA_N2SBUFFSZ];

lua_numbertocstring(L, idx, buff);

lua_pushstring(L, buff);

break;

}

case LUA_TSTRING:

lua_pushvalue(L, idx);

break;

case LUA_TBOOLEAN:

lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false"));

break;

case LUA_TNIL:

lua_pushliteral(L, "nil");

break;

default: {

int tt = luaL_getmetafield(L, idx, "__name"); /* try name */

const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) :

luaL_typename(L, idx);

lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx));

if (tt != LUA_TNIL)

lua_remove(L, -2); /* remove '__name' */

break;

}

}

}

return lua_tolstring(L, -1, len);

}

LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {

luaL_checkstack(L, nup, "too many upvalues");

for (; l->name != NULL; l++) { /* fill the table with given functions */

if (l->func == NULL) /* placeholder? */

lua_pushboolean(L, 0);

else {

int i;

for (i = 0; i < nup; i++) /* copy upvalues to the top */

lua_pushvalue(L, -nup);

lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */

}

lua_setfield(L, -(nup + 2), l->name);

}

lua_pop(L, nup); /* remove upvalues */

}

LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {

if (lua_getfield(L, idx, fname) == LUA_TTABLE)

return 1; /* table already there */

else {

lua_pop(L, 1); /* remove previous result */

idx = lua_absindex(L, idx);

lua_newtable(L);

lua_pushvalue(L, -1); /* copy to be left at top */

lua_setfield(L, idx, fname); /* assign new table to field */

return 0; /* false, because did not find table there */

}

}