/*

 ** $Id: lobject.c,v 2.22.1.1 2007/12/27 13:02:25 roberto Exp $

 ** Some generic functions over Lua objects

 ** See Copyright Notice in lua.h

 */

 

 #include <ctype.h>

 #include <stdarg.h>

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

 

 #define lobject_c

 #define LUA_CORE

 

 #include "lua.h"

 

 #include "ldo.h"

 #include "lmem.h"

 #include "lobject.h"

 #include "lstate.h"

 #include "lstring.h"

 #include "lvm.h"

 

 

 

 const TValue luaO_nilobject_ = {{NULL}, LUA_TNIL};

 

 

 /*

 ** converts an integer to a "floating point byte", represented as

 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if

 ** eeeee != 0 and (xxx) otherwise.

 */

 int luaO_int2fb (unsigned int x) {

   int e = 0;  /* expoent */

   while (x >= 16) {

     x = (x+1) >> 1;

     e++;

   }

   if (x < 8) return x;

   else return ((e+1) << 3) | (cast_int(x) - 8);

 }

 

 

 /* converts back */

 int luaO_fb2int (int x) {

   int e = (x >> 3) & 31;

   if (e == 0) return x;

   else return ((x & 7)+8) << (e - 1);

 }

 

 

 int luaO_log2 (unsigned int x) {

   static const lu_byte log_2[256] = {

     0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,

     6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,

     7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

     7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,

     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,

     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,

     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8

   };

   int l = -1;

   while (x >= 256) { l += 8; x >>= 8; }

   return l + log_2[x];

 

 }

 

 

 int luaO_rawequalObj (const TValue *t1, const TValue *t2) {

   if (ttype(t1) != ttype(t2)) return 0;

   else switch (ttype(t1)) {

     case LUA_TNIL:

       return 1;

     case LUA_TNUMBER:

       return luai_numeq(nvalue(t1), nvalue(t2));

     case LUA_TBOOLEAN:

       return bvalue(t1) == bvalue(t2);  /* boolean true must be 1 !! */

     case LUA_TLIGHTUSERDATA:

       return pvalue(t1) == pvalue(t2);

     default:

       lua_assert(iscollectable(t1));

       return gcvalue(t1) == gcvalue(t2);

   }

 }

 

 

 int luaO_str2d (const char *s, lua_Number *result) {

   char *endptr;

   *result = lua_str2number(s, &endptr);

   if (endptr == s) return 0;  /* conversion failed */

   if (*endptr == 'x' || *endptr == 'X')  /* maybe an hexadecimal constant? */

     *result = cast_num(strtoul(s, &endptr, 16));

   if (*endptr == '\0') return 1;  /* most common case */

   while (isspace(cast(unsigned char, *endptr))) endptr++;

   if (*endptr != '\0') return 0;  /* invalid trailing characters? */

   return 1;

 }

 

 

 

 static void pushstr (lua_State *L, const char *str) {

   setsvalue2s(L, L->top, luaS_new(L, str));

   incr_top(L);

 }

 

 

 /* this function handles only `%d', `%c', %f, %p, and `%s' formats */

 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {

   int n = 1;

   pushstr(L, "");

   for (;;) {

     const char *e = strchr(fmt, '%');

     if (e == NULL) break;

     setsvalue2s(L, L->top, luaS_newlstr(L, fmt, e-fmt));

     incr_top(L);

     switch (*(e+1)) {

       case 's': {

         const char *s = va_arg(argp, char *);

         if (s == NULL) s = "(null)";

         pushstr(L, s);

         break;

       }

       case 'c': {

         char buff[2];

         buff[0] = cast(char, va_arg(argp, int));

         buff[1] = '\0';

         pushstr(L, buff);

         break;

       }

       case 'd': {

         setnvalue(L->top, cast_num(va_arg(argp, int)));

         incr_top(L);

         break;

       }

       case 'f': {

         setnvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));

         incr_top(L);

         break;

       }

       case 'p': {

         char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */

         sprintf(buff, "%p", va_arg(argp, void *));

         pushstr(L, buff);

         break;

       }

       case '%': {

         pushstr(L, "%");

         break;

       }

       default: {

         char buff[3];

         buff[0] = '%';

         buff[1] = *(e+1);

         buff[2] = '\0';

         pushstr(L, buff);

         break;

       }

     }

     n += 2;

     fmt = e+2;

   }

   pushstr(L, fmt);

   luaV_concat(L, n+1, cast_int(L->top - L->base) - 1);

   L->top -= n;

   return svalue(L->top - 1);

 }

 

 

 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {

   const char *msg;

   va_list argp;

   va_start(argp, fmt);

   msg = luaO_pushvfstring(L, fmt, argp);

   va_end(argp);

   return msg;

 }

 

 

 void luaO_chunkid (char *out, const char *source, size_t bufflen) {

   if (*source == '=') {

     strncpy(out, source+1, bufflen);  /* remove first char */

     out[bufflen-1] = '\0';  /* ensures null termination */

   }

   else {  /* out = "source", or "...source" */

     if (*source == '@') {

       size_t l;

       source++;  /* skip the `@' */

       bufflen -= sizeof(" '...' ");

       l = strlen(source);

       strcpy(out, "");

       if (l > bufflen) {

         source += (l-bufflen);  /* get last part of file name */

         strcat(out, "...");

       }

       strcat(out, source);

     }

     else {  /* out = [string "string"] */

       size_t len = strcspn(source, "\n\r");  /* stop at first newline */

       bufflen -= sizeof(" [string \"...\"] ");

       if (len > bufflen) len = bufflen;

       strcpy(out, "[string \"");

       if (source[len] != '\0') {  /* must truncate? */

         strncat(out, source, len);

         strcat(out, "...");

       }

       else

         strcat(out, source);

       strcat(out, "\"]");

     }

   }

 }