/*

** $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, "\"]");

    }

  }

}