/*
** $Id: lobject.c,v 2.22.1.1 2007年12月27日 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円') return 1; /* most common case */
 while (isspace(cast(unsigned char, *endptr))) endptr++;
 if (*endptr != '0円') 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円';
 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円';
 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円'; /* 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円') { /* must truncate? */
 strncat(out, source, len);
 strcat(out, "...");
 }
 else
 strcat(out, source);
 strcat(out, "\"]");
 }
 }
}