lobject.c
(5.0.3)
/*
** $Id: lobject.c,v 1.97 2003/04/03 13:35:34 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
#include <ctype.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#define lobject_c
#include "lua.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"
/* function to convert a string to a lua_Number */
#ifndef lua_str2number
#define lua_str2number(s,p) strtod((s), (p))
#endif
const TObject luaO_nilobject = {LUA_TNIL, {NULL}};
/*
** converts an integer to a "floating point byte", represented as
** (mmmmmxxx), where the real value is (xxx) * 2^(mmmmm)
*/
int luaO_int2fb (unsigned int x) {
int m = 0; /* mantissa */
while (x >= (1<<3)) {
x = (x+1) >> 1;
m++;
}
return (m << 3) | cast(int, x);
}
int luaO_log2 (unsigned int x) {
static const lu_byte log_8[255] = {
0,
1,1,
2,2,2,2,
3,3,3,3,3,3,3,3,
4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
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,
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,
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
};
if (x >= 0x00010000) {
if (x >= 0x01000000) return log_8[((x>>24) & 0xff) - 1]+24;
else return log_8[((x>>16) & 0xff) - 1]+16;
}
else {
if (x >= 0x00000100) return log_8[((x>>8) & 0xff) - 1]+8;
else if (x) return log_8[(x & 0xff) - 1];
return -1; /* special `log' for 0 */
}
}
int luaO_rawequalObj (const TObject *t1, const TObject *t2) {
if (ttype(t1) != ttype(t2)) return 0;
else switch (ttype(t1)) {
case LUA_TNIL:
return 1;
case LUA_TNUMBER:
return 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;
lua_Number res = lua_str2number(s, &endptr);
if (endptr == s) return 0; /* no conversion */
while (isspace((unsigned char)(*endptr))) endptr++;
if (*endptr != '\0') return 0; /* invalid trailing characters? */
*result = res;
return 1;
}
static void pushstr (lua_State *L, const char *str) {
setsvalue2s(L->top, luaS_new(L, str));
incr_top(L);
}
/* this function handles only `%d', `%c', %f, 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->top, luaS_newlstr(L, fmt, e-fmt));
incr_top(L);
switch (*(e+1)) {
case 's':
pushstr(L, va_arg(argp, char *));
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(lua_Number, va_arg(argp, int)));
incr_top(L);
break;
case 'f':
setnvalue(L->top, cast(lua_Number, va_arg(argp, l_uacNumber)));
incr_top(L);
break;
case '%':
pushstr(L, "%");
break;
default: lua_assert(0);
}
n += 2;
fmt = e+2;
}
pushstr(L, fmt);
luaV_concat(L, n+1, 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, int 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 == '@') {
int 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"] */
int len = strcspn(source, "\n"); /* 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, "\"]");
}
}
}