lua/lobject.c

111 lines
2.5 KiB
C

/*
** $Id: lobject.c,v 1.35 2000/03/29 20:19:20 roberto Exp roberto $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
#include <ctype.h>
#include <stdlib.h>
#define LUA_REENTRANT
#include "lobject.h"
#include "lua.h"
const char *const luaO_typenames[] = { /* ORDER LUA_T */
"userdata", "number", "string", "table", "function", "function", "nil",
"function", "function", "line"
};
const TObject luaO_nilobject = {TAG_NIL, {NULL}};
/*
** returns smaller power of 2 larger than `n' (minimum is MINPOWER2)
*/
unsigned long luaO_power2 (unsigned long n) {
unsigned long p = MINPOWER2;
while (p<=n) p<<=1;
return p;
}
int luaO_equalval (const TObject *t1, const TObject *t2) {
switch (ttype(t1)) {
case TAG_NUMBER:
return nvalue(t1) == nvalue(t2);
case TAG_STRING: case TAG_USERDATA:
return svalue(t1) == svalue(t2);
case TAG_TABLE:
return avalue(t1) == avalue(t2);
case TAG_CCLOSURE: case TAG_LCLOSURE:
return clvalue(t1) == clvalue(t2);
default:
LUA_ASSERT(L, ttype(t1) == TAG_NIL, "invalid type");
return 1; /* TAG_NIL */
}
}
static double expten (unsigned int e) {
double exp = 10.0;
double res = 1.0;
for (; e; e>>=1) {
if (e & 1) res *= exp;
exp *= exp;
}
return res;
}
int luaO_str2d (const char *s, Number *result) { /* LUA_NUMBER */
double a = 0.0;
int point = 0; /* number of decimal digits */
int sig;
while (isspace((unsigned char)*s)) s++;
sig = 0;
switch (*s) {
case '-': sig = 1; /* go through */
case '+': s++;
}
if (! (isdigit((unsigned char)*s) ||
(*s == '.' && isdigit((unsigned char)*(s+1)))))
return 0; /* not (at least one digit before or after the point) */
while (isdigit((unsigned char)*s))
a = 10.0*a + (*(s++)-'0');
if (*s == '.') {
s++;
while (isdigit((unsigned char)*s)) {
a = 10.0*a + (*(s++)-'0');
point++;
}
}
if (sig) a = -a;
if (*s == 'e' || *s == 'E') {
int e = 0;
s++;
sig = 0;
switch (*s) {
case '-': sig = 1; /* go through */
case '+': s++;
}
if (!isdigit((unsigned char)*s)) return 0; /* no digit in the exponent? */
do {
e = 10*e + (*(s++)-'0');
} while (isdigit((unsigned char)*s));
if (sig) e = -e;
point -= e;
}
while (isspace((unsigned char)*s)) s++;
if (*s != '\0') return 0; /* invalid trailing characters? */
if (point != 0) {
if (point > 0) a /= expten(point);
else a *= expten(-point);
}
*result = a;
return 1;
}