nik/lush
1
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

new function "luaO_str2d" to convert strings to numbers, because

Browse Source 
old "lex" algorithm had aproximation errors, but strtod (and atof
and scanf) are too slow.
This commit is contained in:
Roberto Ierusalimschy
1998-12-27 18:25:20 -02:00
parent d2de2d5eda
commit 4c94d8cc2c
4 changed files with 108 additions and 76 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
lobject.c
View File

@@ -1,9 +1,10 @@
/*
** $Id: lobject.c,v 1.12 1998/06/18 16:57:03 roberto Exp roberto $
** $Id: lobject.c,v 1.13 1998/06/19 16:14:09 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
#include <ctype.h>
#include <stdlib.h>
#include "lobject.h"
@@ -64,20 +65,67 @@ void luaO_insertlist (GCnode *root, GCnode *node)
node->marked = 0;
}
#ifdef OLD_ANSI
void luaO_memup (void *dest, void *src, int size)
{
char *d = dest;
char *s = src;
while (size--) d[size]=s[size];
void luaO_memup (void *dest, void *src, int size) {
while (size--)
((char *)dest)[size]=((char *)src)[size];
}
void luaO_memdown (void *dest, void *src, int size)
{
char *d = dest;
char *s = src;
void luaO_memdown (void *dest, void *src, int size) {
int i;
for (i=0; i<size; i++) d[i]=s[i];
for (i=0; i<size; i++)
((char *)dest)[i]=((char *)src)[i];
}
#endif
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;
}
double luaO_str2d (char *s) {
double a = 0.0;
int point = 0;
if (!isdigit((unsigned char)*s) && !isdigit((unsigned char)*(s+1)))
return -1; /* no digit before or after decimal 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 (toupper((unsigned char)*s) == 'E') {
int e = 0;
int sig = 1;
s++;
if (*s == '+') s++;
else if (*s == '-') {
s++;
sig = -1;
}
if (!isdigit((unsigned char)*s)) return -1; /* no digit in expoent part? */
do {
e = 10*e + (*(s++)-'0');
} while (isdigit((unsigned char)*s));
point -= sig*e;
}
while (isspace((unsigned char)*s)) s++;
if (*s != '\0') return -1; /* invalid trailing characters? */
if (point > 0)
a /= expten(point);
else if (point < 0)
a *= expten(-point);
return a;
}