view Python/atof.c @ 52039:bebc4eef9e89

Blocked revisions 70166-70167,70169,70176,70178,70197 via svnmerge ........ r70166 | georg.brandl | 2009-03-04 12:24:41 -0600 (Wed, 04 Mar 2009) | 2 lines Remove obsolete stuff from string module docs. ........ r70167 | ronald.oussoren | 2009-03-04 15:07:19 -0600 (Wed, 04 Mar 2009) | 2 lines Fix issue 5224. ........ r70169 | ronald.oussoren | 2009-03-04 15:12:17 -0600 (Wed, 04 Mar 2009) | 2 lines Fix for issue 5226. ........ r70176 | ronald.oussoren | 2009-03-04 15:35:05 -0600 (Wed, 04 Mar 2009) | 2 lines Fixes issues 3883 and 5194 ........ r70178 | ronald.oussoren | 2009-03-04 16:49:36 -0600 (Wed, 04 Mar 2009) | 2 lines Fix for issue #1113328. ........ r70197 | jesus.cea | 2009-03-05 13:37:37 -0600 (Thu, 05 Mar 2009) | 1 line Minor bsddb documentation glitch ........
author Benjamin Peterson <benjamin@python.org>
date Thu, 05 Mar 2009 22:53:54 +0000
parents 2dea40e40d9d
children fd25030223b0
line wrap: on
line source


/* Just in case you haven't got an atof() around...
   This one doesn't check for bad syntax or overflow,
   and is slow and inaccurate.
   But it's good enough for the occasional string literal... */

#include "pyconfig.h"

#include <ctype.h>

double atof(char *s)
{
	double a = 0.0;
	int e = 0;
	int c;
	while ((c = *s++) != '\0' && isdigit(c)) {
		a = a*10.0 + (c - '0');
	}
	if (c == '.') {
		while ((c = *s++) != '\0' && isdigit(c)) {
			a = a*10.0 + (c - '0');
			e = e-1;
		}
	}
	if (c == 'e' || c == 'E') {
		int sign = 1;
		int i = 0;
		c = *s++;
		if (c == '+')
			c = *s++;
		else if (c == '-') {
			c = *s++;
			sign = -1;
		}
		while (isdigit(c)) {
			i = i*10 + (c - '0');
			c = *s++;
		}
		e += i*sign;
	}
	while (e > 0) {
		a *= 10.0;
		e--;
	}
	while (e < 0) {
		a *= 0.1;
		e++;
	}
	return a;
}