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comparison Python/atof.c @ 52949:31582485fbfc

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Revert removal of atof.c and strtod.c in r71341. We're not quite ready for this yet---this removal should happen as part of the py3k-short-float-repr merge.
author Mark Dickinson <dickinsm@gmail.com>
date Tue, 07 Apr 2009 11:53:52 +0000
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52948:6f4a088d359d 52949:31582485fbfc
1
2 /* Just in case you haven't got an atof() around...
3 This one doesn't check for bad syntax or overflow,
4 and is slow and inaccurate.
5 But it's good enough for the occasional string literal... */
6
7 #include "pyconfig.h"
8
9 #include <ctype.h>
10
11 double atof(char *s)
12 {
13 double a = 0.0;
14 int e = 0;
15 int c;
16 while ((c = *s++) != '\0' && isdigit(c)) {
17 a = a*10.0 + (c - '0');
18 }
19 if (c == '.') {
20 while ((c = *s++) != '\0' && isdigit(c)) {
21 a = a*10.0 + (c - '0');
22 e = e-1;
23 }
24 }
25 if (c == 'e' || c == 'E') {
26 int sign = 1;
27 int i = 0;
28 c = *s++;
29 if (c == '+')
30 c = *s++;
31 else if (c == '-') {
32 c = *s++;
33 sign = -1;
34 }
35 while (isdigit(c)) {
36 i = i*10 + (c - '0');
37 c = *s++;
38 }
39 e += i*sign;
40 }
41 while (e > 0) {
42 a *= 10.0;
43 e--;
44 }
45 while (e < 0) {
46 a *= 0.1;
47 e++;
48 }
49 return a;
50 }