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v0.8.1
Revision 1563f164e52d886d7f5ee7019bf176c8514b0243 authored by Benjamin Peterson on 11 June 2016, 21:46:26 UTC, committed by Benjamin Peterson on 11 June 2016, 21:46:26 UTC
1 parent 4b27f14
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atof.c

/* 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;
}
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