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Applied patch #1635: Float patch for inf and nan on Windows (and other platforms).

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The patch unifies float("inf") and repr(float("inf")) on all platforms.
This commit is contained in:
Christian Heimes 2007-12-18 23:22:54 +00:00
parent 8777bcae27
commit 0a8143f646
18 changed files with 394 additions and 9 deletions
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50
Objects/floatobject.c
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@ -128,7 +128,7 @@ still supported but now *officially* useless: if pend is not NULL,
PyObject *
PyFloat_FromString(PyObject *v, char **pend)
{
const char *s, *last, *end;
const char *s, *last, *end, *sp;
double x;
char buffer[256]; /* for errors */
#ifdef Py_USING_UNICODE
@ -171,6 +171,7 @@ PyFloat_FromString(PyObject *v, char **pend)
PyErr_SetString(PyExc_ValueError, "empty string for float()");
return NULL;
}
sp = s;
/* We don't care about overflow or underflow. If the platform supports
* them, infinities and signed zeroes (on underflow) are fine.
* However, strtod can return 0 for denormalized numbers, where atof
@ -186,7 +187,26 @@ PyFloat_FromString(PyObject *v, char **pend)
byte at the end of the string, when the input is inf(inity). */
if (end > last)
end = last;
/* Check for inf and nan. This is done late because it rarely happens. */
if (end == s) {
char *p = (char*)sp;
int sign = 1;
if (*p == '-') {
sign = -1;
p++;
}
if (*p == '+') {
p++;
}
if (PyOS_strnicmp(p, "inf", 4) == 0) {
return PyFloat_FromDouble(sign * Py_HUGE_VAL);
}
#ifdef Py_NAN
if(PyOS_strnicmp(p, "nan", 4) == 0) {
return PyFloat_FromDouble(Py_NAN);
}
#endif
PyOS_snprintf(buffer, sizeof(buffer),
"invalid literal for float(): %.200s", s);
PyErr_SetString(PyExc_ValueError, buffer);
@ -271,6 +291,8 @@ format_float(char *buf, size_t buflen, PyFloatObject *v, int precision)
{
register char *cp;
char format[32];
int i;
/* Subroutine for float_repr and float_print.
We want float numbers to be recognizable as such,
i.e., they should contain a decimal point or an exponent.
@ -293,7 +315,33 @@ format_float(char *buf, size_t buflen, PyFloatObject *v, int precision)
*cp++ = '.';
*cp++ = '0';
*cp++ = '\0';
return;
}
/* Checking the next three chars should be more than enough to
* detect inf or nan, even on Windows. We check for inf or nan
* at last because they are rare cases.
*/
for (i=0; *cp != '\0' && i<3; cp++, i++) {
if (isdigit(Py_CHARMASK(*cp)) || *cp == '.')
continue;
/* found something that is neither a digit nor point
* it might be a NaN or INF
*/
#ifdef Py_NAN
if (Py_IS_NAN(v->ob_fval)) {
strcpy(buf, "nan");
}
else
#endif
if (Py_IS_INFINITY(v->ob_fval)) {
cp = buf;
if (*cp == '-')
cp++;
strcpy(cp, "inf");
}
break;
}
}
/* XXX PyFloat_AsStringEx should not be a public API function (for one