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Refactor to remove duplicated nan/inf parsing code in

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pystrtod.c, floatobject.c and dtoa.c.
This commit is contained in:
Mark Dickinson 2009-05-20 22:05:25 +00:00
parent 4db6ff683d
commit bd16edd305
5 changed files with 85 additions and 125 deletions
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99
Python/pystrtod.c
View file

@ -3,6 +3,57 @@
#include <Python.h>
#include <locale.h>
/* _Py_parse_inf_or_nan: Attempt to parse a string of the form "nan", "inf" or
"infinity", with an optional leading sign of "+" or "-". On success,
return the NaN or Infinity as a double and set *endptr to point just beyond
the successfully parsed portion of the string. On failure, return -1.0 and
set *endptr to point to the start of the string. */
static int
case_insensitive_match(const char *s, const char *t)
{
while(*t && Py_TOLOWER(*s) == *t) {
s++;
t++;
}
return *t ? 0 : 1;
}
double
_Py_parse_inf_or_nan(const char *p, char **endptr)
{
double retval;
const char *s;
int negate = 0;
s = p;
if (*s == '-') {
negate = 1;
s++;
}
else if (*s == '+') {
s++;
}
if (case_insensitive_match(s, "inf")) {
s += 3;
if (case_insensitive_match(s, "inity"))
s += 5;
retval = negate ? -Py_HUGE_VAL : Py_HUGE_VAL;
}
#ifdef Py_NAN
else if (case_insensitive_match(s, "nan")) {
s += 3;
retval = negate ? -Py_NAN : Py_NAN;
}
#endif
else {
s = p;
retval = -1.0;
}
*endptr = (char *)s;
return retval;
}
/**
* PyOS_ascii_strtod:
* @nptr: the string to convert to a numeric value.
@ -49,6 +100,10 @@ _PyOS_ascii_strtod(const char *nptr, char **endptr)
result = _Py_dg_strtod(nptr, endptr);
_Py_SET_53BIT_PRECISION_END;
if (*endptr == nptr)
/* string might represent and inf or nan */
result = _Py_parse_inf_or_nan(nptr, endptr);
return result;
}
@ -63,19 +118,6 @@ _PyOS_ascii_strtod(const char *nptr, char **endptr)
correctly rounded results.
*/
/* Case-insensitive string match used for nan and inf detection; t should be
lower-case. Returns 1 for a successful match, 0 otherwise. */
static int
case_insensitive_match(const char *s, const char *t)
{
while(*t && Py_TOLOWER(*s) == *t) {
s++;
t++;
}
return *t ? 0 : 1;
}
double
_PyOS_ascii_strtod(const char *nptr, char **endptr)
{
@ -101,6 +143,11 @@ _PyOS_ascii_strtod(const char *nptr, char **endptr)
decimal_point_pos = NULL;
/* Parse infinities and nans */
val = _Py_parse_inf_or_nan(nptr, endptr);
if (*endptr != nptr)
return val;
/* Set errno to zero, so that we can distinguish zero results
and underflows */
errno = 0;
@ -118,31 +165,6 @@ _PyOS_ascii_strtod(const char *nptr, char **endptr)
p++;
}
/* Parse infinities and nans */
if (*p == 'i' || *p == 'I') {
if (case_insensitive_match(p+1, "nf")) {
val = Py_HUGE_VAL;
if (case_insensitive_match(p+3, "inity"))
fail_pos = (char *)p+8;
else
fail_pos = (char *)p+3;
goto got_val;
}
else
goto invalid_string;
}
#ifdef Py_NAN
if (*p == 'n' || *p == 'N') {
if (case_insensitive_match(p+1, "an")) {
val = Py_NAN;
fail_pos = (char *)p+3;
goto got_val;
}
else
goto invalid_string;
}
#endif
/* Some platform strtods accept hex floats; Python shouldn't (at the
moment), so we check explicitly for strings starting with '0x'. */
if (*p == '0' && (*(p+1) == 'x' || *(p+1) == 'X'))
@ -231,7 +253,6 @@ _PyOS_ascii_strtod(const char *nptr, char **endptr)
if (fail_pos == digits_pos)
goto invalid_string;
got_val:
if (negate && fail_pos != nptr)
val = -val;
*endptr = fail_pos;