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Now that I've learnt about structseq objects I felt like converting sys.float_info to a structseq. It's

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readonly and help(sys.float_info) explains the attributes nicely.
This commit is contained in:
Christian Heimes 2008-01-14 04:13:37 +00:00
parent f31b69f9db
commit c94e2b5c12
5 changed files with 81 additions and 29 deletions
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99
Objects/floatobject.c
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@ -5,10 +5,12 @@
for any kind of float exception without losing portability. */
#include "Python.h"
#include "structseq.h"
#include <ctype.h>
#include <float.h>
#if !defined(__STDC__)
extern double fmod(double, double);
extern double pow(double, double);
@ -59,40 +61,87 @@ PyFloat_GetMin(void)
return DBL_MIN;
}
static PyTypeObject FloatInfoType = {0};
PyDoc_STRVAR(floatinfo__doc__,
"sys.floatinfo\n\
\n\
A structseq holding information about the float type. It contains low level\n\
information about the precision and internal representation. Please study\n\
your system's :file:`float.h` for more information.");
static PyStructSequence_Field floatinfo_fields[] = {
{"max", "DBL_MAX -- maximum representable finite float"},
{"max_exp", "DBL_MAX_EXP -- maximum int e such that radix**(e-1) "
"is representable"},
{"max_10_exp", "DBL_MAX_10_EXP -- maximum int e such that 10**e "
"is representable"},
{"min", "DBL_MIN -- Minimum positive normalizer float"},
{"min_exp", "DBL_MIN_EXP -- minimum int e such that radix**(e-1) "
"is a normalized float"},
{"min_10_exp", "DBL_MIN_10_EXP -- minimum int e such that 10**e is "
"a normalized"},
{"dig", "DBL_DIG -- digits"},
{"mant_dig", "DBL_MANT_DIG -- mantissa digits"},
{"epsilon", "DBL_EPSILON -- Difference between 1 and the next "
"representable float"},
{"radix", "FLT_RADIX -- radix of exponent"},
{"rounds", "FLT_ROUNDS -- addition rounds"},
{0}
};
static PyStructSequence_Desc floatinfo_desc = {
"sys.floatinfo", /* name */
floatinfo__doc__, /* doc */
floatinfo_fields, /* fields */
11
};
PyObject *
PyFloat_GetInfo(void)
{
PyObject *d, *tmp;
static PyObject* floatinfo;
int pos = 0;
#define SET_FLOAT_CONST(d, key, const) \
tmp = PyFloat_FromDouble(const); \
if (tmp == NULL) return NULL; \
if (PyDict_SetItemString(d, key, tmp)) return NULL; \
Py_DECREF(tmp)
#define SET_INT_CONST(d, key, const) \
tmp = PyInt_FromLong(const); \
if (tmp == NULL) return NULL; \
if (PyDict_SetItemString(d, key, tmp)) return NULL; \
Py_DECREF(tmp)
if (floatinfo != NULL) {
Py_INCREF(floatinfo);
return floatinfo;
}
PyStructSequence_InitType(&FloatInfoType, &floatinfo_desc);
floatinfo = PyStructSequence_New(&FloatInfoType);
if (floatinfo == NULL) {
return NULL;
}
d = PyDict_New();
#define SetIntFlag(flag) \
PyStructSequence_SET_ITEM(floatinfo, pos++, PyInt_FromLong(flag))
#define SetDblFlag(flag) \
PyStructSequence_SET_ITEM(floatinfo, pos++, PyFloat_FromDouble(flag))
SET_FLOAT_CONST(d, "max", DBL_MAX);
SET_INT_CONST(d, "max_exp", DBL_MAX_EXP);
SET_INT_CONST(d, "max_10_exp", DBL_MAX_10_EXP);
SET_FLOAT_CONST(d, "min", DBL_MIN);
SET_INT_CONST(d, "min_exp", DBL_MIN_EXP);
SET_INT_CONST(d, "min_10_exp", DBL_MIN_10_EXP);
SET_INT_CONST(d, "dig", DBL_DIG);
SET_INT_CONST(d, "mant_dig", DBL_MANT_DIG);
SET_FLOAT_CONST(d, "epsilon", DBL_EPSILON);
SET_INT_CONST(d, "radix", FLT_RADIX);
SET_INT_CONST(d, "rounds", FLT_ROUNDS);
SetDblFlag(DBL_MAX);
SetIntFlag(DBL_MAX_EXP);
SetIntFlag(DBL_MAX_10_EXP);
SetDblFlag(DBL_MIN);
SetIntFlag(DBL_MIN_EXP);
SetIntFlag(DBL_MIN_10_EXP);
SetIntFlag(DBL_DIG);
SetIntFlag(DBL_MANT_DIG);
SetDblFlag(DBL_EPSILON);
SetIntFlag(FLT_RADIX);
SetIntFlag(FLT_ROUNDS);
#undef SetIntFlag
#undef SetDblFlag
if (PyErr_Occurred()) {
Py_CLEAR(floatinfo);
return NULL;
}
return d;
Py_INCREF(floatinfo);
return floatinfo;
}
PyObject *
PyFloat_FromDouble(double fval)
{