/* Float object interface */ | |
/* | |
PyFloatObject represents a (double precision) floating point number. | |
*/ | |
#ifndef Py_FLOATOBJECT_H | |
#define Py_FLOATOBJECT_H | |
#ifdef __cplusplus | |
extern "C" { | |
#endif | |
typedef struct { | |
PyObject_HEAD | |
double ob_fval; | |
} PyFloatObject; | |
PyAPI_DATA(PyTypeObject) PyFloat_Type; | |
#define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type) | |
#define PyFloat_CheckExact(op) (Py_TYPE(op) == &PyFloat_Type) | |
/* The str() precision PyFloat_STR_PRECISION is chosen so that in most cases, | |
the rounding noise created by various operations is suppressed, while | |
giving plenty of precision for practical use. */ | |
#define PyFloat_STR_PRECISION 12 | |
#ifdef Py_NAN | |
#define Py_RETURN_NAN return PyFloat_FromDouble(Py_NAN) | |
#endif | |
#define Py_RETURN_INF(sign) do \ | |
if (copysign(1., sign) == 1.) { \ | |
return PyFloat_FromDouble(Py_HUGE_VAL); \ | |
} else { \ | |
return PyFloat_FromDouble(-Py_HUGE_VAL); \ | |
} while(0) | |
PyAPI_FUNC(double) PyFloat_GetMax(void); | |
PyAPI_FUNC(double) PyFloat_GetMin(void); | |
PyAPI_FUNC(PyObject *) PyFloat_GetInfo(void); | |
/* Return Python float from string PyObject. Second argument ignored on | |
input, and, if non-NULL, NULL is stored into *junk (this tried to serve a | |
purpose once but can't be made to work as intended). */ | |
PyAPI_FUNC(PyObject *) PyFloat_FromString(PyObject*, char** junk); | |
/* Return Python float from C double. */ | |
PyAPI_FUNC(PyObject *) PyFloat_FromDouble(double); | |
/* Extract C double from Python float. The macro version trades safety for | |
speed. */ | |
PyAPI_FUNC(double) PyFloat_AsDouble(PyObject *); | |
#define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval) | |
/* Write repr(v) into the char buffer argument, followed by null byte. The | |
buffer must be "big enough"; >= 100 is very safe. | |
PyFloat_AsReprString(buf, x) strives to print enough digits so that | |
PyFloat_FromString(buf) then reproduces x exactly. */ | |
PyAPI_FUNC(void) PyFloat_AsReprString(char*, PyFloatObject *v); | |
/* Write str(v) into the char buffer argument, followed by null byte. The | |
buffer must be "big enough"; >= 100 is very safe. Note that it's | |
unusual to be able to get back the float you started with from | |
PyFloat_AsString's result -- use PyFloat_AsReprString() if you want to | |
preserve precision across conversions. */ | |
PyAPI_FUNC(void) PyFloat_AsString(char*, PyFloatObject *v); | |
/* _PyFloat_{Pack,Unpack}{4,8} | |
* | |
* The struct and pickle (at least) modules need an efficient platform- | |
* independent way to store floating-point values as byte strings. | |
* The Pack routines produce a string from a C double, and the Unpack | |
* routines produce a C double from such a string. The suffix (4 or 8) | |
* specifies the number of bytes in the string. | |
* | |
* On platforms that appear to use (see _PyFloat_Init()) IEEE-754 formats | |
* these functions work by copying bits. On other platforms, the formats the | |
* 4- byte format is identical to the IEEE-754 single precision format, and | |
* the 8-byte format to the IEEE-754 double precision format, although the | |
* packing of INFs and NaNs (if such things exist on the platform) isn't | |
* handled correctly, and attempting to unpack a string containing an IEEE | |
* INF or NaN will raise an exception. | |
* | |
* On non-IEEE platforms with more precision, or larger dynamic range, than | |
* 754 supports, not all values can be packed; on non-IEEE platforms with less | |
* precision, or smaller dynamic range, not all values can be unpacked. What | |
* happens in such cases is partly accidental (alas). | |
*/ | |
/* The pack routines write 4 or 8 bytes, starting at p. le is a bool | |
* argument, true if you want the string in little-endian format (exponent | |
* last, at p+3 or p+7), false if you want big-endian format (exponent | |
* first, at p). | |
* Return value: 0 if all is OK, -1 if error (and an exception is | |
* set, most likely OverflowError). | |
* There are two problems on non-IEEE platforms: | |
* 1): What this does is undefined if x is a NaN or infinity. | |
* 2): -0.0 and +0.0 produce the same string. | |
*/ | |
PyAPI_FUNC(int) _PyFloat_Pack4(double x, unsigned char *p, int le); | |
PyAPI_FUNC(int) _PyFloat_Pack8(double x, unsigned char *p, int le); | |
/* Used to get the important decimal digits of a double */ | |
PyAPI_FUNC(int) _PyFloat_Digits(char *buf, double v, int *signum); | |
PyAPI_FUNC(void) _PyFloat_DigitsInit(void); | |
/* The unpack routines read 4 or 8 bytes, starting at p. le is a bool | |
* argument, true if the string is in little-endian format (exponent | |
* last, at p+3 or p+7), false if big-endian (exponent first, at p). | |
* Return value: The unpacked double. On error, this is -1.0 and | |
* PyErr_Occurred() is true (and an exception is set, most likely | |
* OverflowError). Note that on a non-IEEE platform this will refuse | |
* to unpack a string that represents a NaN or infinity. | |
*/ | |
PyAPI_FUNC(double) _PyFloat_Unpack4(const unsigned char *p, int le); | |
PyAPI_FUNC(double) _PyFloat_Unpack8(const unsigned char *p, int le); | |
/* free list api */ | |
PyAPI_FUNC(int) PyFloat_ClearFreeList(void); | |
/* Format the object based on the format_spec, as defined in PEP 3101 | |
(Advanced String Formatting). */ | |
PyAPI_FUNC(PyObject *) _PyFloat_FormatAdvanced(PyObject *obj, | |
char *format_spec, | |
Py_ssize_t format_spec_len); | |
/* Round a C double x to the closest multiple of 10**-ndigits. Returns a | |
Python float on success, or NULL (with an appropriate exception set) on | |
failure. Used in builtin_round in bltinmodule.c. */ | |
PyAPI_FUNC(PyObject *) _Py_double_round(double x, int ndigits); | |
#ifdef __cplusplus | |
} | |
#endif | |
#endif /* !Py_FLOATOBJECT_H */ |