mirror of
https://github.com/python/cpython.git
synced 2024-12-18 06:14:00 +08:00
125 lines
4.6 KiB
C
125 lines
4.6 KiB
C
|
|
/* Float object interface */
|
|
|
|
/*
|
|
PyFloatObject represents a (double precision) floating point number.
|
|
*/
|
|
|
|
#ifndef Py_FLOATOBJECT_H
|
|
#define Py_FLOATOBJECT_H
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifndef Py_LIMITED_API
|
|
typedef struct {
|
|
PyObject_HEAD
|
|
double ob_fval;
|
|
} PyFloatObject;
|
|
#endif
|
|
|
|
PyAPI_DATA(PyTypeObject) PyFloat_Type;
|
|
|
|
#define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type)
|
|
#define PyFloat_CheckExact(op) (Py_TYPE(op) == &PyFloat_Type)
|
|
|
|
#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. */
|
|
PyAPI_FUNC(PyObject *) PyFloat_FromString(PyObject*);
|
|
|
|
/* 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 *);
|
|
#ifndef Py_LIMITED_API
|
|
#define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval)
|
|
#endif
|
|
|
|
#ifndef Py_LIMITED_API
|
|
/* _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);
|
|
|
|
/* Needed for the old way for marshal to store a floating point number.
|
|
Returns the string length copied into p, -1 on error.
|
|
*/
|
|
PyAPI_FUNC(int) _PyFloat_Repr(double x, char *p, size_t len);
|
|
|
|
/* 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,
|
|
PyObject *format_spec,
|
|
Py_ssize_t start,
|
|
Py_ssize_t end);
|
|
#endif /* Py_LIMITED_API */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#endif /* !Py_FLOATOBJECT_H */
|