

/* 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)



#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);



#ifdef __cplusplus

}

#endif

#endif /* !Py_FLOATOBJECT_H */

