Chris@87: Chris@87: /* Float object interface */ Chris@87: Chris@87: /* Chris@87: PyFloatObject represents a (double precision) floating point number. Chris@87: */ Chris@87: Chris@87: #ifndef Py_FLOATOBJECT_H Chris@87: #define Py_FLOATOBJECT_H Chris@87: #ifdef __cplusplus Chris@87: extern "C" { Chris@87: #endif Chris@87: Chris@87: typedef struct { Chris@87: PyObject_HEAD Chris@87: double ob_fval; Chris@87: } PyFloatObject; Chris@87: Chris@87: PyAPI_DATA(PyTypeObject) PyFloat_Type; Chris@87: Chris@87: #define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type) Chris@87: #define PyFloat_CheckExact(op) (Py_TYPE(op) == &PyFloat_Type) Chris@87: Chris@87: /* The str() precision PyFloat_STR_PRECISION is chosen so that in most cases, Chris@87: the rounding noise created by various operations is suppressed, while Chris@87: giving plenty of precision for practical use. */ Chris@87: Chris@87: #define PyFloat_STR_PRECISION 12 Chris@87: Chris@87: #ifdef Py_NAN Chris@87: #define Py_RETURN_NAN return PyFloat_FromDouble(Py_NAN) Chris@87: #endif Chris@87: Chris@87: #define Py_RETURN_INF(sign) do \ Chris@87: if (copysign(1., sign) == 1.) { \ Chris@87: return PyFloat_FromDouble(Py_HUGE_VAL); \ Chris@87: } else { \ Chris@87: return PyFloat_FromDouble(-Py_HUGE_VAL); \ Chris@87: } while(0) Chris@87: Chris@87: PyAPI_FUNC(double) PyFloat_GetMax(void); Chris@87: PyAPI_FUNC(double) PyFloat_GetMin(void); Chris@87: PyAPI_FUNC(PyObject *) PyFloat_GetInfo(void); Chris@87: Chris@87: /* Return Python float from string PyObject. Second argument ignored on Chris@87: input, and, if non-NULL, NULL is stored into *junk (this tried to serve a Chris@87: purpose once but can't be made to work as intended). */ Chris@87: PyAPI_FUNC(PyObject *) PyFloat_FromString(PyObject*, char** junk); Chris@87: Chris@87: /* Return Python float from C double. */ Chris@87: PyAPI_FUNC(PyObject *) PyFloat_FromDouble(double); Chris@87: Chris@87: /* Extract C double from Python float. The macro version trades safety for Chris@87: speed. */ Chris@87: PyAPI_FUNC(double) PyFloat_AsDouble(PyObject *); Chris@87: #define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval) Chris@87: Chris@87: /* Write repr(v) into the char buffer argument, followed by null byte. The Chris@87: buffer must be "big enough"; >= 100 is very safe. Chris@87: PyFloat_AsReprString(buf, x) strives to print enough digits so that Chris@87: PyFloat_FromString(buf) then reproduces x exactly. */ Chris@87: PyAPI_FUNC(void) PyFloat_AsReprString(char*, PyFloatObject *v); Chris@87: Chris@87: /* Write str(v) into the char buffer argument, followed by null byte. The Chris@87: buffer must be "big enough"; >= 100 is very safe. Note that it's Chris@87: unusual to be able to get back the float you started with from Chris@87: PyFloat_AsString's result -- use PyFloat_AsReprString() if you want to Chris@87: preserve precision across conversions. */ Chris@87: PyAPI_FUNC(void) PyFloat_AsString(char*, PyFloatObject *v); Chris@87: Chris@87: /* _PyFloat_{Pack,Unpack}{4,8} Chris@87: * Chris@87: * The struct and pickle (at least) modules need an efficient platform- Chris@87: * independent way to store floating-point values as byte strings. Chris@87: * The Pack routines produce a string from a C double, and the Unpack Chris@87: * routines produce a C double from such a string. The suffix (4 or 8) Chris@87: * specifies the number of bytes in the string. Chris@87: * Chris@87: * On platforms that appear to use (see _PyFloat_Init()) IEEE-754 formats Chris@87: * these functions work by copying bits. On other platforms, the formats the Chris@87: * 4- byte format is identical to the IEEE-754 single precision format, and Chris@87: * the 8-byte format to the IEEE-754 double precision format, although the Chris@87: * packing of INFs and NaNs (if such things exist on the platform) isn't Chris@87: * handled correctly, and attempting to unpack a string containing an IEEE Chris@87: * INF or NaN will raise an exception. Chris@87: * Chris@87: * On non-IEEE platforms with more precision, or larger dynamic range, than Chris@87: * 754 supports, not all values can be packed; on non-IEEE platforms with less Chris@87: * precision, or smaller dynamic range, not all values can be unpacked. What Chris@87: * happens in such cases is partly accidental (alas). Chris@87: */ Chris@87: Chris@87: /* The pack routines write 4 or 8 bytes, starting at p. le is a bool Chris@87: * argument, true if you want the string in little-endian format (exponent Chris@87: * last, at p+3 or p+7), false if you want big-endian format (exponent Chris@87: * first, at p). Chris@87: * Return value: 0 if all is OK, -1 if error (and an exception is Chris@87: * set, most likely OverflowError). Chris@87: * There are two problems on non-IEEE platforms: Chris@87: * 1): What this does is undefined if x is a NaN or infinity. Chris@87: * 2): -0.0 and +0.0 produce the same string. Chris@87: */ Chris@87: PyAPI_FUNC(int) _PyFloat_Pack4(double x, unsigned char *p, int le); Chris@87: PyAPI_FUNC(int) _PyFloat_Pack8(double x, unsigned char *p, int le); Chris@87: Chris@87: /* Used to get the important decimal digits of a double */ Chris@87: PyAPI_FUNC(int) _PyFloat_Digits(char *buf, double v, int *signum); Chris@87: PyAPI_FUNC(void) _PyFloat_DigitsInit(void); Chris@87: Chris@87: /* The unpack routines read 4 or 8 bytes, starting at p. le is a bool Chris@87: * argument, true if the string is in little-endian format (exponent Chris@87: * last, at p+3 or p+7), false if big-endian (exponent first, at p). Chris@87: * Return value: The unpacked double. On error, this is -1.0 and Chris@87: * PyErr_Occurred() is true (and an exception is set, most likely Chris@87: * OverflowError). Note that on a non-IEEE platform this will refuse Chris@87: * to unpack a string that represents a NaN or infinity. Chris@87: */ Chris@87: PyAPI_FUNC(double) _PyFloat_Unpack4(const unsigned char *p, int le); Chris@87: PyAPI_FUNC(double) _PyFloat_Unpack8(const unsigned char *p, int le); Chris@87: Chris@87: /* free list api */ Chris@87: PyAPI_FUNC(int) PyFloat_ClearFreeList(void); Chris@87: Chris@87: /* Format the object based on the format_spec, as defined in PEP 3101 Chris@87: (Advanced String Formatting). */ Chris@87: PyAPI_FUNC(PyObject *) _PyFloat_FormatAdvanced(PyObject *obj, Chris@87: char *format_spec, Chris@87: Py_ssize_t format_spec_len); Chris@87: Chris@87: /* Round a C double x to the closest multiple of 10**-ndigits. Returns a Chris@87: Python float on success, or NULL (with an appropriate exception set) on Chris@87: failure. Used in builtin_round in bltinmodule.c. */ Chris@87: PyAPI_FUNC(PyObject *) _Py_double_round(double x, int ndigits); Chris@87: Chris@87: Chris@87: Chris@87: #ifdef __cplusplus Chris@87: } Chris@87: #endif Chris@87: #endif /* !Py_FLOATOBJECT_H */