/* 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); PyAPI_FUNC(void) _PyFloat_DebugMallocStats(FILE* out); #ifdef __cplusplus } #endif #endif /* !Py_FLOATOBJECT_H */ SIMPAN PERUBAHAN