1 2 /* Float object interface */ 3 4 /* 5 PyFloatObject represents a (double precision) floating point number. 6 */ 7 8 #ifndef Py_FLOATOBJECT_H 9 #define Py_FLOATOBJECT_H 10 #ifdef __cplusplus 11 extern "C" { 12 #endif 13 14 #ifndef Py_LIMITED_API 15 typedef struct { 16 PyObject_HEAD 17 double ob_fval; 18 } PyFloatObject; 19 #endif 20 21 PyAPI_DATA(PyTypeObject) PyFloat_Type; 22 23 #define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type) 24 #define PyFloat_CheckExact(op) (Py_TYPE(op) == &PyFloat_Type) 25 26 #ifdef Py_NAN 27 #define Py_RETURN_NAN return PyFloat_FromDouble(Py_NAN) 28 #endif 29 30 #define Py_RETURN_INF(sign) do \ 31 if (copysign(1., sign) == 1.) { \ 32 return PyFloat_FromDouble(Py_HUGE_VAL); \ 33 } else { \ 34 return PyFloat_FromDouble(-Py_HUGE_VAL); \ 35 } while(0) 36 37 PyAPI_FUNC(double) PyFloat_GetMax(void); 38 PyAPI_FUNC(double) PyFloat_GetMin(void); 39 PyAPI_FUNC(PyObject *) PyFloat_GetInfo(void); 40 41 /* Return Python float from string PyObject. */ 42 PyAPI_FUNC(PyObject *) PyFloat_FromString(PyObject*); 43 44 /* Return Python float from C double. */ 45 PyAPI_FUNC(PyObject *) PyFloat_FromDouble(double); 46 47 /* Extract C double from Python float. The macro version trades safety for 48 speed. */ 49 PyAPI_FUNC(double) PyFloat_AsDouble(PyObject *); 50 #ifndef Py_LIMITED_API 51 #define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval) 52 #endif 53 54 #ifndef Py_LIMITED_API 55 /* _PyFloat_{Pack,Unpack}{4,8} 56 * 57 * The struct and pickle (at least) modules need an efficient platform- 58 * independent way to store floating-point values as byte strings. 59 * The Pack routines produce a string from a C double, and the Unpack 60 * routines produce a C double from such a string. The suffix (4 or 8) 61 * specifies the number of bytes in the string. 62 * 63 * On platforms that appear to use (see _PyFloat_Init()) IEEE-754 formats 64 * these functions work by copying bits. On other platforms, the formats the 65 * 4- byte format is identical to the IEEE-754 single precision format, and 66 * the 8-byte format to the IEEE-754 double precision format, although the 67 * packing of INFs and NaNs (if such things exist on the platform) isn't 68 * handled correctly, and attempting to unpack a string containing an IEEE 69 * INF or NaN will raise an exception. 70 * 71 * On non-IEEE platforms with more precision, or larger dynamic range, than 72 * 754 supports, not all values can be packed; on non-IEEE platforms with less 73 * precision, or smaller dynamic range, not all values can be unpacked. What 74 * happens in such cases is partly accidental (alas). 75 */ 76 77 /* The pack routines write 2, 4 or 8 bytes, starting at p. le is a bool 78 * argument, true if you want the string in little-endian format (exponent 79 * last, at p+1, p+3 or p+7), false if you want big-endian format (exponent 80 * first, at p). 81 * Return value: 0 if all is OK, -1 if error (and an exception is 82 * set, most likely OverflowError). 83 * There are two problems on non-IEEE platforms: 84 * 1): What this does is undefined if x is a NaN or infinity. 85 * 2): -0.0 and +0.0 produce the same string. 86 */ 87 PyAPI_FUNC(int) _PyFloat_Pack2(double x, unsigned char *p, int le); 88 PyAPI_FUNC(int) _PyFloat_Pack4(double x, unsigned char *p, int le); 89 PyAPI_FUNC(int) _PyFloat_Pack8(double x, unsigned char *p, int le); 90 91 /* Needed for the old way for marshal to store a floating point number. 92 Returns the string length copied into p, -1 on error. 93 */ 94 PyAPI_FUNC(int) _PyFloat_Repr(double x, char *p, size_t len); 95 96 /* Used to get the important decimal digits of a double */ 97 PyAPI_FUNC(int) _PyFloat_Digits(char *buf, double v, int *signum); 98 PyAPI_FUNC(void) _PyFloat_DigitsInit(void); 99 100 /* The unpack routines read 2, 4 or 8 bytes, starting at p. le is a bool 101 * argument, true if the string is in little-endian format (exponent 102 * last, at p+1, p+3 or p+7), false if big-endian (exponent first, at p). 103 * Return value: The unpacked double. On error, this is -1.0 and 104 * PyErr_Occurred() is true (and an exception is set, most likely 105 * OverflowError). Note that on a non-IEEE platform this will refuse 106 * to unpack a string that represents a NaN or infinity. 107 */ 108 PyAPI_FUNC(double) _PyFloat_Unpack2(const unsigned char *p, int le); 109 PyAPI_FUNC(double) _PyFloat_Unpack4(const unsigned char *p, int le); 110 PyAPI_FUNC(double) _PyFloat_Unpack8(const unsigned char *p, int le); 111 112 /* free list api */ 113 PyAPI_FUNC(int) PyFloat_ClearFreeList(void); 114 115 PyAPI_FUNC(void) _PyFloat_DebugMallocStats(FILE* out); 116 117 /* Format the object based on the format_spec, as defined in PEP 3101 118 (Advanced String Formatting). */ 119 PyAPI_FUNC(int) _PyFloat_FormatAdvancedWriter( 120 _PyUnicodeWriter *writer, 121 PyObject *obj, 122 PyObject *format_spec, 123 Py_ssize_t start, 124 Py_ssize_t end); 125 #endif /* Py_LIMITED_API */ 126 127 #ifdef __cplusplus 128 } 129 #endif 130 #endif /* !Py_FLOATOBJECT_H */ 131
