Guido van Rossum | f70e43a | 1991-02-19 12:39:46 +0000 | [diff] [blame] | 1 | |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 2 | /* Float object interface */ |
| 3 | |
| 4 | /* |
Guido van Rossum | caa6380 | 1995-01-12 11:45:45 +0000 | [diff] [blame] | 5 | PyFloatObject represents a (double precision) floating point number. |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 6 | */ |
| 7 | |
Fred Drake | ea9cb5a | 2000-07-09 00:20:36 +0000 | [diff] [blame] | 8 | #ifndef Py_FLOATOBJECT_H |
| 9 | #define Py_FLOATOBJECT_H |
| 10 | #ifdef __cplusplus |
| 11 | extern "C" { |
| 12 | #endif |
| 13 | |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 14 | typedef struct { |
Fred Drake | ea9cb5a | 2000-07-09 00:20:36 +0000 | [diff] [blame] | 15 | PyObject_HEAD |
| 16 | double ob_fval; |
Guido van Rossum | caa6380 | 1995-01-12 11:45:45 +0000 | [diff] [blame] | 17 | } PyFloatObject; |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 18 | |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 19 | PyAPI_DATA(PyTypeObject) PyFloat_Type; |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 20 | |
Guido van Rossum | c16fcdf | 2001-08-29 15:45:32 +0000 | [diff] [blame] | 21 | #define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type) |
Christian Heimes | e93237d | 2007-12-19 02:37:44 +0000 | [diff] [blame] | 22 | #define PyFloat_CheckExact(op) (Py_TYPE(op) == &PyFloat_Type) |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 23 | |
Christian Heimes | 6f34109 | 2008-04-18 23:13:07 +0000 | [diff] [blame] | 24 | #ifdef Py_NAN |
Christian Heimes | c873550 | 2008-04-18 23:49:11 +0000 | [diff] [blame] | 25 | #define Py_RETURN_NAN return PyFloat_FromDouble(Py_NAN) |
Christian Heimes | 6f34109 | 2008-04-18 23:13:07 +0000 | [diff] [blame] | 26 | #endif |
| 27 | |
| 28 | #define Py_RETURN_INF(sign) do \ |
| 29 | if (copysign(1., sign) == 1.) { \ |
| 30 | return PyFloat_FromDouble(Py_HUGE_VAL); \ |
| 31 | } else { \ |
| 32 | return PyFloat_FromDouble(-Py_HUGE_VAL); \ |
| 33 | } while(0) |
| 34 | |
Christian Heimes | dfdfaab | 2007-12-01 11:20:10 +0000 | [diff] [blame] | 35 | PyAPI_FUNC(double) PyFloat_GetMax(void); |
| 36 | PyAPI_FUNC(double) PyFloat_GetMin(void); |
| 37 | PyAPI_FUNC(PyObject *) PyFloat_GetInfo(void); |
| 38 | |
Tim Peters | 72f98e9 | 2001-05-08 15:19:57 +0000 | [diff] [blame] | 39 | /* Return Python float from string PyObject. Second argument ignored on |
| 40 | input, and, if non-NULL, NULL is stored into *junk (this tried to serve a |
| 41 | purpose once but can't be made to work as intended). */ |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 42 | PyAPI_FUNC(PyObject *) PyFloat_FromString(PyObject*, char** junk); |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 43 | |
Tim Peters | 72f98e9 | 2001-05-08 15:19:57 +0000 | [diff] [blame] | 44 | /* Return Python float from C double. */ |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 45 | PyAPI_FUNC(PyObject *) PyFloat_FromDouble(double); |
Tim Peters | 72f98e9 | 2001-05-08 15:19:57 +0000 | [diff] [blame] | 46 | |
| 47 | /* Extract C double from Python float. The macro version trades safety for |
| 48 | speed. */ |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 49 | PyAPI_FUNC(double) PyFloat_AsDouble(PyObject *); |
Guido van Rossum | 2981bc7 | 1997-08-02 02:40:58 +0000 | [diff] [blame] | 50 | #define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval) |
Guido van Rossum | a330996 | 1993-07-28 09:05:47 +0000 | [diff] [blame] | 51 | |
Tim Peters | 72f98e9 | 2001-05-08 15:19:57 +0000 | [diff] [blame] | 52 | /* Write repr(v) into the char buffer argument, followed by null byte. The |
| 53 | buffer must be "big enough"; >= 100 is very safe. |
| 54 | PyFloat_AsReprString(buf, x) strives to print enough digits so that |
| 55 | PyFloat_FromString(buf) then reproduces x exactly. */ |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 56 | PyAPI_FUNC(void) PyFloat_AsReprString(char*, PyFloatObject *v); |
Tim Peters | 72f98e9 | 2001-05-08 15:19:57 +0000 | [diff] [blame] | 57 | |
| 58 | /* Write str(v) into the char buffer argument, followed by null byte. The |
| 59 | buffer must be "big enough"; >= 100 is very safe. Note that it's |
| 60 | unusual to be able to get back the float you started with from |
| 61 | PyFloat_AsString's result -- use PyFloat_AsReprString() if you want to |
| 62 | preserve precision across conversions. */ |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 63 | PyAPI_FUNC(void) PyFloat_AsString(char*, PyFloatObject *v); |
Tim Peters | 72f98e9 | 2001-05-08 15:19:57 +0000 | [diff] [blame] | 64 | |
Tim Peters | 9905b94 | 2003-03-20 20:53:32 +0000 | [diff] [blame] | 65 | /* _PyFloat_{Pack,Unpack}{4,8} |
| 66 | * |
| 67 | * The struct and pickle (at least) modules need an efficient platform- |
| 68 | * independent way to store floating-point values as byte strings. |
| 69 | * The Pack routines produce a string from a C double, and the Unpack |
| 70 | * routines produce a C double from such a string. The suffix (4 or 8) |
| 71 | * specifies the number of bytes in the string. |
| 72 | * |
Michael W. Hudson | ba283e2 | 2005-05-27 15:23:20 +0000 | [diff] [blame] | 73 | * On platforms that appear to use (see _PyFloat_Init()) IEEE-754 formats |
| 74 | * these functions work by copying bits. On other platforms, the formats the |
| 75 | * 4- byte format is identical to the IEEE-754 single precision format, and |
| 76 | * the 8-byte format to the IEEE-754 double precision format, although the |
| 77 | * packing of INFs and NaNs (if such things exist on the platform) isn't |
| 78 | * handled correctly, and attempting to unpack a string containing an IEEE |
| 79 | * INF or NaN will raise an exception. |
| 80 | * |
| 81 | * On non-IEEE platforms with more precision, or larger dynamic range, than |
| 82 | * 754 supports, not all values can be packed; on non-IEEE platforms with less |
| 83 | * precision, or smaller dynamic range, not all values can be unpacked. What |
| 84 | * happens in such cases is partly accidental (alas). |
Tim Peters | 9905b94 | 2003-03-20 20:53:32 +0000 | [diff] [blame] | 85 | */ |
| 86 | |
| 87 | /* The pack routines write 4 or 8 bytes, starting at p. le is a bool |
| 88 | * argument, true if you want the string in little-endian format (exponent |
| 89 | * last, at p+3 or p+7), false if you want big-endian format (exponent |
| 90 | * first, at p). |
| 91 | * Return value: 0 if all is OK, -1 if error (and an exception is |
| 92 | * set, most likely OverflowError). |
Michael W. Hudson | ba283e2 | 2005-05-27 15:23:20 +0000 | [diff] [blame] | 93 | * There are two problems on non-IEEE platforms: |
| 94 | * 1): What this does is undefined if x is a NaN or infinity. |
| 95 | * 2): -0.0 and +0.0 produce the same string. |
Tim Peters | 9905b94 | 2003-03-20 20:53:32 +0000 | [diff] [blame] | 96 | */ |
| 97 | PyAPI_FUNC(int) _PyFloat_Pack4(double x, unsigned char *p, int le); |
| 98 | PyAPI_FUNC(int) _PyFloat_Pack8(double x, unsigned char *p, int le); |
| 99 | |
Christian Heimes | 284d927 | 2007-12-10 22:28:56 +0000 | [diff] [blame] | 100 | /* Used to get the important decimal digits of a double */ |
| 101 | PyAPI_FUNC(int) _PyFloat_Digits(char *buf, double v, int *signum); |
| 102 | PyAPI_FUNC(void) _PyFloat_DigitsInit(void); |
| 103 | |
Tim Peters | 9905b94 | 2003-03-20 20:53:32 +0000 | [diff] [blame] | 104 | /* The unpack routines read 4 or 8 bytes, starting at p. le is a bool |
| 105 | * argument, true if the string is in little-endian format (exponent |
| 106 | * last, at p+3 or p+7), false if big-endian (exponent first, at p). |
| 107 | * Return value: The unpacked double. On error, this is -1.0 and |
| 108 | * PyErr_Occurred() is true (and an exception is set, most likely |
Michael W. Hudson | ba283e2 | 2005-05-27 15:23:20 +0000 | [diff] [blame] | 109 | * OverflowError). Note that on a non-IEEE platform this will refuse |
| 110 | * to unpack a string that represents a NaN or infinity. |
Tim Peters | 9905b94 | 2003-03-20 20:53:32 +0000 | [diff] [blame] | 111 | */ |
| 112 | PyAPI_FUNC(double) _PyFloat_Unpack4(const unsigned char *p, int le); |
| 113 | PyAPI_FUNC(double) _PyFloat_Unpack8(const unsigned char *p, int le); |
| 114 | |
Christian Heimes | 422051a | 2008-02-04 18:00:12 +0000 | [diff] [blame] | 115 | /* free list api */ |
Gregory P. Smith | 2fe7706 | 2008-07-06 03:35:58 +0000 | [diff] [blame] | 116 | PyAPI_FUNC(int) PyFloat_ClearFreeList(void); |
Tim Peters | 9905b94 | 2003-03-20 20:53:32 +0000 | [diff] [blame] | 117 | |
Eric Smith | dc13b79 | 2008-05-30 18:10:04 +0000 | [diff] [blame] | 118 | /* Format the object based on the format_spec, as defined in PEP 3101 |
| 119 | (Advanced String Formatting). */ |
| 120 | PyAPI_FUNC(PyObject *) _PyFloat_FormatAdvanced(PyObject *obj, |
| 121 | char *format_spec, |
| 122 | Py_ssize_t format_spec_len); |
| 123 | |
Guido van Rossum | a330996 | 1993-07-28 09:05:47 +0000 | [diff] [blame] | 124 | #ifdef __cplusplus |
| 125 | } |
| 126 | #endif |
| 127 | #endif /* !Py_FLOATOBJECT_H */ |