You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
95 lines
3.7 KiB
95 lines
3.7 KiB
|
|
/* 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) ((op)->ob_type == &PyFloat_Type) |
|
|
|
/* 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. |
|
* |
|
* Excepting NaNs and infinities (which aren't handled correctly), 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. 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). |
|
* Bug: What this does is undefined if x is a NaN or infinity. |
|
* Bug: -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); |
|
|
|
/* 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). |
|
* Bug: What this does is undefined if the string 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); |
|
|
|
|
|
#ifdef __cplusplus |
|
} |
|
#endif |
|
#endif /* !Py_FLOATOBJECT_H */
|
|
|