floatobject.h 4.7 KB

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