Include/stringobject.h

   1
   2 /* String (str/bytes) object interface */
   3
   4 #ifndef Py_STRINGOBJECT_H
   5 #define Py_STRINGOBJECT_H
   6 #ifdef __cplusplus
   7 extern "C" {
   8 #endif
   9
  10 #include <stdarg.h>
  11
  12 /*
  13 Type PyStringObject represents a character string.  An extra zero byte is
  14 reserved at the end to ensure it is zero-terminated, but a size is
  15 present so strings with null bytes in them can be represented.  This
  16 is an immutable object type.
  17
  18 There are functions to create new string objects, to test
  19 an object for string-ness, and to get the
  20 string value.  The latter function returns a null pointer
  21 if the object is not of the proper type.
  22 There is a variant that takes an explicit size as well as a
  23 variant that assumes a zero-terminated string.  Note that none of the
  24 functions should be applied to nil objects.
  25 */
  26
  27 /* Caching the hash (ob_shash) saves recalculation of a string's hash value.
  28    Interning strings (ob_sstate) tries to ensure that only one string
  29    object with a given value exists, so equality tests can be one pointer
  30    comparison.  This is generally restricted to strings that "look like"
  31    Python identifiers, although the intern() builtin can be used to force
  32    interning of any string.
  33    Together, these sped the interpreter by up to 20%. */
  34
  35 typedef struct {
  36     PyObject_VAR_HEAD
  37     long ob_shash;
  38     int ob_sstate;
  39     char ob_sval[1];
  40
  41     /* Invariants:
  42      *     ob_sval contains space for 'ob_size+1' elements.
  43      *     ob_sval[ob_size] == 0.
  44      *     ob_shash is the hash of the string or -1 if not computed yet.
  45      *     ob_sstate != 0 iff the string object is in stringobject.c's
  46      *       'interned' dictionary; in this case the two references
  47      *       from 'interned' to this object are *not counted* in ob_refcnt.
  48      */
  49 } PyStringObject;
  50
  51 #define SSTATE_NOT_INTERNED 0
  52 #define SSTATE_INTERNED_MORTAL 1
  53 #define SSTATE_INTERNED_IMMORTAL 2
  54
  55 PyAPI_DATA(PyTypeObject) PyBaseString_Type;
  56 PyAPI_DATA(PyTypeObject) PyString_Type;
  57
  58 #define PyString_Check(op) \
  59                  PyType_FastSubclass(Py_TYPE(op), Py_TPFLAGS_STRING_SUBCLASS)
  60 #define PyString_CheckExact(op) (Py_TYPE(op) == &PyString_Type)
  61
  62 PyAPI_FUNC(PyObject *) PyString_FromStringAndSize(const char *, Py_ssize_t);
  63 PyAPI_FUNC(PyObject *) PyString_FromString(const char *);
  64 PyAPI_FUNC(PyObject *) PyString_FromFormatV(const char*, va_list)
  65                                 Py_GCC_ATTRIBUTE((format(printf, 1, 0)));
  66 PyAPI_FUNC(PyObject *) PyString_FromFormat(const char*, ...)
  67                                 Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
  68 PyAPI_FUNC(Py_ssize_t) PyString_Size(PyObject *);
  69 PyAPI_FUNC(char *) PyString_AsString(PyObject *);
  70 PyAPI_FUNC(PyObject *) PyString_Repr(PyObject *, int);
  71 PyAPI_FUNC(void) PyString_Concat(PyObject **, PyObject *);
  72 PyAPI_FUNC(void) PyString_ConcatAndDel(PyObject **, PyObject *);
  73 PyAPI_FUNC(int) _PyString_Resize(PyObject **, Py_ssize_t);
  74 PyAPI_FUNC(int) _PyString_Eq(PyObject *, PyObject*);
  75 PyAPI_FUNC(PyObject *) PyString_Format(PyObject *, PyObject *);
  76 PyAPI_FUNC(PyObject *) _PyString_FormatLong(PyObject*, int, int,
  77                                                   int, char**, int*);
  78 PyAPI_FUNC(PyObject *) PyString_DecodeEscape(const char *, Py_ssize_t,
  79                                                    const char *, Py_ssize_t,
  80                                                    const char *);
  81
  82 PyAPI_FUNC(void) PyString_InternInPlace(PyObject **);
  83 PyAPI_FUNC(void) PyString_InternImmortal(PyObject **);
  84 PyAPI_FUNC(PyObject *) PyString_InternFromString(const char *);
  85 PyAPI_FUNC(void) _Py_ReleaseInternedStrings(void);
  86
  87 /* Use only if you know it's a string */
  88 #define PyString_CHECK_INTERNED(op) (((PyStringObject *)(op))->ob_sstate)
  89
  90 /* Macro, trading safety for speed */
  91 #define PyString_AS_STRING(op) (((PyStringObject *)(op))->ob_sval)
  92 #define PyString_GET_SIZE(op)  Py_SIZE(op)
  93
  94 /* _PyString_Join(sep, x) is like sep.join(x).  sep must be PyStringObject*,
  95    x must be an iterable object. */
  96 PyAPI_FUNC(PyObject *) _PyString_Join(PyObject *sep, PyObject *x);
  97
  98 /* --- Generic Codecs ----------------------------------------------------- */
  99
 100 /* Create an object by decoding the encoded string s of the
 101    given size. */
 102
 103 PyAPI_FUNC(PyObject*) PyString_Decode(
 104     const char *s,              /* encoded string */
 105     Py_ssize_t size,            /* size of buffer */
 106     const char *encoding,       /* encoding */
 107     const char *errors          /* error handling */
 108     );
 109
 110 /* Encodes a char buffer of the given size and returns a
 111    Python object. */
 112
 113 PyAPI_FUNC(PyObject*) PyString_Encode(
 114     const char *s,              /* string char buffer */
 115     Py_ssize_t size,            /* number of chars to encode */
 116     const char *encoding,       /* encoding */
 117     const char *errors          /* error handling */
 118     );
 119
 120 /* Encodes a string object and returns the result as Python
 121    object. */
 122
 123 PyAPI_FUNC(PyObject*) PyString_AsEncodedObject(
 124     PyObject *str,              /* string object */
 125     const char *encoding,       /* encoding */
 126     const char *errors          /* error handling */
 127     );
 128
 129 /* Encodes a string object and returns the result as Python string
 130    object.
 131
 132    If the codec returns an Unicode object, the object is converted
 133    back to a string using the default encoding.
 134
 135    DEPRECATED - use PyString_AsEncodedObject() instead. */
 136
 137 PyAPI_FUNC(PyObject*) PyString_AsEncodedString(
 138     PyObject *str,              /* string object */
 139     const char *encoding,       /* encoding */
 140     const char *errors          /* error handling */
 141     );
 142
 143 /* Decodes a string object and returns the result as Python
 144    object. */
 145
 146 PyAPI_FUNC(PyObject*) PyString_AsDecodedObject(
 147     PyObject *str,              /* string object */
 148     const char *encoding,       /* encoding */
 149     const char *errors          /* error handling */
 150     );
 151
 152 /* Decodes a string object and returns the result as Python string
 153    object.
 154
 155    If the codec returns an Unicode object, the object is converted
 156    back to a string using the default encoding.
 157
 158    DEPRECATED - use PyString_AsDecodedObject() instead. */
 159
 160 PyAPI_FUNC(PyObject*) PyString_AsDecodedString(
 161     PyObject *str,              /* string object */
 162     const char *encoding,       /* encoding */
 163     const char *errors          /* error handling */
 164     );
 165
 166 /* Provides access to the internal data buffer and size of a string
 167    object or the default encoded version of an Unicode object. Passing
 168    NULL as *len parameter will force the string buffer to be
 169    0-terminated (passing a string with embedded NULL characters will
 170    cause an exception).  */
 171
 172 PyAPI_FUNC(int) PyString_AsStringAndSize(
 173     register PyObject *obj,     /* string or Unicode object */
 174     register char **s,          /* pointer to buffer variable */
 175     register Py_ssize_t *len    /* pointer to length variable or NULL
 176                                    (only possible for 0-terminated
 177                                    strings) */
 178     );
 179
 180
 181 /* Using the current locale, insert the thousands grouping
 182    into the string pointed to by buffer.  For the argument descriptions,
 183    see Objects/stringlib/localeutil.h */
 184 PyAPI_FUNC(Py_ssize_t) _PyString_InsertThousandsGroupingLocale(char *buffer,
 185                                   Py_ssize_t n_buffer,
 186                                   char *digits,
 187                                   Py_ssize_t n_digits,
 188                                   Py_ssize_t min_width);
 189
 190 /* Using explicit passed-in values, insert the thousands grouping
 191    into the string pointed to by buffer.  For the argument descriptions,
 192    see Objects/stringlib/localeutil.h */
 193 PyAPI_FUNC(Py_ssize_t) _PyString_InsertThousandsGrouping(char *buffer,
 194                                   Py_ssize_t n_buffer,
 195                                   char *digits,
 196                                   Py_ssize_t n_digits,
 197                                   Py_ssize_t min_width,
 198                                   const char *grouping,
 199                                   const char *thousands_sep);
 200
 201 /* Format the object based on the format_spec, as defined in PEP 3101
 202    (Advanced String Formatting). */
 203 PyAPI_FUNC(PyObject *) _PyBytes_FormatAdvanced(PyObject *obj,
 204                                                char *format_spec,
 205                                                Py_ssize_t format_spec_len);
 206
 207 #ifdef __cplusplus
 208 }
 209 #endif
 210 #endif /* !Py_STRINGOBJECT_H */