This commit was manufactured by cvs2svn to create tag 'r221'.

[python/dscho.git] / Objects / unicodeobject.c

/* 

Unicode implementation based on original code by Fredrik Lundh,
modified by Marc-Andre Lemburg <mal@lemburg.com> according to the
Unicode Integration Proposal (see file Misc/unicode.txt).

Copyright (c) Corporation for National Research Initiatives.

--------------------------------------------------------------------
The original string type implementation is:

    Copyright (c) 1999 by Secret Labs AB
    Copyright (c) 1999 by Fredrik Lundh

By obtaining, using, and/or copying this software and/or its
associated documentation, you agree that you have read, understood,
and will comply with the following terms and conditions:

Permission to use, copy, modify, and distribute this software and its
associated documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appears in all
copies, and that both that copyright notice and this permission notice
appear in supporting documentation, and that the name of Secret Labs
AB or the author not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR BE LIABLE FOR
ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--------------------------------------------------------------------

*/

#include "Python.h"

#include "unicodeobject.h"
#include "ucnhash.h"

#ifdef MS_WIN32
#include <windows.h>
#endif

/* Limit for the Unicode object free list */

#define MAX_UNICODE_FREELIST_SIZE       1024

/* Limit for the Unicode object free list stay alive optimization.

   The implementation will keep allocated Unicode memory intact for
   all objects on the free list having a size less than this
   limit. This reduces malloc() overhead for small Unicode objects.  

   At worst this will result in MAX_UNICODE_FREELIST_SIZE *
   (sizeof(PyUnicodeObject) + KEEPALIVE_SIZE_LIMIT +
   malloc()-overhead) bytes of unused garbage.

   Setting the limit to 0 effectively turns the feature off.

   Note: This is an experimental feature ! If you get core dumps when
   using Unicode objects, turn this feature off.

*/

#define KEEPALIVE_SIZE_LIMIT       9

/* Endianness switches; defaults to little endian */

#ifdef WORDS_BIGENDIAN
# define BYTEORDER_IS_BIG_ENDIAN
#else
# define BYTEORDER_IS_LITTLE_ENDIAN
#endif

/* --- Globals ------------------------------------------------------------

   The globals are initialized by the _PyUnicode_Init() API and should
   not be used before calling that API.

*/

/* Free list for Unicode objects */
static PyUnicodeObject *unicode_freelist;
static int unicode_freelist_size;

/* The empty Unicode object is shared to improve performance. */
static PyUnicodeObject *unicode_empty;

/* Single character Unicode strings in the Latin-1 range are being
   shared as well. */
static PyUnicodeObject *unicode_latin1[256];

/* Default encoding to use and assume when NULL is passed as encoding
   parameter; it is initialized by _PyUnicode_Init().

   Always use the PyUnicode_SetDefaultEncoding() and
   PyUnicode_GetDefaultEncoding() APIs to access this global. 

*/
static char unicode_default_encoding[100];

Py_UNICODE
PyUnicode_GetMax(void)
{
#ifdef Py_UNICODE_WIDE
        return 0x10FFFF;
#else
        /* This is actually an illegal character, so it should
           not be passed to unichr. */
        return 0xFFFF;
#endif
}

/* --- Unicode Object ----------------------------------------------------- */

static
int unicode_resize(register PyUnicodeObject *unicode,
                      int length)
{
    void *oldstr;
    
    /* Shortcut if there's nothing much to do. */
    if (unicode->length == length)
        goto reset;

    /* Resizing shared object (unicode_empty or single character
       objects) in-place is not allowed. Use PyUnicode_Resize()
       instead ! */
    if (unicode == unicode_empty || 
        (unicode->length == 1 && 
         unicode->str[0] < 256 &&
         unicode_latin1[unicode->str[0]] == unicode)) {
        PyErr_SetString(PyExc_SystemError,
                        "can't resize shared unicode objects");
        return -1;
    }

    /* We allocate one more byte to make sure the string is
       Ux0000 terminated -- XXX is this needed ? */
    oldstr = unicode->str;
    PyMem_RESIZE(unicode->str, Py_UNICODE, length + 1);
    if (!unicode->str) {
        unicode->str = oldstr;
        PyErr_NoMemory();
        return -1;
    }
    unicode->str[length] = 0;
    unicode->length = length;

 reset:
    /* Reset the object caches */
    if (unicode->defenc) {
        Py_DECREF(unicode->defenc);
        unicode->defenc = NULL;
    }
    unicode->hash = -1;
    
    return 0;
}

/* We allocate one more byte to make sure the string is
   Ux0000 terminated -- XXX is this needed ? 

   XXX This allocator could further be enhanced by assuring that the
       free list never reduces its size below 1.

*/

static
PyUnicodeObject *_PyUnicode_New(int length)
{
    register PyUnicodeObject *unicode;

    /* Optimization for empty strings */
    if (length == 0 && unicode_empty != NULL) {
        Py_INCREF(unicode_empty);
        return unicode_empty;
    }

    /* Unicode freelist & memory allocation */
    if (unicode_freelist) {
        unicode = unicode_freelist;
        unicode_freelist = *(PyUnicodeObject **)unicode;
        unicode_freelist_size--;
        if (unicode->str) {
            /* Keep-Alive optimization: we only upsize the buffer,
               never downsize it. */
            if ((unicode->length < length) &&
                unicode_resize(unicode, length)) {
                PyMem_DEL(unicode->str);
                goto onError;
            }
        }
        else {
            unicode->str = PyMem_NEW(Py_UNICODE, length + 1);
        }
        PyObject_INIT(unicode, &PyUnicode_Type);
    }
    else {
        unicode = PyObject_NEW(PyUnicodeObject, &PyUnicode_Type);
        if (unicode == NULL)
            return NULL;
        unicode->str = PyMem_NEW(Py_UNICODE, length + 1);
    }

    if (!unicode->str) {
        PyErr_NoMemory();
        goto onError;
    }
    unicode->str[length] = 0;
    unicode->length = length;
    unicode->hash = -1;
    unicode->defenc = NULL;
    return unicode;

 onError:
    _Py_ForgetReference((PyObject *)unicode);
    PyObject_DEL(unicode);
    return NULL;
}

static
void unicode_dealloc(register PyUnicodeObject *unicode)
{
    if (PyUnicode_CheckExact(unicode) &&
        unicode_freelist_size < MAX_UNICODE_FREELIST_SIZE) {
        /* Keep-Alive optimization */
        if (unicode->length >= KEEPALIVE_SIZE_LIMIT) {
            PyMem_DEL(unicode->str);
            unicode->str = NULL;
            unicode->length = 0;
        }
        if (unicode->defenc) {
            Py_DECREF(unicode->defenc);
            unicode->defenc = NULL;
        }
        /* Add to free list */
        *(PyUnicodeObject **)unicode = unicode_freelist;
        unicode_freelist = unicode;
        unicode_freelist_size++;
    }
    else {
        PyMem_DEL(unicode->str);
        Py_XDECREF(unicode->defenc);
        unicode->ob_type->tp_free((PyObject *)unicode);
    }
}

int PyUnicode_Resize(PyObject **unicode,
                     int length)
{
    register PyUnicodeObject *v;

    /* Argument checks */
    if (unicode == NULL) {
        PyErr_BadInternalCall();
        return -1;
    }
    v = (PyUnicodeObject *)*unicode;
    if (v == NULL || !PyUnicode_Check(v) || v->ob_refcnt != 1) {
        PyErr_BadInternalCall();
        return -1;
    }

    /* Resizing unicode_empty and single character objects is not
       possible since these are being shared. We simply return a fresh
       copy with the same Unicode content. */
    if (v->length != length && 
        (v == unicode_empty || v->length == 1)) {
        PyUnicodeObject *w = _PyUnicode_New(length);
        if (w == NULL)
            return -1;
        Py_UNICODE_COPY(w->str, v->str,
                        length < v->length ? length : v->length);
        *unicode = (PyObject *)w;
        return 0;
    }

    /* Note that we don't have to modify *unicode for unshared Unicode
       objects, since we can modify them in-place. */
    return unicode_resize(v, length);
}

/* Internal API for use in unicodeobject.c only ! */
#define _PyUnicode_Resize(unicodevar, length) \
        PyUnicode_Resize(((PyObject **)(unicodevar)), length)

PyObject *PyUnicode_FromUnicode(const Py_UNICODE *u,
                                int size)
{
    PyUnicodeObject *unicode;

    /* If the Unicode data is known at construction time, we can apply
       some optimizations which share commonly used objects. */
    if (u != NULL) {

        /* Optimization for empty strings */
        if (size == 0 && unicode_empty != NULL) {
            Py_INCREF(unicode_empty);
            return (PyObject *)unicode_empty;
        }

        /* Single character Unicode objects in the Latin-1 range are
           shared when using this constructor */
        if (size == 1 && *u < 256) {
            unicode = unicode_latin1[*u];
            if (!unicode) {
                unicode = _PyUnicode_New(1);
                if (!unicode)
                    return NULL;
                unicode->str[0] = *u;
                unicode_latin1[*u] = unicode;
            }
            Py_INCREF(unicode);
            return (PyObject *)unicode;
        }
    }
    
    unicode = _PyUnicode_New(size);
    if (!unicode)
        return NULL;

    /* Copy the Unicode data into the new object */
    if (u != NULL)
        Py_UNICODE_COPY(unicode->str, u, size);

    return (PyObject *)unicode;
}

#ifdef HAVE_WCHAR_H

PyObject *PyUnicode_FromWideChar(register const wchar_t *w,
                                 int size)
{
    PyUnicodeObject *unicode;

    if (w == NULL) {
        PyErr_BadInternalCall();
        return NULL;
    }

    unicode = _PyUnicode_New(size);
    if (!unicode)
        return NULL;

    /* Copy the wchar_t data into the new object */
#ifdef HAVE_USABLE_WCHAR_T
    memcpy(unicode->str, w, size * sizeof(wchar_t));
#else    
    {
        register Py_UNICODE *u;
        register int i;
        u = PyUnicode_AS_UNICODE(unicode);
        for (i = size; i >= 0; i--)
            *u++ = *w++;
    }
#endif

    return (PyObject *)unicode;
}

int PyUnicode_AsWideChar(PyUnicodeObject *unicode,
                         register wchar_t *w,
                         int size)
{
    if (unicode == NULL) {
        PyErr_BadInternalCall();
        return -1;
    }
    if (size > PyUnicode_GET_SIZE(unicode))
        size = PyUnicode_GET_SIZE(unicode);
#ifdef HAVE_USABLE_WCHAR_T
    memcpy(w, unicode->str, size * sizeof(wchar_t));
#else
    {
        register Py_UNICODE *u;
        register int i;
        u = PyUnicode_AS_UNICODE(unicode);
        for (i = size; i >= 0; i--)
            *w++ = *u++;
    }
#endif

    return size;
}

#endif

PyObject *PyUnicode_FromObject(register PyObject *obj)
{
    /* XXX Perhaps we should make this API an alias of
           PyObject_Unicode() instead ?! */
    if (PyUnicode_CheckExact(obj)) {
        Py_INCREF(obj);
        return obj;
    }
    if (PyUnicode_Check(obj)) {
        /* For a Unicode subtype that's not a Unicode object,
           return a true Unicode object with the same data. */
        return PyUnicode_FromUnicode(PyUnicode_AS_UNICODE(obj),
                                     PyUnicode_GET_SIZE(obj));
    }
    return PyUnicode_FromEncodedObject(obj, NULL, "strict");
}

PyObject *PyUnicode_FromEncodedObject(register PyObject *obj,
                                      const char *encoding,
                                      const char *errors)
{
    const char *s = NULL;
    int len;
    int owned = 0;
    PyObject *v;
    
    if (obj == NULL) {
        PyErr_BadInternalCall();
        return NULL;
    }

#if 0
    /* For b/w compatibility we also accept Unicode objects provided
       that no encodings is given and then redirect to
       PyObject_Unicode() which then applies the additional logic for
       Unicode subclasses.

       NOTE: This API should really only be used for object which
             represent *encoded* Unicode !

    */
        if (PyUnicode_Check(obj)) {
            if (encoding) {
                PyErr_SetString(PyExc_TypeError,
                                "decoding Unicode is not supported");
            return NULL;
            }
        return PyObject_Unicode(obj);
            }
#else
    if (PyUnicode_Check(obj)) {
        PyErr_SetString(PyExc_TypeError,
                        "decoding Unicode is not supported");
        return NULL;
        }
#endif

    /* Coerce object */
    if (PyString_Check(obj)) {
            s = PyString_AS_STRING(obj);
            len = PyString_GET_SIZE(obj);
            }
    else if (PyObject_AsCharBuffer(obj, &s, &len)) {
        /* Overwrite the error message with something more useful in
           case of a TypeError. */
        if (PyErr_ExceptionMatches(PyExc_TypeError))
        PyErr_Format(PyExc_TypeError,
                         "coercing to Unicode: need string or buffer, "
                         "%.80s found",
                     obj->ob_type->tp_name);
        goto onError;
    }
    
    /* Convert to Unicode */
    if (len == 0) {
        Py_INCREF(unicode_empty);
        v = (PyObject *)unicode_empty;
    }
    else 
        v = PyUnicode_Decode(s, len, encoding, errors);

    if (owned) {
        Py_DECREF(obj);
    }
    return v;

 onError:
    if (owned) {
        Py_DECREF(obj);
    }
    return NULL;
}

PyObject *PyUnicode_Decode(const char *s,
                           int size,
                           const char *encoding,
                           const char *errors)
{
    PyObject *buffer = NULL, *unicode;
    
    if (encoding == NULL) 
        encoding = PyUnicode_GetDefaultEncoding();

    /* Shortcuts for common default encodings */
    if (strcmp(encoding, "utf-8") == 0)
        return PyUnicode_DecodeUTF8(s, size, errors);
    else if (strcmp(encoding, "latin-1") == 0)
        return PyUnicode_DecodeLatin1(s, size, errors);
    else if (strcmp(encoding, "ascii") == 0)
        return PyUnicode_DecodeASCII(s, size, errors);

    /* Decode via the codec registry */
    buffer = PyBuffer_FromMemory((void *)s, size);
    if (buffer == NULL)
        goto onError;
    unicode = PyCodec_Decode(buffer, encoding, errors);
    if (unicode == NULL)
        goto onError;
    if (!PyUnicode_Check(unicode)) {
        PyErr_Format(PyExc_TypeError,
                     "decoder did not return an unicode object (type=%.400s)",
                     unicode->ob_type->tp_name);
        Py_DECREF(unicode);
        goto onError;
    }
    Py_DECREF(buffer);
    return unicode;
    
 onError:
    Py_XDECREF(buffer);
    return NULL;
}

PyObject *PyUnicode_Encode(const Py_UNICODE *s,
                           int size,
                           const char *encoding,
                           const char *errors)
{
    PyObject *v, *unicode;
    
    unicode = PyUnicode_FromUnicode(s, size);
    if (unicode == NULL)
        return NULL;
    v = PyUnicode_AsEncodedString(unicode, encoding, errors);
    Py_DECREF(unicode);
    return v;
}

PyObject *PyUnicode_AsEncodedString(PyObject *unicode,
                                    const char *encoding,
                                    const char *errors)
{
    PyObject *v;
    
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        goto onError;
    }

    if (encoding == NULL) 
        encoding = PyUnicode_GetDefaultEncoding();

    /* Shortcuts for common default encodings */
    if (errors == NULL) {
        if (strcmp(encoding, "utf-8") == 0)
            return PyUnicode_AsUTF8String(unicode);
        else if (strcmp(encoding, "latin-1") == 0)
            return PyUnicode_AsLatin1String(unicode);
        else if (strcmp(encoding, "ascii") == 0)
            return PyUnicode_AsASCIIString(unicode);
    }

    /* Encode via the codec registry */
    v = PyCodec_Encode(unicode, encoding, errors);
    if (v == NULL)
        goto onError;
    /* XXX Should we really enforce this ? */
    if (!PyString_Check(v)) {
        PyErr_Format(PyExc_TypeError,
                     "encoder did not return a string object (type=%.400s)",
                     v->ob_type->tp_name);
        Py_DECREF(v);
        goto onError;
    }
    return v;
    
 onError:
    return NULL;
}

PyObject *_PyUnicode_AsDefaultEncodedString(PyObject *unicode,
                                            const char *errors)
{
    PyObject *v = ((PyUnicodeObject *)unicode)->defenc;

    if (v)
        return v;
    v = PyUnicode_AsEncodedString(unicode, NULL, errors);
    if (v && errors == NULL)
        ((PyUnicodeObject *)unicode)->defenc = v;
    return v;
}

Py_UNICODE *PyUnicode_AsUnicode(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        goto onError;
    }
    return PyUnicode_AS_UNICODE(unicode);

 onError:
    return NULL;
}

int PyUnicode_GetSize(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        goto onError;
    }
    return PyUnicode_GET_SIZE(unicode);

 onError:
    return -1;
}

const char *PyUnicode_GetDefaultEncoding(void)
{
    return unicode_default_encoding;
}

int PyUnicode_SetDefaultEncoding(const char *encoding)
{
    PyObject *v;
    
    /* Make sure the encoding is valid. As side effect, this also
       loads the encoding into the codec registry cache. */
    v = _PyCodec_Lookup(encoding);
    if (v == NULL)
        goto onError;
    Py_DECREF(v);
    strncpy(unicode_default_encoding,
            encoding, 
            sizeof(unicode_default_encoding));
    return 0;

 onError:
    return -1;
}

/* --- UTF-7 Codec -------------------------------------------------------- */

/* see RFC2152 for details */

static 
char utf7_special[128] = {
    /* indicate whether a UTF-7 character is special i.e. cannot be directly
       encoded:
           0 - not special
           1 - special
           2 - whitespace (optional)
           3 - RFC2152 Set O (optional) */
    1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    2, 3, 3, 3, 3, 3, 3, 0, 0, 0, 3, 1, 0, 0, 0, 1,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 0,
    3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 1, 3, 3, 3,
    3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 1, 1,

};

#define SPECIAL(c, encodeO, encodeWS) \
        (((c)>127 || utf7_special[(c)] == 1) || \
         (encodeWS && (utf7_special[(c)] == 2)) || \
     (encodeO && (utf7_special[(c)] == 3)))

#define B64(n)  ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[(n) & 0x3f])
#define B64CHAR(c) (isalnum(c) || (c) == '+' || (c) == '/')
#define UB64(c)        ((c) == '+' ? 62 : (c) == '/' ? 63 : (c) >= 'a' ? \
                        (c) - 71 : (c) >= 'A' ? (c) - 65 : (c) + 4)

#define ENCODE(out, ch, bits) \
    while (bits >= 6) { \
        *out++ = B64(ch >> (bits-6)); \
        bits -= 6; \
    }

#define DECODE(out, ch, bits, surrogate) \
    while (bits >= 16) { \
        Py_UNICODE outCh = (Py_UNICODE) ((ch >> (bits-16)) & 0xffff); \
        bits -= 16; \
                if (surrogate) { \
                        /* We have already generated an error for the high surrogate
               so let's not bother seeing if the low surrogate is correct or not */\
                        surrogate = 0; \
                } else if (0xDC00 <= outCh && outCh <= 0xDFFF) { \
            /* This is a surrogate pair. Unfortunately we can't represent \
               it in a 16-bit character */ \
                        surrogate = 1; \
            errmsg = "code pairs are not supported"; \
                goto utf7Error; \
                } else { \
                                *out++ = outCh; \
                } \
    } \

static
int utf7_decoding_error(Py_UNICODE **dest,
                        const char *errors,
                        const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "UTF-7 decoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        if (dest != NULL) {
            **dest = Py_UNICODE_REPLACEMENT_CHARACTER;
            (*dest)++;
        }
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "UTF-7 decoding error; unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_DecodeUTF7(const char *s,
                               int size,
                               const char *errors)
{
    const char *e;
    PyUnicodeObject *unicode;
    Py_UNICODE *p;
    const char *errmsg = "";
    int inShift = 0;
    unsigned int bitsleft = 0;
    unsigned long charsleft = 0;
        int surrogate = 0;

    unicode = _PyUnicode_New(size);
    if (!unicode)
        return NULL;
    if (size == 0)
        return (PyObject *)unicode;

    p = unicode->str;
    e = s + size;

    while (s < e) {
        Py_UNICODE ch = *s;

        if (inShift) {
            if ((ch == '-') || !B64CHAR(ch)) {
                inShift = 0;
                s++;
                    
                /* p, charsleft, bitsleft, surrogate = */ DECODE(p, charsleft, bitsleft, surrogate);
                if (bitsleft >= 6) {
                    /* The shift sequence has a partial character in it. If
                       bitsleft < 6 then we could just classify it as padding
                       but that is not the case here */

                    errmsg = "partial character in shift sequence";
                    goto utf7Error; 
                }
                /* According to RFC2152 the remaining bits should be zero. We
                   choose to signal an error/insert a replacement character 
                   here so indicate the potential of a misencoded character. */

                /* On x86, a << b == a << (b%32) so make sure that bitsleft != 0 */
                if (bitsleft && charsleft << (sizeof(charsleft) * 8 - bitsleft)) {
                    errmsg = "non-zero padding bits in shift sequence";
                    goto utf7Error; 
                }

                if (ch == '-') {
                    if ((s < e) && (*(s) == '-')) {
                        *p++ = '-';   
                        inShift = 1;
                    }
                } else if (SPECIAL(ch,0,0)) {
                    errmsg = "unexpected special character";
                        goto utf7Error;  
                } else  {
                    *p++ = ch;
                }
            } else {
                charsleft = (charsleft << 6) | UB64(ch);
                bitsleft += 6;
                s++;
                /* p, charsleft, bitsleft, surrogate = */ DECODE(p, charsleft, bitsleft, surrogate);
            }
        }
        else if ( ch == '+' ) {
            s++;
            if (s < e && *s == '-') {
                s++;
                *p++ = '+';
            } else
            {
                inShift = 1;
                bitsleft = 0;
            }
        }
        else if (SPECIAL(ch,0,0)) {
            errmsg = "unexpected special character";
            s++;
                goto utf7Error;  
        }
        else {
            *p++ = ch;
            s++;
        }
        continue;
    utf7Error:
      if (utf7_decoding_error(&p, errors, errmsg))
          goto onError;
    }

    if (inShift) {
        if (utf7_decoding_error(&p, errors, "unterminated shift sequence"))
            goto onError;
    }

    if (_PyUnicode_Resize(&unicode, p - unicode->str))
        goto onError;

    return (PyObject *)unicode;

onError:
    Py_DECREF(unicode);
    return NULL;
}


PyObject *PyUnicode_EncodeUTF7(const Py_UNICODE *s,
                   int size,
                   int encodeSetO,
                   int encodeWhiteSpace,
                   const char *errors)
{
    PyObject *v;
    /* It might be possible to tighten this worst case */
    unsigned int cbAllocated = 5 * size;
    int inShift = 0;
    int i = 0;
    unsigned int bitsleft = 0;
    unsigned long charsleft = 0;
    char * out;
    char * start;

    if (size == 0)
                return PyString_FromStringAndSize(NULL, 0);

    v = PyString_FromStringAndSize(NULL, cbAllocated);
    if (v == NULL)
        return NULL;

    start = out = PyString_AS_STRING(v);
    for (;i < size; ++i) {
        Py_UNICODE ch = s[i];

        if (!inShift) {
                        if (ch == '+') {
                                *out++ = '+';
                *out++ = '-';
            } else if (SPECIAL(ch, encodeSetO, encodeWhiteSpace)) {
                charsleft = ch;
                bitsleft = 16;
                *out++ = '+';
                                /* out, charsleft, bitsleft = */ ENCODE(out, charsleft, bitsleft);
                inShift = bitsleft > 0;
                        } else {
                                *out++ = (char) ch;
                        }
                } else {
            if (!SPECIAL(ch, encodeSetO, encodeWhiteSpace)) {
                *out++ = B64(charsleft << (6-bitsleft));
                charsleft = 0;
                bitsleft = 0;
                /* Characters not in the BASE64 set implicitly unshift the sequence
                   so no '-' is required, except if the character is itself a '-' */
                if (B64CHAR(ch) || ch == '-') {
                    *out++ = '-';
                }
                inShift = 0;
                *out++ = (char) ch;
            } else {
                bitsleft += 16;
                charsleft = (charsleft << 16) | ch;
                /* out, charsleft, bitsleft = */ ENCODE(out, charsleft, bitsleft);

                /* If the next character is special then we dont' need to terminate
                   the shift sequence. If the next character is not a BASE64 character 
                   or '-' then the shift sequence will be terminated implicitly and we
                   don't have to insert a '-'. */

                if (bitsleft == 0) {
                    if (i + 1 < size) {
                        Py_UNICODE ch2 = s[i+1];

                        if (SPECIAL(ch2, encodeSetO, encodeWhiteSpace)) {
                           
                        } else if (B64CHAR(ch2) || ch2 == '-') {
                            *out++ = '-';
                            inShift = 0;
                        } else {
                            inShift = 0;
                        }

                    }
                    else {
                        *out++ = '-';
                        inShift = 0;
                    }
                }
            }            
        }
        }
    if (bitsleft) {
        *out++= B64(charsleft << (6-bitsleft) );
        *out++ = '-';
    }

    if (_PyString_Resize(&v, out - start)) {
        Py_DECREF(v);
        return NULL;
    }
    return v;
}

#undef SPECIAL
#undef B64
#undef B64CHAR
#undef UB64
#undef ENCODE
#undef DECODE

/* --- UTF-8 Codec -------------------------------------------------------- */

static 
char utf8_code_length[256] = {
    /* Map UTF-8 encoded prefix byte to sequence length.  zero means
       illegal prefix.  see RFC 2279 for details */
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 0, 0
};

static
int utf8_decoding_error(const char **source,
                        Py_UNICODE **dest,
                        const char *errors,
                        const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "UTF-8 decoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        (*source)++;
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        (*source)++;
        **dest = Py_UNICODE_REPLACEMENT_CHARACTER;
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "UTF-8 decoding error; unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_DecodeUTF8(const char *s,
                               int size,
                               const char *errors)
{
    int n;
    const char *e;
    PyUnicodeObject *unicode;
    Py_UNICODE *p;
    const char *errmsg = "";

    /* Note: size will always be longer than the resulting Unicode
       character count */
    unicode = _PyUnicode_New(size);
    if (!unicode)
        return NULL;
    if (size == 0)
        return (PyObject *)unicode;

    /* Unpack UTF-8 encoded data */
    p = unicode->str;
    e = s + size;

    while (s < e) {
        Py_UCS4 ch = (unsigned char)*s;

        if (ch < 0x80) {
            *p++ = (Py_UNICODE)ch;
            s++;
            continue;
        }

        n = utf8_code_length[ch];

        if (s + n > e) {
            errmsg = "unexpected end of data";
            goto utf8Error;
        }

        switch (n) {

        case 0:
            errmsg = "unexpected code byte";
            goto utf8Error;

        case 1:
            errmsg = "internal error";
            goto utf8Error;

        case 2:
            if ((s[1] & 0xc0) != 0x80) {
                errmsg = "invalid data";
                goto utf8Error;
            }
            ch = ((s[0] & 0x1f) << 6) + (s[1] & 0x3f);
            if (ch < 0x80) {
                errmsg = "illegal encoding";
                goto utf8Error;
            }
            else
                *p++ = (Py_UNICODE)ch;
            break;

        case 3:
            if ((s[1] & 0xc0) != 0x80 || 
                (s[2] & 0xc0) != 0x80) {
                errmsg = "invalid data";
                goto utf8Error;
            }
            ch = ((s[0] & 0x0f) << 12) + ((s[1] & 0x3f) << 6) + (s[2] & 0x3f);
            if (ch < 0x800 || (ch >= 0xd800 && ch < 0xe000)) {
                errmsg = "illegal encoding";
                goto utf8Error;
            }
            else
                                *p++ = (Py_UNICODE)ch;
            break;

        case 4:
            if ((s[1] & 0xc0) != 0x80 ||
                (s[2] & 0xc0) != 0x80 ||
                (s[3] & 0xc0) != 0x80) {
                errmsg = "invalid data";
                goto utf8Error;
            }
            ch = ((s[0] & 0x7) << 18) + ((s[1] & 0x3f) << 12) +
                 ((s[2] & 0x3f) << 6) + (s[3] & 0x3f);
            /* validate and convert to UTF-16 */
            if ((ch < 0x10000)        /* minimum value allowed for 4
                                       byte encoding */
                || (ch > 0x10ffff))   /* maximum value allowed for
                                       UTF-16 */
            {
                errmsg = "illegal encoding";
                goto utf8Error;
            }
#ifdef Py_UNICODE_WIDE
            *p++ = (Py_UNICODE)ch;
#else
            /*  compute and append the two surrogates: */
            
            /*  translate from 10000..10FFFF to 0..FFFF */
            ch -= 0x10000;
                    
            /*  high surrogate = top 10 bits added to D800 */
            *p++ = (Py_UNICODE)(0xD800 + (ch >> 10));
                    
            /*  low surrogate = bottom 10 bits added to DC00 */
            *p++ = (Py_UNICODE)(0xDC00 + (ch & 0x03FF));
#endif
            break;

        default:
            /* Other sizes are only needed for UCS-4 */
            errmsg = "unsupported Unicode code range";
            goto utf8Error;
        }
        s += n;
        continue;
        
    utf8Error:
      if (utf8_decoding_error(&s, &p, errors, errmsg))
          goto onError;
    }

    /* Adjust length */
    if (_PyUnicode_Resize(&unicode, p - unicode->str))
        goto onError;

    return (PyObject *)unicode;

onError:
    Py_DECREF(unicode);
    return NULL;
}

/* Not used anymore, now that the encoder supports UTF-16
   surrogates. */
#if 0
static
int utf8_encoding_error(const Py_UNICODE **source,
                        char **dest,
                        const char *errors,
                        const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "UTF-8 encoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = '?';
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "UTF-8 encoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}
#endif

PyObject *PyUnicode_EncodeUTF8(const Py_UNICODE *s,
                               int size,
                               const char *errors)
{
    PyObject *v;
    char *p;
    char *q;
    Py_UCS4 ch2;
    unsigned int cbAllocated = 3 * size;
    int i = 0;

    v = PyString_FromStringAndSize(NULL, cbAllocated);
    if (v == NULL)
        return NULL;
    if (size == 0)
        return v;

    p = q = PyString_AS_STRING(v);
    while (i < size) {
        Py_UCS4 ch = s[i++];
        if (ch < 0x80)
            *p++ = (char) ch;

        else if (ch < 0x0800) {
            *p++ = 0xc0 | (ch >> 6);
            *p++ = 0x80 | (ch & 0x3f);
        }

        else if (ch < 0x10000) {
            /* Check for high surrogate */
            if (0xD800 <= ch && ch <= 0xDBFF) {
                if (i != size) {
                    ch2 = s[i];
                    if (0xDC00 <= ch2 && ch2 <= 0xDFFF) {
                        
                        if ((Py_uintptr_t)(p - q) >= (cbAllocated - 4)) {
                            /* Provide enough room for some more
                               surrogates */
                            cbAllocated += 4*10;
                            if (_PyString_Resize(&v, cbAllocated))
                                goto onError;
                            p = PyString_AS_STRING(v) + (p - q);
                            q = PyString_AS_STRING(v);
                        }
                        
                        /* combine the two values */
                        ch = ((ch - 0xD800)<<10 | (ch2-0xDC00))+0x10000;
                        
                        *p++ = (char)((ch >> 18) | 0xf0);
                        *p++ = (char)(0x80 | ((ch >> 12) & 0x3f));
                        i++;
                    }
                }
            }
            else
                *p++ = (char)(0xe0 | (ch >> 12));

            *p++ = (char)(0x80 | ((ch >> 6) & 0x3f));
            *p++ = (char)(0x80 | (ch & 0x3f));

        } else {
            if ((Py_uintptr_t)(p - q) >= (cbAllocated - 4)) {
                /* Provide enough room for some more
                   surrogates */
                cbAllocated += 4*10;
                if (_PyString_Resize(&v, cbAllocated))
                    goto onError;
                p = PyString_AS_STRING(v) + (p - q);
                q = PyString_AS_STRING(v);
            }

            *p++ = 0xf0 | (ch>>18);
            *p++ = 0x80 | ((ch>>12) & 0x3f);
            *p++ = 0x80 | ((ch>>6) & 0x3f);
            *p++ = 0x80 | (ch & 0x3f);
        }
    }
    *p = '\0';
    if (_PyString_Resize(&v, p - q))
        goto onError;
    return v;

 onError:
    Py_XDECREF(v);
    return NULL;
}

PyObject *PyUnicode_AsUTF8String(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeUTF8(PyUnicode_AS_UNICODE(unicode),
                                PyUnicode_GET_SIZE(unicode),
                                NULL);
}

/* --- UTF-16 Codec ------------------------------------------------------- */

static
int utf16_decoding_error(Py_UNICODE **dest,
                         const char *errors,
                         const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "UTF-16 decoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        if (dest) {
            **dest = Py_UNICODE_REPLACEMENT_CHARACTER;
            (*dest)++;
        }
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "UTF-16 decoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *
PyUnicode_DecodeUTF16(const char *s,
                      int size,
                      const char *errors,
                      int *byteorder)
{
    PyUnicodeObject *unicode;
    Py_UNICODE *p;
    const unsigned char *q, *e;
    int bo = 0;       /* assume native ordering by default */
    const char *errmsg = "";
    /* Offsets from q for retrieving byte pairs in the right order. */
#ifdef BYTEORDER_IS_LITTLE_ENDIAN
    int ihi = 1, ilo = 0;
#else
    int ihi = 0, ilo = 1;
#endif

    /* size should be an even number */
    if (size & 1) {
        if (utf16_decoding_error(NULL, errors, "truncated data"))
            return NULL;
        --size;  /* else ignore the oddball byte */
    }

    /* Note: size will always be longer than the resulting Unicode
       character count */
    unicode = _PyUnicode_New(size);
    if (!unicode)
        return NULL;
    if (size == 0)
        return (PyObject *)unicode;

    /* Unpack UTF-16 encoded data */
    p = unicode->str;
    q = (unsigned char *)s;
    e = q + size;

    if (byteorder)
        bo = *byteorder;

    /* Check for BOM marks (U+FEFF) in the input and adjust current
       byte order setting accordingly. In native mode, the leading BOM
       mark is skipped, in all other modes, it is copied to the output
       stream as-is (giving a ZWNBSP character). */
    if (bo == 0) {
        const Py_UNICODE bom = (q[ihi] << 8) | q[ilo];
#ifdef BYTEORDER_IS_LITTLE_ENDIAN
        if (bom == 0xFEFF) {
            q += 2;
            bo = -1;
        }
        else if (bom == 0xFFFE) {
            q += 2;
            bo = 1;
        }
#else    
        if (bom == 0xFEFF) {
            q += 2;
            bo = 1;
        }
        else if (bom == 0xFFFE) {
            q += 2;
            bo = -1;
        }
#endif
    }

    if (bo == -1) {
        /* force LE */
        ihi = 1;
        ilo = 0;
    }
    else if (bo == 1) {
        /* force BE */
        ihi = 0;
        ilo = 1;
    }

    while (q < e) {
        Py_UNICODE ch = (q[ihi] << 8) | q[ilo];
        q += 2;

        if (ch < 0xD800 || ch > 0xDFFF) {
            *p++ = ch;
            continue;
        }

        /* UTF-16 code pair: */
        if (q >= e) {
            errmsg = "unexpected end of data";
            goto utf16Error;
        }
        if (0xD800 <= ch && ch <= 0xDBFF) {
            Py_UNICODE ch2 = (q[ihi] << 8) | q[ilo];
            q += 2;
            if (0xDC00 <= ch2 && ch2 <= 0xDFFF) {
#ifndef Py_UNICODE_WIDE
                *p++ = ch;
                *p++ = ch2;
#else
                *p++ = (((ch & 0x3FF)<<10) | (ch2 & 0x3FF)) + 0x10000;
#endif
                continue;
            }
            else {
                errmsg = "illegal UTF-16 surrogate";
                goto utf16Error;
            }

        }
        errmsg = "illegal encoding";
        /* Fall through to report the error */

    utf16Error:
        if (utf16_decoding_error(&p, errors, errmsg))
            goto onError;
    }

    if (byteorder)
        *byteorder = bo;

    /* Adjust length */
    if (_PyUnicode_Resize(&unicode, p - unicode->str))
        goto onError;

    return (PyObject *)unicode;

onError:
    Py_DECREF(unicode);
    return NULL;
}

PyObject *
PyUnicode_EncodeUTF16(const Py_UNICODE *s,
                      int size,
                      const char *errors,
                      int byteorder)
{
    PyObject *v;
    unsigned char *p;
    int i, pairs;
    /* Offsets from p for storing byte pairs in the right order. */
#ifdef BYTEORDER_IS_LITTLE_ENDIAN
    int ihi = 1, ilo = 0;
#else
    int ihi = 0, ilo = 1;
#endif

#define STORECHAR(CH)                   \
    do {                                \
        p[ihi] = ((CH) >> 8) & 0xff;    \
        p[ilo] = (CH) & 0xff;           \
        p += 2;                         \
    } while(0)

    for (i = pairs = 0; i < size; i++)
        if (s[i] >= 0x10000)
            pairs++;
    v = PyString_FromStringAndSize(NULL, 
                  2 * (size + pairs + (byteorder == 0)));
    if (v == NULL)
        return NULL;

    p = (unsigned char *)PyString_AS_STRING(v);
    if (byteorder == 0)
        STORECHAR(0xFEFF);
    if (size == 0)
        return v;

    if (byteorder == -1) {
        /* force LE */
        ihi = 1;
        ilo = 0;
    }
    else if (byteorder == 1) {
        /* force BE */
        ihi = 0;
        ilo = 1;
    }

    while (size-- > 0) {
        Py_UNICODE ch = *s++;
        Py_UNICODE ch2 = 0;
        if (ch >= 0x10000) {
            ch2 = 0xDC00 | ((ch-0x10000) & 0x3FF);
            ch  = 0xD800 | ((ch-0x10000) >> 10);
        }
        STORECHAR(ch);
        if (ch2)
            STORECHAR(ch2);
    }
    return v;
#undef STORECHAR
}

PyObject *PyUnicode_AsUTF16String(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(unicode),
                                 PyUnicode_GET_SIZE(unicode),
                                 NULL,
                                 0);
}

/* --- Unicode Escape Codec ----------------------------------------------- */

static
int unicodeescape_decoding_error(Py_UNICODE **x,
                                 const char *errors,
                                 const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "Unicode-Escape decoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **x = Py_UNICODE_REPLACEMENT_CHARACTER;
        (*x)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "Unicode-Escape decoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

static _PyUnicode_Name_CAPI *ucnhash_CAPI = NULL;

PyObject *PyUnicode_DecodeUnicodeEscape(const char *s,
                                        int size,
                                        const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p, *buf;
    const char *end;
    char* message;
    Py_UCS4 chr = 0xffffffff; /* in case 'getcode' messes up */

    /* Escaped strings will always be longer than the resulting
       Unicode string, so we start with size here and then reduce the
       length after conversion to the true value. */
    v = _PyUnicode_New(size);
    if (v == NULL)
        goto onError;
    if (size == 0)
        return (PyObject *)v;

    p = buf = PyUnicode_AS_UNICODE(v);
    end = s + size;

    while (s < end) {
        unsigned char c;
        Py_UNICODE x;
        int i, digits;

        /* Non-escape characters are interpreted as Unicode ordinals */
        if (*s != '\\') {
            *p++ = (unsigned char) *s++;
            continue;
        }

        /* \ - Escapes */
        s++;
        switch (*s++) {

        /* \x escapes */
        case '\n': break;
        case '\\': *p++ = '\\'; break;
        case '\'': *p++ = '\''; break;
        case '\"': *p++ = '\"'; break;
        case 'b': *p++ = '\b'; break;
        case 'f': *p++ = '\014'; break; /* FF */
        case 't': *p++ = '\t'; break;
        case 'n': *p++ = '\n'; break;
        case 'r': *p++ = '\r'; break;
        case 'v': *p++ = '\013'; break; /* VT */
        case 'a': *p++ = '\007'; break; /* BEL, not classic C */

        /* \OOO (octal) escapes */
        case '0': case '1': case '2': case '3':
        case '4': case '5': case '6': case '7':
            x = s[-1] - '0';
            if ('0' <= *s && *s <= '7') {
                x = (x<<3) + *s++ - '0';
                if ('0' <= *s && *s <= '7')
                    x = (x<<3) + *s++ - '0';
            }
            *p++ = x;
            break;

        /* hex escapes */
        /* \xXX */
        case 'x':
            digits = 2;
            message = "truncated \\xXX escape";
            goto hexescape;

        /* \uXXXX */
        case 'u':
            digits = 4;
            message = "truncated \\uXXXX escape";
            goto hexescape;

        /* \UXXXXXXXX */
        case 'U':
            digits = 8;
            message = "truncated \\UXXXXXXXX escape";
        hexescape:
            chr = 0;
            for (i = 0; i < digits; i++) {
                c = (unsigned char) s[i];
                if (!isxdigit(c)) {
                    if (unicodeescape_decoding_error(&p, errors, message))
                        goto onError;
                    chr = 0xffffffff;
                    i++;
                    break;
                }
                chr = (chr<<4) & ~0xF;
                if (c >= '0' && c <= '9')
                    chr += c - '0';
                else if (c >= 'a' && c <= 'f')
                    chr += 10 + c - 'a';
                else
                    chr += 10 + c - 'A';
            }
            s += i;
            if (chr == 0xffffffff)
                    /* _decoding_error will have already written into the
                       target buffer. */
                    break;
        store:
            /* when we get here, chr is a 32-bit unicode character */
            if (chr <= 0xffff)
                /* UCS-2 character */
                *p++ = (Py_UNICODE) chr;
            else if (chr <= 0x10ffff) {
                /* UCS-4 character. Either store directly, or as
                   surrogate pair. */
#ifdef Py_UNICODE_WIDE
                *p++ = chr;
#else
                chr -= 0x10000L;
                *p++ = 0xD800 + (Py_UNICODE) (chr >> 10);
                *p++ = 0xDC00 + (Py_UNICODE) (chr & 0x03FF);
#endif
            } else {
                if (unicodeescape_decoding_error(
                    &p, errors,
                    "illegal Unicode character")
                    )
                    goto onError;
            }
            break;

        /* \N{name} */
        case 'N':
            message = "malformed \\N character escape";
            if (ucnhash_CAPI == NULL) {
                /* load the unicode data module */
                PyObject *m, *v;
                m = PyImport_ImportModule("unicodedata");
                if (m == NULL)
                    goto ucnhashError;
                v = PyObject_GetAttrString(m, "ucnhash_CAPI");
                Py_DECREF(m);
                if (v == NULL)
                    goto ucnhashError;
                ucnhash_CAPI = PyCObject_AsVoidPtr(v);
                Py_DECREF(v);
                if (ucnhash_CAPI == NULL)
                    goto ucnhashError;
            }
            if (*s == '{') {
                const char *start = s+1;
                /* look for the closing brace */
                while (*s != '}' && s < end)
                    s++;
                if (s > start && s < end && *s == '}') {
                    /* found a name.  look it up in the unicode database */
                    message = "unknown Unicode character name";
                    s++;
                    if (ucnhash_CAPI->getcode(start, s-start-1, &chr))
                        goto store;
                }
            }
            if (unicodeescape_decoding_error(&p, errors, message))
                goto onError;
            break;

        default:
            if (s > end) {
                if (unicodeescape_decoding_error(&p, errors, "\\ at end of string"))
                    goto onError;
            }
            else {
                *p++ = '\\';
                *p++ = (unsigned char)s[-1];
            }
            break;
        }
    }
    if (_PyUnicode_Resize(&v, (int)(p - buf)))
                goto onError;
    return (PyObject *)v;
    
ucnhashError:
    PyErr_SetString(
        PyExc_UnicodeError,
        "\\N escapes not supported (can't load unicodedata module)"
        );
    return NULL;

onError:
    Py_XDECREF(v);
    return NULL;
}

/* Return a Unicode-Escape string version of the Unicode object.

   If quotes is true, the string is enclosed in u"" or u'' quotes as
   appropriate.

*/

static const Py_UNICODE *findchar(const Py_UNICODE *s,
                                  int size,
                                  Py_UNICODE ch);

static
PyObject *unicodeescape_string(const Py_UNICODE *s,
                               int size,
                               int quotes)
{
    PyObject *repr;
    char *p;

    static const char *hexdigit = "0123456789abcdef";

    repr = PyString_FromStringAndSize(NULL, 2 + 6*size + 1);
    if (repr == NULL)
        return NULL;

    p = PyString_AS_STRING(repr);

    if (quotes) {
        *p++ = 'u';
        *p++ = (findchar(s, size, '\'') && 
                !findchar(s, size, '"')) ? '"' : '\'';
    }
    while (size-- > 0) {
        Py_UNICODE ch = *s++;

        /* Escape quotes */
        if (quotes && 
            (ch == (Py_UNICODE) PyString_AS_STRING(repr)[1] || ch == '\\')) {
            *p++ = '\\';
            *p++ = (char) ch;
            continue;
        } 

#ifdef Py_UNICODE_WIDE
        /* Map 21-bit characters to '\U00xxxxxx' */
        else if (ch >= 0x10000) {
            int offset = p - PyString_AS_STRING(repr);
            
            /* Resize the string if necessary */
            if (offset + 12 > PyString_GET_SIZE(repr)) {
                if (_PyString_Resize(&repr, PyString_GET_SIZE(repr) + 100))
                    goto onError;
                p = PyString_AS_STRING(repr) + offset;
            }

            *p++ = '\\';
            *p++ = 'U';
            *p++ = hexdigit[(ch >> 28) & 0x0000000F];
            *p++ = hexdigit[(ch >> 24) & 0x0000000F];
            *p++ = hexdigit[(ch >> 20) & 0x0000000F];
            *p++ = hexdigit[(ch >> 16) & 0x0000000F];
            *p++ = hexdigit[(ch >> 12) & 0x0000000F];
            *p++ = hexdigit[(ch >> 8) & 0x0000000F];
            *p++ = hexdigit[(ch >> 4) & 0x0000000F];
            *p++ = hexdigit[ch & 0x0000000F];
            continue;
        }
#endif
        /* Map UTF-16 surrogate pairs to Unicode \UXXXXXXXX escapes */
        else if (ch >= 0xD800 && ch < 0xDC00) {
            Py_UNICODE ch2;
            Py_UCS4 ucs;
            
            ch2 = *s++;
            size--;
            if (ch2 >= 0xDC00 && ch2 <= 0xDFFF) {
                ucs = (((ch & 0x03FF) << 10) | (ch2 & 0x03FF)) + 0x00010000;
                *p++ = '\\';
                *p++ = 'U';
                *p++ = hexdigit[(ucs >> 28) & 0x0000000F];
                *p++ = hexdigit[(ucs >> 24) & 0x0000000F];
                *p++ = hexdigit[(ucs >> 20) & 0x0000000F];
                *p++ = hexdigit[(ucs >> 16) & 0x0000000F];
                *p++ = hexdigit[(ucs >> 12) & 0x0000000F];
                *p++ = hexdigit[(ucs >> 8) & 0x0000000F];
                *p++ = hexdigit[(ucs >> 4) & 0x0000000F];
                *p++ = hexdigit[ucs & 0x0000000F];
                continue;
            }
            /* Fall through: isolated surrogates are copied as-is */
            s--;
            size++;
        }

        /* Map 16-bit characters to '\uxxxx' */
        if (ch >= 256) {
            *p++ = '\\';
            *p++ = 'u';
            *p++ = hexdigit[(ch >> 12) & 0x000F];
            *p++ = hexdigit[(ch >> 8) & 0x000F];
            *p++ = hexdigit[(ch >> 4) & 0x000F];
            *p++ = hexdigit[ch & 0x000F];
        }

        /* Map special whitespace to '\t', \n', '\r' */
        else if (ch == '\t') {
            *p++ = '\\';
            *p++ = 't';
        }
        else if (ch == '\n') {
            *p++ = '\\';
            *p++ = 'n';
        }
        else if (ch == '\r') {
            *p++ = '\\';
            *p++ = 'r';
        }

        /* Map non-printable US ASCII to '\xhh' */
        else if (ch < ' ' || ch >= 0x7F) {
            *p++ = '\\';
            *p++ = 'x';
            *p++ = hexdigit[(ch >> 4) & 0x000F];
            *p++ = hexdigit[ch & 0x000F];
        } 

        /* Copy everything else as-is */
        else
            *p++ = (char) ch;
    }
    if (quotes)
        *p++ = PyString_AS_STRING(repr)[1];

    *p = '\0';
    if (_PyString_Resize(&repr, p - PyString_AS_STRING(repr)))
        goto onError;

    return repr;

 onError:
    Py_DECREF(repr);
    return NULL;
}

PyObject *PyUnicode_EncodeUnicodeEscape(const Py_UNICODE *s,
                                        int size)
{
    return unicodeescape_string(s, size, 0);
}

PyObject *PyUnicode_AsUnicodeEscapeString(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeUnicodeEscape(PyUnicode_AS_UNICODE(unicode),
                                         PyUnicode_GET_SIZE(unicode));
}

/* --- Raw Unicode Escape Codec ------------------------------------------- */

PyObject *PyUnicode_DecodeRawUnicodeEscape(const char *s,
                                           int size,
                                           const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p, *buf;
    const char *end;
    const char *bs;
    
    /* Escaped strings will always be longer than the resulting
       Unicode string, so we start with size here and then reduce the
       length after conversion to the true value. */
    v = _PyUnicode_New(size);
    if (v == NULL)
        goto onError;
    if (size == 0)
        return (PyObject *)v;
    p = buf = PyUnicode_AS_UNICODE(v);
    end = s + size;
    while (s < end) {
        unsigned char c;
        Py_UCS4 x;
        int i;

        /* Non-escape characters are interpreted as Unicode ordinals */
        if (*s != '\\') {
            *p++ = (unsigned char)*s++;
            continue;
        }

        /* \u-escapes are only interpreted iff the number of leading
           backslashes if odd */
        bs = s;
        for (;s < end;) {
            if (*s != '\\')
                break;
            *p++ = (unsigned char)*s++;
        }
        if (((s - bs) & 1) == 0 ||
            s >= end ||
            *s != 'u') {
            continue;
        }
        p--;
        s++;

        /* \uXXXX with 4 hex digits */
        for (x = 0, i = 0; i < 4; i++) {
            c = (unsigned char)s[i];
            if (!isxdigit(c)) {
                if (unicodeescape_decoding_error(&p, errors,
                                                 "truncated \\uXXXX"))
                    goto onError;
                x = 0xffffffff;
                i++;
                break;
            }
            x = (x<<4) & ~0xF;
            if (c >= '0' && c <= '9')
                x += c - '0';
            else if (c >= 'a' && c <= 'f')
                x += 10 + c - 'a';
            else
                x += 10 + c - 'A';
        }
        s += i;
        if (x != 0xffffffff)
                *p++ = x;
    }
    if (_PyUnicode_Resize(&v, (int)(p - buf)))
        goto onError;
    return (PyObject *)v;
    
 onError:
    Py_XDECREF(v);
    return NULL;
}

PyObject *PyUnicode_EncodeRawUnicodeEscape(const Py_UNICODE *s,
                                           int size)
{
    PyObject *repr;
    char *p;
    char *q;

    static const char *hexdigit = "0123456789abcdef";

    repr = PyString_FromStringAndSize(NULL, 6 * size);
    if (repr == NULL)
        return NULL;
    if (size == 0)
        return repr;

    p = q = PyString_AS_STRING(repr);
    while (size-- > 0) {
        Py_UNICODE ch = *s++;
        /* Map 16-bit characters to '\uxxxx' */
        if (ch >= 256) {
            *p++ = '\\';
            *p++ = 'u';
            *p++ = hexdigit[(ch >> 12) & 0xf];
            *p++ = hexdigit[(ch >> 8) & 0xf];
            *p++ = hexdigit[(ch >> 4) & 0xf];
            *p++ = hexdigit[ch & 15];
        }
        /* Copy everything else as-is */
        else
            *p++ = (char) ch;
    }
    *p = '\0';
    if (_PyString_Resize(&repr, p - q))
        goto onError;

    return repr;

 onError:
    Py_DECREF(repr);
    return NULL;
}

PyObject *PyUnicode_AsRawUnicodeEscapeString(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeRawUnicodeEscape(PyUnicode_AS_UNICODE(unicode),
                                            PyUnicode_GET_SIZE(unicode));
}

/* --- Latin-1 Codec ------------------------------------------------------ */

PyObject *PyUnicode_DecodeLatin1(const char *s,
                                 int size,
                                 const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p;
    
    /* Latin-1 is equivalent to the first 256 ordinals in Unicode. */
    if (size == 1 && *(unsigned char*)s < 256) {
        Py_UNICODE r = *(unsigned char*)s;
        return PyUnicode_FromUnicode(&r, 1);
    }

    v = _PyUnicode_New(size);
    if (v == NULL)
        goto onError;
    if (size == 0)
        return (PyObject *)v;
    p = PyUnicode_AS_UNICODE(v);
    while (size-- > 0)
        *p++ = (unsigned char)*s++;
    return (PyObject *)v;
    
 onError:
    Py_XDECREF(v);
    return NULL;
}

static
int latin1_encoding_error(const Py_UNICODE **source,
                          char **dest,
                          const char *errors,
                          const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "Latin-1 encoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = '?';
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "Latin-1 encoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_EncodeLatin1(const Py_UNICODE *p,
                                 int size,
                                 const char *errors)
{
    PyObject *repr;
    char *s, *start;

    repr = PyString_FromStringAndSize(NULL, size);
    if (repr == NULL)
        return NULL;
    if (size == 0)
        return repr;

    s = PyString_AS_STRING(repr);
    start = s;
    while (size-- > 0) {
        Py_UNICODE ch = *p++;
        if (ch >= 256) {
            if (latin1_encoding_error(&p, &s, errors, 
                                      "ordinal not in range(256)"))
                goto onError;
        }
        else
            *s++ = (char)ch;
    }
    /* Resize if error handling skipped some characters */
    if (s - start < PyString_GET_SIZE(repr))
        if (_PyString_Resize(&repr, s - start))
            goto onError;
    return repr;

 onError:
    Py_DECREF(repr);
    return NULL;
}

PyObject *PyUnicode_AsLatin1String(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeLatin1(PyUnicode_AS_UNICODE(unicode),
                                  PyUnicode_GET_SIZE(unicode),
                                  NULL);
}

/* --- 7-bit ASCII Codec -------------------------------------------------- */

static
int ascii_decoding_error(const char **source,
                         Py_UNICODE **dest,
                         const char *errors,
                         const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "ASCII decoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = Py_UNICODE_REPLACEMENT_CHARACTER;
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "ASCII decoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_DecodeASCII(const char *s,
                                int size,
                                const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p;
    
    /* ASCII is equivalent to the first 128 ordinals in Unicode. */
    if (size == 1 && *(unsigned char*)s < 128) {
        Py_UNICODE r = *(unsigned char*)s;
        return PyUnicode_FromUnicode(&r, 1);
    }
    
    v = _PyUnicode_New(size);
    if (v == NULL)
        goto onError;
    if (size == 0)
        return (PyObject *)v;
    p = PyUnicode_AS_UNICODE(v);
    while (size-- > 0) {
        register unsigned char c;

        c = (unsigned char)*s++;
        if (c < 128)
            *p++ = c;
        else if (ascii_decoding_error(&s, &p, errors, 
                                      "ordinal not in range(128)"))
                goto onError;
    }
    if (p - PyUnicode_AS_UNICODE(v) < PyString_GET_SIZE(v))
        if (_PyUnicode_Resize(&v, (int)(p - PyUnicode_AS_UNICODE(v))))
            goto onError;
    return (PyObject *)v;
    
 onError:
    Py_XDECREF(v);
    return NULL;
}

static
int ascii_encoding_error(const Py_UNICODE **source,
                         char **dest,
                         const char *errors,
                         const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "ASCII encoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = '?';
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "ASCII encoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_EncodeASCII(const Py_UNICODE *p,
                                int size,
                                const char *errors)
{
    PyObject *repr;
    char *s, *start;

    repr = PyString_FromStringAndSize(NULL, size);
    if (repr == NULL)
        return NULL;
    if (size == 0)
        return repr;

    s = PyString_AS_STRING(repr);
    start = s;
    while (size-- > 0) {
        Py_UNICODE ch = *p++;
        if (ch >= 128) {
            if (ascii_encoding_error(&p, &s, errors, 
                                      "ordinal not in range(128)"))
                goto onError;
        }
        else
            *s++ = (char)ch;
    }
    /* Resize if error handling skipped some characters */
    if (s - start < PyString_GET_SIZE(repr))
        if (_PyString_Resize(&repr, s - start))
            goto onError;
    return repr;

 onError:
    Py_DECREF(repr);
    return NULL;
}

PyObject *PyUnicode_AsASCIIString(PyObject *unicode)
{
    if (!PyUnicode_Check(unicode)) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeASCII(PyUnicode_AS_UNICODE(unicode),
                                 PyUnicode_GET_SIZE(unicode),
                                 NULL);
}

#if defined(MS_WIN32) && defined(HAVE_USABLE_WCHAR_T)

/* --- MBCS codecs for Windows -------------------------------------------- */

PyObject *PyUnicode_DecodeMBCS(const char *s,
                                int size,
                                const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p;

    /* First get the size of the result */
    DWORD usize = MultiByteToWideChar(CP_ACP, 0, s, size, NULL, 0);
    if (size > 0 && usize==0)
        return PyErr_SetFromWindowsErrWithFilename(0, NULL);

    v = _PyUnicode_New(usize);
    if (v == NULL)
        return NULL;
    if (usize == 0)
        return (PyObject *)v;
    p = PyUnicode_AS_UNICODE(v);
    if (0 == MultiByteToWideChar(CP_ACP, 0, s, size, p, usize)) {
        Py_DECREF(v);
        return PyErr_SetFromWindowsErrWithFilename(0, NULL);
    }

    return (PyObject *)v;
}

PyObject *PyUnicode_EncodeMBCS(const Py_UNICODE *p,
                                int size,
                                const char *errors)
{
    PyObject *repr;
    char *s;
    DWORD mbcssize;

    /* If there are no characters, bail now! */
    if (size==0)
            return PyString_FromString("");

    /* First get the size of the result */
    mbcssize = WideCharToMultiByte(CP_ACP, 0, p, size, NULL, 0, NULL, NULL);
    if (mbcssize==0)
        return PyErr_SetFromWindowsErrWithFilename(0, NULL);

    repr = PyString_FromStringAndSize(NULL, mbcssize);
    if (repr == NULL)
        return NULL;
    if (mbcssize == 0)
        return repr;

    /* Do the conversion */
    s = PyString_AS_STRING(repr);
    if (0 == WideCharToMultiByte(CP_ACP, 0, p, size, s, mbcssize, NULL, NULL)) {
        Py_DECREF(repr);
        return PyErr_SetFromWindowsErrWithFilename(0, NULL);
    }
    return repr;
}

#endif /* MS_WIN32 */

/* --- Character Mapping Codec -------------------------------------------- */

static
int charmap_decoding_error(const char **source,
                         Py_UNICODE **dest,
                         const char *errors,
                         const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "charmap decoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = Py_UNICODE_REPLACEMENT_CHARACTER;
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "charmap decoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_DecodeCharmap(const char *s,
                                  int size,
                                  PyObject *mapping,
                                  const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p;
    int extrachars = 0;
    
    /* Default to Latin-1 */
    if (mapping == NULL)
        return PyUnicode_DecodeLatin1(s, size, errors);

    v = _PyUnicode_New(size);
    if (v == NULL)
        goto onError;
    if (size == 0)
        return (PyObject *)v;
    p = PyUnicode_AS_UNICODE(v);
    while (size-- > 0) {
        unsigned char ch = *s++;
        PyObject *w, *x;

        /* Get mapping (char ordinal -> integer, Unicode char or None) */
        w = PyInt_FromLong((long)ch);
        if (w == NULL)
            goto onError;
        x = PyObject_GetItem(mapping, w);
        Py_DECREF(w);
        if (x == NULL) {
            if (PyErr_ExceptionMatches(PyExc_LookupError)) {
                /* No mapping found means: mapping is undefined. */
                PyErr_Clear();
                x = Py_None;
                Py_INCREF(x);
            } else
                goto onError;
        }

        /* Apply mapping */
        if (PyInt_Check(x)) {
            long value = PyInt_AS_LONG(x);
            if (value < 0 || value > 65535) {
                PyErr_SetString(PyExc_TypeError,
                                "character mapping must be in range(65536)");
                Py_DECREF(x);
                goto onError;
            }
            *p++ = (Py_UNICODE)value;
        }
        else if (x == Py_None) {
            /* undefined mapping */
            if (charmap_decoding_error(&s, &p, errors, 
                                       "character maps to <undefined>")) {
                Py_DECREF(x);
                goto onError;
            }
        }
        else if (PyUnicode_Check(x)) {
            int targetsize = PyUnicode_GET_SIZE(x);

            if (targetsize == 1)
                /* 1-1 mapping */
                *p++ = *PyUnicode_AS_UNICODE(x);

            else if (targetsize > 1) {
                /* 1-n mapping */
                if (targetsize > extrachars) {
                    /* resize first */
                    int oldpos = (int)(p - PyUnicode_AS_UNICODE(v));
                    int needed = (targetsize - extrachars) + \
                                 (targetsize << 2);
                    extrachars += needed;
                    if (_PyUnicode_Resize(&v, 
                                         PyUnicode_GET_SIZE(v) + needed)) {
                        Py_DECREF(x);
                        goto onError;
                    }
                    p = PyUnicode_AS_UNICODE(v) + oldpos;
                }
                Py_UNICODE_COPY(p,
                                PyUnicode_AS_UNICODE(x),
                                targetsize);
                p += targetsize;
                extrachars -= targetsize;
            }
            /* 1-0 mapping: skip the character */
        }
        else {
            /* wrong return value */
            PyErr_SetString(PyExc_TypeError,
                  "character mapping must return integer, None or unicode");
            Py_DECREF(x);
            goto onError;
        }
        Py_DECREF(x);
    }
    if (p - PyUnicode_AS_UNICODE(v) < PyUnicode_GET_SIZE(v))
        if (_PyUnicode_Resize(&v, (int)(p - PyUnicode_AS_UNICODE(v))))
            goto onError;
    return (PyObject *)v;
    
 onError:
    Py_XDECREF(v);
    return NULL;
}

static
int charmap_encoding_error(const Py_UNICODE **source,
                           char **dest,
                           const char *errors,
                           const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "charmap encoding error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = '?';
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "charmap encoding error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_EncodeCharmap(const Py_UNICODE *p,
                                  int size,
                                  PyObject *mapping,
                                  const char *errors)
{
    PyObject *v;
    char *s;
    int extrachars = 0;

    /* Default to Latin-1 */
    if (mapping == NULL)
        return PyUnicode_EncodeLatin1(p, size, errors);

    v = PyString_FromStringAndSize(NULL, size);
    if (v == NULL)
        return NULL;
    if (size == 0)
        return v;
    s = PyString_AS_STRING(v);
    while (size-- > 0) {
        Py_UNICODE ch = *p++;
        PyObject *w, *x;

        /* Get mapping (Unicode ordinal -> string char, integer or None) */
        w = PyInt_FromLong((long)ch);
        if (w == NULL)
            goto onError;
        x = PyObject_GetItem(mapping, w);
        Py_DECREF(w);
        if (x == NULL) {
            if (PyErr_ExceptionMatches(PyExc_LookupError)) {
                /* No mapping found means: mapping is undefined. */
                PyErr_Clear();
                x = Py_None;
                Py_INCREF(x);
            } else
                goto onError;
        }

        /* Apply mapping */
        if (PyInt_Check(x)) {
            long value = PyInt_AS_LONG(x);
            if (value < 0 || value > 255) {
                PyErr_SetString(PyExc_TypeError,
                                "character mapping must be in range(256)");
                Py_DECREF(x);
                goto onError;
            }
            *s++ = (char)value;
        }
        else if (x == Py_None) {
            /* undefined mapping */
            if (charmap_encoding_error(&p, &s, errors, 
                                       "character maps to <undefined>")) {
                Py_DECREF(x);
                goto onError;
            }
        }
        else if (PyString_Check(x)) {
            int targetsize = PyString_GET_SIZE(x);

            if (targetsize == 1)
                /* 1-1 mapping */
                *s++ = *PyString_AS_STRING(x);

            else if (targetsize > 1) {
                /* 1-n mapping */
                if (targetsize > extrachars) {
                    /* resize first */
                    int oldpos = (int)(s - PyString_AS_STRING(v));
                    int needed = (targetsize - extrachars) + \
                                 (targetsize << 2);
                    extrachars += needed;
                    if (_PyString_Resize(&v, PyString_GET_SIZE(v) + needed)) {
                        Py_DECREF(x);
                        goto onError;
                    }
                    s = PyString_AS_STRING(v) + oldpos;
                }
                memcpy(s, PyString_AS_STRING(x), targetsize);
                s += targetsize;
                extrachars -= targetsize;
            }
            /* 1-0 mapping: skip the character */
        }
        else {
            /* wrong return value */
            PyErr_SetString(PyExc_TypeError,
                  "character mapping must return integer, None or unicode");
            Py_DECREF(x);
            goto onError;
        }
        Py_DECREF(x);
    }
    if (s - PyString_AS_STRING(v) < PyString_GET_SIZE(v))
        if (_PyString_Resize(&v, (int)(s - PyString_AS_STRING(v))))
            goto onError;
    return v;

 onError:
    Py_DECREF(v);
    return NULL;
}

PyObject *PyUnicode_AsCharmapString(PyObject *unicode,
                                    PyObject *mapping)
{
    if (!PyUnicode_Check(unicode) || mapping == NULL) {
        PyErr_BadArgument();
        return NULL;
    }
    return PyUnicode_EncodeCharmap(PyUnicode_AS_UNICODE(unicode),
                                   PyUnicode_GET_SIZE(unicode),
                                   mapping,
                                   NULL);
}

static
int translate_error(const Py_UNICODE **source,
                    Py_UNICODE **dest,
                    const char *errors,
                    const char *details) 
{
    if ((errors == NULL) ||
        (strcmp(errors,"strict") == 0)) {
        PyErr_Format(PyExc_UnicodeError,
                     "translate error: %.400s",
                     details);
        return -1;
    }
    else if (strcmp(errors,"ignore") == 0) {
        return 0;
    }
    else if (strcmp(errors,"replace") == 0) {
        **dest = '?';
        (*dest)++;
        return 0;
    }
    else {
        PyErr_Format(PyExc_ValueError,
                     "translate error; "
                     "unknown error handling code: %.400s",
                     errors);
        return -1;
    }
}

PyObject *PyUnicode_TranslateCharmap(const Py_UNICODE *s,
                                     int size,
                                     PyObject *mapping,
                                     const char *errors)
{
    PyUnicodeObject *v;
    Py_UNICODE *p;
    
    if (mapping == NULL) {
        PyErr_BadArgument();
        return NULL;
    }
    
    /* Output will never be longer than input */
    v = _PyUnicode_New(size);
    if (v == NULL)
        goto onError;
    if (size == 0)
        goto done;
    p = PyUnicode_AS_UNICODE(v);
    while (size-- > 0) {
        Py_UNICODE ch = *s++;
        PyObject *w, *x;

        /* Get mapping */
        w = PyInt_FromLong(ch);
        if (w == NULL)
            goto onError;
        x = PyObject_GetItem(mapping, w);
        Py_DECREF(w);
        if (x == NULL) {
            if (PyErr_ExceptionMatches(PyExc_LookupError)) {
                /* No mapping found: default to 1-1 mapping */
                PyErr_Clear();
                *p++ = ch;
                continue;
            }
            goto onError;
        }

        /* Apply mapping */
        if (PyInt_Check(x))
            *p++ = (Py_UNICODE)PyInt_AS_LONG(x);
        else if (x == Py_None) {
            /* undefined mapping */
            if (translate_error(&s, &p, errors, 
                                "character maps to <undefined>")) {
                Py_DECREF(x);
                goto onError;
            }
        }
        else if (PyUnicode_Check(x)) {
            if (PyUnicode_GET_SIZE(x) != 1) {
                /* 1-n mapping */
                PyErr_SetString(PyExc_NotImplementedError,
                                "1-n mappings are currently not implemented");
                Py_DECREF(x);
                goto onError;
            }
            *p++ = *PyUnicode_AS_UNICODE(x);
        }
        else {
            /* wrong return value */
            PyErr_SetString(PyExc_TypeError,
                  "translate mapping must return integer, None or unicode");
            Py_DECREF(x);
            goto onError;
        }
        Py_DECREF(x);
    }
    if (p - PyUnicode_AS_UNICODE(v) < PyUnicode_GET_SIZE(v))
        if (_PyUnicode_Resize(&v, (int)(p - PyUnicode_AS_UNICODE(v))))
            goto onError;

 done:
    return (PyObject *)v;
    
 onError:
    Py_XDECREF(v);
    return NULL;
}

PyObject *PyUnicode_Translate(PyObject *str,
                              PyObject *mapping,
                              const char *errors)
{
    PyObject *result;
    
    str = PyUnicode_FromObject(str);
    if (str == NULL)
        goto onError;
    result = PyUnicode_TranslateCharmap(PyUnicode_AS_UNICODE(str),
                                        PyUnicode_GET_SIZE(str),
                                        mapping,
                                        errors);
    Py_DECREF(str);
    return result;
    
 onError:
    Py_XDECREF(str);
    return NULL;
}
    
/* --- Decimal Encoder ---------------------------------------------------- */

int PyUnicode_EncodeDecimal(Py_UNICODE *s,
                            int length,
                            char *output,
                            const char *errors)
{
    Py_UNICODE *p, *end;

    if (output == NULL) {
        PyErr_BadArgument();
        return -1;
    }

    p = s;
    end = s + length;
    while (p < end) {
        register Py_UNICODE ch = *p++;
        int decimal;
        
        if (Py_UNICODE_ISSPACE(ch)) {
            *output++ = ' ';
            continue;
        }
        decimal = Py_UNICODE_TODECIMAL(ch);
        if (decimal >= 0) {
            *output++ = '0' + decimal;
            continue;
        }
        if (0 < ch && ch < 256) {
            *output++ = (char)ch;
            continue;
        }
        /* All other characters are considered invalid */
        if (errors == NULL || strcmp(errors, "strict") == 0) {
            PyErr_SetString(PyExc_ValueError,
                            "invalid decimal Unicode string");
            goto onError;
        }
        else if (strcmp(errors, "ignore") == 0)
            continue;
        else if (strcmp(errors, "replace") == 0) {
            *output++ = '?';
            continue;
        }
    }
    /* 0-terminate the output string */
    *output++ = '\0';
    return 0;

 onError:
    return -1;
}

/* --- Helpers ------------------------------------------------------------ */

static 
int count(PyUnicodeObject *self,
          int start,
          int end,
          PyUnicodeObject *substring)
{
    int count = 0;

    if (start < 0)
        start += self->length;
    if (start < 0)
        start = 0;
    if (end > self->length)
        end = self->length;
    if (end < 0)
        end += self->length;
    if (end < 0)
        end = 0;

    if (substring->length == 0)
        return (end - start + 1);

    end -= substring->length;

    while (start <= end)
        if (Py_UNICODE_MATCH(self, start, substring)) {
            count++;
            start += substring->length;
        } else
            start++;

    return count;
}

int PyUnicode_Count(PyObject *str,
                    PyObject *substr,
                    int start,
                    int end)
{
    int result;
    
    str = PyUnicode_FromObject(str);
    if (str == NULL)
        return -1;
    substr = PyUnicode_FromObject(substr);
    if (substr == NULL) {
        Py_DECREF(str);
        return -1;
    }
    
    result = count((PyUnicodeObject *)str,
                   start, end,
                   (PyUnicodeObject *)substr);
    
    Py_DECREF(str);
    Py_DECREF(substr);
    return result;
}

static 
int findstring(PyUnicodeObject *self,
               PyUnicodeObject *substring,
               int start,
               int end,
               int direction)
{
    if (start < 0)
        start += self->length;
    if (start < 0)
        start = 0;

    if (substring->length == 0)
        return start;

    if (end > self->length)
        end = self->length;
    if (end < 0)
        end += self->length;
    if (end < 0)
        end = 0;

    end -= substring->length;

    if (direction < 0) {
        for (; end >= start; end--)
            if (Py_UNICODE_MATCH(self, end, substring))
                return end;
    } else {
        for (; start <= end; start++)
            if (Py_UNICODE_MATCH(self, start, substring))
                return start;
    }

    return -1;
}

int PyUnicode_Find(PyObject *str,
                   PyObject *substr,
                   int start,
                   int end,
                   int direction)
{
    int result;
    
    str = PyUnicode_FromObject(str);
    if (str == NULL)
        return -1;
    substr = PyUnicode_FromObject(substr);
    if (substr == NULL) {
        Py_DECREF(substr);
        return -1;
    }
    
    result = findstring((PyUnicodeObject *)str,
                        (PyUnicodeObject *)substr,
                        start, end, direction);
    Py_DECREF(str);
    Py_DECREF(substr);
    return result;
}

static 
int tailmatch(PyUnicodeObject *self,
              PyUnicodeObject *substring,
              int start,
              int end,
              int direction)
{
    if (start < 0)
        start += self->length;
    if (start < 0)
        start = 0;

    if (substring->length == 0)
        return 1;

    if (end > self->length)
        end = self->length;
    if (end < 0)
        end += self->length;
    if (end < 0)
        end = 0;

    end -= substring->length;
    if (end < start)
        return 0;

    if (direction > 0) {
        if (Py_UNICODE_MATCH(self, end, substring))
            return 1;
    } else {
        if (Py_UNICODE_MATCH(self, start, substring))
            return 1;
    }

    return 0;
}

int PyUnicode_Tailmatch(PyObject *str,
                        PyObject *substr,
                        int start,
                        int end,
                        int direction)
{
    int result;
    
    str = PyUnicode_FromObject(str);
    if (str == NULL)
        return -1;
    substr = PyUnicode_FromObject(substr);
    if (substr == NULL) {
        Py_DECREF(substr);
        return -1;
    }
    
    result = tailmatch((PyUnicodeObject *)str,
                       (PyUnicodeObject *)substr,
                       start, end, direction);
    Py_DECREF(str);
    Py_DECREF(substr);
    return result;
}

static 
const Py_UNICODE *findchar(const Py_UNICODE *s,
                     int size,
                     Py_UNICODE ch)
{
    /* like wcschr, but doesn't stop at NULL characters */

    while (size-- > 0) {
        if (*s == ch)
            return s;
        s++;
    }

    return NULL;
}

/* Apply fixfct filter to the Unicode object self and return a
   reference to the modified object */

static 
PyObject *fixup(PyUnicodeObject *self,
                int (*fixfct)(PyUnicodeObject *s))
{

    PyUnicodeObject *u;

    u = (PyUnicodeObject*) PyUnicode_FromUnicode(NULL, self->length);
    if (u == NULL)
        return NULL;

    Py_UNICODE_COPY(u->str, self->str, self->length);

    if (!fixfct(u) && PyUnicode_CheckExact(self)) {
        /* fixfct should return TRUE if it modified the buffer. If
           FALSE, return a reference to the original buffer instead
           (to save space, not time) */
        Py_INCREF(self);
        Py_DECREF(u);
        return (PyObject*) self;
    }
    return (PyObject*) u;
}

static 
int fixupper(PyUnicodeObject *self)
{
    int len = self->length;
    Py_UNICODE *s = self->str;
    int status = 0;
    
    while (len-- > 0) {
        register Py_UNICODE ch;
        
        ch = Py_UNICODE_TOUPPER(*s);
        if (ch != *s) {
            status = 1;
            *s = ch;
        }
        s++;
    }

    return status;
}

static 
int fixlower(PyUnicodeObject *self)
{
    int len = self->length;
    Py_UNICODE *s = self->str;
    int status = 0;
    
    while (len-- > 0) {
        register Py_UNICODE ch;
        
        ch = Py_UNICODE_TOLOWER(*s);
        if (ch != *s) {
            status = 1;
            *s = ch;
        }
        s++;
    }

    return status;
}

static 
int fixswapcase(PyUnicodeObject *self)
{
    int len = self->length;
    Py_UNICODE *s = self->str;
    int status = 0;
    
    while (len-- > 0) {
        if (Py_UNICODE_ISUPPER(*s)) {
            *s = Py_UNICODE_TOLOWER(*s);
            status = 1;
        } else if (Py_UNICODE_ISLOWER(*s)) {
            *s = Py_UNICODE_TOUPPER(*s);
            status = 1;
        }
        s++;
    }

    return status;
}

static 
int fixcapitalize(PyUnicodeObject *self)
{
    int len = self->length;
    Py_UNICODE *s = self->str;
    int status = 0;
    
    if (len == 0)
        return 0;
    if (Py_UNICODE_ISLOWER(*s)) {
        *s = Py_UNICODE_TOUPPER(*s);
        status = 1;
    }
    s++;
    while (--len > 0) {
        if (Py_UNICODE_ISUPPER(*s)) {
            *s = Py_UNICODE_TOLOWER(*s);
            status = 1;
        }
        s++;
    }
    return status;
}

static
int fixtitle(PyUnicodeObject *self)
{
    register Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register Py_UNICODE *e;
    int previous_is_cased;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1) {
        Py_UNICODE ch = Py_UNICODE_TOTITLE(*p);
        if (*p != ch) {
            *p = ch;
            return 1;
        }
        else
            return 0;
    }
    
    e = p + PyUnicode_GET_SIZE(self);
    previous_is_cased = 0;
    for (; p < e; p++) {
        register const Py_UNICODE ch = *p;
        
        if (previous_is_cased)
            *p = Py_UNICODE_TOLOWER(ch);
        else
            *p = Py_UNICODE_TOTITLE(ch);
        
        if (Py_UNICODE_ISLOWER(ch) || 
            Py_UNICODE_ISUPPER(ch) || 
            Py_UNICODE_ISTITLE(ch))
            previous_is_cased = 1;
        else
            previous_is_cased = 0;
    }
    return 1;
}

PyObject *PyUnicode_Join(PyObject *separator,
                         PyObject *seq)
{
    Py_UNICODE *sep;
    int seplen;
    PyUnicodeObject *res = NULL;
    int reslen = 0;
    Py_UNICODE *p;
    int sz = 100;
    int i;
    PyObject *it;

    it = PyObject_GetIter(seq);
    if (it == NULL)
        return NULL;

    if (separator == NULL) {
        Py_UNICODE blank = ' ';
        sep = &blank;
        seplen = 1;
    }
    else {
        separator = PyUnicode_FromObject(separator);
        if (separator == NULL)
            goto onError;
        sep = PyUnicode_AS_UNICODE(separator);
        seplen = PyUnicode_GET_SIZE(separator);
    }
    
    res = _PyUnicode_New(sz);
    if (res == NULL)
        goto onError;
    p = PyUnicode_AS_UNICODE(res);
    reslen = 0;

    for (i = 0; ; ++i) {
        int itemlen;
        PyObject *item = PyIter_Next(it);
        if (item == NULL) {
            if (PyErr_Occurred())
                goto onError;
            break;
        }
        if (!PyUnicode_Check(item)) {
            PyObject *v;
            if (!PyString_Check(item)) {
                PyErr_Format(PyExc_TypeError,
                             "sequence item %i: expected string or Unicode,"
                             " %.80s found",
                             i, item->ob_type->tp_name);
                Py_DECREF(item);
                goto onError;
            }
            v = PyUnicode_FromObject(item);
            Py_DECREF(item);
            item = v;
            if (item == NULL)
                goto onError;
        }
        itemlen = PyUnicode_GET_SIZE(item);
        while (reslen + itemlen + seplen >= sz) {
            if (_PyUnicode_Resize(&res, sz*2)) {
                Py_DECREF(item);
                goto onError;
            }
            sz *= 2;
            p = PyUnicode_AS_UNICODE(res) + reslen;
        }
        if (i > 0) {
            Py_UNICODE_COPY(p, sep, seplen);
            p += seplen;
            reslen += seplen;
        }
        Py_UNICODE_COPY(p, PyUnicode_AS_UNICODE(item), itemlen);
        p += itemlen;
        reslen += itemlen;
        Py_DECREF(item);
    }
    if (_PyUnicode_Resize(&res, reslen))
        goto onError;

    Py_XDECREF(separator);
    Py_DECREF(it);
    return (PyObject *)res;

 onError:
    Py_XDECREF(separator);
    Py_XDECREF(res);
    Py_DECREF(it);
    return NULL;
}

static 
PyUnicodeObject *pad(PyUnicodeObject *self, 
                     int left, 
                     int right,
                     Py_UNICODE fill)
{
    PyUnicodeObject *u;

    if (left < 0)
        left = 0;
    if (right < 0)
        right = 0;

    if (left == 0 && right == 0 && PyUnicode_CheckExact(self)) {
        Py_INCREF(self);
        return self;
    }

    u = _PyUnicode_New(left + self->length + right);
    if (u) {
        if (left)
            Py_UNICODE_FILL(u->str, fill, left);
        Py_UNICODE_COPY(u->str + left, self->str, self->length);
        if (right)
            Py_UNICODE_FILL(u->str + left + self->length, fill, right);
    }

    return u;
}

#define SPLIT_APPEND(data, left, right)                                 \
        str = PyUnicode_FromUnicode(data + left, right - left);         \
        if (!str)                                                       \
            goto onError;                                               \
        if (PyList_Append(list, str)) {                                 \
            Py_DECREF(str);                                             \
            goto onError;                                               \
        }                                                               \
        else                                                            \
            Py_DECREF(str);

static
PyObject *split_whitespace(PyUnicodeObject *self,
                           PyObject *list,
                           int maxcount)
{
    register int i;
    register int j;
    int len = self->length;
    PyObject *str;

    for (i = j = 0; i < len; ) {
        /* find a token */
        while (i < len && Py_UNICODE_ISSPACE(self->str[i]))
            i++;
        j = i;
        while (i < len && !Py_UNICODE_ISSPACE(self->str[i]))
            i++;
        if (j < i) {
            if (maxcount-- <= 0)
                break;
            SPLIT_APPEND(self->str, j, i);
            while (i < len && Py_UNICODE_ISSPACE(self->str[i]))
                i++;
            j = i;
        }
    }
    if (j < len) {
        SPLIT_APPEND(self->str, j, len);
    }
    return list;

 onError:
    Py_DECREF(list);
    return NULL;
}

PyObject *PyUnicode_Splitlines(PyObject *string,
                               int keepends)
{
    register int i;
    register int j;
    int len;
    PyObject *list;
    PyObject *str;
    Py_UNICODE *data;

    string = PyUnicode_FromObject(string);
    if (string == NULL)
        return NULL;
    data = PyUnicode_AS_UNICODE(string);
    len = PyUnicode_GET_SIZE(string);

    list = PyList_New(0);
    if (!list)
        goto onError;

    for (i = j = 0; i < len; ) {
        int eol;
        
        /* Find a line and append it */
        while (i < len && !Py_UNICODE_ISLINEBREAK(data[i]))
            i++;

        /* Skip the line break reading CRLF as one line break */
        eol = i;
        if (i < len) {
            if (data[i] == '\r' && i + 1 < len &&
                data[i+1] == '\n')
                i += 2;
            else
                i++;
            if (keepends)
                eol = i;
        }
        SPLIT_APPEND(data, j, eol);
        j = i;
    }
    if (j < len) {
        SPLIT_APPEND(data, j, len);
    }

    Py_DECREF(string);
    return list;

 onError:
    Py_DECREF(list);
    Py_DECREF(string);
    return NULL;
}

static 
PyObject *split_char(PyUnicodeObject *self,
                     PyObject *list,
                     Py_UNICODE ch,
                     int maxcount)
{
    register int i;
    register int j;
    int len = self->length;
    PyObject *str;

    for (i = j = 0; i < len; ) {
        if (self->str[i] == ch) {
            if (maxcount-- <= 0)
                break;
            SPLIT_APPEND(self->str, j, i);
            i = j = i + 1;
        } else
            i++;
    }
    if (j <= len) {
        SPLIT_APPEND(self->str, j, len);
    }
    return list;

 onError:
    Py_DECREF(list);
    return NULL;
}

static 
PyObject *split_substring(PyUnicodeObject *self,
                          PyObject *list,
                          PyUnicodeObject *substring,
                          int maxcount)
{
    register int i;
    register int j;
    int len = self->length;
    int sublen = substring->length;
    PyObject *str;

    for (i = j = 0; i <= len - sublen; ) {
        if (Py_UNICODE_MATCH(self, i, substring)) {
            if (maxcount-- <= 0)
                break;
            SPLIT_APPEND(self->str, j, i);
            i = j = i + sublen;
        } else
            i++;
    }
    if (j <= len) {
        SPLIT_APPEND(self->str, j, len);
    }
    return list;

 onError:
    Py_DECREF(list);
    return NULL;
}

#undef SPLIT_APPEND

static
PyObject *split(PyUnicodeObject *self,
                PyUnicodeObject *substring,
                int maxcount)
{
    PyObject *list;

    if (maxcount < 0)
        maxcount = INT_MAX;

    list = PyList_New(0);
    if (!list)
        return NULL;

    if (substring == NULL)
        return split_whitespace(self,list,maxcount);

    else if (substring->length == 1)
        return split_char(self,list,substring->str[0],maxcount);

    else if (substring->length == 0) {
        Py_DECREF(list);
        PyErr_SetString(PyExc_ValueError, "empty separator");
        return NULL;
    }
    else
        return split_substring(self,list,substring,maxcount);
}

static 
PyObject *strip(PyUnicodeObject *self,
                int left,
                int right)
{
    Py_UNICODE *p = self->str;
    int start = 0;
    int end = self->length;

    if (left)
        while (start < end && Py_UNICODE_ISSPACE(p[start]))
            start++;

    if (right)
        while (end > start && Py_UNICODE_ISSPACE(p[end-1]))
            end--;

    if (start == 0 && end == self->length && PyUnicode_CheckExact(self)) {
        /* couldn't strip anything off, return original string */
        Py_INCREF(self);
        return (PyObject*) self;
    }

    return (PyObject*) PyUnicode_FromUnicode(
        self->str + start,
        end - start
        );
}

static 
PyObject *replace(PyUnicodeObject *self,
                  PyUnicodeObject *str1,
                  PyUnicodeObject *str2,
                  int maxcount)
{
    PyUnicodeObject *u;

    if (maxcount < 0)
        maxcount = INT_MAX;

    if (str1->length == 1 && str2->length == 1) {
        int i;

        /* replace characters */
        if (!findchar(self->str, self->length, str1->str[0]) &&
            PyUnicode_CheckExact(self)) {
            /* nothing to replace, return original string */
            Py_INCREF(self);
            u = self;
        } else {
            Py_UNICODE u1 = str1->str[0];
            Py_UNICODE u2 = str2->str[0];
            
            u = (PyUnicodeObject*) PyUnicode_FromUnicode(
                NULL,
                self->length
                );
            if (u != NULL) {
                Py_UNICODE_COPY(u->str, self->str, 
                                self->length);
                for (i = 0; i < u->length; i++)
                    if (u->str[i] == u1) {
                        if (--maxcount < 0)
                            break;
                        u->str[i] = u2;
                    }
        }
        }

    } else {
        int n, i;
        Py_UNICODE *p;

        /* replace strings */
        n = count(self, 0, self->length, str1);
        if (n > maxcount)
            n = maxcount;
        if (n == 0 && PyUnicode_CheckExact(self)) {
            /* nothing to replace, return original string */
            Py_INCREF(self);
            u = self;
        } else {
            u = _PyUnicode_New(
                self->length + n * (str2->length - str1->length));
            if (u) {
                i = 0;
                p = u->str;
                while (i <= self->length - str1->length)
                    if (Py_UNICODE_MATCH(self, i, str1)) {
                        /* replace string segment */
                        Py_UNICODE_COPY(p, str2->str, str2->length);
                        p += str2->length;
                        i += str1->length;
                        if (--n <= 0) {
                            /* copy remaining part */
                            Py_UNICODE_COPY(p, self->str+i, self->length-i);
                            break;
                        }
                    } else
                        *p++ = self->str[i++];
            }
        }
    }
    
    return (PyObject *) u;
}

/* --- Unicode Object Methods --------------------------------------------- */

static char title__doc__[] =
"S.title() -> unicode\n\
\n\
Return a titlecased version of S, i.e. words start with title case\n\
characters, all remaining cased characters have lower case.";

static PyObject*
unicode_title(PyUnicodeObject *self)
{
    return fixup(self, fixtitle);
}

static char capitalize__doc__[] =
"S.capitalize() -> unicode\n\
\n\
Return a capitalized version of S, i.e. make the first character\n\
have upper case.";

static PyObject*
unicode_capitalize(PyUnicodeObject *self)
{
    return fixup(self, fixcapitalize);
}

#if 0
static char capwords__doc__[] =
"S.capwords() -> unicode\n\
\n\
Apply .capitalize() to all words in S and return the result with\n\
normalized whitespace (all whitespace strings are replaced by ' ').";

static PyObject*
unicode_capwords(PyUnicodeObject *self)
{
    PyObject *list;
    PyObject *item;
    int i;

    /* Split into words */
    list = split(self, NULL, -1);
    if (!list)
        return NULL;

    /* Capitalize each word */
    for (i = 0; i < PyList_GET_SIZE(list); i++) {
        item = fixup((PyUnicodeObject *)PyList_GET_ITEM(list, i),
                     fixcapitalize);
        if (item == NULL)
            goto onError;
        Py_DECREF(PyList_GET_ITEM(list, i));
        PyList_SET_ITEM(list, i, item);
    }

    /* Join the words to form a new string */
    item = PyUnicode_Join(NULL, list);

onError:
    Py_DECREF(list);
    return (PyObject *)item;
}
#endif

static char center__doc__[] =
"S.center(width) -> unicode\n\
\n\
Return S centered in a Unicode string of length width. Padding is done\n\
using spaces.";

static PyObject *
unicode_center(PyUnicodeObject *self, PyObject *args)
{
    int marg, left;
    int width;

    if (!PyArg_ParseTuple(args, "i:center", &width))
        return NULL;

    if (self->length >= width && PyUnicode_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    marg = width - self->length;
    left = marg / 2 + (marg & width & 1);

    return (PyObject*) pad(self, left, marg - left, ' ');
}

#if 0

/* This code should go into some future Unicode collation support
   module. The basic comparison should compare ordinals on a naive
   basis (this is what Java does and thus JPython too). */

/* speedy UTF-16 code point order comparison */
/* gleaned from: */
/* http://www-4.ibm.com/software/developer/library/utf16.html?dwzone=unicode */

static short utf16Fixup[32] =
{
    0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0x2000, -0x800, -0x800, -0x800, -0x800
};

static int
unicode_compare(PyUnicodeObject *str1, PyUnicodeObject *str2)
{
    int len1, len2;

    Py_UNICODE *s1 = str1->str;
    Py_UNICODE *s2 = str2->str;

    len1 = str1->length;
    len2 = str2->length;
    
    while (len1 > 0 && len2 > 0) {
        Py_UNICODE c1, c2;     

        c1 = *s1++;
        c2 = *s2++;

        if (c1 > (1<<11) * 26)
            c1 += utf16Fixup[c1>>11];
        if (c2 > (1<<11) * 26)
            c2 += utf16Fixup[c2>>11];
        /* now c1 and c2 are in UTF-32-compatible order */

        if (c1 != c2)
            return (c1 < c2) ? -1 : 1;
        
        len1--; len2--;
    }

    return (len1 < len2) ? -1 : (len1 != len2);
}

#else

static int
unicode_compare(PyUnicodeObject *str1, PyUnicodeObject *str2)
{
    register int len1, len2;

    Py_UNICODE *s1 = str1->str;
    Py_UNICODE *s2 = str2->str;

    len1 = str1->length;
    len2 = str2->length;
    
    while (len1 > 0 && len2 > 0) {
        Py_UNICODE c1, c2;     

        c1 = *s1++;
        c2 = *s2++;

        if (c1 != c2)
            return (c1 < c2) ? -1 : 1;

        len1--; len2--;
    }

    return (len1 < len2) ? -1 : (len1 != len2);
}

#endif

int PyUnicode_Compare(PyObject *left,
                      PyObject *right)
{
    PyUnicodeObject *u = NULL, *v = NULL;
    int result;

    /* Coerce the two arguments */
    u = (PyUnicodeObject *)PyUnicode_FromObject(left);
    if (u == NULL)
        goto onError;
    v = (PyUnicodeObject *)PyUnicode_FromObject(right);
    if (v == NULL)
        goto onError;

    /* Shortcut for empty or interned objects */
    if (v == u) {
        Py_DECREF(u);
        Py_DECREF(v);
        return 0;
    }

    result = unicode_compare(u, v);

    Py_DECREF(u);
    Py_DECREF(v);
    return result;

onError:
    Py_XDECREF(u);
    Py_XDECREF(v);
    return -1;
}

int PyUnicode_Contains(PyObject *container,
                       PyObject *element)
{
    PyUnicodeObject *u = NULL, *v = NULL;
    int result;
    register const Py_UNICODE *p, *e;
    register Py_UNICODE ch;

    /* Coerce the two arguments */
    v = (PyUnicodeObject *)PyUnicode_FromObject(element);
    if (v == NULL) {
        PyErr_SetString(PyExc_TypeError,
            "'in <string>' requires character as left operand");
        goto onError;
    }
    u = (PyUnicodeObject *)PyUnicode_FromObject(container);
    if (u == NULL) {
        Py_DECREF(v);
        goto onError;
    }

    /* Check v in u */
    if (PyUnicode_GET_SIZE(v) != 1) {
        PyErr_SetString(PyExc_TypeError,
            "'in <string>' requires character as left operand");
        goto onError;
    }
    ch = *PyUnicode_AS_UNICODE(v);
    p = PyUnicode_AS_UNICODE(u);
    e = p + PyUnicode_GET_SIZE(u);
    result = 0;
    while (p < e) {
        if (*p++ == ch) {
            result = 1;
            break;
        }
    }

    Py_DECREF(u);
    Py_DECREF(v);
    return result;

onError:
    Py_XDECREF(u);
    Py_XDECREF(v);
    return -1;
}

/* Concat to string or Unicode object giving a new Unicode object. */

PyObject *PyUnicode_Concat(PyObject *left,
                           PyObject *right)
{
    PyUnicodeObject *u = NULL, *v = NULL, *w;

    /* Coerce the two arguments */
    u = (PyUnicodeObject *)PyUnicode_FromObject(left);
    if (u == NULL)
        goto onError;
    v = (PyUnicodeObject *)PyUnicode_FromObject(right);
    if (v == NULL)
        goto onError;

    /* Shortcuts */
    if (v == unicode_empty) {
        Py_DECREF(v);
        return (PyObject *)u;
    }
    if (u == unicode_empty) {
        Py_DECREF(u);
        return (PyObject *)v;
    }

    /* Concat the two Unicode strings */
    w = _PyUnicode_New(u->length + v->length);
    if (w == NULL)
        goto onError;
    Py_UNICODE_COPY(w->str, u->str, u->length);
    Py_UNICODE_COPY(w->str + u->length, v->str, v->length);

    Py_DECREF(u);
    Py_DECREF(v);
    return (PyObject *)w;

onError:
    Py_XDECREF(u);
    Py_XDECREF(v);
    return NULL;
}

static char count__doc__[] =
"S.count(sub[, start[, end]]) -> int\n\
\n\
Return the number of occurrences of substring sub in Unicode string\n\
S[start:end].  Optional arguments start and end are\n\
interpreted as in slice notation.";

static PyObject *
unicode_count(PyUnicodeObject *self, PyObject *args)
{
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "O|O&O&:count", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;

    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;
    
    if (start < 0)
        start += self->length;
    if (start < 0)
        start = 0;
    if (end > self->length)
        end = self->length;
    if (end < 0)
        end += self->length;
    if (end < 0)
        end = 0;

    result = PyInt_FromLong((long) count(self, start, end, substring));

    Py_DECREF(substring);
    return result;
}

static char encode__doc__[] =
"S.encode([encoding[,errors]]) -> string\n\
\n\
Return an encoded string version of S. Default encoding is the current\n\
default string encoding. errors may be given to set a different error\n\
handling scheme. Default is 'strict' meaning that encoding errors raise\n\
a ValueError. Other possible values are 'ignore' and 'replace'.";

static PyObject *
unicode_encode(PyUnicodeObject *self, PyObject *args)
{
    char *encoding = NULL;
    char *errors = NULL;
    if (!PyArg_ParseTuple(args, "|ss:encode", &encoding, &errors))
        return NULL;
    return PyUnicode_AsEncodedString((PyObject *)self, encoding, errors);
}

static char expandtabs__doc__[] =
"S.expandtabs([tabsize]) -> unicode\n\
\n\
Return a copy of S where all tab characters are expanded using spaces.\n\
If tabsize is not given, a tab size of 8 characters is assumed.";

static PyObject*
unicode_expandtabs(PyUnicodeObject *self, PyObject *args)
{
    Py_UNICODE *e;
    Py_UNICODE *p;
    Py_UNICODE *q;
    int i, j;
    PyUnicodeObject *u;
    int tabsize = 8;

    if (!PyArg_ParseTuple(args, "|i:expandtabs", &tabsize))
        return NULL;

    /* First pass: determine size of output string */
    i = j = 0;
    e = self->str + self->length;
    for (p = self->str; p < e; p++)
        if (*p == '\t') {
            if (tabsize > 0)
                j += tabsize - (j % tabsize);
        }
        else {
            j++;
            if (*p == '\n' || *p == '\r') {
                i += j;
                j = 0;
            }
        }

    /* Second pass: create output string and fill it */
    u = _PyUnicode_New(i + j);
    if (!u)
        return NULL;

    j = 0;
    q = u->str;

    for (p = self->str; p < e; p++)
        if (*p == '\t') {
            if (tabsize > 0) {
                i = tabsize - (j % tabsize);
                j += i;
                while (i--)
                    *q++ = ' ';
            }
        }
        else {
            j++;
            *q++ = *p;
            if (*p == '\n' || *p == '\r')
                j = 0;
        }

    return (PyObject*) u;
}

static char find__doc__[] =
"S.find(sub [,start [,end]]) -> int\n\
\n\
Return the lowest index in S where substring sub is found,\n\
such that sub is contained within s[start,end].  Optional\n\
arguments start and end are interpreted as in slice notation.\n\
\n\
Return -1 on failure.";

static PyObject *
unicode_find(PyUnicodeObject *self, PyObject *args)
{
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "O|O&O&:find", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;

    result = PyInt_FromLong(findstring(self, substring, start, end, 1));

    Py_DECREF(substring);
    return result;
}

static PyObject *
unicode_getitem(PyUnicodeObject *self, int index)
{
    if (index < 0 || index >= self->length) {
        PyErr_SetString(PyExc_IndexError, "string index out of range");
        return NULL;
    }

    return (PyObject*) PyUnicode_FromUnicode(&self->str[index], 1);
}

static long
unicode_hash(PyUnicodeObject *self)
{
    /* Since Unicode objects compare equal to their ASCII string
       counterparts, they should use the individual character values
       as basis for their hash value.  This is needed to assure that
       strings and Unicode objects behave in the same way as
       dictionary keys. */

    register int len;
    register Py_UNICODE *p;
    register long x;

    if (self->hash != -1)
        return self->hash;
    len = PyUnicode_GET_SIZE(self);
    p = PyUnicode_AS_UNICODE(self);
    x = *p << 7;
    while (--len >= 0)
        x = (1000003*x) ^ *p++;
    x ^= PyUnicode_GET_SIZE(self);
    if (x == -1)
        x = -2;
    self->hash = x;
    return x;
}

static char index__doc__[] =
"S.index(sub [,start [,end]]) -> int\n\
\n\
Like S.find() but raise ValueError when the substring is not found.";

static PyObject *
unicode_index(PyUnicodeObject *self, PyObject *args)
{
    int result;
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;

    if (!PyArg_ParseTuple(args, "O|O&O&:index", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    
    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;

    result = findstring(self, substring, start, end, 1);

    Py_DECREF(substring);
    if (result < 0) {
        PyErr_SetString(PyExc_ValueError, "substring not found");
        return NULL;
    }
    return PyInt_FromLong(result);
}

static char islower__doc__[] =
"S.islower() -> int\n\
\n\
Return 1 if  all cased characters in S are lowercase and there is\n\
at least one cased character in S, 0 otherwise.";

static PyObject*
unicode_islower(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;
    int cased;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1)
        return PyInt_FromLong(Py_UNICODE_ISLOWER(*p) != 0);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    cased = 0;
    for (; p < e; p++) {
        register const Py_UNICODE ch = *p;
        
        if (Py_UNICODE_ISUPPER(ch) || Py_UNICODE_ISTITLE(ch))
            return PyInt_FromLong(0);
        else if (!cased && Py_UNICODE_ISLOWER(ch))
            cased = 1;
    }
    return PyInt_FromLong(cased);
}

static char isupper__doc__[] =
"S.isupper() -> int\n\
\n\
Return 1 if  all cased characters in S are uppercase and there is\n\
at least one cased character in S, 0 otherwise.";

static PyObject*
unicode_isupper(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;
    int cased;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1)
        return PyInt_FromLong(Py_UNICODE_ISUPPER(*p) != 0);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    cased = 0;
    for (; p < e; p++) {
        register const Py_UNICODE ch = *p;
        
        if (Py_UNICODE_ISLOWER(ch) || Py_UNICODE_ISTITLE(ch))
            return PyInt_FromLong(0);
        else if (!cased && Py_UNICODE_ISUPPER(ch))
            cased = 1;
    }
    return PyInt_FromLong(cased);
}

static char istitle__doc__[] =
"S.istitle() -> int\n\
\n\
Return 1 if S is a titlecased string, i.e. upper- and titlecase characters\n\
may only follow uncased characters and lowercase characters only cased\n\
ones. Return 0 otherwise.";

static PyObject*
unicode_istitle(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;
    int cased, previous_is_cased;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1)
        return PyInt_FromLong((Py_UNICODE_ISTITLE(*p) != 0) ||
                              (Py_UNICODE_ISUPPER(*p) != 0));

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    cased = 0;
    previous_is_cased = 0;
    for (; p < e; p++) {
        register const Py_UNICODE ch = *p;
        
        if (Py_UNICODE_ISUPPER(ch) || Py_UNICODE_ISTITLE(ch)) {
            if (previous_is_cased)
                return PyInt_FromLong(0);
            previous_is_cased = 1;
            cased = 1;
        }
        else if (Py_UNICODE_ISLOWER(ch)) {
            if (!previous_is_cased)
                return PyInt_FromLong(0);
            previous_is_cased = 1;
            cased = 1;
        }
        else
            previous_is_cased = 0;
    }
    return PyInt_FromLong(cased);
}

static char isspace__doc__[] =
"S.isspace() -> int\n\
\n\
Return 1 if there are only whitespace characters in S,\n\
0 otherwise.";

static PyObject*
unicode_isspace(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1 &&
        Py_UNICODE_ISSPACE(*p))
        return PyInt_FromLong(1);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    for (; p < e; p++) {
        if (!Py_UNICODE_ISSPACE(*p))
            return PyInt_FromLong(0);
    }
    return PyInt_FromLong(1);
}

static char isalpha__doc__[] =
"S.isalpha() -> int\n\
\n\
Return 1 if  all characters in S are alphabetic\n\
and there is at least one character in S, 0 otherwise.";

static PyObject*
unicode_isalpha(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1 &&
        Py_UNICODE_ISALPHA(*p))
        return PyInt_FromLong(1);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    for (; p < e; p++) {
        if (!Py_UNICODE_ISALPHA(*p))
            return PyInt_FromLong(0);
    }
    return PyInt_FromLong(1);
}

static char isalnum__doc__[] =
"S.isalnum() -> int\n\
\n\
Return 1 if  all characters in S are alphanumeric\n\
and there is at least one character in S, 0 otherwise.";

static PyObject*
unicode_isalnum(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1 &&
        Py_UNICODE_ISALNUM(*p))
        return PyInt_FromLong(1);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    for (; p < e; p++) {
        if (!Py_UNICODE_ISALNUM(*p))
            return PyInt_FromLong(0);
    }
    return PyInt_FromLong(1);
}

static char isdecimal__doc__[] =
"S.isdecimal() -> int\n\
\n\
Return 1 if there are only decimal characters in S,\n\
0 otherwise.";

static PyObject*
unicode_isdecimal(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1 &&
        Py_UNICODE_ISDECIMAL(*p))
        return PyInt_FromLong(1);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    for (; p < e; p++) {
        if (!Py_UNICODE_ISDECIMAL(*p))
            return PyInt_FromLong(0);
    }
    return PyInt_FromLong(1);
}

static char isdigit__doc__[] =
"S.isdigit() -> int\n\
\n\
Return 1 if there are only digit characters in S,\n\
0 otherwise.";

static PyObject*
unicode_isdigit(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1 &&
        Py_UNICODE_ISDIGIT(*p))
        return PyInt_FromLong(1);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    for (; p < e; p++) {
        if (!Py_UNICODE_ISDIGIT(*p))
            return PyInt_FromLong(0);
    }
    return PyInt_FromLong(1);
}

static char isnumeric__doc__[] =
"S.isnumeric() -> int\n\
\n\
Return 1 if there are only numeric characters in S,\n\
0 otherwise.";

static PyObject*
unicode_isnumeric(PyUnicodeObject *self)
{
    register const Py_UNICODE *p = PyUnicode_AS_UNICODE(self);
    register const Py_UNICODE *e;

    /* Shortcut for single character strings */
    if (PyUnicode_GET_SIZE(self) == 1 &&
        Py_UNICODE_ISNUMERIC(*p))
        return PyInt_FromLong(1);

    /* Special case for empty strings */
    if (PyString_GET_SIZE(self) == 0)
        return PyInt_FromLong(0);

    e = p + PyUnicode_GET_SIZE(self);
    for (; p < e; p++) {
        if (!Py_UNICODE_ISNUMERIC(*p))
            return PyInt_FromLong(0);
    }
    return PyInt_FromLong(1);
}

static char join__doc__[] =
"S.join(sequence) -> unicode\n\
\n\
Return a string which is the concatenation of the strings in the\n\
sequence.  The separator between elements is S.";

static PyObject*
unicode_join(PyObject *self, PyObject *data)
{
    return PyUnicode_Join(self, data);
}

static int
unicode_length(PyUnicodeObject *self)
{
    return self->length;
}

static char ljust__doc__[] =
"S.ljust(width) -> unicode\n\
\n\
Return S left justified in a Unicode string of length width. Padding is\n\
done using spaces.";

static PyObject *
unicode_ljust(PyUnicodeObject *self, PyObject *args)
{
    int width;
    if (!PyArg_ParseTuple(args, "i:ljust", &width))
        return NULL;

    if (self->length >= width && PyUnicode_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    return (PyObject*) pad(self, 0, width - self->length, ' ');
}

static char lower__doc__[] =
"S.lower() -> unicode\n\
\n\
Return a copy of the string S converted to lowercase.";

static PyObject*
unicode_lower(PyUnicodeObject *self)
{
    return fixup(self, fixlower);
}

static char lstrip__doc__[] =
"S.lstrip() -> unicode\n\
\n\
Return a copy of the string S with leading whitespace removed.";

static PyObject *
unicode_lstrip(PyUnicodeObject *self)
{
    return strip(self, 1, 0);
}

static PyObject*
unicode_repeat(PyUnicodeObject *str, int len)
{
    PyUnicodeObject *u;
    Py_UNICODE *p;
    int nchars;
    size_t nbytes;

    if (len < 0)
        len = 0;

    if (len == 1 && PyUnicode_CheckExact(str)) {
        /* no repeat, return original string */
        Py_INCREF(str);
        return (PyObject*) str;
    }

    /* ensure # of chars needed doesn't overflow int and # of bytes
     * needed doesn't overflow size_t
     */
    nchars = len * str->length;
    if (len && nchars / len != str->length) {
        PyErr_SetString(PyExc_OverflowError,
                        "repeated string is too long");
        return NULL;
    }
    nbytes = (nchars + 1) * sizeof(Py_UNICODE);
    if (nbytes / sizeof(Py_UNICODE) != (size_t)(nchars + 1)) {
        PyErr_SetString(PyExc_OverflowError,
                        "repeated string is too long");
        return NULL;
    }
    u = _PyUnicode_New(nchars);
    if (!u)
        return NULL;

    p = u->str;

    while (len-- > 0) {
        Py_UNICODE_COPY(p, str->str, str->length);
        p += str->length;
    }

    return (PyObject*) u;
}

PyObject *PyUnicode_Replace(PyObject *obj,
                            PyObject *subobj,
                            PyObject *replobj,
                            int maxcount)
{
    PyObject *self;
    PyObject *str1;
    PyObject *str2;
    PyObject *result;

    self = PyUnicode_FromObject(obj);
    if (self == NULL)
        return NULL;
    str1 = PyUnicode_FromObject(subobj);
    if (str1 == NULL) {
        Py_DECREF(self);
        return NULL;
    }
    str2 = PyUnicode_FromObject(replobj);
    if (str2 == NULL) {
        Py_DECREF(self);
        Py_DECREF(str1);
        return NULL;
    }
    result = replace((PyUnicodeObject *)self, 
                     (PyUnicodeObject *)str1, 
                     (PyUnicodeObject *)str2, 
                     maxcount);
    Py_DECREF(self);
    Py_DECREF(str1);
    Py_DECREF(str2);
    return result;
}

static char replace__doc__[] =
"S.replace (old, new[, maxsplit]) -> unicode\n\
\n\
Return a copy of S with all occurrences of substring\n\
old replaced by new.  If the optional argument maxsplit is\n\
given, only the first maxsplit occurrences are replaced.";

static PyObject*
unicode_replace(PyUnicodeObject *self, PyObject *args)
{
    PyUnicodeObject *str1;
    PyUnicodeObject *str2;
    int maxcount = -1;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "OO|i:replace", &str1, &str2, &maxcount))
        return NULL;
    str1 = (PyUnicodeObject *)PyUnicode_FromObject((PyObject *)str1);
    if (str1 == NULL)
        return NULL;
    str2 = (PyUnicodeObject *)PyUnicode_FromObject((PyObject *)str2);
    if (str2 == NULL)
        return NULL;

    result = replace(self, str1, str2, maxcount);

    Py_DECREF(str1);
    Py_DECREF(str2);
    return result;
}

static
PyObject *unicode_repr(PyObject *unicode)
{
    return unicodeescape_string(PyUnicode_AS_UNICODE(unicode),
                                PyUnicode_GET_SIZE(unicode),
                                1);
}

static char rfind__doc__[] =
"S.rfind(sub [,start [,end]]) -> int\n\
\n\
Return the highest index in S where substring sub is found,\n\
such that sub is contained within s[start,end].  Optional\n\
arguments start and end are interpreted as in slice notation.\n\
\n\
Return -1 on failure.";

static PyObject *
unicode_rfind(PyUnicodeObject *self, PyObject *args)
{
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "O|O&O&:rfind", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;

    result = PyInt_FromLong(findstring(self, substring, start, end, -1));

    Py_DECREF(substring);
    return result;
}

static char rindex__doc__[] =
"S.rindex(sub [,start [,end]]) -> int\n\
\n\
Like S.rfind() but raise ValueError when the substring is not found.";

static PyObject *
unicode_rindex(PyUnicodeObject *self, PyObject *args)
{
    int result;
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;

    if (!PyArg_ParseTuple(args, "O|O&O&:rindex", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;

    result = findstring(self, substring, start, end, -1);

    Py_DECREF(substring);
    if (result < 0) {
        PyErr_SetString(PyExc_ValueError, "substring not found");
        return NULL;
    }
    return PyInt_FromLong(result);
}

static char rjust__doc__[] =
"S.rjust(width) -> unicode\n\
\n\
Return S right justified in a Unicode string of length width. Padding is\n\
done using spaces.";

static PyObject *
unicode_rjust(PyUnicodeObject *self, PyObject *args)
{
    int width;
    if (!PyArg_ParseTuple(args, "i:rjust", &width))
        return NULL;

    if (self->length >= width && PyUnicode_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    return (PyObject*) pad(self, width - self->length, 0, ' ');
}

static char rstrip__doc__[] =
"S.rstrip() -> unicode\n\
\n\
Return a copy of the string S with trailing whitespace removed.";

static PyObject *
unicode_rstrip(PyUnicodeObject *self)
{
    return strip(self, 0, 1);
}

static PyObject*
unicode_slice(PyUnicodeObject *self, int start, int end)
{
    /* standard clamping */
    if (start < 0)
        start = 0;
    if (end < 0)
        end = 0;
    if (end > self->length)
        end = self->length;
    if (start == 0 && end == self->length && PyUnicode_CheckExact(self)) {
        /* full slice, return original string */
        Py_INCREF(self);
        return (PyObject*) self;
    }
    if (start > end)
        start = end;
    /* copy slice */
    return (PyObject*) PyUnicode_FromUnicode(self->str + start,
                                             end - start);
}

PyObject *PyUnicode_Split(PyObject *s,
                          PyObject *sep,
                          int maxsplit)
{
    PyObject *result;
    
    s = PyUnicode_FromObject(s);
    if (s == NULL)
        return NULL;
    if (sep != NULL) {
        sep = PyUnicode_FromObject(sep);
        if (sep == NULL) {
            Py_DECREF(s);
            return NULL;
        }
    }

    result = split((PyUnicodeObject *)s, (PyUnicodeObject *)sep, maxsplit);

    Py_DECREF(s);
    Py_XDECREF(sep);
    return result;
}

static char split__doc__[] =
"S.split([sep [,maxsplit]]) -> list of strings\n\
\n\
Return a list of the words in S, using sep as the\n\
delimiter string.  If maxsplit is given, at most maxsplit\n\
splits are done. If sep is not specified, any whitespace string\n\
is a separator.";

static PyObject*
unicode_split(PyUnicodeObject *self, PyObject *args)
{
    PyObject *substring = Py_None;
    int maxcount = -1;

    if (!PyArg_ParseTuple(args, "|Oi:split", &substring, &maxcount))
        return NULL;

    if (substring == Py_None)
        return split(self, NULL, maxcount);
    else if (PyUnicode_Check(substring))
        return split(self, (PyUnicodeObject *)substring, maxcount);
    else
        return PyUnicode_Split((PyObject *)self, substring, maxcount);
}

static char splitlines__doc__[] =
"S.splitlines([keepends]]) -> list of strings\n\
\n\
Return a list of the lines in S, breaking at line boundaries.\n\
Line breaks are not included in the resulting list unless keepends\n\
is given and true.";

static PyObject*
unicode_splitlines(PyUnicodeObject *self, PyObject *args)
{
    int keepends = 0;

    if (!PyArg_ParseTuple(args, "|i:splitlines", &keepends))
        return NULL;

    return PyUnicode_Splitlines((PyObject *)self, keepends);
}

static
PyObject *unicode_str(PyUnicodeObject *self)
{
    return PyUnicode_AsEncodedString((PyObject *)self, NULL, NULL);
}

static char strip__doc__[] =
"S.strip() -> unicode\n\
\n\
Return a copy of S with leading and trailing whitespace removed.";

static PyObject *
unicode_strip(PyUnicodeObject *self)
{
    return strip(self, 1, 1);
}

static char swapcase__doc__[] =
"S.swapcase() -> unicode\n\
\n\
Return a copy of S with uppercase characters converted to lowercase\n\
and vice versa.";

static PyObject*
unicode_swapcase(PyUnicodeObject *self)
{
    return fixup(self, fixswapcase);
}

static char translate__doc__[] =
"S.translate(table) -> unicode\n\
\n\
Return a copy of the string S, where all characters have been mapped\n\
through the given translation table, which must be a mapping of\n\
Unicode ordinals to Unicode ordinals or None. Unmapped characters\n\
are left untouched. Characters mapped to None are deleted.";

static PyObject*
unicode_translate(PyUnicodeObject *self, PyObject *table)
{
    return PyUnicode_TranslateCharmap(self->str, 
                                      self->length,
                                      table, 
                                      "ignore");
}

static char upper__doc__[] =
"S.upper() -> unicode\n\
\n\
Return a copy of S converted to uppercase.";

static PyObject*
unicode_upper(PyUnicodeObject *self)
{
    return fixup(self, fixupper);
}

#if 0
static char zfill__doc__[] =
"S.zfill(width) -> unicode\n\
\n\
Pad a numeric string x with zeros on the left, to fill a field\n\
of the specified width. The string x is never truncated.";

static PyObject *
unicode_zfill(PyUnicodeObject *self, PyObject *args)
{
    int fill;
    PyUnicodeObject *u;

    int width;
    if (!PyArg_ParseTuple(args, "i:zfill", &width))
        return NULL;

    if (self->length >= width) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    fill = width - self->length;

    u = pad(self, fill, 0, '0');

    if (u->str[fill] == '+' || u->str[fill] == '-') {
        /* move sign to beginning of string */
        u->str[0] = u->str[fill];
        u->str[fill] = '0';
    }

    return (PyObject*) u;
}
#endif

#if 0
static PyObject*
unicode_freelistsize(PyUnicodeObject *self)
{
    return PyInt_FromLong(unicode_freelist_size);
}
#endif

static char startswith__doc__[] =
"S.startswith(prefix[, start[, end]]) -> int\n\
\n\
Return 1 if S starts with the specified prefix, otherwise return 0.  With\n\
optional start, test S beginning at that position.  With optional end, stop\n\
comparing S at that position.";

static PyObject *
unicode_startswith(PyUnicodeObject *self,
                   PyObject *args)
{
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;

    result = PyInt_FromLong(tailmatch(self, substring, start, end, -1));

    Py_DECREF(substring);
    return result;
}


static char endswith__doc__[] =
"S.endswith(suffix[, start[, end]]) -> int\n\
\n\
Return 1 if S ends with the specified suffix, otherwise return 0.  With\n\
optional start, test S beginning at that position.  With optional end, stop\n\
comparing S at that position.";

static PyObject *
unicode_endswith(PyUnicodeObject *self,
                 PyObject *args)
{
    PyUnicodeObject *substring;
    int start = 0;
    int end = INT_MAX;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &substring,
                _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    substring = (PyUnicodeObject *)PyUnicode_FromObject(
                                                (PyObject *)substring);
    if (substring == NULL)
        return NULL;

    result = PyInt_FromLong(tailmatch(self, substring, start, end, +1));

    Py_DECREF(substring);
    return result;
}


static PyMethodDef unicode_methods[] = {

    /* Order is according to common usage: often used methods should
       appear first, since lookup is done sequentially. */

    {"encode", (PyCFunction) unicode_encode, METH_VARARGS, encode__doc__},
    {"replace", (PyCFunction) unicode_replace, METH_VARARGS, replace__doc__},
    {"split", (PyCFunction) unicode_split, METH_VARARGS, split__doc__},
    {"join", (PyCFunction) unicode_join, METH_O, join__doc__},
    {"capitalize", (PyCFunction) unicode_capitalize, METH_NOARGS, capitalize__doc__},
    {"title", (PyCFunction) unicode_title, METH_NOARGS, title__doc__},
    {"center", (PyCFunction) unicode_center, METH_VARARGS, center__doc__},
    {"count", (PyCFunction) unicode_count, METH_VARARGS, count__doc__},
    {"expandtabs", (PyCFunction) unicode_expandtabs, METH_VARARGS, expandtabs__doc__},
    {"find", (PyCFunction) unicode_find, METH_VARARGS, find__doc__},
    {"index", (PyCFunction) unicode_index, METH_VARARGS, index__doc__},
    {"ljust", (PyCFunction) unicode_ljust, METH_VARARGS, ljust__doc__},
    {"lower", (PyCFunction) unicode_lower, METH_NOARGS, lower__doc__},
    {"lstrip", (PyCFunction) unicode_lstrip, METH_NOARGS, lstrip__doc__},
/*  {"maketrans", (PyCFunction) unicode_maketrans, METH_VARARGS, maketrans__doc__}, */
    {"rfind", (PyCFunction) unicode_rfind, METH_VARARGS, rfind__doc__},
    {"rindex", (PyCFunction) unicode_rindex, METH_VARARGS, rindex__doc__},
    {"rjust", (PyCFunction) unicode_rjust, METH_VARARGS, rjust__doc__},
    {"rstrip", (PyCFunction) unicode_rstrip, METH_NOARGS, rstrip__doc__},
    {"splitlines", (PyCFunction) unicode_splitlines, METH_VARARGS, splitlines__doc__},
    {"strip", (PyCFunction) unicode_strip, METH_NOARGS, strip__doc__},
    {"swapcase", (PyCFunction) unicode_swapcase, METH_NOARGS, swapcase__doc__},
    {"translate", (PyCFunction) unicode_translate, METH_O, translate__doc__},
    {"upper", (PyCFunction) unicode_upper, METH_NOARGS, upper__doc__},
    {"startswith", (PyCFunction) unicode_startswith, METH_VARARGS, startswith__doc__},
    {"endswith", (PyCFunction) unicode_endswith, METH_VARARGS, endswith__doc__},
    {"islower", (PyCFunction) unicode_islower, METH_NOARGS, islower__doc__},
    {"isupper", (PyCFunction) unicode_isupper, METH_NOARGS, isupper__doc__},
    {"istitle", (PyCFunction) unicode_istitle, METH_NOARGS, istitle__doc__},
    {"isspace", (PyCFunction) unicode_isspace, METH_NOARGS, isspace__doc__},
    {"isdecimal", (PyCFunction) unicode_isdecimal, METH_NOARGS, isdecimal__doc__},
    {"isdigit", (PyCFunction) unicode_isdigit, METH_NOARGS, isdigit__doc__},
    {"isnumeric", (PyCFunction) unicode_isnumeric, METH_NOARGS, isnumeric__doc__},
    {"isalpha", (PyCFunction) unicode_isalpha, METH_NOARGS, isalpha__doc__},
    {"isalnum", (PyCFunction) unicode_isalnum, METH_NOARGS, isalnum__doc__},
#if 0
    {"zfill", (PyCFunction) unicode_zfill, METH_VARARGS, zfill__doc__},
    {"capwords", (PyCFunction) unicode_capwords, METH_NOARGS, capwords__doc__},
#endif

#if 0
    /* This one is just used for debugging the implementation. */
    {"freelistsize", (PyCFunction) unicode_freelistsize, METH_NOARGS},
#endif

    {NULL, NULL}
};

static PySequenceMethods unicode_as_sequence = {
    (inquiry) unicode_length,           /* sq_length */
    (binaryfunc) PyUnicode_Concat,      /* sq_concat */
    (intargfunc) unicode_repeat,        /* sq_repeat */
    (intargfunc) unicode_getitem,       /* sq_item */
    (intintargfunc) unicode_slice,      /* sq_slice */
    0,                                  /* sq_ass_item */
    0,                                  /* sq_ass_slice */
    (objobjproc)PyUnicode_Contains,     /*sq_contains*/
};

static int
unicode_buffer_getreadbuf(PyUnicodeObject *self,
                          int index,
                          const void **ptr)
{
    if (index != 0) {
        PyErr_SetString(PyExc_SystemError,
                        "accessing non-existent unicode segment");
        return -1;
    }
    *ptr = (void *) self->str;
    return PyUnicode_GET_DATA_SIZE(self);
}

static int
unicode_buffer_getwritebuf(PyUnicodeObject *self, int index,
                           const void **ptr)
{
    PyErr_SetString(PyExc_TypeError,
                    "cannot use unicode as modifyable buffer");
    return -1;
}

static int
unicode_buffer_getsegcount(PyUnicodeObject *self,
                           int *lenp)
{
    if (lenp)
        *lenp = PyUnicode_GET_DATA_SIZE(self);
    return 1;
}

static int
unicode_buffer_getcharbuf(PyUnicodeObject *self,
                          int index,
                          const void **ptr)
{
    PyObject *str;
    
    if (index != 0) {
        PyErr_SetString(PyExc_SystemError,
                        "accessing non-existent unicode segment");
        return -1;
    }
    str = _PyUnicode_AsDefaultEncodedString((PyObject *)self, NULL);
    if (str == NULL)
        return -1;
    *ptr = (void *) PyString_AS_STRING(str);
    return PyString_GET_SIZE(str);
}

/* Helpers for PyUnicode_Format() */

static PyObject *
getnextarg(PyObject *args, int arglen, int *p_argidx)
{
    int argidx = *p_argidx;
    if (argidx < arglen) {
        (*p_argidx)++;
        if (arglen < 0)
            return args;
        else
            return PyTuple_GetItem(args, argidx);
    }
    PyErr_SetString(PyExc_TypeError,
                    "not enough arguments for format string");
    return NULL;
}

#define F_LJUST (1<<0)
#define F_SIGN  (1<<1)
#define F_BLANK (1<<2)
#define F_ALT   (1<<3)
#define F_ZERO  (1<<4)

static
int usprintf(register Py_UNICODE *buffer, char *format, ...)
{
    register int i;
    int len;
    va_list va;
    char *charbuffer;
    va_start(va, format);

    /* First, format the string as char array, then expand to Py_UNICODE
       array. */
    charbuffer = (char *)buffer;
    len = vsprintf(charbuffer, format, va);
    for (i = len - 1; i >= 0; i--)
        buffer[i] = (Py_UNICODE) charbuffer[i];

    va_end(va);
    return len;
}

static int
formatfloat(Py_UNICODE *buf,
            size_t buflen,
            int flags,
            int prec,
            int type,
            PyObject *v)
{
    /* fmt = '%#.' + `prec` + `type`
       worst case length = 3 + 10 (len of INT_MAX) + 1 = 14 (use 20)*/
    char fmt[20];
    double x;
    
    x = PyFloat_AsDouble(v);
    if (x == -1.0 && PyErr_Occurred())
        return -1;
    if (prec < 0)
        prec = 6;
    if (type == 'f' && (fabs(x) / 1e25) >= 1e25)
        type = 'g';
    PyOS_snprintf(fmt, sizeof(fmt), "%%%s.%d%c",
                  (flags & F_ALT) ? "#" : "", prec, type);
    /* worst case length calc to ensure no buffer overrun:
         fmt = %#.<prec>g
         buf = '-' + [0-9]*prec + '.' + 'e+' + (longest exp
            for any double rep.)
         len = 1 + prec + 1 + 2 + 5 = 9 + prec
       If prec=0 the effective precision is 1 (the leading digit is
       always given), therefore increase by one to 10+prec. */
    if (buflen <= (size_t)10 + (size_t)prec) {
        PyErr_SetString(PyExc_OverflowError,
            "formatted float is too long (precision too long?)");
        return -1;
    }
    return usprintf(buf, fmt, x);
}

static PyObject*
formatlong(PyObject *val, int flags, int prec, int type)
{
        char *buf;
        int i, len;
        PyObject *str; /* temporary string object. */
        PyUnicodeObject *result;

        str = _PyString_FormatLong(val, flags, prec, type, &buf, &len);
        if (!str)
                return NULL;
        result = _PyUnicode_New(len);
        for (i = 0; i < len; i++)
                result->str[i] = buf[i];
        result->str[len] = 0;
        Py_DECREF(str);
        return (PyObject*)result;
}

static int
formatint(Py_UNICODE *buf,
          size_t buflen,
          int flags,
          int prec,
          int type,
          PyObject *v)
{
    /* fmt = '%#.' + `prec` + 'l' + `type`
       worst case length = 3 + 19 (worst len of INT_MAX on 64-bit machine)
       + 1 + 1 = 24*/
    char fmt[64]; /* plenty big enough! */
    long x;
    int use_native_c_format = 1;

    x = PyInt_AsLong(v);
    if (x == -1 && PyErr_Occurred())
        return -1;
    if (prec < 0)
        prec = 1;
    /* buf = '+'/'-'/'0'/'0x' + '[0-9]'*max(prec,len(x in octal))
       worst case buf = '0x' + [0-9]*prec, where prec >= 11 */
    if (buflen <= 13 || buflen <= (size_t)2+(size_t)prec) {
        PyErr_SetString(PyExc_OverflowError,
            "formatted integer is too long (precision too long?)");
        return -1;
    }
    /* When converting 0 under %#x or %#X, C leaves off the base marker,
     * but we want it (for consistency with other %#x conversions, and
     * for consistency with Python's hex() function).
     * BUG 28-Apr-2001 tim:  At least two platform Cs (Metrowerks &
     * Compaq Tru64) violate the std by converting 0 w/ leading 0x anyway.
     * So add it only if the platform doesn't already.
     */
    if (x == 0 && (flags & F_ALT) && (type == 'x' || type == 'X')) {
        /* Only way to know what the platform does is to try it. */
        PyOS_snprintf(fmt, sizeof(fmt), type == 'x' ? "%#x" : "%#X", 0);
        if (fmt[1] != (char)type) {
            /* Supply our own leading 0x/0X -- needed under std C */
            use_native_c_format = 0;
            PyOS_snprintf(fmt, sizeof(fmt), "0%c%%#.%dl%c", type, prec, type);
        }
    }
    if (use_native_c_format)
         PyOS_snprintf(fmt, sizeof(fmt), "%%%s.%dl%c",
                       (flags & F_ALT) ? "#" : "", prec, type);
    return usprintf(buf, fmt, x);
}

static int
formatchar(Py_UNICODE *buf,
           size_t buflen,
           PyObject *v)
{
    /* presume that the buffer is at least 2 characters long */
    if (PyUnicode_Check(v)) {
        if (PyUnicode_GET_SIZE(v) != 1)
            goto onError;
        buf[0] = PyUnicode_AS_UNICODE(v)[0];
    }

    else if (PyString_Check(v)) {
        if (PyString_GET_SIZE(v) != 1) 
            goto onError;
        buf[0] = (Py_UNICODE)PyString_AS_STRING(v)[0];
    }

    else {
        /* Integer input truncated to a character */
        long x;
        x = PyInt_AsLong(v);
        if (x == -1 && PyErr_Occurred())
            goto onError;
        buf[0] = (char) x;
    }
    buf[1] = '\0';
    return 1;

 onError:
    PyErr_SetString(PyExc_TypeError,
                    "%c requires int or char");
    return -1;
}

/* fmt%(v1,v2,...) is roughly equivalent to sprintf(fmt, v1, v2, ...)

   FORMATBUFLEN is the length of the buffer in which the floats, ints, &
   chars are formatted. XXX This is a magic number. Each formatting
   routine does bounds checking to ensure no overflow, but a better
   solution may be to malloc a buffer of appropriate size for each
   format. For now, the current solution is sufficient.
*/
#define FORMATBUFLEN (size_t)120

PyObject *PyUnicode_Format(PyObject *format,
                           PyObject *args)
{
    Py_UNICODE *fmt, *res;
    int fmtcnt, rescnt, reslen, arglen, argidx;
    int args_owned = 0;
    PyUnicodeObject *result = NULL;
    PyObject *dict = NULL;
    PyObject *uformat;
        
    if (format == NULL || args == NULL) {
        PyErr_BadInternalCall();
        return NULL;
    }
    uformat = PyUnicode_FromObject(format);
    if (uformat == NULL)
        return NULL;
    fmt = PyUnicode_AS_UNICODE(uformat);
    fmtcnt = PyUnicode_GET_SIZE(uformat);

    reslen = rescnt = fmtcnt + 100;
    result = _PyUnicode_New(reslen);
    if (result == NULL)
        goto onError;
    res = PyUnicode_AS_UNICODE(result);

    if (PyTuple_Check(args)) {
        arglen = PyTuple_Size(args);
        argidx = 0;
    }
    else {
        arglen = -1;
        argidx = -2;
    }
    if (args->ob_type->tp_as_mapping)
        dict = args;

    while (--fmtcnt >= 0) {
        if (*fmt != '%') {
            if (--rescnt < 0) {
                rescnt = fmtcnt + 100;
                reslen += rescnt;
                if (_PyUnicode_Resize(&result, reslen) < 0)
                    return NULL;
                res = PyUnicode_AS_UNICODE(result) + reslen - rescnt;
                --rescnt;
            }
            *res++ = *fmt++;
        }
        else {
            /* Got a format specifier */
            int flags = 0;
            int width = -1;
            int prec = -1;
            Py_UNICODE c = '\0';
            Py_UNICODE fill;
            PyObject *v = NULL;
            PyObject *temp = NULL;
            Py_UNICODE *pbuf;
            Py_UNICODE sign;
            int len;
            Py_UNICODE formatbuf[FORMATBUFLEN]; /* For format{float,int,char}() */

            fmt++;
            if (*fmt == '(') {
                Py_UNICODE *keystart;
                int keylen;
                PyObject *key;
                int pcount = 1;

                if (dict == NULL) {
                    PyErr_SetString(PyExc_TypeError,
                                    "format requires a mapping"); 
                    goto onError;
                }
                ++fmt;
                --fmtcnt;
                keystart = fmt;
                /* Skip over balanced parentheses */
                while (pcount > 0 && --fmtcnt >= 0) {
                    if (*fmt == ')')
                        --pcount;
                    else if (*fmt == '(')
                        ++pcount;
                    fmt++;
                }
                keylen = fmt - keystart - 1;
                if (fmtcnt < 0 || pcount > 0) {
                    PyErr_SetString(PyExc_ValueError,
                                    "incomplete format key");
                    goto onError;
                }
#if 0
                /* keys are converted to strings using UTF-8 and
                   then looked up since Python uses strings to hold
                   variables names etc. in its namespaces and we
                   wouldn't want to break common idioms. */
                key = PyUnicode_EncodeUTF8(keystart,
                                           keylen,
                                           NULL);
#else
                key = PyUnicode_FromUnicode(keystart, keylen);
#endif
                if (key == NULL)
                    goto onError;
                if (args_owned) {
                    Py_DECREF(args);
                    args_owned = 0;
                }
                args = PyObject_GetItem(dict, key);
                Py_DECREF(key);
                if (args == NULL) {
                    goto onError;
                }
                args_owned = 1;
                arglen = -1;
                argidx = -2;
            }
            while (--fmtcnt >= 0) {
                switch (c = *fmt++) {
                case '-': flags |= F_LJUST; continue;
                case '+': flags |= F_SIGN; continue;
                case ' ': flags |= F_BLANK; continue;
                case '#': flags |= F_ALT; continue;
                case '0': flags |= F_ZERO; continue;
                }
                break;
            }
            if (c == '*') {
                v = getnextarg(args, arglen, &argidx);
                if (v == NULL)
                    goto onError;
                if (!PyInt_Check(v)) {
                    PyErr_SetString(PyExc_TypeError,
                                    "* wants int");
                    goto onError;
                }
                width = PyInt_AsLong(v);
                if (width < 0) {
                    flags |= F_LJUST;
                    width = -width;
                }
                if (--fmtcnt >= 0)
                    c = *fmt++;
            }
            else if (c >= '0' && c <= '9') {
                width = c - '0';
                while (--fmtcnt >= 0) {
                    c = *fmt++;
                    if (c < '0' || c > '9')
                        break;
                    if ((width*10) / 10 != width) {
                        PyErr_SetString(PyExc_ValueError,
                                        "width too big");
                        goto onError;
                    }
                    width = width*10 + (c - '0');
                }
            }
            if (c == '.') {
                prec = 0;
                if (--fmtcnt >= 0)
                    c = *fmt++;
                if (c == '*') {
                    v = getnextarg(args, arglen, &argidx);
                    if (v == NULL)
                        goto onError;
                    if (!PyInt_Check(v)) {
                        PyErr_SetString(PyExc_TypeError,
                                        "* wants int");
                        goto onError;
                    }
                    prec = PyInt_AsLong(v);
                    if (prec < 0)
                        prec = 0;
                    if (--fmtcnt >= 0)
                        c = *fmt++;
                }
                else if (c >= '0' && c <= '9') {
                    prec = c - '0';
                    while (--fmtcnt >= 0) {
                        c = Py_CHARMASK(*fmt++);
                        if (c < '0' || c > '9')
                            break;
                        if ((prec*10) / 10 != prec) {
                            PyErr_SetString(PyExc_ValueError,
                                            "prec too big");
                            goto onError;
                        }
                        prec = prec*10 + (c - '0');
                    }
                }
            } /* prec */
            if (fmtcnt >= 0) {
                if (c == 'h' || c == 'l' || c == 'L') {
                    if (--fmtcnt >= 0)
                        c = *fmt++;
                }
            }
            if (fmtcnt < 0) {
                PyErr_SetString(PyExc_ValueError,
                                "incomplete format");
                goto onError;
            }
            if (c != '%') {
                v = getnextarg(args, arglen, &argidx);
                if (v == NULL)
                    goto onError;
            }
            sign = 0;
            fill = ' ';
            switch (c) {

            case '%':
                pbuf = formatbuf;
                /* presume that buffer length is at least 1 */
                pbuf[0] = '%';
                len = 1;
                break;

            case 's':
            case 'r':
                if (PyUnicode_Check(v) && c == 's') {
                    temp = v;
                    Py_INCREF(temp);
                }
                else {
                    PyObject *unicode;
                    if (c == 's')
                        temp = PyObject_Str(v);
                    else
                        temp = PyObject_Repr(v);
                    if (temp == NULL)
                        goto onError;
                    if (!PyString_Check(temp)) {
                        /* XXX Note: this should never happen, since
                               PyObject_Repr() and PyObject_Str() assure
                               this */
                        Py_DECREF(temp);
                        PyErr_SetString(PyExc_TypeError,
                                        "%s argument has non-string str()");
                        goto onError;
                    }
                    unicode = PyUnicode_Decode(PyString_AS_STRING(temp),
                                                   PyString_GET_SIZE(temp),
                                               NULL,
                                                   "strict");
                    Py_DECREF(temp);
                    temp = unicode;
                    if (temp == NULL)
                        goto onError;
                }
                pbuf = PyUnicode_AS_UNICODE(temp);
                len = PyUnicode_GET_SIZE(temp);
                if (prec >= 0 && len > prec)
                    len = prec;
                break;

            case 'i':
            case 'd':
            case 'u':
            case 'o':
            case 'x':
            case 'X':
                if (c == 'i')
                    c = 'd';
                if (PyLong_Check(v)) {
                    temp = formatlong(v, flags, prec, c);
                    if (!temp)
                        goto onError;
                    pbuf = PyUnicode_AS_UNICODE(temp);
                    len = PyUnicode_GET_SIZE(temp);
                    /* unbounded ints can always produce
                       a sign character! */
                    sign = 1;
                }
                else {
                    pbuf = formatbuf;
                    len = formatint(pbuf, sizeof(formatbuf)/sizeof(Py_UNICODE),
                                    flags, prec, c, v);
                    if (len < 0)
                        goto onError;
                    /* only d conversion is signed */
                    sign = c == 'd';
                }
                if (flags & F_ZERO)
                    fill = '0';
                break;

            case 'e':
            case 'E':
            case 'f':
            case 'g':
            case 'G':
                pbuf = formatbuf;
                len = formatfloat(pbuf, sizeof(formatbuf)/sizeof(Py_UNICODE),
                        flags, prec, c, v);
                if (len < 0)
                    goto onError;
                sign = 1;
                if (flags & F_ZERO)
                    fill = '0';
                break;

            case 'c':
                pbuf = formatbuf;
                len = formatchar(pbuf, sizeof(formatbuf)/sizeof(Py_UNICODE), v);
                if (len < 0)
                    goto onError;
                break;

            default:
                PyErr_Format(PyExc_ValueError,
                             "unsupported format character '%c' (0x%x) "
                             "at index %i",
                             (31<=c && c<=126) ? (int)c : '?', 
                             (int)c, (fmt -1 - PyUnicode_AS_UNICODE(uformat)));
                goto onError;
            }
            if (sign) {
                if (*pbuf == '-' || *pbuf == '+') {
                    sign = *pbuf++;
                    len--;
                }
                else if (flags & F_SIGN)
                    sign = '+';
                else if (flags & F_BLANK)
                    sign = ' ';
                else
                    sign = 0;
            }
            if (width < len)
                width = len;
            if (rescnt < width + (sign != 0)) {
                reslen -= rescnt;
                rescnt = width + fmtcnt + 100;
                reslen += rescnt;
                if (_PyUnicode_Resize(&result, reslen) < 0)
                    return NULL;
                res = PyUnicode_AS_UNICODE(result)
                    + reslen - rescnt;
            }
            if (sign) {
                if (fill != ' ')
                    *res++ = sign;
                rescnt--;
                if (width > len)
                    width--;
            }
            if ((flags & F_ALT) && (c == 'x' || c == 'X')) {
                assert(pbuf[0] == '0');
                assert(pbuf[1] == c);
                if (fill != ' ') {
                    *res++ = *pbuf++;
                    *res++ = *pbuf++;
                }
                rescnt -= 2;
                width -= 2;
                if (width < 0)
                    width = 0;
                len -= 2;
            }
            if (width > len && !(flags & F_LJUST)) {
                do {
                    --rescnt;
                    *res++ = fill;
                } while (--width > len);
            }
            if (fill == ' ') {
                if (sign)
                    *res++ = sign;
                if ((flags & F_ALT) && (c == 'x' || c == 'X')) {
                    assert(pbuf[0] == '0');
                    assert(pbuf[1] == c);
                    *res++ = *pbuf++;
                    *res++ = *pbuf++;
                }
            }
            Py_UNICODE_COPY(res, pbuf, len);
            res += len;
            rescnt -= len;
            while (--width >= len) {
                --rescnt;
                *res++ = ' ';
            }
            if (dict && (argidx < arglen) && c != '%') {
                PyErr_SetString(PyExc_TypeError,
                                "not all arguments converted");
                goto onError;
            }
            Py_XDECREF(temp);
        } /* '%' */
    } /* until end */
    if (argidx < arglen && !dict) {
        PyErr_SetString(PyExc_TypeError,
                        "not all arguments converted");
        goto onError;
    }

    if (args_owned) {
        Py_DECREF(args);
    }
    Py_DECREF(uformat);
    if (_PyUnicode_Resize(&result, reslen - rescnt))
        goto onError;
    return (PyObject *)result;

 onError:
    Py_XDECREF(result);
    Py_DECREF(uformat);
    if (args_owned) {
        Py_DECREF(args);
    }
    return NULL;
}

static PyBufferProcs unicode_as_buffer = {
    (getreadbufferproc) unicode_buffer_getreadbuf,
    (getwritebufferproc) unicode_buffer_getwritebuf,
    (getsegcountproc) unicode_buffer_getsegcount,
    (getcharbufferproc) unicode_buffer_getcharbuf,
};

staticforward PyObject *
unicode_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);

static PyObject *
unicode_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
        PyObject *x = NULL;
        static char *kwlist[] = {"string", "encoding", "errors", 0};
        char *encoding = NULL;
        char *errors = NULL;

        if (type != &PyUnicode_Type)
                return unicode_subtype_new(type, args, kwds);
        if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oss:unicode",
                                          kwlist, &x, &encoding, &errors))
            return NULL;
        if (x == NULL)
                return (PyObject *)_PyUnicode_New(0);
        if (encoding == NULL && errors == NULL)
            return PyObject_Unicode(x);
        else
        return PyUnicode_FromEncodedObject(x, encoding, errors);
}

static PyObject *
unicode_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
        PyUnicodeObject *tmp, *pnew;
        int n;

        assert(PyType_IsSubtype(type, &PyUnicode_Type));
        tmp = (PyUnicodeObject *)unicode_new(&PyUnicode_Type, args, kwds);
        if (tmp == NULL)
                return NULL;
        assert(PyUnicode_Check(tmp));
        pnew = (PyUnicodeObject *) type->tp_alloc(type, n = tmp->length);
        if (pnew == NULL)
                return NULL;
        pnew->str = PyMem_NEW(Py_UNICODE, n+1);
        if (pnew->str == NULL) {
                _Py_ForgetReference((PyObject *)pnew);
                PyObject_DEL(pnew);
                return NULL;
        }
        Py_UNICODE_COPY(pnew->str, tmp->str, n+1);
        pnew->length = n;
        pnew->hash = tmp->hash;
        Py_DECREF(tmp);
        return (PyObject *)pnew;
}

static char unicode_doc[] =
"unicode(string [, encoding[, errors]]) -> object\n\
\n\
Create a new Unicode object from the given encoded string.\n\
encoding defaults to the current default string encoding and \n\
errors, defining the error handling, to 'strict'.";

PyTypeObject PyUnicode_Type = {
    PyObject_HEAD_INIT(&PyType_Type)
    0,                                  /* ob_size */
    "unicode",                          /* tp_name */
    sizeof(PyUnicodeObject),            /* tp_size */
    0,                                  /* tp_itemsize */
    /* Slots */
    (destructor)unicode_dealloc,        /* tp_dealloc */
    0,                                  /* tp_print */
    0,                                  /* tp_getattr */
    0,                                  /* tp_setattr */
    (cmpfunc) unicode_compare,          /* tp_compare */
    (reprfunc) unicode_repr,            /* tp_repr */
    0,                                  /* tp_as_number */
    &unicode_as_sequence,               /* tp_as_sequence */
    0,                                  /* tp_as_mapping */
    (hashfunc) unicode_hash,            /* tp_hash*/
    0,                                  /* tp_call*/
    (reprfunc) unicode_str,             /* tp_str */
    PyObject_GenericGetAttr,            /* tp_getattro */
    0,                                  /* tp_setattro */
    &unicode_as_buffer,                 /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
    unicode_doc,                        /* tp_doc */
    0,                                  /* tp_traverse */
    0,                                  /* tp_clear */
    0,                                  /* tp_richcompare */
    0,                                  /* tp_weaklistoffset */
    0,                                  /* tp_iter */
    0,                                  /* tp_iternext */
    unicode_methods,                    /* tp_methods */
    0,                                  /* tp_members */
    0,                                  /* tp_getset */
    0,                                  /* tp_base */
    0,                                  /* tp_dict */
    0,                                  /* tp_descr_get */
    0,                                  /* tp_descr_set */
    0,                                  /* tp_dictoffset */
    0,                                  /* tp_init */
    0,                                  /* tp_alloc */
    unicode_new,                        /* tp_new */
    _PyObject_Del,                      /* tp_free */
};

/* Initialize the Unicode implementation */

void _PyUnicode_Init(void)
{
    int i;

    /* Init the implementation */
    unicode_freelist = NULL;
    unicode_freelist_size = 0;
    unicode_empty = _PyUnicode_New(0);
    strcpy(unicode_default_encoding, "ascii");
    for (i = 0; i < 256; i++)
        unicode_latin1[i] = NULL;
}

/* Finalize the Unicode implementation */

void
_PyUnicode_Fini(void)
{
    PyUnicodeObject *u;
    int i;

    Py_XDECREF(unicode_empty);
    unicode_empty = NULL;

    for (i = 0; i < 256; i++) {
        if (unicode_latin1[i]) {
            Py_DECREF(unicode_latin1[i]);
            unicode_latin1[i] = NULL;
        }
    }

    for (u = unicode_freelist; u != NULL;) {
        PyUnicodeObject *v = u;
        u = *(PyUnicodeObject **)u;
        if (v->str)
            PyMem_DEL(v->str);
        Py_XDECREF(v->defenc);
        PyObject_DEL(v);
    }
    unicode_freelist = NULL;
    unicode_freelist_size = 0;
}