cpython/Objects/stringobject.c

/* String object implementation */

#include "Python.h"

#include <ctype.h>

#ifdef COUNT_ALLOCS
int null_strings, one_strings;
#endif

#if !defined(HAVE_LIMITS_H) && !defined(UCHAR_MAX)
#define UCHAR_MAX 255
#endif

static PyStringObject *characters[UCHAR_MAX + 1];
static PyStringObject *nullstring;

/* This dictionary holds all interned strings.  Note that references to
   strings in this dictionary are *not* counted in the string's ob_refcnt.
   When the interned string reaches a refcnt of 0 the string deallocation
   function will delete the reference from this dictionary.

   Another way to look at this is that to say that the actual reference 
   count of a string is:  s->ob_refcnt + (s->ob_sstate?2:0)
*/
static PyObject *interned;


/*
   For both PyString_FromString() and PyString_FromStringAndSize(), the
   parameter `size' denotes number of characters to allocate, not counting any
   null terminating character.

   For PyString_FromString(), the parameter `str' points to a null-terminated
   string containing exactly `size' bytes.

   For PyString_FromStringAndSize(), the parameter the parameter `str' is
   either NULL or else points to a string containing at least `size' bytes.
   For PyString_FromStringAndSize(), the string in the `str' parameter does
   not have to be null-terminated.  (Therefore it is safe to construct a
   substring by calling `PyString_FromStringAndSize(origstring, substrlen)'.)
   If `str' is NULL then PyString_FromStringAndSize() will allocate `size+1'
   bytes (setting the last byte to the null terminating character) and you can
   fill in the data yourself.  If `str' is non-NULL then the resulting
   PyString object must be treated as immutable and you must not fill in nor
   alter the data yourself, since the strings may be shared.

   The PyObject member `op->ob_size', which denotes the number of "extra
   items" in a variable-size object, will contain the number of bytes
   allocated for string data, not counting the null terminating character.  It
   is therefore equal to the equal to the `size' parameter (for
   PyString_FromStringAndSize()) or the length of the string in the `str'
   parameter (for PyString_FromString()).
*/
PyObject *
PyString_FromStringAndSize(const char *str, int size)
{
	register PyStringObject *op;
	if (size == 0 && (op = nullstring) != NULL) {
#ifdef COUNT_ALLOCS
		null_strings++;
#endif
		Py_INCREF(op);
		return (PyObject *)op;
	}
	if (size == 1 && str != NULL &&
	    (op = characters[*str & UCHAR_MAX]) != NULL)
	{
#ifdef COUNT_ALLOCS
		one_strings++;
#endif
		Py_INCREF(op);
		return (PyObject *)op;
	}

	/* Inline PyObject_NewVar */
	op = (PyStringObject *)
		PyObject_MALLOC(sizeof(PyStringObject) + size * sizeof(char));
	if (op == NULL)
		return PyErr_NoMemory();
	PyObject_INIT_VAR(op, &PyString_Type, size);
	op->ob_shash = -1;
	op->ob_sstate = SSTATE_NOT_INTERNED;
	if (str != NULL)
		memcpy(op->ob_sval, str, size);
	op->ob_sval[size] = '\0';
	/* share short strings */
	if (size == 0) {
		PyObject *t = (PyObject *)op;
		PyString_InternInPlace(&t);
		op = (PyStringObject *)t;
		nullstring = op;
		Py_INCREF(op);
	} else if (size == 1 && str != NULL) {
		PyObject *t = (PyObject *)op;
		PyString_InternInPlace(&t);
		op = (PyStringObject *)t;
		characters[*str & UCHAR_MAX] = op;
		Py_INCREF(op);
	}
	return (PyObject *) op;
}

PyObject *
PyString_FromString(const char *str)
{
	register size_t size;
	register PyStringObject *op;

	assert(str != NULL);
	size = strlen(str);
	if (size > INT_MAX) {
		PyErr_SetString(PyExc_OverflowError,
			"string is too long for a Python string");
		return NULL;
	}
	if (size == 0 && (op = nullstring) != NULL) {
#ifdef COUNT_ALLOCS
		null_strings++;
#endif
		Py_INCREF(op);
		return (PyObject *)op;
	}
	if (size == 1 && (op = characters[*str & UCHAR_MAX]) != NULL) {
#ifdef COUNT_ALLOCS
		one_strings++;
#endif
		Py_INCREF(op);
		return (PyObject *)op;
	}

	/* Inline PyObject_NewVar */
	op = (PyStringObject *)
		PyObject_MALLOC(sizeof(PyStringObject) + size * sizeof(char));
	if (op == NULL)
		return PyErr_NoMemory();
	PyObject_INIT_VAR(op, &PyString_Type, size);
	op->ob_shash = -1;
	op->ob_sstate = SSTATE_NOT_INTERNED;
	memcpy(op->ob_sval, str, size+1);
	/* share short strings */
	if (size == 0) {
		PyObject *t = (PyObject *)op;
		PyString_InternInPlace(&t);
		op = (PyStringObject *)t;
		nullstring = op;
		Py_INCREF(op);
	} else if (size == 1) {
		PyObject *t = (PyObject *)op;
		PyString_InternInPlace(&t);
		op = (PyStringObject *)t;
		characters[*str & UCHAR_MAX] = op;
		Py_INCREF(op);
	}
	return (PyObject *) op;
}

PyObject *
PyString_FromFormatV(const char *format, va_list vargs)
{
	va_list count;
	int n = 0;
	const char* f;
	char *s;
	PyObject* string;

#ifdef VA_LIST_IS_ARRAY
	memcpy(count, vargs, sizeof(va_list));
#else
#ifdef  __va_copy
	__va_copy(count, vargs);
#else
	count = vargs;
#endif
#endif
	/* step 1: figure out how large a buffer we need */
	for (f = format; *f; f++) {
		if (*f == '%') {
			const char* p = f;
			while (*++f && *f != '%' && !isalpha(Py_CHARMASK(*f)))
				;

			/* skip the 'l' in %ld, since it doesn't change the
			   width.  although only %d is supported (see
			   "expand" section below), others can be easily
			   added */
			if (*f == 'l' && *(f+1) == 'd')
				++f;

			switch (*f) {
			case 'c':
				(void)va_arg(count, int);
				/* fall through... */
			case '%':
				n++;
				break;
			case 'd': case 'i': case 'x':
				(void) va_arg(count, int);
				/* 20 bytes is enough to hold a 64-bit
				   integer.  Decimal takes the most space.
				   This isn't enough for octal. */
				n += 20;
				break;
			case 's':
				s = va_arg(count, char*);
				n += strlen(s);
				break;
			case 'p':
				(void) va_arg(count, int);
				/* maximum 64-bit pointer representation:
				 * 0xffffffffffffffff
				 * so 19 characters is enough.
				 * XXX I count 18 -- what's the extra for?
				 */
				n += 19;
				break;
			default:
				/* if we stumble upon an unknown
				   formatting code, copy the rest of
				   the format string to the output
				   string. (we cannot just skip the
				   code, since there's no way to know
				   what's in the argument list) */
				n += strlen(p);
				goto expand;
			}
		} else
			n++;
	}
 expand:
	/* step 2: fill the buffer */
	/* Since we've analyzed how much space we need for the worst case,
	   use sprintf directly instead of the slower PyOS_snprintf. */
	string = PyString_FromStringAndSize(NULL, n);
	if (!string)
		return NULL;

	s = PyString_AsString(string);

	for (f = format; *f; f++) {
		if (*f == '%') {
			const char* p = f++;
			int i, longflag = 0;
			/* parse the width.precision part (we're only
			   interested in the precision value, if any) */
			n = 0;
			while (isdigit(Py_CHARMASK(*f)))
				n = (n*10) + *f++ - '0';
			if (*f == '.') {
				f++;
				n = 0;
				while (isdigit(Py_CHARMASK(*f)))
					n = (n*10) + *f++ - '0';
			}
			while (*f && *f != '%' && !isalpha(Py_CHARMASK(*f)))
				f++;
			/* handle the long flag, but only for %ld.  others
			   can be added when necessary. */
			if (*f == 'l' && *(f+1) == 'd') {
				longflag = 1;
				++f;
			}

			switch (*f) {
			case 'c':
				*s++ = va_arg(vargs, int);
				break;
			case 'd':
				if (longflag)
					sprintf(s, "%ld", va_arg(vargs, long));
				else
					sprintf(s, "%d", va_arg(vargs, int));
				s += strlen(s);
				break;
			case 'i':
				sprintf(s, "%i", va_arg(vargs, int));
				s += strlen(s);
				break;
			case 'x':
				sprintf(s, "%x", va_arg(vargs, int));
				s += strlen(s);
				break;
			case 's':
				p = va_arg(vargs, char*);
				i = strlen(p);
				if (n > 0 && i > n)
					i = n;
				memcpy(s, p, i);
				s += i;
				break;
			case 'p':
				sprintf(s, "%p", va_arg(vargs, void*));
				/* %p is ill-defined:  ensure leading 0x. */
				if (s[1] == 'X')
					s[1] = 'x';
				else if (s[1] != 'x') {
					memmove(s+2, s, strlen(s)+1);
					s[0] = '0';
					s[1] = 'x';
				}
				s += strlen(s);
				break;
			case '%':
				*s++ = '%';
				break;
			default:
				strcpy(s, p);
				s += strlen(s);
				goto end;
			}
		} else
			*s++ = *f;
	}

 end:
	_PyString_Resize(&string, s - PyString_AS_STRING(string));
	return string;
}

PyObject *
PyString_FromFormat(const char *format, ...)
{
	PyObject* ret;
	va_list vargs;

#ifdef HAVE_STDARG_PROTOTYPES
	va_start(vargs, format);
#else
	va_start(vargs);
#endif
	ret = PyString_FromFormatV(format, vargs);
	va_end(vargs);
	return ret;
}


PyObject *PyString_Decode(const char *s,
			  int size,
			  const char *encoding,
			  const char *errors)
{
    PyObject *v, *str;

    str = PyString_FromStringAndSize(s, size);
    if (str == NULL)
	return NULL;
    v = PyString_AsDecodedString(str, encoding, errors);
    Py_DECREF(str);
    return v;
}

PyObject *PyString_AsDecodedObject(PyObject *str,
				   const char *encoding,
				   const char *errors)
{
    PyObject *v;

    if (!PyString_Check(str)) {
        PyErr_BadArgument();
        goto onError;
    }

    if (encoding == NULL) {
#ifdef Py_USING_UNICODE
	encoding = PyUnicode_GetDefaultEncoding();
#else
	PyErr_SetString(PyExc_ValueError, "no encoding specified");
	goto onError;
#endif
    }

    /* Decode via the codec registry */
    v = PyCodec_Decode(str, encoding, errors);
    if (v == NULL)
        goto onError;

    return v;

 onError:
    return NULL;
}

PyObject *PyString_AsDecodedString(PyObject *str,
				   const char *encoding,
				   const char *errors)
{
    PyObject *v;

    v = PyString_AsDecodedObject(str, encoding, errors);
    if (v == NULL)
        goto onError;

#ifdef Py_USING_UNICODE
    /* Convert Unicode to a string using the default encoding */
    if (PyUnicode_Check(v)) {
	PyObject *temp = v;
	v = PyUnicode_AsEncodedString(v, NULL, NULL);
	Py_DECREF(temp);
	if (v == NULL)
	    goto onError;
    }
#endif
    if (!PyString_Check(v)) {
        PyErr_Format(PyExc_TypeError,
                     "decoder did not return a string object (type=%.400s)",
                     v->ob_type->tp_name);
        Py_DECREF(v);
        goto onError;
    }

    return v;

 onError:
    return NULL;
}

PyObject *PyString_Encode(const char *s,
			  int size,
			  const char *encoding,
			  const char *errors)
{
    PyObject *v, *str;

    str = PyString_FromStringAndSize(s, size);
    if (str == NULL)
	return NULL;
    v = PyString_AsEncodedString(str, encoding, errors);
    Py_DECREF(str);
    return v;
}

PyObject *PyString_AsEncodedObject(PyObject *str,
				   const char *encoding,
				   const char *errors)
{
    PyObject *v;

    if (!PyString_Check(str)) {
        PyErr_BadArgument();
        goto onError;
    }

    if (encoding == NULL) {
#ifdef Py_USING_UNICODE
	encoding = PyUnicode_GetDefaultEncoding();
#else
	PyErr_SetString(PyExc_ValueError, "no encoding specified");
	goto onError;
#endif
    }

    /* Encode via the codec registry */
    v = PyCodec_Encode(str, encoding, errors);
    if (v == NULL)
        goto onError;

    return v;

 onError:
    return NULL;
}

PyObject *PyString_AsEncodedString(PyObject *str,
				   const char *encoding,
				   const char *errors)
{
    PyObject *v;

    v = PyString_AsEncodedObject(str, encoding, errors);
    if (v == NULL)
        goto onError;

#ifdef Py_USING_UNICODE
    /* Convert Unicode to a string using the default encoding */
    if (PyUnicode_Check(v)) {
	PyObject *temp = v;
	v = PyUnicode_AsEncodedString(v, NULL, NULL);
	Py_DECREF(temp);
	if (v == NULL)
	    goto onError;
    }
#endif
    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;
}

static void
string_dealloc(PyObject *op)
{
	switch (PyString_CHECK_INTERNED(op)) {
		case SSTATE_NOT_INTERNED:
			break;

		case SSTATE_INTERNED_MORTAL:
			/* revive dead object temporarily for DelItem */
			op->ob_refcnt = 3;
			if (PyDict_DelItem(interned, op) != 0)
				Py_FatalError(
					"deletion of interned string failed");
			break;

		case SSTATE_INTERNED_IMMORTAL:
			Py_FatalError("Immortal interned string died.");

		default:
			Py_FatalError("Inconsistent interned string state.");
	}
	op->ob_type->tp_free(op);
}

/* Unescape a backslash-escaped string. If unicode is non-zero,
   the string is a u-literal. If recode_encoding is non-zero,
   the string is UTF-8 encoded and should be re-encoded in the
   specified encoding.  */

PyObject *PyString_DecodeEscape(const char *s,
				int len,
				const char *errors,
				int unicode,
				const char *recode_encoding)
{
	int c;
	char *p, *buf;
	const char *end;
	PyObject *v;
	int newlen = recode_encoding ? 4*len:len;
	v = PyString_FromStringAndSize((char *)NULL, newlen);
	if (v == NULL)
		return NULL;
	p = buf = PyString_AsString(v);
	end = s + len;
	while (s < end) {
		if (*s != '\\') {
		  non_esc:
#ifdef Py_USING_UNICODE
			if (recode_encoding && (*s & 0x80)) {
				PyObject *u, *w;
				char *r;
				const char* t;
				int rn;
				t = s;
				/* Decode non-ASCII bytes as UTF-8. */
				while (t < end && (*t & 0x80)) t++;
				u = PyUnicode_DecodeUTF8(s, t - s, errors);
				if(!u) goto failed;

				/* Recode them in target encoding. */
				w = PyUnicode_AsEncodedString(
					u, recode_encoding, errors);
				Py_DECREF(u);
				if (!w)	goto failed;

				/* Append bytes to output buffer. */
				r = PyString_AsString(w);
				rn = PyString_Size(w);
				memcpy(p, r, rn);
				p += rn;
				Py_DECREF(w);
				s = t;
			} else {
				*p++ = *s++;
			}
#else
			*p++ = *s++;
#endif
			continue;
		}
		s++;
                if (s==end) {
			PyErr_SetString(PyExc_ValueError,
					"Trailing \\ in string");
			goto failed;
		}
		switch (*s++) {
		/* XXX This assumes ASCII! */
		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 */
		case '0': case '1': case '2': case '3':
		case '4': case '5': case '6': case '7':
			c = s[-1] - '0';
			if ('0' <= *s && *s <= '7') {
				c = (c<<3) + *s++ - '0';
				if ('0' <= *s && *s <= '7')
					c = (c<<3) + *s++ - '0';
			}
			*p++ = c;
			break;
		case 'x':
			if (isxdigit(Py_CHARMASK(s[0])) 
			    && isxdigit(Py_CHARMASK(s[1]))) {
				unsigned int x = 0;
				c = Py_CHARMASK(*s);
				s++;
				if (isdigit(c))
					x = c - '0';
				else if (islower(c))
					x = 10 + c - 'a';
				else
					x = 10 + c - 'A';
				x = x << 4;
				c = Py_CHARMASK(*s);
				s++;
				if (isdigit(c))
					x += c - '0';
				else if (islower(c))
					x += 10 + c - 'a';
				else
					x += 10 + c - 'A';
				*p++ = x;
				break;
			}
			if (!errors || strcmp(errors, "strict") == 0) {
				PyErr_SetString(PyExc_ValueError, 
						"invalid \\x escape");
				goto failed;
			}
			if (strcmp(errors, "replace") == 0) {
				*p++ = '?';
			} else if (strcmp(errors, "ignore") == 0)
				/* do nothing */;
			else {
				PyErr_Format(PyExc_ValueError,
					     "decoding error; "
					     "unknown error handling code: %.400s",
					     errors);
				goto failed;
			}
#ifndef Py_USING_UNICODE
		case 'u':
		case 'U':
		case 'N':
			if (unicode) {
				PyErr_SetString(PyExc_ValueError,
					  "Unicode escapes not legal "
					  "when Unicode disabled");
				goto failed;
			}
#endif
		default:
			*p++ = '\\';
			s--;
			goto non_esc; /* an arbitry number of unescaped
					 UTF-8 bytes may follow. */
		}
	}
	if (p-buf < newlen)
		_PyString_Resize(&v, (int)(p - buf));
	return v;
  failed:
	Py_DECREF(v);
	return NULL;
}

static int
string_getsize(register PyObject *op)
{
    	char *s;
    	int len;
	if (PyString_AsStringAndSize(op, &s, &len))
		return -1;
	return len;
}

static /*const*/ char *
string_getbuffer(register PyObject *op)
{
    	char *s;
    	int len;
	if (PyString_AsStringAndSize(op, &s, &len))
		return NULL;
	return s;
}

int
PyString_Size(register PyObject *op)
{
	if (!PyString_Check(op))
		return string_getsize(op);
	return ((PyStringObject *)op) -> ob_size;
}

/*const*/ char *
PyString_AsString(register PyObject *op)
{
	if (!PyString_Check(op))
		return string_getbuffer(op);
	return ((PyStringObject *)op) -> ob_sval;
}

int
PyString_AsStringAndSize(register PyObject *obj,
			 register char **s,
			 register int *len)
{
	if (s == NULL) {
		PyErr_BadInternalCall();
		return -1;
	}

	if (!PyString_Check(obj)) {
#ifdef Py_USING_UNICODE
		if (PyUnicode_Check(obj)) {
			obj = _PyUnicode_AsDefaultEncodedString(obj, NULL);
			if (obj == NULL)
				return -1;
		}
		else
#endif
		{
			PyErr_Format(PyExc_TypeError,
				     "expected string or Unicode object, "
				     "%.200s found", obj->ob_type->tp_name);
			return -1;
		}
	}

	*s = PyString_AS_STRING(obj);
	if (len != NULL)
		*len = PyString_GET_SIZE(obj);
	else if ((int)strlen(*s) != PyString_GET_SIZE(obj)) {
		PyErr_SetString(PyExc_TypeError,
				"expected string without null bytes");
		return -1;
	}
	return 0;
}

/* Methods */

static int
string_print(PyStringObject *op, FILE *fp, int flags)
{
	int i;
	char c;
	int quote;

	/* XXX Ought to check for interrupts when writing long strings */
	if (! PyString_CheckExact(op)) {
		int ret;
		/* A str subclass may have its own __str__ method. */
		op = (PyStringObject *) PyObject_Str((PyObject *)op);
		if (op == NULL)
			return -1;
		ret = string_print(op, fp, flags);
		Py_DECREF(op);
		return ret;
	}
	if (flags & Py_PRINT_RAW) {
		fwrite(op->ob_sval, 1, (int) op->ob_size, fp);
		return 0;
	}

	/* figure out which quote to use; single is preferred */
	quote = '\'';
	if (memchr(op->ob_sval, '\'', op->ob_size) &&
	    !memchr(op->ob_sval, '"', op->ob_size))
		quote = '"';

	fputc(quote, fp);
	for (i = 0; i < op->ob_size; i++) {
		c = op->ob_sval[i];
		if (c == quote || c == '\\')
			fprintf(fp, "\\%c", c);
                else if (c == '\t')
                        fprintf(fp, "\\t");
                else if (c == '\n')
                        fprintf(fp, "\\n");
                else if (c == '\r')
                        fprintf(fp, "\\r");
		else if (c < ' ' || c >= 0x7f)
			fprintf(fp, "\\x%02x", c & 0xff);
		else
			fputc(c, fp);
	}
	fputc(quote, fp);
	return 0;
}

PyObject *
PyString_Repr(PyObject *obj, int smartquotes)
{
	register PyStringObject* op = (PyStringObject*) obj;
	size_t newsize = 2 + 4 * op->ob_size * sizeof(char);
	PyObject *v;
	if (newsize > INT_MAX) {
		PyErr_SetString(PyExc_OverflowError,
			"string is too large to make repr");
	}
	v = PyString_FromStringAndSize((char *)NULL, newsize);
	if (v == NULL) {
		return NULL;
	}
	else {
		register int i;
		register char c;
		register char *p;
		int quote;

		/* figure out which quote to use; single is preferred */
		quote = '\'';
		if (smartquotes && 
		    memchr(op->ob_sval, '\'', op->ob_size) &&
		    !memchr(op->ob_sval, '"', op->ob_size))
			quote = '"';

		p = PyString_AS_STRING(v);
		*p++ = quote;
		for (i = 0; i < op->ob_size; i++) {
			/* There's at least enough room for a hex escape
			   and a closing quote. */
			assert(newsize - (p - PyString_AS_STRING(v)) >= 5);
			c = op->ob_sval[i];
			if (c == quote || c == '\\')
				*p++ = '\\', *p++ = c;
			else if (c == '\t')
				*p++ = '\\', *p++ = 't';
			else if (c == '\n')
				*p++ = '\\', *p++ = 'n';
			else if (c == '\r')
				*p++ = '\\', *p++ = 'r';
			else if (c < ' ' || c >= 0x7f) {
				/* For performance, we don't want to call
				   PyOS_snprintf here (extra layers of
				   function call). */
				sprintf(p, "\\x%02x", c & 0xff);
                                p += 4;
			}
			else
				*p++ = c;
		}
		assert(newsize - (p - PyString_AS_STRING(v)) >= 1);
		*p++ = quote;
		*p = '\0';
		_PyString_Resize(
			&v, (int) (p - PyString_AS_STRING(v)));
		return v;
	}
}

static PyObject *
string_repr(PyObject *op)
{
	return PyString_Repr(op, 1);
}

static PyObject *
string_str(PyObject *s)
{
	assert(PyString_Check(s));
	if (PyString_CheckExact(s)) {
		Py_INCREF(s);
		return s;
	}
	else {
		/* Subtype -- return genuine string with the same value. */
		PyStringObject *t = (PyStringObject *) s;
		return PyString_FromStringAndSize(t->ob_sval, t->ob_size);
	}
}

static int
string_length(PyStringObject *a)
{
	return a->ob_size;
}

static PyObject *
string_concat(register PyStringObject *a, register PyObject *bb)
{
	register unsigned int size;
	register PyStringObject *op;
	if (!PyString_Check(bb)) {
#ifdef Py_USING_UNICODE
		if (PyUnicode_Check(bb))
		    return PyUnicode_Concat((PyObject *)a, bb);
#endif
		PyErr_Format(PyExc_TypeError,
			     "cannot concatenate 'str' and '%.200s' objects",
			     bb->ob_type->tp_name);
		return NULL;
	}
#define b ((PyStringObject *)bb)
	/* Optimize cases with empty left or right operand */
	if ((a->ob_size == 0 || b->ob_size == 0) &&
	    PyString_CheckExact(a) && PyString_CheckExact(b)) {
		if (a->ob_size == 0) {
			Py_INCREF(bb);
			return bb;
		}
		Py_INCREF(a);
		return (PyObject *)a;
	}
	size = a->ob_size + b->ob_size;
	/* Inline PyObject_NewVar */
	op = (PyStringObject *)
		PyObject_MALLOC(sizeof(PyStringObject) + size * sizeof(char));
	if (op == NULL)
		return PyErr_NoMemory();
	PyObject_INIT_VAR(op, &PyString_Type, size);
	op->ob_shash = -1;
	op->ob_sstate = SSTATE_NOT_INTERNED;
	memcpy(op->ob_sval, a->ob_sval, (int) a->ob_size);
	memcpy(op->ob_sval + a->ob_size, b->ob_sval, (int) b->ob_size);
	op->ob_sval[size] = '\0';
	return (PyObject *) op;
#undef b
}

static PyObject *
string_repeat(register PyStringObject *a, register int n)
{
	register int i;
	register int size;
	register PyStringObject *op;
	size_t nbytes;
	if (n < 0)
		n = 0;
	/* watch out for overflows:  the size can overflow int,
	 * and the # of bytes needed can overflow size_t
	 */
	size = a->ob_size * n;
	if (n && size / n != a->ob_size) {
		PyErr_SetString(PyExc_OverflowError,
			"repeated string is too long");
		return NULL;
	}
	if (size == a->ob_size && PyString_CheckExact(a)) {
		Py_INCREF(a);
		return (PyObject *)a;
	}
	nbytes = size * sizeof(char);
	if (nbytes / sizeof(char) != (size_t)size ||
	    nbytes + sizeof(PyStringObject) <= nbytes) {
		PyErr_SetString(PyExc_OverflowError,
			"repeated string is too long");
		return NULL;
	}
	op = (PyStringObject *)
		PyObject_MALLOC(sizeof(PyStringObject) + nbytes);
	if (op == NULL)
		return PyErr_NoMemory();
	PyObject_INIT_VAR(op, &PyString_Type, size);
	op->ob_shash = -1;
	op->ob_sstate = SSTATE_NOT_INTERNED;
	for (i = 0; i < size; i += a->ob_size)
		memcpy(op->ob_sval+i, a->ob_sval, (int) a->ob_size);
	op->ob_sval[size] = '\0';
	return (PyObject *) op;
}

/* String slice a[i:j] consists of characters a[i] ... a[j-1] */

static PyObject *
string_slice(register PyStringObject *a, register int i, register int j)
     /* j -- may be negative! */
{
	if (i < 0)
		i = 0;
	if (j < 0)
		j = 0; /* Avoid signed/unsigned bug in next line */
	if (j > a->ob_size)
		j = a->ob_size;
	if (i == 0 && j == a->ob_size && PyString_CheckExact(a)) {
		/* It's the same as a */
		Py_INCREF(a);
		return (PyObject *)a;
	}
	if (j < i)
		j = i;
	return PyString_FromStringAndSize(a->ob_sval + i, (int) (j-i));
}

static int
string_contains(PyObject *a, PyObject *el)
{
	const char *lhs, *rhs, *end;
	int size;

	if (!PyString_CheckExact(el)) {
#ifdef Py_USING_UNICODE
		if (PyUnicode_Check(el))
			return PyUnicode_Contains(a, el);
#endif
		if (!PyString_Check(el)) {
			PyErr_SetString(PyExc_TypeError,
			    "'in <string>' requires string as left operand");
			return -1;
		}
	}
	size = PyString_GET_SIZE(el);
	rhs = PyString_AS_STRING(el);
	lhs = PyString_AS_STRING(a);

	/* optimize for a single character */
	if (size == 1)
		return memchr(lhs, *rhs, PyString_GET_SIZE(a)) != NULL;

	end = lhs + (PyString_GET_SIZE(a) - size);
	while (lhs <= end) {
		if (memcmp(lhs++, rhs, size) == 0)
			return 1;
	}

	return 0;
}

static PyObject *
string_item(PyStringObject *a, register int i)
{
	PyObject *v;
	char *pchar;
	if (i < 0 || i >= a->ob_size) {
		PyErr_SetString(PyExc_IndexError, "string index out of range");
		return NULL;
	}
	pchar = a->ob_sval + i;
	v = (PyObject *)characters[*pchar & UCHAR_MAX];
	if (v == NULL)
		v = PyString_FromStringAndSize(pchar, 1);
	else {
#ifdef COUNT_ALLOCS
		one_strings++;
#endif
		Py_INCREF(v);
	}
	return v;
}

static PyObject*
string_richcompare(PyStringObject *a, PyStringObject *b, int op)
{
	int c;
	int len_a, len_b;
	int min_len;
	PyObject *result;

	/* Make sure both arguments are strings. */
	if (!(PyString_Check(a) && PyString_Check(b))) {
		result = Py_NotImplemented;
		goto out;
	}
	if (a == b) {
		switch (op) {
		case Py_EQ:case Py_LE:case Py_GE:
			result = Py_True;
			goto out;
		case Py_NE:case Py_LT:case Py_GT:
			result = Py_False;
			goto out;
		}
	}
	if (op == Py_EQ) {
		/* Supporting Py_NE here as well does not save
		   much time, since Py_NE is rarely used.  */
		if (a->ob_size == b->ob_size
		    && (a->ob_sval[0] == b->ob_sval[0]
			&& memcmp(a->ob_sval, b->ob_sval,
				  a->ob_size) == 0)) {
			result = Py_True;
		} else {
			result = Py_False;
		}
		goto out;
	}
	len_a = a->ob_size; len_b = b->ob_size;
	min_len = (len_a < len_b) ? len_a : len_b;
	if (min_len > 0) {
		c = Py_CHARMASK(*a->ob_sval) - Py_CHARMASK(*b->ob_sval);
		if (c==0)
			c = memcmp(a->ob_sval, b->ob_sval, min_len);
	}else
		c = 0;
	if (c == 0)
		c = (len_a < len_b) ? -1 : (len_a > len_b) ? 1 : 0;
	switch (op) {
	case Py_LT: c = c <  0; break;
	case Py_LE: c = c <= 0; break;
	case Py_EQ: assert(0);  break; /* unreachable */
	case Py_NE: c = c != 0; break;
	case Py_GT: c = c >  0; break;
	case Py_GE: c = c >= 0; break;
	default:
		result = Py_NotImplemented;
		goto out;
	}
	result = c ? Py_True : Py_False;
  out:
	Py_INCREF(result);
	return result;
}

int
_PyString_Eq(PyObject *o1, PyObject *o2)
{
	PyStringObject *a, *b;
	a = (PyStringObject*)o1;
	b = (PyStringObject*)o2;
        return a->ob_size == b->ob_size
          && *a->ob_sval == *b->ob_sval
          && memcmp(a->ob_sval, b->ob_sval, a->ob_size) == 0;
}

static long
string_hash(PyStringObject *a)
{
	register int len;
	register unsigned char *p;
	register long x;

	if (a->ob_shash != -1)
		return a->ob_shash;
	len = a->ob_size;
	p = (unsigned char *) a->ob_sval;
	x = *p << 7;
	while (--len >= 0)
		x = (1000003*x) ^ *p++;
	x ^= a->ob_size;
	if (x == -1)
		x = -2;
	a->ob_shash = x;
	return x;
}

static PyObject*
string_subscript(PyStringObject* self, PyObject* item)
{
	if (PyInt_Check(item)) {
		long i = PyInt_AS_LONG(item);
		if (i < 0)
			i += PyString_GET_SIZE(self);
		return string_item(self,i);
	}
	else if (PyLong_Check(item)) {
		long i = PyLong_AsLong(item);
		if (i == -1 && PyErr_Occurred())
			return NULL;
		if (i < 0)
			i += PyString_GET_SIZE(self);
		return string_item(self,i);
	}
	else if (PySlice_Check(item)) {
		int start, stop, step, slicelength, cur, i;
		char* source_buf;
		char* result_buf;
		PyObject* result;

		if (PySlice_GetIndicesEx((PySliceObject*)item, 
				 PyString_GET_SIZE(self),
				 &start, &stop, &step, &slicelength) < 0) {
			return NULL;
		}

		if (slicelength <= 0) {
			return PyString_FromStringAndSize("", 0);
		}
		else {
			source_buf = PyString_AsString((PyObject*)self);
			result_buf = PyMem_Malloc(slicelength);

			for (cur = start, i = 0; i < slicelength; 
			     cur += step, i++) {
				result_buf[i] = source_buf[cur];
			}
			
			result = PyString_FromStringAndSize(result_buf, 
							    slicelength);
			PyMem_Free(result_buf);
			return result;
		}
	} 
	else {
		PyErr_SetString(PyExc_TypeError, 
				"string indices must be integers");
		return NULL;
	}
}

static int
string_buffer_getreadbuf(PyStringObject *self, int index, const void **ptr)
{
	if ( index != 0 ) {
		PyErr_SetString(PyExc_SystemError,
				"accessing non-existent string segment");
		return -1;
	}
	*ptr = (void *)self->ob_sval;
	return self->ob_size;
}

static int
string_buffer_getwritebuf(PyStringObject *self, int index, const void **ptr)
{
	PyErr_SetString(PyExc_TypeError,
			"Cannot use string as modifiable buffer");
	return -1;
}

static int
string_buffer_getsegcount(PyStringObject *self, int *lenp)
{
	if ( lenp )
		*lenp = self->ob_size;
	return 1;
}

static int
string_buffer_getcharbuf(PyStringObject *self, int index, const char **ptr)
{
	if ( index != 0 ) {
		PyErr_SetString(PyExc_SystemError,
				"accessing non-existent string segment");
		return -1;
	}
	*ptr = self->ob_sval;
	return self->ob_size;
}

static PySequenceMethods string_as_sequence = {
	(inquiry)string_length, /*sq_length*/
	(binaryfunc)string_concat, /*sq_concat*/
	(intargfunc)string_repeat, /*sq_repeat*/
	(intargfunc)string_item, /*sq_item*/
	(intintargfunc)string_slice, /*sq_slice*/
	0,		/*sq_ass_item*/
	0,		/*sq_ass_slice*/
	(objobjproc)string_contains /*sq_contains*/
};

static PyMappingMethods string_as_mapping = {
	(inquiry)string_length,
	(binaryfunc)string_subscript,
	0,
};

static PyBufferProcs string_as_buffer = {
	(getreadbufferproc)string_buffer_getreadbuf,
	(getwritebufferproc)string_buffer_getwritebuf,
	(getsegcountproc)string_buffer_getsegcount,
	(getcharbufferproc)string_buffer_getcharbuf,
};



#define LEFTSTRIP 0
#define RIGHTSTRIP 1
#define BOTHSTRIP 2

/* Arrays indexed by above */
static const char *stripformat[] = {"|O:lstrip", "|O:rstrip", "|O:strip"};

#define STRIPNAME(i) (stripformat[i]+3)


static PyObject *
split_whitespace(const char *s, int len, int maxsplit)
{
	int i, j, err;
	PyObject* item;
	PyObject *list = PyList_New(0);

	if (list == NULL)
		return NULL;

	for (i = j = 0; i < len; ) {
		while (i < len && isspace(Py_CHARMASK(s[i])))
			i++;
		j = i;
		while (i < len && !isspace(Py_CHARMASK(s[i])))
			i++;
		if (j < i) {
			if (maxsplit-- <= 0)
				break;
			item = PyString_FromStringAndSize(s+j, (int)(i-j));
			if (item == NULL)
				goto finally;
			err = PyList_Append(list, item);
			Py_DECREF(item);
			if (err < 0)
				goto finally;
			while (i < len && isspace(Py_CHARMASK(s[i])))
				i++;
			j = i;
		}
	}
	if (j < len) {
		item = PyString_FromStringAndSize(s+j, (int)(len - j));
		if (item == NULL)
			goto finally;
		err = PyList_Append(list, item);
		Py_DECREF(item);
		if (err < 0)
			goto finally;
	}
	return list;
  finally:
	Py_DECREF(list);
	return NULL;
}


PyDoc_STRVAR(split__doc__,
"S.split([sep [,maxsplit]]) -> list of strings\n\
\n\
Return a list of the words in the string S, using sep as the\n\
delimiter string.  If maxsplit is given, at most maxsplit\n\
splits are done. If sep is not specified or is None, any\n\
whitespace string is a separator.");

static PyObject *
string_split(PyStringObject *self, PyObject *args)
{
	int len = PyString_GET_SIZE(self), n, i, j, err;
	int maxsplit = -1;
	const char *s = PyString_AS_STRING(self), *sub;
	PyObject *list, *item, *subobj = Py_None;

	if (!PyArg_ParseTuple(args, "|Oi:split", &subobj, &maxsplit))
		return NULL;
	if (maxsplit < 0)
		maxsplit = INT_MAX;
	if (subobj == Py_None)
		return split_whitespace(s, len, maxsplit);
	if (PyString_Check(subobj)) {
		sub = PyString_AS_STRING(subobj);
		n = PyString_GET_SIZE(subobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(subobj))
		return PyUnicode_Split((PyObject *)self, subobj, maxsplit);
#endif
	else if (PyObject_AsCharBuffer(subobj, &sub, &n))
		return NULL;
	if (n == 0) {
		PyErr_SetString(PyExc_ValueError, "empty separator");
		return NULL;
	}

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

	i = j = 0;
	while (i+n <= len) {
		if (s[i] == sub[0] && memcmp(s+i, sub, n) == 0) {
			if (maxsplit-- <= 0)
				break;
			item = PyString_FromStringAndSize(s+j, (int)(i-j));
			if (item == NULL)
				goto fail;
			err = PyList_Append(list, item);
			Py_DECREF(item);
			if (err < 0)
				goto fail;
			i = j = i + n;
		}
		else
			i++;
	}
	item = PyString_FromStringAndSize(s+j, (int)(len-j));
	if (item == NULL)
		goto fail;
	err = PyList_Append(list, item);
	Py_DECREF(item);
	if (err < 0)
		goto fail;

	return list;

 fail:
	Py_DECREF(list);
	return NULL;
}


PyDoc_STRVAR(join__doc__,
"S.join(sequence) -> string\n\
\n\
Return a string which is the concatenation of the strings in the\n\
sequence.  The separator between elements is S.");

static PyObject *
string_join(PyStringObject *self, PyObject *orig)
{
	char *sep = PyString_AS_STRING(self);
	const int seplen = PyString_GET_SIZE(self);
	PyObject *res = NULL;
	char *p;
	int seqlen = 0;
	size_t sz = 0;
	int i;
	PyObject *seq, *item;

	seq = PySequence_Fast(orig, "");
	if (seq == NULL) {
		if (PyErr_ExceptionMatches(PyExc_TypeError))
			PyErr_Format(PyExc_TypeError,
				     "sequence expected, %.80s found",
				     orig->ob_type->tp_name);
		return NULL;
	}

	seqlen = PySequence_Size(seq);
	if (seqlen == 0) {
		Py_DECREF(seq);
		return PyString_FromString("");
	}
	if (seqlen == 1) {
		item = PySequence_Fast_GET_ITEM(seq, 0);
		if (!PyString_Check(item) && !PyUnicode_Check(item)) {
			PyErr_Format(PyExc_TypeError,
				     "sequence item 0: expected string,"
				     " %.80s found",
				     item->ob_type->tp_name);
			Py_DECREF(seq);
			return NULL;
		}
		Py_INCREF(item);
		Py_DECREF(seq);
		return item;
	}

	/* There are at least two things to join.  Do a pre-pass to figure out
	 * the total amount of space we'll need (sz), see whether any argument
	 * is absurd, and defer to the Unicode join if appropriate.
	 */
	for (i = 0; i < seqlen; i++) {
		const size_t old_sz = sz;
		item = PySequence_Fast_GET_ITEM(seq, i);
		if (!PyString_Check(item)){
#ifdef Py_USING_UNICODE
			if (PyUnicode_Check(item)) {
				/* Defer to Unicode join.
				 * CAUTION:  There's no gurantee that the
				 * original sequence can be iterated over
				 * again, so we must pass seq here.
				 */
				PyObject *result;
				result = PyUnicode_Join((PyObject *)self, seq);
				Py_DECREF(seq);
				return result;
			}
#endif
			PyErr_Format(PyExc_TypeError,
				     "sequence item %i: expected string,"
				     " %.80s found",
				     i, item->ob_type->tp_name);
			Py_DECREF(seq);
			return NULL;
		}
		sz += PyString_GET_SIZE(item);
		if (i != 0)
			sz += seplen;
		if (sz < old_sz || sz > INT_MAX) {
			PyErr_SetString(PyExc_OverflowError,
				"join() is too long for a Python string");
			Py_DECREF(seq);
			return NULL;
		}
	}

	/* Allocate result space. */
	res = PyString_FromStringAndSize((char*)NULL, (int)sz);
	if (res == NULL) {
		Py_DECREF(seq);
		return NULL;
	}

	/* Catenate everything. */
	p = PyString_AS_STRING(res);
	for (i = 0; i < seqlen; ++i) {
		size_t n;
		item = PySequence_Fast_GET_ITEM(seq, i);
		n = PyString_GET_SIZE(item);
		memcpy(p, PyString_AS_STRING(item), n);
		p += n;
		if (i < seqlen - 1) {
			memcpy(p, sep, seplen);
			p += seplen;
		}
	}

	Py_DECREF(seq);
	return res;
}

PyObject *
_PyString_Join(PyObject *sep, PyObject *x)
{
	assert(sep != NULL && PyString_Check(sep));
	assert(x != NULL);
	return string_join((PyStringObject *)sep, x);
}

static void
string_adjust_indices(int *start, int *end, int len)
{
	if (*end > len)
		*end = len;
	else if (*end < 0)
		*end += len;
	if (*end < 0)
		*end = 0;
	if (*start < 0)
		*start += len;
	if (*start < 0)
		*start = 0;
}

static long
string_find_internal(PyStringObject *self, PyObject *args, int dir)
{
	const char *s = PyString_AS_STRING(self), *sub;
	int len = PyString_GET_SIZE(self);
	int n, i = 0, last = INT_MAX;
	PyObject *subobj;

	if (!PyArg_ParseTuple(args, "O|O&O&:find/rfind/index/rindex",
		&subobj, _PyEval_SliceIndex, &i, _PyEval_SliceIndex, &last))
		return -2;
	if (PyString_Check(subobj)) {
		sub = PyString_AS_STRING(subobj);
		n = PyString_GET_SIZE(subobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(subobj))
		return PyUnicode_Find((PyObject *)self, subobj, i, last, dir);
#endif
	else if (PyObject_AsCharBuffer(subobj, &sub, &n))
		return -2;

	string_adjust_indices(&i, &last, len);

	if (dir > 0) {
		if (n == 0 && i <= last)
			return (long)i;
		last -= n;
		for (; i <= last; ++i)
			if (s[i] == sub[0] && memcmp(&s[i], sub, n) == 0)
				return (long)i;
	}
	else {
		int j;

        	if (n == 0 && i <= last)
			return (long)last;
		for (j = last-n; j >= i; --j)
			if (s[j] == sub[0] && memcmp(&s[j], sub, n) == 0)
				return (long)j;
	}

	return -1;
}


PyDoc_STRVAR(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 *
string_find(PyStringObject *self, PyObject *args)
{
	long result = string_find_internal(self, args, +1);
	if (result == -2)
		return NULL;
	return PyInt_FromLong(result);
}


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

static PyObject *
string_index(PyStringObject *self, PyObject *args)
{
	long result = string_find_internal(self, args, +1);
	if (result == -2)
		return NULL;
	if (result == -1) {
		PyErr_SetString(PyExc_ValueError,
				"substring not found in string.index");
		return NULL;
	}
	return PyInt_FromLong(result);
}


PyDoc_STRVAR(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 *
string_rfind(PyStringObject *self, PyObject *args)
{
	long result = string_find_internal(self, args, -1);
	if (result == -2)
		return NULL;
	return PyInt_FromLong(result);
}


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

static PyObject *
string_rindex(PyStringObject *self, PyObject *args)
{
	long result = string_find_internal(self, args, -1);
	if (result == -2)
		return NULL;
	if (result == -1) {
		PyErr_SetString(PyExc_ValueError,
				"substring not found in string.rindex");
		return NULL;
	}
	return PyInt_FromLong(result);
}


static PyObject *
do_xstrip(PyStringObject *self, int striptype, PyObject *sepobj)
{
	char *s = PyString_AS_STRING(self);
	int len = PyString_GET_SIZE(self);
	char *sep = PyString_AS_STRING(sepobj);
	int seplen = PyString_GET_SIZE(sepobj);
	int i, j;

	i = 0;
	if (striptype != RIGHTSTRIP) {
		while (i < len && memchr(sep, Py_CHARMASK(s[i]), seplen)) {
			i++;
		}
	}

	j = len;
	if (striptype != LEFTSTRIP) {
		do {
			j--;
		} while (j >= i && memchr(sep, Py_CHARMASK(s[j]), seplen));
		j++;
	}

	if (i == 0 && j == len && PyString_CheckExact(self)) {
		Py_INCREF(self);
		return (PyObject*)self;
	}
	else
		return PyString_FromStringAndSize(s+i, j-i);
}


static PyObject *
do_strip(PyStringObject *self, int striptype)
{
	char *s = PyString_AS_STRING(self);
	int len = PyString_GET_SIZE(self), i, j;

	i = 0;
	if (striptype != RIGHTSTRIP) {
		while (i < len && isspace(Py_CHARMASK(s[i]))) {
			i++;
		}
	}

	j = len;
	if (striptype != LEFTSTRIP) {
		do {
			j--;
		} while (j >= i && isspace(Py_CHARMASK(s[j])));
		j++;
	}

	if (i == 0 && j == len && PyString_CheckExact(self)) {
		Py_INCREF(self);
		return (PyObject*)self;
	}
	else
		return PyString_FromStringAndSize(s+i, j-i);
}


static PyObject *
do_argstrip(PyStringObject *self, int striptype, PyObject *args)
{
	PyObject *sep = NULL;

	if (!PyArg_ParseTuple(args, (char *)stripformat[striptype], &sep))
		return NULL;

	if (sep != NULL && sep != Py_None) {
		if (PyString_Check(sep))
			return do_xstrip(self, striptype, sep);
#ifdef Py_USING_UNICODE
		else if (PyUnicode_Check(sep)) {
			PyObject *uniself = PyUnicode_FromObject((PyObject *)self);
			PyObject *res;
			if (uniself==NULL)
				return NULL;
			res = _PyUnicode_XStrip((PyUnicodeObject *)uniself,
				striptype, sep);
			Py_DECREF(uniself);
			return res;
		}
#endif
		else {
			PyErr_Format(PyExc_TypeError,
#ifdef Py_USING_UNICODE
				     "%s arg must be None, str or unicode",
#else
				     "%s arg must be None or str",
#endif
				     STRIPNAME(striptype));
			return NULL;
		}
		return do_xstrip(self, striptype, sep);
	}

	return do_strip(self, striptype);
}


PyDoc_STRVAR(strip__doc__,
"S.strip([sep]) -> string or unicode\n\
\n\
Return a copy of the string S with leading and trailing\n\
whitespace removed.\n\
If sep is given and not None, remove characters in sep instead.\n\
If sep is unicode, S will be converted to unicode before stripping");

static PyObject *
string_strip(PyStringObject *self, PyObject *args)
{
	if (PyTuple_GET_SIZE(args) == 0)
		return do_strip(self, BOTHSTRIP); /* Common case */
	else
		return do_argstrip(self, BOTHSTRIP, args);
}


PyDoc_STRVAR(lstrip__doc__,
"S.lstrip([sep]) -> string or unicode\n\
\n\
Return a copy of the string S with leading whitespace removed.\n\
If sep is given and not None, remove characters in sep instead.\n\
If sep is unicode, S will be converted to unicode before stripping");

static PyObject *
string_lstrip(PyStringObject *self, PyObject *args)
{
	if (PyTuple_GET_SIZE(args) == 0)
		return do_strip(self, LEFTSTRIP); /* Common case */
	else
		return do_argstrip(self, LEFTSTRIP, args);
}


PyDoc_STRVAR(rstrip__doc__,
"S.rstrip([sep]) -> string or unicode\n\
\n\
Return a copy of the string S with trailing whitespace removed.\n\
If sep is given and not None, remove characters in sep instead.\n\
If sep is unicode, S will be converted to unicode before stripping");

static PyObject *
string_rstrip(PyStringObject *self, PyObject *args)
{
	if (PyTuple_GET_SIZE(args) == 0)
		return do_strip(self, RIGHTSTRIP); /* Common case */
	else
		return do_argstrip(self, RIGHTSTRIP, args);
}


PyDoc_STRVAR(lower__doc__,
"S.lower() -> string\n\
\n\
Return a copy of the string S converted to lowercase.");

static PyObject *
string_lower(PyStringObject *self)
{
	char *s = PyString_AS_STRING(self), *s_new;
	int i, n = PyString_GET_SIZE(self);
	PyObject *new;

	new = PyString_FromStringAndSize(NULL, n);
	if (new == NULL)
		return NULL;
	s_new = PyString_AsString(new);
	for (i = 0; i < n; i++) {
		int c = Py_CHARMASK(*s++);
		if (isupper(c)) {
			*s_new = tolower(c);
		} else
			*s_new = c;
		s_new++;
	}
	return new;
}


PyDoc_STRVAR(upper__doc__,
"S.upper() -> string\n\
\n\
Return a copy of the string S converted to uppercase.");

static PyObject *
string_upper(PyStringObject *self)
{
	char *s = PyString_AS_STRING(self), *s_new;
	int i, n = PyString_GET_SIZE(self);
	PyObject *new;

	new = PyString_FromStringAndSize(NULL, n);
	if (new == NULL)
		return NULL;
	s_new = PyString_AsString(new);
	for (i = 0; i < n; i++) {
		int c = Py_CHARMASK(*s++);
		if (islower(c)) {
			*s_new = toupper(c);
		} else
			*s_new = c;
		s_new++;
	}
	return new;
}


PyDoc_STRVAR(title__doc__,
"S.title() -> string\n\
\n\
Return a titlecased version of S, i.e. words start with uppercase\n\
characters, all remaining cased characters have lowercase.");

static PyObject*
string_title(PyStringObject *self)
{
	char *s = PyString_AS_STRING(self), *s_new;
	int i, n = PyString_GET_SIZE(self);
	int previous_is_cased = 0;
	PyObject *new;

	new = PyString_FromStringAndSize(NULL, n);
	if (new == NULL)
		return NULL;
	s_new = PyString_AsString(new);
	for (i = 0; i < n; i++) {
		int c = Py_CHARMASK(*s++);
		if (islower(c)) {
			if (!previous_is_cased)
			    c = toupper(c);
			previous_is_cased = 1;
		} else if (isupper(c)) {
			if (previous_is_cased)
			    c = tolower(c);
			previous_is_cased = 1;
		} else
			previous_is_cased = 0;
		*s_new++ = c;
	}
	return new;
}

PyDoc_STRVAR(capitalize__doc__,
"S.capitalize() -> string\n\
\n\
Return a copy of the string S with only its first character\n\
capitalized.");

static PyObject *
string_capitalize(PyStringObject *self)
{
	char *s = PyString_AS_STRING(self), *s_new;
	int i, n = PyString_GET_SIZE(self);
	PyObject *new;

	new = PyString_FromStringAndSize(NULL, n);
	if (new == NULL)
		return NULL;
	s_new = PyString_AsString(new);
	if (0 < n) {
		int c = Py_CHARMASK(*s++);
		if (islower(c))
			*s_new = toupper(c);
		else
			*s_new = c;
		s_new++;
	}
	for (i = 1; i < n; i++) {
		int c = Py_CHARMASK(*s++);
		if (isupper(c))
			*s_new = tolower(c);
		else
			*s_new = c;
		s_new++;
	}
	return new;
}


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

static PyObject *
string_count(PyStringObject *self, PyObject *args)
{
	const char *s = PyString_AS_STRING(self), *sub;
	int len = PyString_GET_SIZE(self), n;
	int i = 0, last = INT_MAX;
	int m, r;
	PyObject *subobj;

	if (!PyArg_ParseTuple(args, "O|O&O&:count", &subobj,
		_PyEval_SliceIndex, &i, _PyEval_SliceIndex, &last))
		return NULL;

	if (PyString_Check(subobj)) {
		sub = PyString_AS_STRING(subobj);
		n = PyString_GET_SIZE(subobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(subobj)) {
		int count;
		count = PyUnicode_Count((PyObject *)self, subobj, i, last);
		if (count == -1)
			return NULL;
		else
		    	return PyInt_FromLong((long) count);
	}
#endif
	else if (PyObject_AsCharBuffer(subobj, &sub, &n))
		return NULL;

	string_adjust_indices(&i, &last, len);

	m = last + 1 - n;
	if (n == 0)
		return PyInt_FromLong((long) (m-i));

	r = 0;
	while (i < m) {
		if (!memcmp(s+i, sub, n)) {
			r++;
			i += n;
		} else {
			i++;
		}
	}
	return PyInt_FromLong((long) r);
}


PyDoc_STRVAR(swapcase__doc__,
"S.swapcase() -> string\n\
\n\
Return a copy of the string S with uppercase characters\n\
converted to lowercase and vice versa.");

static PyObject *
string_swapcase(PyStringObject *self)
{
	char *s = PyString_AS_STRING(self), *s_new;
	int i, n = PyString_GET_SIZE(self);
	PyObject *new;

	new = PyString_FromStringAndSize(NULL, n);
	if (new == NULL)
		return NULL;
	s_new = PyString_AsString(new);
	for (i = 0; i < n; i++) {
		int c = Py_CHARMASK(*s++);
		if (islower(c)) {
			*s_new = toupper(c);
		}
		else if (isupper(c)) {
			*s_new = tolower(c);
		}
		else
			*s_new = c;
		s_new++;
	}
	return new;
}


PyDoc_STRVAR(translate__doc__,
"S.translate(table [,deletechars]) -> string\n\
\n\
Return a copy of the string S, where all characters occurring\n\
in the optional argument deletechars are removed, and the\n\
remaining characters have been mapped through the given\n\
translation table, which must be a string of length 256.");

static PyObject *
string_translate(PyStringObject *self, PyObject *args)
{
	register char *input, *output;
	register const char *table;
	register int i, c, changed = 0;
	PyObject *input_obj = (PyObject*)self;
	const char *table1, *output_start, *del_table=NULL;
	int inlen, tablen, dellen = 0;
	PyObject *result;
	int trans_table[256];
	PyObject *tableobj, *delobj = NULL;

	if (!PyArg_ParseTuple(args, "O|O:translate",
			      &tableobj, &delobj))
		return NULL;

	if (PyString_Check(tableobj)) {
		table1 = PyString_AS_STRING(tableobj);
		tablen = PyString_GET_SIZE(tableobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(tableobj)) {
		/* Unicode .translate() does not support the deletechars
		   parameter; instead a mapping to None will cause characters
		   to be deleted. */
		if (delobj != NULL) {
			PyErr_SetString(PyExc_TypeError,
			"deletions are implemented differently for unicode");
			return NULL;
		}
		return PyUnicode_Translate((PyObject *)self, tableobj, NULL);
	}
#endif
	else if (PyObject_AsCharBuffer(tableobj, &table1, &tablen))
		return NULL;

	if (delobj != NULL) {
		if (PyString_Check(delobj)) {
			del_table = PyString_AS_STRING(delobj);
			dellen = PyString_GET_SIZE(delobj);
		}
#ifdef Py_USING_UNICODE
		else if (PyUnicode_Check(delobj)) {
			PyErr_SetString(PyExc_TypeError,
			"deletions are implemented differently for unicode");
			return NULL;
		}
#endif
		else if (PyObject_AsCharBuffer(delobj, &del_table, &dellen))
			return NULL;

		if (tablen != 256) {
			PyErr_SetString(PyExc_ValueError,
			  "translation table must be 256 characters long");
			return NULL;
		}
	}
	else {
		del_table = NULL;
		dellen = 0;
	}

	table = table1;
	inlen = PyString_Size(input_obj);
	result = PyString_FromStringAndSize((char *)NULL, inlen);
	if (result == NULL)
		return NULL;
	output_start = output = PyString_AsString(result);
	input = PyString_AsString(input_obj);

	if (dellen == 0) {
		/* If no deletions are required, use faster code */
		for (i = inlen; --i >= 0; ) {
			c = Py_CHARMASK(*input++);
			if (Py_CHARMASK((*output++ = table[c])) != c)
				changed = 1;
		}
		if (changed || !PyString_CheckExact(input_obj))
			return result;
		Py_DECREF(result);
		Py_INCREF(input_obj);
		return input_obj;
	}

	for (i = 0; i < 256; i++)
		trans_table[i] = Py_CHARMASK(table[i]);

	for (i = 0; i < dellen; i++)
		trans_table[(int) Py_CHARMASK(del_table[i])] = -1;

	for (i = inlen; --i >= 0; ) {
		c = Py_CHARMASK(*input++);
		if (trans_table[c] != -1)
			if (Py_CHARMASK(*output++ = (char)trans_table[c]) == c)
				continue;
		changed = 1;
	}
	if (!changed && PyString_CheckExact(input_obj)) {
		Py_DECREF(result);
		Py_INCREF(input_obj);
		return input_obj;
	}
	/* Fix the size of the resulting string */
	if (inlen > 0)
		_PyString_Resize(&result, output - output_start);
	return result;
}


/* What follows is used for implementing replace().  Perry Stoll. */

/*
  mymemfind

  strstr replacement for arbitrary blocks of memory.

  Locates the first occurrence in the memory pointed to by MEM of the
  contents of memory pointed to by PAT.  Returns the index into MEM if
  found, or -1 if not found.  If len of PAT is greater than length of
  MEM, the function returns -1.
*/
static int
mymemfind(const char *mem, int len, const char *pat, int pat_len)
{
	register int ii;

	/* pattern can not occur in the last pat_len-1 chars */
	len -= pat_len;

	for (ii = 0; ii <= len; ii++) {
		if (mem[ii] == pat[0] && memcmp(&mem[ii], pat, pat_len) == 0) {
			return ii;
		}
	}
	return -1;
}

/*
  mymemcnt

   Return the number of distinct times PAT is found in MEM.
   meaning mem=1111 and pat==11 returns 2.
           mem=11111 and pat==11 also return 2.
 */
static int
mymemcnt(const char *mem, int len, const char *pat, int pat_len)
{
	register int offset = 0;
	int nfound = 0;

	while (len >= 0) {
		offset = mymemfind(mem, len, pat, pat_len);
		if (offset == -1)
			break;
		mem += offset + pat_len;
		len -= offset + pat_len;
		nfound++;
	}
	return nfound;
}

/*
   mymemreplace

   Return a string in which all occurrences of PAT in memory STR are
   replaced with SUB.

   If length of PAT is less than length of STR or there are no occurrences
   of PAT in STR, then the original string is returned. Otherwise, a new
   string is allocated here and returned.

   on return, out_len is:
       the length of output string, or
       -1 if the input string is returned, or
       unchanged if an error occurs (no memory).

   return value is:
       the new string allocated locally, or
       NULL if an error occurred.
*/
static char *
mymemreplace(const char *str, int len,		/* input string */
             const char *pat, int pat_len,	/* pattern string to find */
             const char *sub, int sub_len,	/* substitution string */
             int count,				/* number of replacements */
	     int *out_len)
{
	char *out_s;
	char *new_s;
	int nfound, offset, new_len;

	if (len == 0 || (pat_len == 0 && sub_len == 0) || pat_len > len)
		goto return_same;

	/* find length of output string */
	nfound = (pat_len > 0) ? mymemcnt(str, len, pat, pat_len) : len + 1;
	if (count < 0)
		count = INT_MAX;
	else if (nfound > count)
		nfound = count;
	if (nfound == 0)
		goto return_same;

	new_len = len + nfound*(sub_len - pat_len);
	if (new_len == 0) {
		/* Have to allocate something for the caller to free(). */
		out_s = (char *)PyMem_MALLOC(1);
		if (out_s == NULL)
			return NULL;
		out_s[0] = '\0';
	}
	else {
		assert(new_len > 0);
		new_s = (char *)PyMem_MALLOC(new_len);
		if (new_s == NULL)
			return NULL;
		out_s = new_s;

		if (pat_len > 0) {
			for (; nfound > 0; --nfound) {
				/* find index of next instance of pattern */
				offset = mymemfind(str, len, pat, pat_len);
				if (offset == -1)
					break;

				/* copy non matching part of input string */
				memcpy(new_s, str, offset);
				str += offset + pat_len;
				len -= offset + pat_len;

				/* copy substitute into the output string */
				new_s += offset;
				memcpy(new_s, sub, sub_len);
				new_s += sub_len;
			}
			/* copy any remaining values into output string */
			if (len > 0)
				memcpy(new_s, str, len);
		}
		else {
			for (;;++str, --len) {
				memcpy(new_s, sub, sub_len);
				new_s += sub_len;
				if (--nfound <= 0) {
					memcpy(new_s, str, len);
					break;
				}
				*new_s++ = *str;
			}
		}
	}
	*out_len = new_len;
	return out_s;

  return_same:
	*out_len = -1;
	return (char *)str; /* cast away const */
}


PyDoc_STRVAR(replace__doc__,
"S.replace (old, new[, maxsplit]) -> string\n\
\n\
Return a copy of string 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 *
string_replace(PyStringObject *self, PyObject *args)
{
	const char *str = PyString_AS_STRING(self), *sub, *repl;
	char *new_s;
	const int len = PyString_GET_SIZE(self);
	int sub_len, repl_len, out_len;
	int count = -1;
	PyObject *new;
	PyObject *subobj, *replobj;

	if (!PyArg_ParseTuple(args, "OO|i:replace",
			      &subobj, &replobj, &count))
		return NULL;

	if (PyString_Check(subobj)) {
		sub = PyString_AS_STRING(subobj);
		sub_len = PyString_GET_SIZE(subobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(subobj))
		return PyUnicode_Replace((PyObject *)self,
					 subobj, replobj, count);
#endif
	else if (PyObject_AsCharBuffer(subobj, &sub, &sub_len))
		return NULL;

	if (PyString_Check(replobj)) {
		repl = PyString_AS_STRING(replobj);
		repl_len = PyString_GET_SIZE(replobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(replobj))
		return PyUnicode_Replace((PyObject *)self,
					 subobj, replobj, count);
#endif
	else if (PyObject_AsCharBuffer(replobj, &repl, &repl_len))
		return NULL;

	new_s = mymemreplace(str,len,sub,sub_len,repl,repl_len,count,&out_len);
	if (new_s == NULL) {
		PyErr_NoMemory();
		return NULL;
	}
	if (out_len == -1) {
		if (PyString_CheckExact(self)) {
			/* we're returning another reference to self */
			new = (PyObject*)self;
			Py_INCREF(new);
		}
		else {
			new = PyString_FromStringAndSize(str, len);
			if (new == NULL)
				return NULL;
		}
	}
	else {
		new = PyString_FromStringAndSize(new_s, out_len);
		PyMem_FREE(new_s);
	}
	return new;
}


PyDoc_STRVAR(startswith__doc__,
"S.startswith(prefix[, start[, end]]) -> bool\n\
\n\
Return True if S starts with the specified prefix, False otherwise.  With\n\
optional start, test S beginning at that position.  With optional end, stop\n\
comparing S at that position.");

static PyObject *
string_startswith(PyStringObject *self, PyObject *args)
{
	const char* str = PyString_AS_STRING(self);
	int len = PyString_GET_SIZE(self);
	const char* prefix;
	int plen;
	int start = 0;
	int end = INT_MAX;
	PyObject *subobj;

	if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &subobj,
		_PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
		return NULL;
	if (PyString_Check(subobj)) {
		prefix = PyString_AS_STRING(subobj);
		plen = PyString_GET_SIZE(subobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(subobj)) {
	    	int rc;
		rc = PyUnicode_Tailmatch((PyObject *)self,
					  subobj, start, end, -1);
		if (rc == -1)
			return NULL;
		else
			return PyBool_FromLong((long) rc);
	}
#endif
	else if (PyObject_AsCharBuffer(subobj, &prefix, &plen))
		return NULL;

	string_adjust_indices(&start, &end, len);

	if (start+plen > len)
		return PyBool_FromLong(0);

	if (end-start >= plen)
		return PyBool_FromLong(!memcmp(str+start, prefix, plen));
	else
		return PyBool_FromLong(0);
}


PyDoc_STRVAR(endswith__doc__,
"S.endswith(suffix[, start[, end]]) -> bool\n\
\n\
Return True if S ends with the specified suffix, False otherwise.  With\n\
optional start, test S beginning at that position.  With optional end, stop\n\
comparing S at that position.");

static PyObject *
string_endswith(PyStringObject *self, PyObject *args)
{
	const char* str = PyString_AS_STRING(self);
	int len = PyString_GET_SIZE(self);
	const char* suffix;
	int slen;
	int start = 0;
	int end = INT_MAX;
	PyObject *subobj;

	if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &subobj,
		_PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
		return NULL;
	if (PyString_Check(subobj)) {
		suffix = PyString_AS_STRING(subobj);
		slen = PyString_GET_SIZE(subobj);
	}
#ifdef Py_USING_UNICODE
	else if (PyUnicode_Check(subobj)) {
	    	int rc;
		rc = PyUnicode_Tailmatch((PyObject *)self,
					  subobj, start, end, +1);
		if (rc == -1)
			return NULL;
		else
			return PyBool_FromLong((long) rc);
	}
#endif
	else if (PyObject_AsCharBuffer(subobj, &suffix, &slen))
		return NULL;

	string_adjust_indices(&start, &end, len);

	if (end-start < slen || start > len)
		return PyBool_FromLong(0);

	if (end-slen > start)
		start = end - slen;
	if (end-start >= slen)
		return PyBool_FromLong(!memcmp(str+start, suffix, slen));
	else
		return PyBool_FromLong(0);
}


PyDoc_STRVAR(encode__doc__,
"S.encode([encoding[,errors]]) -> object\n\
\n\
Encodes S using the codec registered for encoding. encoding defaults\n\
to the default encoding. errors may be given to set a different error\n\
handling scheme. Default is 'strict' meaning that encoding errors raise\n\
a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and\n\
'xmlcharrefreplace' as well as any other name registered with\n\
codecs.register_error that is able to handle UnicodeEncodeErrors.");

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


PyDoc_STRVAR(decode__doc__,
"S.decode([encoding[,errors]]) -> object\n\
\n\
Decodes S using the codec registered for encoding. encoding defaults\n\
to the default encoding. errors may be given to set a different error\n\
handling scheme. Default is 'strict' meaning that encoding errors raise\n\
a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'\n\
as well as any other name registerd with codecs.register_error that is\n\
able to handle UnicodeDecodeErrors.");

static PyObject *
string_decode(PyStringObject *self, PyObject *args)
{
    char *encoding = NULL;
    char *errors = NULL;
    if (!PyArg_ParseTuple(args, "|ss:decode", &encoding, &errors))
        return NULL;
    return PyString_AsDecodedObject((PyObject *)self, encoding, errors);
}


PyDoc_STRVAR(expandtabs__doc__,
"S.expandtabs([tabsize]) -> string\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*
string_expandtabs(PyStringObject *self, PyObject *args)
{
    const char *e, *p;
    char *q;
    int i, j;
    PyObject *u;
    int tabsize = 8;

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

    /* First pass: determine size of output string */
    i = j = 0;
    e = PyString_AS_STRING(self) + PyString_GET_SIZE(self);
    for (p = PyString_AS_STRING(self); 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 = PyString_FromStringAndSize(NULL, i + j);
    if (!u)
        return NULL;

    j = 0;
    q = PyString_AS_STRING(u);

    for (p = PyString_AS_STRING(self); 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 u;
}

static PyObject *
pad(PyStringObject *self, int left, int right, char fill)
{
    PyObject *u;

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

    if (left == 0 && right == 0 && PyString_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject *)self;
    }

    u = PyString_FromStringAndSize(NULL,
				   left + PyString_GET_SIZE(self) + right);
    if (u) {
        if (left)
            memset(PyString_AS_STRING(u), fill, left);
        memcpy(PyString_AS_STRING(u) + left,
	       PyString_AS_STRING(self),
	       PyString_GET_SIZE(self));
        if (right)
            memset(PyString_AS_STRING(u) + left + PyString_GET_SIZE(self),
		   fill, right);
    }

    return u;
}

PyDoc_STRVAR(ljust__doc__,
"S.ljust(width) -> string\n"
"\n"
"Return S left justified in a string of length width. Padding is\n"
"done using spaces.");

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

    if (PyString_GET_SIZE(self) >= width && PyString_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    return pad(self, 0, width - PyString_GET_SIZE(self), ' ');
}


PyDoc_STRVAR(rjust__doc__,
"S.rjust(width) -> string\n"
"\n"
"Return S right justified in a string of length width. Padding is\n"
"done using spaces.");

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

    if (PyString_GET_SIZE(self) >= width && PyString_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

    return pad(self, width - PyString_GET_SIZE(self), 0, ' ');
}


PyDoc_STRVAR(center__doc__,
"S.center(width) -> string\n"
"\n"
"Return S centered in a string of length width. Padding is done\n"
"using spaces.");

static PyObject *
string_center(PyStringObject *self, PyObject *args)
{
    int marg, left;
    int width;

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

    if (PyString_GET_SIZE(self) >= width && PyString_CheckExact(self)) {
        Py_INCREF(self);
        return (PyObject*) self;
    }

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

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

PyDoc_STRVAR(zfill__doc__,
"S.zfill(width) -> string\n"
"\n"
"Pad a numeric string S with zeros on the left, to fill a field\n"
"of the specified width.  The string S is never truncated.");

static PyObject *
string_zfill(PyStringObject *self, PyObject *args)
{
    int fill;
    PyObject *s;
    char *p;

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

    if (PyString_GET_SIZE(self) >= width) {
        if (PyString_CheckExact(self)) {
            Py_INCREF(self);
            return (PyObject*) self;
        }
        else
            return PyString_FromStringAndSize(
                PyString_AS_STRING(self),
                PyString_GET_SIZE(self)
            );
    }

    fill = width - PyString_GET_SIZE(self);

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

    if (s == NULL)
        return NULL;

    p = PyString_AS_STRING(s);
    if (p[fill] == '+' || p[fill] == '-') {
        /* move sign to beginning of string */
        p[0] = p[fill];
        p[fill] = '0';
    }

    return (PyObject*) s;
}

PyDoc_STRVAR(isspace__doc__,
"S.isspace() -> bool\n"
"\n"
"Return True if there are only whitespace characters in S,\n"
"False otherwise.");

static PyObject*
string_isspace(PyStringObject *self)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1 &&
	isspace(*p))
	return PyBool_FromLong(1);

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

    e = p + PyString_GET_SIZE(self);
    for (; p < e; p++) {
	if (!isspace(*p))
	    return PyBool_FromLong(0);
    }
    return PyBool_FromLong(1);
}


PyDoc_STRVAR(isalpha__doc__,
"S.isalpha() -> bool\n\
\n\
Return True if  all characters in S are alphabetic\n\
and there is at least one character in S, False otherwise.");

static PyObject*
string_isalpha(PyStringObject *self)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1 &&
	isalpha(*p))
	return PyBool_FromLong(1);

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

    e = p + PyString_GET_SIZE(self);
    for (; p < e; p++) {
	if (!isalpha(*p))
	    return PyBool_FromLong(0);
    }
    return PyBool_FromLong(1);
}


PyDoc_STRVAR(isalnum__doc__,
"S.isalnum() -> bool\n\
\n\
Return True if  all characters in S are alphanumeric\n\
and there is at least one character in S, False otherwise.");

static PyObject*
string_isalnum(PyStringObject *self)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1 &&
	isalnum(*p))
	return PyBool_FromLong(1);

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

    e = p + PyString_GET_SIZE(self);
    for (; p < e; p++) {
	if (!isalnum(*p))
	    return PyBool_FromLong(0);
    }
    return PyBool_FromLong(1);
}


PyDoc_STRVAR(isdigit__doc__,
"S.isdigit() -> bool\n\
\n\
Return True if there are only digit characters in S,\n\
False otherwise.");

static PyObject*
string_isdigit(PyStringObject *self)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1 &&
	isdigit(*p))
	return PyBool_FromLong(1);

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

    e = p + PyString_GET_SIZE(self);
    for (; p < e; p++) {
	if (!isdigit(*p))
	    return PyBool_FromLong(0);
    }
    return PyBool_FromLong(1);
}


PyDoc_STRVAR(islower__doc__,
"S.islower() -> bool\n\
\n\
Return True if all cased characters in S are lowercase and there is\n\
at least one cased character in S, False otherwise.");

static PyObject*
string_islower(PyStringObject *self)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;
    int cased;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1)
	return PyBool_FromLong(islower(*p) != 0);

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

    e = p + PyString_GET_SIZE(self);
    cased = 0;
    for (; p < e; p++) {
	if (isupper(*p))
	    return PyBool_FromLong(0);
	else if (!cased && islower(*p))
	    cased = 1;
    }
    return PyBool_FromLong(cased);
}


PyDoc_STRVAR(isupper__doc__,
"S.isupper() -> bool\n\
\n\
Return True if  all cased characters in S are uppercase and there is\n\
at least one cased character in S, False otherwise.");

static PyObject*
string_isupper(PyStringObject *self)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;
    int cased;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1)
	return PyBool_FromLong(isupper(*p) != 0);

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

    e = p + PyString_GET_SIZE(self);
    cased = 0;
    for (; p < e; p++) {
	if (islower(*p))
	    return PyBool_FromLong(0);
	else if (!cased && isupper(*p))
	    cased = 1;
    }
    return PyBool_FromLong(cased);
}


PyDoc_STRVAR(istitle__doc__,
"S.istitle() -> bool\n\
\n\
Return True if S is a titlecased string, i.e. uppercase characters\n\
may only follow uncased characters and lowercase characters only cased\n\
ones. Return False otherwise.");

static PyObject*
string_istitle(PyStringObject *self, PyObject *uncased)
{
    register const unsigned char *p
        = (unsigned char *) PyString_AS_STRING(self);
    register const unsigned char *e;
    int cased, previous_is_cased;

    /* Shortcut for single character strings */
    if (PyString_GET_SIZE(self) == 1)
	return PyBool_FromLong(isupper(*p) != 0);

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

    e = p + PyString_GET_SIZE(self);
    cased = 0;
    previous_is_cased = 0;
    for (; p < e; p++) {
	register const unsigned char ch = *p;

	if (isupper(ch)) {
	    if (previous_is_cased)
		return PyBool_FromLong(0);
	    previous_is_cased = 1;
	    cased = 1;
	}
	else if (islower(ch)) {
	    if (!previous_is_cased)
		return PyBool_FromLong(0);
	    previous_is_cased = 1;
	    cased = 1;
	}
	else
	    previous_is_cased = 0;
    }
    return PyBool_FromLong(cased);
}


PyDoc_STRVAR(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.");

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

static PyObject*
string_splitlines(PyStringObject *self, PyObject *args)
{
    register int i;
    register int j;
    int len;
    int keepends = 0;
    PyObject *list;
    PyObject *str;
    char *data;

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

    data = PyString_AS_STRING(self);
    len = PyString_GET_SIZE(self);

    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 && data[i] != '\n' && data[i] != '\r')
	    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);
    }

    return list;

 onError:
    Py_DECREF(list);
    return NULL;
}

#undef SPLIT_APPEND


static PyMethodDef
string_methods[] = {
	/* Counterparts of the obsolete stropmodule functions; except
	   string.maketrans(). */
	{"join", (PyCFunction)string_join, METH_O, join__doc__},
	{"split", (PyCFunction)string_split, METH_VARARGS, split__doc__},
	{"lower", (PyCFunction)string_lower, METH_NOARGS, lower__doc__},
	{"upper", (PyCFunction)string_upper, METH_NOARGS, upper__doc__},
	{"islower", (PyCFunction)string_islower, METH_NOARGS, islower__doc__},
	{"isupper", (PyCFunction)string_isupper, METH_NOARGS, isupper__doc__},
	{"isspace", (PyCFunction)string_isspace, METH_NOARGS, isspace__doc__},
	{"isdigit", (PyCFunction)string_isdigit, METH_NOARGS, isdigit__doc__},
	{"istitle", (PyCFunction)string_istitle, METH_NOARGS, istitle__doc__},
	{"isalpha", (PyCFunction)string_isalpha, METH_NOARGS, isalpha__doc__},
	{"isalnum", (PyCFunction)string_isalnum, METH_NOARGS, isalnum__doc__},
	{"capitalize", (PyCFunction)string_capitalize, METH_NOARGS,
	 capitalize__doc__},
	{"count", (PyCFunction)string_count, METH_VARARGS, count__doc__},
	{"endswith", (PyCFunction)string_endswith, METH_VARARGS,
	 endswith__doc__},
	{"find", (PyCFunction)string_find, METH_VARARGS, find__doc__},
	{"index", (PyCFunction)string_index, METH_VARARGS, index__doc__},
	{"lstrip", (PyCFunction)string_lstrip, METH_VARARGS, lstrip__doc__},
	{"replace", (PyCFunction)string_replace, METH_VARARGS, replace__doc__},
	{"rfind", (PyCFunction)string_rfind, METH_VARARGS, rfind__doc__},
	{"rindex", (PyCFunction)string_rindex, METH_VARARGS, rindex__doc__},
	{"rstrip", (PyCFunction)string_rstrip, METH_VARARGS, rstrip__doc__},
	{"startswith", (PyCFunction)string_startswith, METH_VARARGS,
	 startswith__doc__},
	{"strip", (PyCFunction)string_strip, METH_VARARGS, strip__doc__},
	{"swapcase", (PyCFunction)string_swapcase, METH_NOARGS,
	 swapcase__doc__},
	{"translate", (PyCFunction)string_translate, METH_VARARGS,
	 translate__doc__},
	{"title", (PyCFunction)string_title, METH_NOARGS, title__doc__},
	{"ljust", (PyCFunction)string_ljust, METH_VARARGS, ljust__doc__},
	{"rjust", (PyCFunction)string_rjust, METH_VARARGS, rjust__doc__},
	{"center", (PyCFunction)string_center, METH_VARARGS, center__doc__},
	{"zfill", (PyCFunction)string_zfill, METH_VARARGS, zfill__doc__},
	{"encode", (PyCFunction)string_encode, METH_VARARGS, encode__doc__},
	{"decode", (PyCFunction)string_decode, METH_VARARGS, decode__doc__},
	{"expandtabs", (PyCFunction)string_expandtabs, METH_VARARGS,
	 expandtabs__doc__},
	{"splitlines", (PyCFunction)string_splitlines, METH_VARARGS,
	 splitlines__doc__},
	{NULL,     NULL}		     /* sentinel */
};

static PyObject *
str_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);

static PyObject *
string_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	PyObject *x = NULL;
	static char *kwlist[] = {"object", 0};

	if (type != &PyString_Type)
		return str_subtype_new(type, args, kwds);
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:str", kwlist, &x))
		return NULL;
	if (x == NULL)
		return PyString_FromString("");
	return PyObject_Str(x);
}

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

	assert(PyType_IsSubtype(type, &PyString_Type));
	tmp = string_new(&PyString_Type, args, kwds);
	if (tmp == NULL)
		return NULL;
	assert(PyString_CheckExact(tmp));
	n = PyString_GET_SIZE(tmp);
	pnew = type->tp_alloc(type, n);
	if (pnew != NULL) {
		memcpy(PyString_AS_STRING(pnew), PyString_AS_STRING(tmp), n+1);
		((PyStringObject *)pnew)->ob_shash =
			((PyStringObject *)tmp)->ob_shash;
		((PyStringObject *)pnew)->ob_sstate = SSTATE_NOT_INTERNED;
	}
	Py_DECREF(tmp);
	return pnew;
}

static PyObject *
basestring_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	PyErr_SetString(PyExc_TypeError,
			"The basestring type cannot be instantiated");
	return NULL;
}

PyDoc_STRVAR(basestring_doc,
"Type basestring cannot be instantiated; it is the base for str and unicode.");

PyTypeObject PyBaseString_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
	0,
	"basestring",
	0,
	0,
 	0,			 		/* tp_dealloc */
	0,			 		/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	0,		 			/* tp_repr */
	0,					/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	0,		 			/* tp_hash */
	0,					/* tp_call */
	0,					/* tp_str */
	0,					/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
	basestring_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	0,					/* tp_methods */
	0,					/* tp_members */
	0,					/* tp_getset */
	&PyBaseObject_Type,			/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	basestring_new,				/* tp_new */
	0,		                	/* tp_free */
};

PyDoc_STRVAR(string_doc,
"str(object) -> string\n\
\n\
Return a nice string representation of the object.\n\
If the argument is a string, the return value is the same object.");

PyTypeObject PyString_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
	0,
	"str",
	sizeof(PyStringObject),
	sizeof(char),
 	(destructor)string_dealloc, 		/* tp_dealloc */
	(printfunc)string_print, 		/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	(reprfunc)string_repr, 			/* tp_repr */
	0,					/* tp_as_number */
	&string_as_sequence,			/* tp_as_sequence */
	&string_as_mapping,			/* tp_as_mapping */
	(hashfunc)string_hash, 			/* tp_hash */
	0,					/* tp_call */
	(reprfunc)string_str,			/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	&string_as_buffer,			/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
	string_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	(richcmpfunc)string_richcompare,	/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	string_methods,				/* tp_methods */
	0,					/* tp_members */
	0,					/* tp_getset */
	&PyBaseString_Type,			/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	string_new,				/* tp_new */
	PyObject_Del,	                	/* tp_free */
};

void
PyString_Concat(register PyObject **pv, register PyObject *w)
{
	register PyObject *v;
	if (*pv == NULL)
		return;
	if (w == NULL || !PyString_Check(*pv)) {
		Py_DECREF(*pv);
		*pv = NULL;
		return;
	}
	v = string_concat((PyStringObject *) *pv, w);
	Py_DECREF(*pv);
	*pv = v;
}

void
PyString_ConcatAndDel(register PyObject **pv, register PyObject *w)
{
	PyString_Concat(pv, w);
	Py_XDECREF(w);
}


/* The following function breaks the notion that strings are immutable:
   it changes the size of a string.  We get away with this only if there
   is only one module referencing the object.  You can also think of it
   as creating a new string object and destroying the old one, only
   more efficiently.  In any case, don't use this if the string may
   already be known to some other part of the code...
   Note that if there's not enough memory to resize the string, the original
   string object at *pv is deallocated, *pv is set to NULL, an "out of
   memory" exception is set, and -1 is returned.  Else (on success) 0 is
   returned, and the value in *pv may or may not be the same as on input.
   As always, an extra byte is allocated for a trailing \0 byte (newsize
   does *not* include that), and a trailing \0 byte is stored.
*/

int
_PyString_Resize(PyObject **pv, int newsize)
{
	register PyObject *v;
	register PyStringObject *sv;
	v = *pv;
	if (!PyString_Check(v) || v->ob_refcnt != 1) {
		*pv = 0;
		Py_DECREF(v);
		PyErr_BadInternalCall();
		return -1;
	}
	/* XXX UNREF/NEWREF interface should be more symmetrical */
	_Py_DEC_REFTOTAL;
	_Py_ForgetReference(v);
	*pv = (PyObject *)
		PyObject_REALLOC((char *)v,
			sizeof(PyStringObject) + newsize * sizeof(char));
	if (*pv == NULL) {
		PyObject_Del(v);
		PyErr_NoMemory();
		return -1;
	}
	_Py_NewReference(*pv);
	sv = (PyStringObject *) *pv;
	sv->ob_size = newsize;
	sv->ob_sval[newsize] = '\0';
	return 0;
}

/* Helpers for formatstring */

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;
}

/* Format codes
 * F_LJUST	'-'
 * F_SIGN	'+'
 * F_BLANK	' '
 * F_ALT	'#'
 * F_ZERO	'0'
 */
#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
formatfloat(char *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()) {
		PyErr_SetString(PyExc_TypeError, "float argument required");
		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 large?)");
		return -1;
	}
	PyOS_snprintf(buf, buflen, fmt, x);
	return strlen(buf);
}

/* _PyString_FormatLong emulates the format codes d, u, o, x and X, and
 * the F_ALT flag, for Python's long (unbounded) ints.  It's not used for
 * Python's regular ints.
 * Return value:  a new PyString*, or NULL if error.
 *  .  *pbuf is set to point into it,
 *     *plen set to the # of chars following that.
 *     Caller must decref it when done using pbuf.
 *     The string starting at *pbuf is of the form
 *         "-"? ("0x" | "0X")? digit+
 *     "0x"/"0X" are present only for x and X conversions, with F_ALT
 *         set in flags.  The case of hex digits will be correct,
 *     There will be at least prec digits, zero-filled on the left if
 *         necessary to get that many.
 * val		object to be converted
 * flags	bitmask of format flags; only F_ALT is looked at
 * prec		minimum number of digits; 0-fill on left if needed
 * type		a character in [duoxX]; u acts the same as d
 *
 * CAUTION:  o, x and X conversions on regular ints can never
 * produce a '-' sign, but can for Python's unbounded ints.
 */
PyObject*
_PyString_FormatLong(PyObject *val, int flags, int prec, int type,
		     char **pbuf, int *plen)
{
	PyObject *result = NULL;
	char *buf;
	int i;
	int sign;	/* 1 if '-', else 0 */
	int len;	/* number of characters */
	int numdigits;	/* len == numnondigits + numdigits */
	int numnondigits = 0;

	switch (type) {
	case 'd':
	case 'u':
		result = val->ob_type->tp_str(val);
		break;
	case 'o':
		result = val->ob_type->tp_as_number->nb_oct(val);
		break;
	case 'x':
	case 'X':
		numnondigits = 2;
		result = val->ob_type->tp_as_number->nb_hex(val);
		break;
	default:
		assert(!"'type' not in [duoxX]");
	}
	if (!result)
		return NULL;

	/* To modify the string in-place, there can only be one reference. */
	if (result->ob_refcnt != 1) {
		PyErr_BadInternalCall();
		return NULL;
	}
	buf = PyString_AsString(result);
	len = PyString_Size(result);
	if (buf[len-1] == 'L') {
		--len;
		buf[len] = '\0';
	}
	sign = buf[0] == '-';
	numnondigits += sign;
	numdigits = len - numnondigits;
	assert(numdigits > 0);

	/* Get rid of base marker unless F_ALT */
	if ((flags & F_ALT) == 0) {
		/* Need to skip 0x, 0X or 0. */
		int skipped = 0;
		switch (type) {
		case 'o':
			assert(buf[sign] == '0');
			/* If 0 is only digit, leave it alone. */
			if (numdigits > 1) {
				skipped = 1;
				--numdigits;
			}
			break;
		case 'x':
		case 'X':
			assert(buf[sign] == '0');
			assert(buf[sign + 1] == 'x');
			skipped = 2;
			numnondigits -= 2;
			break;
		}
		if (skipped) {
			buf += skipped;
			len -= skipped;
			if (sign)
				buf[0] = '-';
		}
		assert(len == numnondigits + numdigits);
		assert(numdigits > 0);
	}

	/* Fill with leading zeroes to meet minimum width. */
	if (prec > numdigits) {
		PyObject *r1 = PyString_FromStringAndSize(NULL,
					numnondigits + prec);
		char *b1;
		if (!r1) {
			Py_DECREF(result);
			return NULL;
		}
		b1 = PyString_AS_STRING(r1);
		for (i = 0; i < numnondigits; ++i)
			*b1++ = *buf++;
		for (i = 0; i < prec - numdigits; i++)
			*b1++ = '0';
		for (i = 0; i < numdigits; i++)
			*b1++ = *buf++;
		*b1 = '\0';
		Py_DECREF(result);
		result = r1;
		buf = PyString_AS_STRING(result);
		len = numnondigits + prec;
	}

	/* Fix up case for hex conversions. */
	switch (type) {
	case 'x':
		/* Need to convert all upper case letters to lower case. */
		for (i = 0; i < len; i++)
			if (buf[i] >= 'A' && buf[i] <= 'F')
				buf[i] += 'a'-'A';
		break;
	case 'X':
		/* Need to convert 0x to 0X (and -0x to -0X). */
		if (buf[sign + 1] == 'x')
			buf[sign + 1] = 'X';
		break;
	}
	*pbuf = buf;
	*plen = len;
	return result;
}

static int
formatint(char *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;

	x = PyInt_AsLong(v);
	if (x == -1 && PyErr_Occurred()) {
		PyErr_SetString(PyExc_TypeError, "int argument required");
		return -1;
	}
	if (x < 0 && type != 'd' && type != 'i') {
		if (PyErr_Warn(PyExc_FutureWarning,
			       "%u/%o/%x/%X of negative int will return "
			       "a signed string in Python 2.4 and up") < 0)
			return -1;
	}
	if (prec < 0)
		prec = 1;

	if ((flags & F_ALT) &&
	    (type == 'x' || type == 'X')) {
		/* When converting under %#x or %#X, there are a number
		 * of issues that cause pain:
		 * - when 0 is being converted, the C standard leaves off
		 *   the '0x' or '0X', which is inconsistent with other
		 *   %#x/%#X conversions and inconsistent with Python's
		 *   hex() function
		 * - there are platforms that violate the standard and
		 *   convert 0 with the '0x' or '0X'
		 *   (Metrowerks, Compaq Tru64)
		 * - there are platforms that give '0x' when converting
		 *   under %#X, but convert 0 in accordance with the
		 *   standard (OS/2 EMX)
		 *
		 * We can achieve the desired consistency by inserting our
		 * own '0x' or '0X' prefix, and substituting %x/%X in place
		 * of %#x/%#X.
		 *
		 * Note that this is the same approach as used in
		 * formatint() in unicodeobject.c
		 */
		PyOS_snprintf(fmt, sizeof(fmt), "0%c%%.%dl%c",
			      type, prec, type);
	}
	else {
		PyOS_snprintf(fmt, sizeof(fmt), "%%%s.%dl%c",
			      (flags&F_ALT) ? "#" : "",
			      prec, type);
	}

	/* 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 large?)");
		return -1;
	}
	PyOS_snprintf(buf, buflen, fmt, x);
	return strlen(buf);
}

static int
formatchar(char *buf, size_t buflen, PyObject *v)
{
	/* presume that the buffer is at least 2 characters long */
	if (PyString_Check(v)) {
		if (!PyArg_Parse(v, "c;%c requires int or char", &buf[0]))
			return -1;
	}
	else {
		if (!PyArg_Parse(v, "b;%c requires int or char", &buf[0]))
			return -1;
	}
	buf[1] = '\0';
	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 *
PyString_Format(PyObject *format, PyObject *args)
{
	char *fmt, *res;
	int fmtcnt, rescnt, reslen, arglen, argidx;
	int args_owned = 0;
	PyObject *result, *orig_args;
#ifdef Py_USING_UNICODE
	PyObject *v, *w;
#endif
	PyObject *dict = NULL;
	if (format == NULL || !PyString_Check(format) || args == NULL) {
		PyErr_BadInternalCall();
		return NULL;
	}
	orig_args = args;
	fmt = PyString_AS_STRING(format);
	fmtcnt = PyString_GET_SIZE(format);
	reslen = rescnt = fmtcnt + 100;
	result = PyString_FromStringAndSize((char *)NULL, reslen);
	if (result == NULL)
		return NULL;
	res = PyString_AsString(result);
	if (PyTuple_Check(args)) {
		arglen = PyTuple_GET_SIZE(args);
		argidx = 0;
	}
	else {
		arglen = -1;
		argidx = -2;
	}
	if (args->ob_type->tp_as_mapping && !PyTuple_Check(args))
		dict = args;
	while (--fmtcnt >= 0) {
		if (*fmt != '%') {
			if (--rescnt < 0) {
				rescnt = fmtcnt + 100;
				reslen += rescnt;
				if (_PyString_Resize(&result, reslen) < 0)
					return NULL;
				res = PyString_AS_STRING(result)
					+ reslen - rescnt;
				--rescnt;
			}
			*res++ = *fmt++;
		}
		else {
			/* Got a format specifier */
			int flags = 0;
			int width = -1;
			int prec = -1;
			int c = '\0';
			int fill;
			PyObject *v = NULL;
			PyObject *temp = NULL;
			char *pbuf;
			int sign;
			int len;
			char formatbuf[FORMATBUFLEN];
			     /* For format{float,int,char}() */
#ifdef Py_USING_UNICODE
			char *fmt_start = fmt;
		        int argidx_start = argidx;
#endif

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

				if (dict == NULL) {
					PyErr_SetString(PyExc_TypeError,
						 "format requires a mapping");
					goto error;
				}
				++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 error;
				}
				key = PyString_FromStringAndSize(keystart,
								 keylen);
				if (key == NULL)
					goto error;
				if (args_owned) {
					Py_DECREF(args);
					args_owned = 0;
				}
				args = PyObject_GetItem(dict, key);
				Py_DECREF(key);
				if (args == NULL) {
					goto error;
				}
				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 error;
				if (!PyInt_Check(v)) {
					PyErr_SetString(PyExc_TypeError,
							"* wants int");
					goto error;
				}
				width = PyInt_AsLong(v);
				if (width < 0) {
					flags |= F_LJUST;
					width = -width;
				}
				if (--fmtcnt >= 0)
					c = *fmt++;
			}
			else if (c >= 0 && isdigit(c)) {
				width = c - '0';
				while (--fmtcnt >= 0) {
					c = Py_CHARMASK(*fmt++);
					if (!isdigit(c))
						break;
					if ((width*10) / 10 != width) {
						PyErr_SetString(
							PyExc_ValueError,
							"width too big");
						goto error;
					}
					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 error;
					if (!PyInt_Check(v)) {
						PyErr_SetString(
							PyExc_TypeError,
							"* wants int");
						goto error;
					}
					prec = PyInt_AsLong(v);
					if (prec < 0)
						prec = 0;
					if (--fmtcnt >= 0)
						c = *fmt++;
				}
				else if (c >= 0 && isdigit(c)) {
					prec = c - '0';
					while (--fmtcnt >= 0) {
						c = Py_CHARMASK(*fmt++);
						if (!isdigit(c))
							break;
						if ((prec*10) / 10 != prec) {
							PyErr_SetString(
							    PyExc_ValueError,
							    "prec too big");
							goto error;
						}
						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 error;
			}
			if (c != '%') {
				v = getnextarg(args, arglen, &argidx);
				if (v == NULL)
					goto error;
			}
			sign = 0;
			fill = ' ';
			switch (c) {
			case '%':
				pbuf = "%";
				len = 1;
				break;
			case 's':
  			case 'r':
#ifdef Py_USING_UNICODE
				if (PyUnicode_Check(v)) {
					fmt = fmt_start;
					argidx = argidx_start;
					goto unicode;
				}
#endif
				if (c == 's')
					temp = PyObject_Str(v);
				else
					temp = PyObject_Repr(v);
				if (temp == NULL)
					goto error;
				if (!PyString_Check(temp)) {
					PyErr_SetString(PyExc_TypeError,
					  "%s argument has non-string str()");
					Py_DECREF(temp);
					goto error;
				}
				pbuf = PyString_AS_STRING(temp);
				len = PyString_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 = _PyString_FormatLong(v, flags,
						prec, c, &pbuf, &len);
					if (!temp)
						goto error;
					/* unbounded ints can always produce
					   a sign character! */
					sign = 1;
				}
				else {
					pbuf = formatbuf;
					len = formatint(pbuf,
							sizeof(formatbuf),
							flags, prec, c, v);
					if (len < 0)
						goto error;
					/* 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),
						  flags, prec, c, v);
				if (len < 0)
					goto error;
				sign = 1;
				if (flags & F_ZERO)
					fill = '0';
				break;
			case 'c':
				pbuf = formatbuf;
				len = formatchar(pbuf, sizeof(formatbuf), v);
				if (len < 0)
					goto error;
				break;
			default:
				PyErr_Format(PyExc_ValueError,
				  "unsupported format character '%c' (0x%x) "
				  "at index %i",
				  c, c,
				  (int)(fmt - 1 - PyString_AsString(format)));
				goto error;
			}
			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 (_PyString_Resize(&result, reslen) < 0)
					return NULL;
				res = PyString_AS_STRING(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++;
				}
			}
			memcpy(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 during string formatting");
                                goto error;
                        }
			Py_XDECREF(temp);
		} /* '%' */
	} /* until end */
	if (argidx < arglen && !dict) {
		PyErr_SetString(PyExc_TypeError,
				"not all arguments converted during string formatting");
		goto error;
	}
	if (args_owned) {
		Py_DECREF(args);
	}
	_PyString_Resize(&result, reslen - rescnt);
	return result;

#ifdef Py_USING_UNICODE
 unicode:
	if (args_owned) {
		Py_DECREF(args);
		args_owned = 0;
	}
	/* Fiddle args right (remove the first argidx arguments) */
	if (PyTuple_Check(orig_args) && argidx > 0) {
		PyObject *v;
		int n = PyTuple_GET_SIZE(orig_args) - argidx;
		v = PyTuple_New(n);
		if (v == NULL)
			goto error;
		while (--n >= 0) {
			PyObject *w = PyTuple_GET_ITEM(orig_args, n + argidx);
			Py_INCREF(w);
			PyTuple_SET_ITEM(v, n, w);
		}
		args = v;
	} else {
		Py_INCREF(orig_args);
		args = orig_args;
	}
	args_owned = 1;
	/* Take what we have of the result and let the Unicode formatting
	   function format the rest of the input. */
	rescnt = res - PyString_AS_STRING(result);
	if (_PyString_Resize(&result, rescnt))
		goto error;
	fmtcnt = PyString_GET_SIZE(format) - \
		 (fmt - PyString_AS_STRING(format));
	format = PyUnicode_Decode(fmt, fmtcnt, NULL, NULL);
	if (format == NULL)
		goto error;
	v = PyUnicode_Format(format, args);
	Py_DECREF(format);
	if (v == NULL)
		goto error;
	/* Paste what we have (result) to what the Unicode formatting
	   function returned (v) and return the result (or error) */
	w = PyUnicode_Concat(result, v);
	Py_DECREF(result);
	Py_DECREF(v);
	Py_DECREF(args);
	return w;
#endif /* Py_USING_UNICODE */

 error:
	Py_DECREF(result);
	if (args_owned) {
		Py_DECREF(args);
	}
	return NULL;
}

void
PyString_InternInPlace(PyObject **p)
{
	register PyStringObject *s = (PyStringObject *)(*p);
	PyObject *t;
	if (s == NULL || !PyString_Check(s))
		Py_FatalError("PyString_InternInPlace: strings only please!");
	if (PyString_CHECK_INTERNED(s))
		return;
	if (interned == NULL) {
		interned = PyDict_New();
		if (interned == NULL) {
			PyErr_Clear(); /* Don't leave an exception */
			return;
		}
	}
	if ((t = PyDict_GetItem(interned, (PyObject *)s)) != NULL) {
		Py_INCREF(t);
		Py_DECREF(*p);
		*p = t;
		return;
	}
	/* Ensure that only true string objects appear in the intern dict */
	if (!PyString_CheckExact(s)) {
		t = PyString_FromStringAndSize(PyString_AS_STRING(s),
						PyString_GET_SIZE(s));
		if (t == NULL) {
			PyErr_Clear();
			return;
		}
	} else {
		t = (PyObject*) s;
		Py_INCREF(t);
	}

	if (PyDict_SetItem(interned, t, t) == 0) {
		/* The two references in interned are not counted by
		refcnt.  The string deallocator will take care of this */
		((PyObject *)t)->ob_refcnt-=2;
		PyString_CHECK_INTERNED(t) = SSTATE_INTERNED_MORTAL;
		Py_DECREF(*p);
		*p = t;
		return;
	}
	Py_DECREF(t);
	PyErr_Clear();
}

void
PyString_InternImmortal(PyObject **p)
{
	PyString_InternInPlace(p);
	if (PyString_CHECK_INTERNED(*p) != SSTATE_INTERNED_IMMORTAL) {
		PyString_CHECK_INTERNED(*p) = SSTATE_INTERNED_IMMORTAL;
		Py_INCREF(*p);
	}
}


PyObject *
PyString_InternFromString(const char *cp)
{
	PyObject *s = PyString_FromString(cp);
	if (s == NULL)
		return NULL;
	PyString_InternInPlace(&s);
	return s;
}

void
PyString_Fini(void)
{
	int i;
	for (i = 0; i < UCHAR_MAX + 1; i++) {
		Py_XDECREF(characters[i]);
		characters[i] = NULL;
	}
	Py_XDECREF(nullstring);
	nullstring = NULL;
}

void _Py_ReleaseInternedStrings(void)
{
	PyObject *keys;
	PyStringObject *s;
	int i, n;

	if (interned == NULL || !PyDict_Check(interned))
		return;
	keys = PyDict_Keys(interned);
	if (keys == NULL || !PyList_Check(keys)) {
		PyErr_Clear();
		return;
	}

	/* Since _Py_ReleaseInternedStrings() is intended to help a leak
	   detector, interned strings are not forcibly deallocated; rather, we
	   give them their stolen references back, and then clear and DECREF
	   the interned dict. */
	   
	fprintf(stderr, "releasing interned strings\n");
	n = PyList_GET_SIZE(keys);
	for (i = 0; i < n; i++) {
		s = (PyStringObject *) PyList_GET_ITEM(keys, i);
		switch (s->ob_sstate) {
		case SSTATE_NOT_INTERNED:
			/* XXX Shouldn't happen */
			break;
		case SSTATE_INTERNED_IMMORTAL:
			s->ob_refcnt += 1;
			break;
		case SSTATE_INTERNED_MORTAL:
			s->ob_refcnt += 2;
			break;
		default:
			Py_FatalError("Inconsistent interned string state.");
		}
		s->ob_sstate = SSTATE_NOT_INTERNED;
	}
	Py_DECREF(keys);
	PyDict_Clear(interned);
	Py_DECREF(interned);
	interned = NULL;
}