symbian-qemu-0.9.1-12/python-2.6.1/Objects/stringlib/string_format.h
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Objects/stringlib/string_format.h	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,1274 @@
+/*
+    string_format.h -- implementation of string.format().
+
+    It uses the Objects/stringlib conventions, so that it can be
+    compiled for both unicode and string objects.
+*/
+
+
+/* Defines for Python 2.6 compatability */
+#if PY_VERSION_HEX < 0x03000000
+#define PyLong_FromSsize_t _PyLong_FromSsize_t
+#endif
+
+/* Defines for more efficiently reallocating the string buffer */
+#define INITIAL_SIZE_INCREMENT 100
+#define SIZE_MULTIPLIER 2
+#define MAX_SIZE_INCREMENT  3200
+
+
+/************************************************************************/
+/***********   Global data structures and forward declarations  *********/
+/************************************************************************/
+
+/*
+   A SubString consists of the characters between two string or
+   unicode pointers.
+*/
+typedef struct {
+    STRINGLIB_CHAR *ptr;
+    STRINGLIB_CHAR *end;
+} SubString;
+
+
+/* forward declaration for recursion */
+static PyObject *
+build_string(SubString *input, PyObject *args, PyObject *kwargs,
+             int recursion_depth);
+
+
+
+/************************************************************************/
+/**************************  Utility  functions  ************************/
+/************************************************************************/
+
+/* fill in a SubString from a pointer and length */
+Py_LOCAL_INLINE(void)
+SubString_init(SubString *str, STRINGLIB_CHAR *p, Py_ssize_t len)
+{
+    str->ptr = p;
+    if (p == NULL)
+        str->end = NULL;
+    else
+        str->end = str->ptr + len;
+}
+
+/* return a new string.  if str->ptr is NULL, return None */
+Py_LOCAL_INLINE(PyObject *)
+SubString_new_object(SubString *str)
+{
+    if (str->ptr == NULL) {
+        Py_INCREF(Py_None);
+        return Py_None;
+    }
+    return STRINGLIB_NEW(str->ptr, str->end - str->ptr);
+}
+
+/* return a new string.  if str->ptr is NULL, return None */
+Py_LOCAL_INLINE(PyObject *)
+SubString_new_object_or_empty(SubString *str)
+{
+    if (str->ptr == NULL) {
+        return STRINGLIB_NEW(NULL, 0);
+    }
+    return STRINGLIB_NEW(str->ptr, str->end - str->ptr);
+}
+
+/************************************************************************/
+/***********    Output string management functions       ****************/
+/************************************************************************/
+
+typedef struct {
+    STRINGLIB_CHAR *ptr;
+    STRINGLIB_CHAR *end;
+    PyObject *obj;
+    Py_ssize_t size_increment;
+} OutputString;
+
+/* initialize an OutputString object, reserving size characters */
+static int
+output_initialize(OutputString *output, Py_ssize_t size)
+{
+    output->obj = STRINGLIB_NEW(NULL, size);
+    if (output->obj == NULL)
+        return 0;
+
+    output->ptr = STRINGLIB_STR(output->obj);
+    output->end = STRINGLIB_LEN(output->obj) + output->ptr;
+    output->size_increment = INITIAL_SIZE_INCREMENT;
+
+    return 1;
+}
+
+/*
+    output_extend reallocates the output string buffer.
+    It returns a status:  0 for a failed reallocation,
+    1 for success.
+*/
+
+static int
+output_extend(OutputString *output, Py_ssize_t count)
+{
+    STRINGLIB_CHAR *startptr = STRINGLIB_STR(output->obj);
+    Py_ssize_t curlen = output->ptr - startptr;
+    Py_ssize_t maxlen = curlen + count + output->size_increment;
+
+    if (STRINGLIB_RESIZE(&output->obj, maxlen) < 0)
+        return 0;
+    startptr = STRINGLIB_STR(output->obj);
+    output->ptr = startptr + curlen;
+    output->end = startptr + maxlen;
+    if (output->size_increment < MAX_SIZE_INCREMENT)
+        output->size_increment *= SIZE_MULTIPLIER;
+    return 1;
+}
+
+/*
+    output_data dumps characters into our output string
+    buffer.
+
+    In some cases, it has to reallocate the string.
+
+    It returns a status:  0 for a failed reallocation,
+    1 for success.
+*/
+static int
+output_data(OutputString *output, const STRINGLIB_CHAR *s, Py_ssize_t count)
+{
+    if ((count > output->end - output->ptr) && !output_extend(output, count))
+        return 0;
+    memcpy(output->ptr, s, count * sizeof(STRINGLIB_CHAR));
+    output->ptr += count;
+    return 1;
+}
+
+/************************************************************************/
+/***********  Format string parsing -- integers and identifiers *********/
+/************************************************************************/
+
+static Py_ssize_t
+get_integer(const SubString *str)
+{
+    Py_ssize_t accumulator = 0;
+    Py_ssize_t digitval;
+    Py_ssize_t oldaccumulator;
+    STRINGLIB_CHAR *p;
+
+    /* empty string is an error */
+    if (str->ptr >= str->end)
+        return -1;
+
+    for (p = str->ptr; p < str->end; p++) {
+        digitval = STRINGLIB_TODECIMAL(*p);
+        if (digitval < 0)
+            return -1;
+        /*
+           This trick was copied from old Unicode format code.  It's cute,
+           but would really suck on an old machine with a slow divide
+           implementation.  Fortunately, in the normal case we do not
+           expect too many digits.
+        */
+        oldaccumulator = accumulator;
+        accumulator *= 10;
+        if ((accumulator+10)/10 != oldaccumulator+1) {
+            PyErr_Format(PyExc_ValueError,
+                         "Too many decimal digits in format string");
+            return -1;
+        }
+        accumulator += digitval;
+    }
+    return accumulator;
+}
+
+/************************************************************************/
+/******** Functions to get field objects and specification strings ******/
+/************************************************************************/
+
+/* do the equivalent of obj.name */
+static PyObject *
+getattr(PyObject *obj, SubString *name)
+{
+    PyObject *newobj;
+    PyObject *str = SubString_new_object(name);
+    if (str == NULL)
+        return NULL;
+    newobj = PyObject_GetAttr(obj, str);
+    Py_DECREF(str);
+    return newobj;
+}
+
+/* do the equivalent of obj[idx], where obj is a sequence */
+static PyObject *
+getitem_sequence(PyObject *obj, Py_ssize_t idx)
+{
+    return PySequence_GetItem(obj, idx);
+}
+
+/* do the equivalent of obj[idx], where obj is not a sequence */
+static PyObject *
+getitem_idx(PyObject *obj, Py_ssize_t idx)
+{
+    PyObject *newobj;
+    PyObject *idx_obj = PyLong_FromSsize_t(idx);
+    if (idx_obj == NULL)
+        return NULL;
+    newobj = PyObject_GetItem(obj, idx_obj);
+    Py_DECREF(idx_obj);
+    return newobj;
+}
+
+/* do the equivalent of obj[name] */
+static PyObject *
+getitem_str(PyObject *obj, SubString *name)
+{
+    PyObject *newobj;
+    PyObject *str = SubString_new_object(name);
+    if (str == NULL)
+        return NULL;
+    newobj = PyObject_GetItem(obj, str);
+    Py_DECREF(str);
+    return newobj;
+}
+
+typedef struct {
+    /* the entire string we're parsing.  we assume that someone else
+       is managing its lifetime, and that it will exist for the
+       lifetime of the iterator.  can be empty */
+    SubString str;
+
+    /* pointer to where we are inside field_name */
+    STRINGLIB_CHAR *ptr;
+} FieldNameIterator;
+
+
+static int
+FieldNameIterator_init(FieldNameIterator *self, STRINGLIB_CHAR *ptr,
+                       Py_ssize_t len)
+{
+    SubString_init(&self->str, ptr, len);
+    self->ptr = self->str.ptr;
+    return 1;
+}
+
+static int
+_FieldNameIterator_attr(FieldNameIterator *self, SubString *name)
+{
+    STRINGLIB_CHAR c;
+
+    name->ptr = self->ptr;
+
+    /* return everything until '.' or '[' */
+    while (self->ptr < self->str.end) {
+        switch (c = *self->ptr++) {
+        case '[':
+        case '.':
+            /* backup so that we this character will be seen next time */
+            self->ptr--;
+            break;
+        default:
+            continue;
+        }
+        break;
+    }
+    /* end of string is okay */
+    name->end = self->ptr;
+    return 1;
+}
+
+static int
+_FieldNameIterator_item(FieldNameIterator *self, SubString *name)
+{
+    int bracket_seen = 0;
+    STRINGLIB_CHAR c;
+
+    name->ptr = self->ptr;
+
+    /* return everything until ']' */
+    while (self->ptr < self->str.end) {
+        switch (c = *self->ptr++) {
+        case ']':
+            bracket_seen = 1;
+            break;
+        default:
+            continue;
+        }
+        break;
+    }
+    /* make sure we ended with a ']' */
+    if (!bracket_seen) {
+        PyErr_SetString(PyExc_ValueError, "Missing ']' in format string");
+        return 0;
+    }
+
+    /* end of string is okay */
+    /* don't include the ']' */
+    name->end = self->ptr-1;
+    return 1;
+}
+
+/* returns 0 on error, 1 on non-error termination, and 2 if it returns a value */
+static int
+FieldNameIterator_next(FieldNameIterator *self, int *is_attribute,
+                       Py_ssize_t *name_idx, SubString *name)
+{
+    /* check at end of input */
+    if (self->ptr >= self->str.end)
+        return 1;
+
+    switch (*self->ptr++) {
+    case '.':
+        *is_attribute = 1;
+        if (_FieldNameIterator_attr(self, name) == 0)
+            return 0;
+        *name_idx = -1;
+        break;
+    case '[':
+        *is_attribute = 0;
+        if (_FieldNameIterator_item(self, name) == 0)
+            return 0;
+        *name_idx = get_integer(name);
+        break;
+    default:
+        /* interal error, can't get here */
+        assert(0);
+        return 0;
+    }
+
+    /* empty string is an error */
+    if (name->ptr == name->end) {
+        PyErr_SetString(PyExc_ValueError, "Empty attribute in format string");
+        return 0;
+    }
+
+    return 2;
+}
+
+
+/* input: field_name
+   output: 'first' points to the part before the first '[' or '.'
+           'first_idx' is -1 if 'first' is not an integer, otherwise
+                       it's the value of first converted to an integer
+           'rest' is an iterator to return the rest
+*/
+static int
+field_name_split(STRINGLIB_CHAR *ptr, Py_ssize_t len, SubString *first,
+                 Py_ssize_t *first_idx, FieldNameIterator *rest)
+{
+    STRINGLIB_CHAR c;
+    STRINGLIB_CHAR *p = ptr;
+    STRINGLIB_CHAR *end = ptr + len;
+
+    /* find the part up until the first '.' or '[' */
+    while (p < end) {
+        switch (c = *p++) {
+        case '[':
+        case '.':
+            /* backup so that we this character is available to the
+               "rest" iterator */
+            p--;
+            break;
+        default:
+            continue;
+        }
+        break;
+    }
+
+    /* set up the return values */
+    SubString_init(first, ptr, p - ptr);
+    FieldNameIterator_init(rest, p, end - p);
+
+    /* see if "first" is an integer, in which case it's used as an index */
+    *first_idx = get_integer(first);
+
+    /* zero length string is an error */
+    if (first->ptr >= first->end) {
+        PyErr_SetString(PyExc_ValueError, "empty field name");
+        goto error;
+    }
+
+    return 1;
+error:
+    return 0;
+}
+
+
+/*
+    get_field_object returns the object inside {}, before the
+    format_spec.  It handles getindex and getattr lookups and consumes
+    the entire input string.
+*/
+static PyObject *
+get_field_object(SubString *input, PyObject *args, PyObject *kwargs)
+{
+    PyObject *obj = NULL;
+    int ok;
+    int is_attribute;
+    SubString name;
+    SubString first;
+    Py_ssize_t index;
+    FieldNameIterator rest;
+
+    if (!field_name_split(input->ptr, input->end - input->ptr, &first,
+                          &index, &rest)) {
+        goto error;
+    }
+
+    if (index == -1) {
+        /* look up in kwargs */
+        PyObject *key = SubString_new_object(&first);
+        if (key == NULL)
+            goto error;
+        if ((kwargs == NULL) || (obj = PyDict_GetItem(kwargs, key)) == NULL) {
+            PyErr_SetObject(PyExc_KeyError, key);
+            Py_DECREF(key);
+            goto error;
+        }
+        Py_DECREF(key);
+        Py_INCREF(obj);
+    }
+    else {
+        /* look up in args */
+        obj = PySequence_GetItem(args, index);
+        if (obj == NULL)
+            goto error;
+    }
+
+    /* iterate over the rest of the field_name */
+    while ((ok = FieldNameIterator_next(&rest, &is_attribute, &index,
+                                        &name)) == 2) {
+        PyObject *tmp;
+
+        if (is_attribute)
+            /* getattr lookup "." */
+            tmp = getattr(obj, &name);
+        else
+            /* getitem lookup "[]" */
+            if (index == -1)
+                tmp = getitem_str(obj, &name);
+            else
+                if (PySequence_Check(obj))
+                    tmp = getitem_sequence(obj, index);
+                else
+                    /* not a sequence */
+                    tmp = getitem_idx(obj, index);
+        if (tmp == NULL)
+            goto error;
+
+        /* assign to obj */
+        Py_DECREF(obj);
+        obj = tmp;
+    }
+    /* end of iterator, this is the non-error case */
+    if (ok == 1)
+        return obj;
+error:
+    Py_XDECREF(obj);
+    return NULL;
+}
+
+/************************************************************************/
+/*****************  Field rendering functions  **************************/
+/************************************************************************/
+
+/*
+    render_field() is the main function in this section.  It takes the
+    field object and field specification string generated by
+    get_field_and_spec, and renders the field into the output string.
+
+    render_field calls fieldobj.__format__(format_spec) method, and
+    appends to the output.
+*/
+static int
+render_field(PyObject *fieldobj, SubString *format_spec, OutputString *output)
+{
+    int ok = 0;
+    PyObject *result = NULL;
+    PyObject *format_spec_object = NULL;
+    PyObject *(*formatter)(PyObject *, STRINGLIB_CHAR *, Py_ssize_t) = NULL;
+    STRINGLIB_CHAR* format_spec_start = format_spec->ptr ?
+	    format_spec->ptr : NULL;
+    Py_ssize_t format_spec_len = format_spec->ptr ?
+	    format_spec->end - format_spec->ptr : 0;
+
+    /* If we know the type exactly, skip the lookup of __format__ and just
+       call the formatter directly. */
+#if STRINGLIB_IS_UNICODE
+    if (PyUnicode_CheckExact(fieldobj))
+	formatter = _PyUnicode_FormatAdvanced;
+    /* Unfortunately, there's a problem with checking for int, long,
+       and float here.  If we're being included as unicode, their
+       formatters expect string format_spec args.  For now, just skip
+       this optimization for unicode.  This could be fixed, but it's a
+       hassle. */
+#else
+    if (PyString_CheckExact(fieldobj))
+	formatter = _PyBytes_FormatAdvanced;
+    else if (PyInt_CheckExact(fieldobj))
+	formatter =_PyInt_FormatAdvanced;
+    else if (PyLong_CheckExact(fieldobj))
+	formatter =_PyLong_FormatAdvanced;
+    else if (PyFloat_CheckExact(fieldobj))
+	formatter = _PyFloat_FormatAdvanced;
+#endif
+
+    if (formatter) {
+	/* we know exactly which formatter will be called when __format__ is
+	   looked up, so call it directly, instead. */
+	result = formatter(fieldobj, format_spec_start, format_spec_len);
+    }
+    else {
+	/* We need to create an object out of the pointers we have, because
+	   __format__ takes a string/unicode object for format_spec. */
+	format_spec_object = STRINGLIB_NEW(format_spec_start,
+					   format_spec_len);
+	if (format_spec_object == NULL)
+	    goto done;
+
+	result = PyObject_Format(fieldobj, format_spec_object);
+    }
+    if (result == NULL)
+        goto done;
+
+#if PY_VERSION_HEX >= 0x03000000
+    assert(PyUnicode_Check(result));
+#else
+    assert(PyString_Check(result) || PyUnicode_Check(result));
+
+    /* Convert result to our type.  We could be str, and result could
+       be unicode */
+    {
+	PyObject *tmp = STRINGLIB_TOSTR(result);
+	if (tmp == NULL)
+	    goto done;
+	Py_DECREF(result);
+	result = tmp;
+    }
+#endif
+
+    ok = output_data(output,
+                     STRINGLIB_STR(result), STRINGLIB_LEN(result));
+done:
+    Py_XDECREF(format_spec_object);
+    Py_XDECREF(result);
+    return ok;
+}
+
+static int
+parse_field(SubString *str, SubString *field_name, SubString *format_spec,
+            STRINGLIB_CHAR *conversion)
+{
+    STRINGLIB_CHAR c = 0;
+
+    /* initialize these, as they may be empty */
+    *conversion = '\0';
+    SubString_init(format_spec, NULL, 0);
+
+    /* search for the field name.  it's terminated by the end of the
+       string, or a ':' or '!' */
+    field_name->ptr = str->ptr;
+    while (str->ptr < str->end) {
+        switch (c = *(str->ptr++)) {
+        case ':':
+        case '!':
+            break;
+        default:
+            continue;
+        }
+        break;
+    }
+
+    if (c == '!' || c == ':') {
+        /* we have a format specifier and/or a conversion */
+        /* don't include the last character */
+        field_name->end = str->ptr-1;
+
+        /* the format specifier is the rest of the string */
+        format_spec->ptr = str->ptr;
+        format_spec->end = str->end;
+
+        /* see if there's a conversion specifier */
+        if (c == '!') {
+            /* there must be another character present */
+            if (format_spec->ptr >= format_spec->end) {
+                PyErr_SetString(PyExc_ValueError,
+                                "end of format while looking for conversion "
+                                "specifier");
+                return 0;
+            }
+            *conversion = *(format_spec->ptr++);
+
+            /* if there is another character, it must be a colon */
+            if (format_spec->ptr < format_spec->end) {
+                c = *(format_spec->ptr++);
+                if (c != ':') {
+                    PyErr_SetString(PyExc_ValueError,
+                                    "expected ':' after format specifier");
+                    return 0;
+                }
+            }
+        }
+
+        return 1;
+
+    }
+    else {
+        /* end of string, there's no format_spec or conversion */
+        field_name->end = str->ptr;
+        return 1;
+    }
+}
+
+/************************************************************************/
+/******* Output string allocation and escape-to-markup processing  ******/
+/************************************************************************/
+
+/* MarkupIterator breaks the string into pieces of either literal
+   text, or things inside {} that need to be marked up.  it is
+   designed to make it easy to wrap a Python iterator around it, for
+   use with the Formatter class */
+
+typedef struct {
+    SubString str;
+} MarkupIterator;
+
+static int
+MarkupIterator_init(MarkupIterator *self, STRINGLIB_CHAR *ptr, Py_ssize_t len)
+{
+    SubString_init(&self->str, ptr, len);
+    return 1;
+}
+
+/* returns 0 on error, 1 on non-error termination, and 2 if it got a
+   string (or something to be expanded) */
+static int
+MarkupIterator_next(MarkupIterator *self, SubString *literal,
+                    SubString *field_name, SubString *format_spec,
+                    STRINGLIB_CHAR *conversion,
+                    int *format_spec_needs_expanding)
+{
+    int at_end;
+    STRINGLIB_CHAR c = 0;
+    STRINGLIB_CHAR *start;
+    int count;
+    Py_ssize_t len;
+    int markup_follows = 0;
+
+    /* initialize all of the output variables */
+    SubString_init(literal, NULL, 0);
+    SubString_init(field_name, NULL, 0);
+    SubString_init(format_spec, NULL, 0);
+    *conversion = '\0';
+    *format_spec_needs_expanding = 0;
+
+    /* No more input, end of iterator.  This is the normal exit
+       path. */
+    if (self->str.ptr >= self->str.end)
+        return 1;
+
+    start = self->str.ptr;
+
+    /* First read any literal text. Read until the end of string, an
+       escaped '{' or '}', or an unescaped '{'.  In order to never
+       allocate memory and so I can just pass pointers around, if
+       there's an escaped '{' or '}' then we'll return the literal
+       including the brace, but no format object.  The next time
+       through, we'll return the rest of the literal, skipping past
+       the second consecutive brace. */
+    while (self->str.ptr < self->str.end) {
+        switch (c = *(self->str.ptr++)) {
+        case '{':
+        case '}':
+            markup_follows = 1;
+            break;
+        default:
+            continue;
+        }
+        break;
+    }
+
+    at_end = self->str.ptr >= self->str.end;
+    len = self->str.ptr - start;
+
+    if ((c == '}') && (at_end || (c != *self->str.ptr))) {
+        PyErr_SetString(PyExc_ValueError, "Single '}' encountered "
+                        "in format string");
+        return 0;
+    }
+    if (at_end && c == '{') {
+        PyErr_SetString(PyExc_ValueError, "Single '{' encountered "
+                        "in format string");
+        return 0;
+    }
+    if (!at_end) {
+        if (c == *self->str.ptr) {
+            /* escaped } or {, skip it in the input.  there is no
+               markup object following us, just this literal text */
+            self->str.ptr++;
+            markup_follows = 0;
+        }
+        else
+            len--;
+    }
+
+    /* record the literal text */
+    literal->ptr = start;
+    literal->end = start + len;
+
+    if (!markup_follows)
+        return 2;
+
+    /* this is markup, find the end of the string by counting nested
+       braces.  note that this prohibits escaped braces, so that
+       format_specs cannot have braces in them. */
+    count = 1;
+
+    start = self->str.ptr;
+
+    /* we know we can't have a zero length string, so don't worry
+       about that case */
+    while (self->str.ptr < self->str.end) {
+        switch (c = *(self->str.ptr++)) {
+        case '{':
+            /* the format spec needs to be recursively expanded.
+               this is an optimization, and not strictly needed */
+            *format_spec_needs_expanding = 1;
+            count++;
+            break;
+        case '}':
+            count--;
+            if (count <= 0) {
+                /* we're done.  parse and get out */
+                SubString s;
+
+                SubString_init(&s, start, self->str.ptr - 1 - start);
+                if (parse_field(&s, field_name, format_spec, conversion) == 0)
+                    return 0;
+
+                /* a zero length field_name is an error */
+                if (field_name->ptr == field_name->end) {
+                    PyErr_SetString(PyExc_ValueError, "zero length field name "
+                                    "in format");
+                    return 0;
+                }
+
+                /* success */
+                return 2;
+            }
+            break;
+        }
+    }
+
+    /* end of string while searching for matching '}' */
+    PyErr_SetString(PyExc_ValueError, "unmatched '{' in format");
+    return 0;
+}
+
+
+/* do the !r or !s conversion on obj */
+static PyObject *
+do_conversion(PyObject *obj, STRINGLIB_CHAR conversion)
+{
+    /* XXX in pre-3.0, do we need to convert this to unicode, since it
+       might have returned a string? */
+    switch (conversion) {
+    case 'r':
+        return PyObject_Repr(obj);
+    case 's':
+        return STRINGLIB_TOSTR(obj);
+    default:
+	if (conversion > 32 && conversion < 127) {
+		/* It's the ASCII subrange; casting to char is safe
+		   (assuming the execution character set is an ASCII
+		   superset). */
+        	PyErr_Format(PyExc_ValueError,
+                     "Unknown conversion specifier %c",
+                     (char)conversion);
+	} else
+		PyErr_Format(PyExc_ValueError,
+		     "Unknown conversion specifier \\x%x",
+		     (unsigned int)conversion);
+        return NULL;
+    }
+}
+
+/* given:
+
+   {field_name!conversion:format_spec}
+
+   compute the result and write it to output.
+   format_spec_needs_expanding is an optimization.  if it's false,
+   just output the string directly, otherwise recursively expand the
+   format_spec string. */
+
+static int
+output_markup(SubString *field_name, SubString *format_spec,
+              int format_spec_needs_expanding, STRINGLIB_CHAR conversion,
+              OutputString *output, PyObject *args, PyObject *kwargs,
+              int recursion_depth)
+{
+    PyObject *tmp = NULL;
+    PyObject *fieldobj = NULL;
+    SubString expanded_format_spec;
+    SubString *actual_format_spec;
+    int result = 0;
+
+    /* convert field_name to an object */
+    fieldobj = get_field_object(field_name, args, kwargs);
+    if (fieldobj == NULL)
+        goto done;
+
+    if (conversion != '\0') {
+        tmp = do_conversion(fieldobj, conversion);
+        if (tmp == NULL)
+            goto done;
+
+        /* do the assignment, transferring ownership: fieldobj = tmp */
+        Py_DECREF(fieldobj);
+        fieldobj = tmp;
+        tmp = NULL;
+    }
+
+    /* if needed, recurively compute the format_spec */
+    if (format_spec_needs_expanding) {
+        tmp = build_string(format_spec, args, kwargs, recursion_depth-1);
+        if (tmp == NULL)
+            goto done;
+
+        /* note that in the case we're expanding the format string,
+           tmp must be kept around until after the call to
+           render_field. */
+        SubString_init(&expanded_format_spec,
+                       STRINGLIB_STR(tmp), STRINGLIB_LEN(tmp));
+        actual_format_spec = &expanded_format_spec;
+    }
+    else
+        actual_format_spec = format_spec;
+
+    if (render_field(fieldobj, actual_format_spec, output) == 0)
+        goto done;
+
+    result = 1;
+
+done:
+    Py_XDECREF(fieldobj);
+    Py_XDECREF(tmp);
+
+    return result;
+}
+
+/*
+    do_markup is the top-level loop for the format() method.  It
+    searches through the format string for escapes to markup codes, and
+    calls other functions to move non-markup text to the output,
+    and to perform the markup to the output.
+*/
+static int
+do_markup(SubString *input, PyObject *args, PyObject *kwargs,
+          OutputString *output, int recursion_depth)
+{
+    MarkupIterator iter;
+    int format_spec_needs_expanding;
+    int result;
+    SubString literal;
+    SubString field_name;
+    SubString format_spec;
+    STRINGLIB_CHAR conversion;
+
+    MarkupIterator_init(&iter, input->ptr, input->end - input->ptr);
+    while ((result = MarkupIterator_next(&iter, &literal, &field_name,
+                                         &format_spec, &conversion,
+                                         &format_spec_needs_expanding)) == 2) {
+        if (!output_data(output, literal.ptr, literal.end - literal.ptr))
+            return 0;
+        if (field_name.ptr != field_name.end)
+            if (!output_markup(&field_name, &format_spec,
+                               format_spec_needs_expanding, conversion, output,
+                               args, kwargs, recursion_depth))
+                return 0;
+    }
+    return result;
+}
+
+
+/*
+    build_string allocates the output string and then
+    calls do_markup to do the heavy lifting.
+*/
+static PyObject *
+build_string(SubString *input, PyObject *args, PyObject *kwargs,
+             int recursion_depth)
+{
+    OutputString output;
+    PyObject *result = NULL;
+    Py_ssize_t count;
+
+    output.obj = NULL; /* needed so cleanup code always works */
+
+    /* check the recursion level */
+    if (recursion_depth <= 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Max string recursion exceeded");
+        goto done;
+    }
+
+    /* initial size is the length of the format string, plus the size
+       increment.  seems like a reasonable default */
+    if (!output_initialize(&output,
+                           input->end - input->ptr +
+                           INITIAL_SIZE_INCREMENT))
+        goto done;
+
+    if (!do_markup(input, args, kwargs, &output, recursion_depth)) {
+        goto done;
+    }
+
+    count = output.ptr - STRINGLIB_STR(output.obj);
+    if (STRINGLIB_RESIZE(&output.obj, count) < 0) {
+        goto done;
+    }
+
+    /* transfer ownership to result */
+    result = output.obj;
+    output.obj = NULL;
+
+done:
+    Py_XDECREF(output.obj);
+    return result;
+}
+
+/************************************************************************/
+/*********** main routine ***********************************************/
+/************************************************************************/
+
+/* this is the main entry point */
+static PyObject *
+do_string_format(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    SubString input;
+
+    /* PEP 3101 says only 2 levels, so that
+       "{0:{1}}".format('abc', 's')            # works
+       "{0:{1:{2}}}".format('abc', 's', '')    # fails
+    */
+    int recursion_depth = 2;
+
+    SubString_init(&input, STRINGLIB_STR(self), STRINGLIB_LEN(self));
+    return build_string(&input, args, kwargs, recursion_depth);
+}
+
+
+
+/************************************************************************/
+/*********** formatteriterator ******************************************/
+/************************************************************************/
+
+/* This is used to implement string.Formatter.vparse().  It exists so
+   Formatter can share code with the built in unicode.format() method.
+   It's really just a wrapper around MarkupIterator that is callable
+   from Python. */
+
+typedef struct {
+    PyObject_HEAD
+
+    STRINGLIB_OBJECT *str;
+
+    MarkupIterator it_markup;
+} formatteriterobject;
+
+static void
+formatteriter_dealloc(formatteriterobject *it)
+{
+    Py_XDECREF(it->str);
+    PyObject_FREE(it);
+}
+
+/* returns a tuple:
+   (literal, field_name, format_spec, conversion)
+
+   literal is any literal text to output.  might be zero length
+   field_name is the string before the ':'.  might be None
+   format_spec is the string after the ':'.  mibht be None
+   conversion is either None, or the string after the '!'
+*/
+static PyObject *
+formatteriter_next(formatteriterobject *it)
+{
+    SubString literal;
+    SubString field_name;
+    SubString format_spec;
+    STRINGLIB_CHAR conversion;
+    int format_spec_needs_expanding;
+    int result = MarkupIterator_next(&it->it_markup, &literal, &field_name,
+                                     &format_spec, &conversion,
+                                     &format_spec_needs_expanding);
+
+    /* all of the SubString objects point into it->str, so no
+       memory management needs to be done on them */
+    assert(0 <= result && result <= 2);
+    if (result == 0 || result == 1)
+        /* if 0, error has already been set, if 1, iterator is empty */
+        return NULL;
+    else {
+        PyObject *literal_str = NULL;
+        PyObject *field_name_str = NULL;
+        PyObject *format_spec_str = NULL;
+        PyObject *conversion_str = NULL;
+        PyObject *tuple = NULL;
+        int has_field = field_name.ptr != field_name.end;
+
+        literal_str = SubString_new_object(&literal);
+        if (literal_str == NULL)
+            goto done;
+
+        field_name_str = SubString_new_object(&field_name);
+        if (field_name_str == NULL)
+            goto done;
+
+        /* if field_name is non-zero length, return a string for
+           format_spec (even if zero length), else return None */
+        format_spec_str = (has_field ?
+                           SubString_new_object_or_empty :
+                           SubString_new_object)(&format_spec);
+        if (format_spec_str == NULL)
+            goto done;
+
+        /* if the conversion is not specified, return a None,
+           otherwise create a one length string with the conversion
+           character */
+        if (conversion == '\0') {
+            conversion_str = Py_None;
+            Py_INCREF(conversion_str);
+        }
+        else
+	    conversion_str = STRINGLIB_NEW(&conversion, 1);
+        if (conversion_str == NULL)
+            goto done;
+
+        tuple = PyTuple_Pack(4, literal_str, field_name_str, format_spec_str,
+                             conversion_str);
+    done:
+        Py_XDECREF(literal_str);
+        Py_XDECREF(field_name_str);
+        Py_XDECREF(format_spec_str);
+        Py_XDECREF(conversion_str);
+        return tuple;
+    }
+}
+
+static PyMethodDef formatteriter_methods[] = {
+    {NULL,		NULL}		/* sentinel */
+};
+
+static PyTypeObject PyFormatterIter_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "formatteriterator",		/* tp_name */
+    sizeof(formatteriterobject),	/* tp_basicsize */
+    0,					/* tp_itemsize */
+    /* methods */
+    (destructor)formatteriter_dealloc,	/* 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 */
+    PyObject_GenericGetAttr,		/* tp_getattro */
+    0,					/* tp_setattro */
+    0,					/* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT,			/* tp_flags */
+    0,					/* tp_doc */
+    0,					/* tp_traverse */
+    0,					/* tp_clear */
+    0,					/* tp_richcompare */
+    0,					/* tp_weaklistoffset */
+    PyObject_SelfIter,			/* tp_iter */
+    (iternextfunc)formatteriter_next,	/* tp_iternext */
+    formatteriter_methods,		/* tp_methods */
+    0,
+};
+
+/* unicode_formatter_parser is used to implement
+   string.Formatter.vformat.  it parses a string and returns tuples
+   describing the parsed elements.  It's a wrapper around
+   stringlib/string_format.h's MarkupIterator */
+static PyObject *
+formatter_parser(STRINGLIB_OBJECT *self)
+{
+    formatteriterobject *it;
+
+    it = PyObject_New(formatteriterobject, &PyFormatterIter_Type);
+    if (it == NULL)
+        return NULL;
+
+    /* take ownership, give the object to the iterator */
+    Py_INCREF(self);
+    it->str = self;
+
+    /* initialize the contained MarkupIterator */
+    MarkupIterator_init(&it->it_markup,
+                        STRINGLIB_STR(self),
+                        STRINGLIB_LEN(self));
+
+    return (PyObject *)it;
+}
+
+
+/************************************************************************/
+/*********** fieldnameiterator ******************************************/
+/************************************************************************/
+
+
+/* This is used to implement string.Formatter.vparse().  It parses the
+   field name into attribute and item values.  It's a Python-callable
+   wrapper around FieldNameIterator */
+
+typedef struct {
+    PyObject_HEAD
+
+    STRINGLIB_OBJECT *str;
+
+    FieldNameIterator it_field;
+} fieldnameiterobject;
+
+static void
+fieldnameiter_dealloc(fieldnameiterobject *it)
+{
+    Py_XDECREF(it->str);
+    PyObject_FREE(it);
+}
+
+/* returns a tuple:
+   (is_attr, value)
+   is_attr is true if we used attribute syntax (e.g., '.foo')
+              false if we used index syntax (e.g., '[foo]')
+   value is an integer or string
+*/
+static PyObject *
+fieldnameiter_next(fieldnameiterobject *it)
+{
+    int result;
+    int is_attr;
+    Py_ssize_t idx;
+    SubString name;
+
+    result = FieldNameIterator_next(&it->it_field, &is_attr,
+                                    &idx, &name);
+    if (result == 0 || result == 1)
+        /* if 0, error has already been set, if 1, iterator is empty */
+        return NULL;
+    else {
+        PyObject* result = NULL;
+        PyObject* is_attr_obj = NULL;
+        PyObject* obj = NULL;
+
+        is_attr_obj = PyBool_FromLong(is_attr);
+        if (is_attr_obj == NULL)
+            goto done;
+
+        /* either an integer or a string */
+        if (idx != -1)
+            obj = PyLong_FromSsize_t(idx);
+        else
+            obj = SubString_new_object(&name);
+        if (obj == NULL)
+            goto done;
+
+        /* return a tuple of values */
+        result = PyTuple_Pack(2, is_attr_obj, obj);
+
+    done:
+        Py_XDECREF(is_attr_obj);
+        Py_XDECREF(obj);
+        return result;
+    }
+}
+
+static PyMethodDef fieldnameiter_methods[] = {
+    {NULL,		NULL}		/* sentinel */
+};
+
+static PyTypeObject PyFieldNameIter_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "fieldnameiterator",		/* tp_name */
+    sizeof(fieldnameiterobject),	/* tp_basicsize */
+    0,					/* tp_itemsize */
+    /* methods */
+    (destructor)fieldnameiter_dealloc,	/* 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 */
+    PyObject_GenericGetAttr,		/* tp_getattro */
+    0,					/* tp_setattro */
+    0,					/* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT,			/* tp_flags */
+    0,					/* tp_doc */
+    0,					/* tp_traverse */
+    0,					/* tp_clear */
+    0,					/* tp_richcompare */
+    0,					/* tp_weaklistoffset */
+    PyObject_SelfIter,			/* tp_iter */
+    (iternextfunc)fieldnameiter_next,	/* tp_iternext */
+    fieldnameiter_methods,		/* tp_methods */
+    0};
+
+/* unicode_formatter_field_name_split is used to implement
+   string.Formatter.vformat.  it takes an PEP 3101 "field name", and
+   returns a tuple of (first, rest): "first", the part before the
+   first '.' or '['; and "rest", an iterator for the rest of the field
+   name.  it's a wrapper around stringlib/string_format.h's
+   field_name_split.  The iterator it returns is a
+   FieldNameIterator */
+static PyObject *
+formatter_field_name_split(STRINGLIB_OBJECT *self)
+{
+    SubString first;
+    Py_ssize_t first_idx;
+    fieldnameiterobject *it;
+
+    PyObject *first_obj = NULL;
+    PyObject *result = NULL;
+
+    it = PyObject_New(fieldnameiterobject, &PyFieldNameIter_Type);
+    if (it == NULL)
+        return NULL;
+
+    /* take ownership, give the object to the iterator.  this is
+       just to keep the field_name alive */
+    Py_INCREF(self);
+    it->str = self;
+
+    if (!field_name_split(STRINGLIB_STR(self),
+                          STRINGLIB_LEN(self),
+                          &first, &first_idx, &it->it_field))
+        goto done;
+
+    /* first becomes an integer, if possible; else a string */
+    if (first_idx != -1)
+        first_obj = PyLong_FromSsize_t(first_idx);
+    else
+        /* convert "first" into a string object */
+        first_obj = SubString_new_object(&first);
+    if (first_obj == NULL)
+        goto done;
+
+    /* return a tuple of values */
+    result = PyTuple_Pack(2, first_obj, it);
+
+done:
+    Py_XDECREF(it);
+    Py_XDECREF(first_obj);
+    return result;
+}