diff options
Diffstat (limited to 'Objects/stringlib/unicode_format.h')
| -rw-r--r-- | Objects/stringlib/unicode_format.h | 1299 |
1 files changed, 1299 insertions, 0 deletions
diff --git a/Objects/stringlib/unicode_format.h b/Objects/stringlib/unicode_format.h new file mode 100644 index 0000000..be580c6 --- /dev/null +++ b/Objects/stringlib/unicode_format.h @@ -0,0 +1,1299 @@ +/* + unicode_format.h -- implementation of str.format(). +*/ + +/* 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 { + PyObject *str; /* borrowed reference */ + Py_ssize_t start, end; +} SubString; + + +typedef enum { + ANS_INIT, + ANS_AUTO, + ANS_MANUAL +} AutoNumberState; /* Keep track if we're auto-numbering fields */ + +/* Keeps track of our auto-numbering state, and which number field we're on */ +typedef struct { + AutoNumberState an_state; + int an_field_number; +} AutoNumber; + + +/* forward declaration for recursion */ +static PyObject * +build_string(SubString *input, PyObject *args, PyObject *kwargs, + int recursion_depth, AutoNumber *auto_number); + + + +/************************************************************************/ +/************************** Utility functions ************************/ +/************************************************************************/ + +static void +AutoNumber_Init(AutoNumber *auto_number) +{ + auto_number->an_state = ANS_INIT; + auto_number->an_field_number = 0; +} + +/* fill in a SubString from a pointer and length */ +Py_LOCAL_INLINE(void) +SubString_init(SubString *str, PyObject *s, Py_ssize_t start, Py_ssize_t end) +{ + str->str = s; + str->start = start; + str->end = end; +} + +/* return a new string. if str->str is NULL, return None */ +Py_LOCAL_INLINE(PyObject *) +SubString_new_object(SubString *str) +{ + if (str->str == NULL) { + Py_INCREF(Py_None); + return Py_None; + } + return PyUnicode_Substring(str->str, str->start, str->end); +} + +/* return a new string. if str->str is NULL, return None */ +Py_LOCAL_INLINE(PyObject *) +SubString_new_object_or_empty(SubString *str) +{ + if (str->str == NULL) { + return PyUnicode_New(0, 0); + } + return SubString_new_object(str); +} + +/* Return 1 if an error has been detected switching between automatic + field numbering and manual field specification, else return 0. Set + ValueError on error. */ +static int +autonumber_state_error(AutoNumberState state, int field_name_is_empty) +{ + if (state == ANS_MANUAL) { + if (field_name_is_empty) { + PyErr_SetString(PyExc_ValueError, "cannot switch from " + "manual field specification to " + "automatic field numbering"); + return 1; + } + } + else { + if (!field_name_is_empty) { + PyErr_SetString(PyExc_ValueError, "cannot switch from " + "automatic field numbering to " + "manual field specification"); + return 1; + } + } + return 0; +} + + +/************************************************************************/ +/*********** 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 i; + + /* empty string is an error */ + if (str->start >= str->end) + return -1; + + for (i = str->start; i < str->end; i++) { + digitval = Py_UNICODE_TODECIMAL(PyUnicode_READ_CHAR(str->str, i)); + if (digitval < 0) + return -1; + /* + Detect possible overflow before it happens: + + accumulator * 10 + digitval > PY_SSIZE_T_MAX if and only if + accumulator > (PY_SSIZE_T_MAX - digitval) / 10. + */ + if (accumulator > (PY_SSIZE_T_MAX - digitval) / 10) { + PyErr_Format(PyExc_ValueError, + "Too many decimal digits in format string"); + return -1; + } + accumulator = accumulator * 10 + 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; + + /* index to where we are inside field_name */ + Py_ssize_t index; +} FieldNameIterator; + + +static int +FieldNameIterator_init(FieldNameIterator *self, PyObject *s, + Py_ssize_t start, Py_ssize_t end) +{ + SubString_init(&self->str, s, start, end); + self->index = start; + return 1; +} + +static int +_FieldNameIterator_attr(FieldNameIterator *self, SubString *name) +{ + Py_UCS4 c; + + name->str = self->str.str; + name->start = self->index; + + /* return everything until '.' or '[' */ + while (self->index < self->str.end) { + c = PyUnicode_READ_CHAR(self->str.str, self->index++); + switch (c) { + case '[': + case '.': + /* backup so that we this character will be seen next time */ + self->index--; + break; + default: + continue; + } + break; + } + /* end of string is okay */ + name->end = self->index; + return 1; +} + +static int +_FieldNameIterator_item(FieldNameIterator *self, SubString *name) +{ + int bracket_seen = 0; + Py_UCS4 c; + + name->str = self->str.str; + name->start = self->index; + + /* return everything until ']' */ + while (self->index < self->str.end) { + c = PyUnicode_READ_CHAR(self->str.str, self->index++); + switch (c) { + 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->index-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->index >= self->str.end) + return 1; + + switch (PyUnicode_READ_CHAR(self->str.str, self->index++)) { + 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); + if (*name_idx == -1 && PyErr_Occurred()) + return 0; + break; + default: + /* Invalid character follows ']' */ + PyErr_SetString(PyExc_ValueError, "Only '.' or '[' may " + "follow ']' in format field specifier"); + return 0; + } + + /* empty string is an error */ + if (name->start == 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(PyObject *str, Py_ssize_t start, Py_ssize_t end, SubString *first, + Py_ssize_t *first_idx, FieldNameIterator *rest, + AutoNumber *auto_number) +{ + Py_UCS4 c; + Py_ssize_t i = start; + int field_name_is_empty; + int using_numeric_index; + + /* find the part up until the first '.' or '[' */ + while (i < end) { + switch (c = PyUnicode_READ_CHAR(str, i++)) { + case '[': + case '.': + /* backup so that we this character is available to the + "rest" iterator */ + i--; + break; + default: + continue; + } + break; + } + + /* set up the return values */ + SubString_init(first, str, start, i); + FieldNameIterator_init(rest, str, i, end); + + /* see if "first" is an integer, in which case it's used as an index */ + *first_idx = get_integer(first); + if (*first_idx == -1 && PyErr_Occurred()) + return 0; + + field_name_is_empty = first->start >= first->end; + + /* If the field name is omitted or if we have a numeric index + specified, then we're doing numeric indexing into args. */ + using_numeric_index = field_name_is_empty || *first_idx != -1; + + /* We always get here exactly one time for each field we're + processing. And we get here in field order (counting by left + braces). So this is the perfect place to handle automatic field + numbering if the field name is omitted. */ + + /* Check if we need to do the auto-numbering. It's not needed if + we're called from string.Format routines, because it's handled + in that class by itself. */ + if (auto_number) { + /* Initialize our auto numbering state if this is the first + time we're either auto-numbering or manually numbering. */ + if (auto_number->an_state == ANS_INIT && using_numeric_index) + auto_number->an_state = field_name_is_empty ? + ANS_AUTO : ANS_MANUAL; + + /* Make sure our state is consistent with what we're doing + this time through. Only check if we're using a numeric + index. */ + if (using_numeric_index) + if (autonumber_state_error(auto_number->an_state, + field_name_is_empty)) + return 0; + /* Zero length field means we want to do auto-numbering of the + fields. */ + if (field_name_is_empty) + *first_idx = (auto_number->an_field_number)++; + } + + return 1; +} + + +/* + 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, + AutoNumber *auto_number) +{ + PyObject *obj = NULL; + int ok; + int is_attribute; + SubString name; + SubString first; + Py_ssize_t index; + FieldNameIterator rest; + + if (!field_name_split(input->str, input->start, input->end, &first, + &index, &rest, auto_number)) { + goto error; + } + + if (index == -1) { + /* look up in kwargs */ + PyObject *key = SubString_new_object(&first); + if (key == NULL) + goto error; + + /* Use PyObject_GetItem instead of PyDict_GetItem because this + code is no longer just used with kwargs. It might be passed + a non-dict when called through format_map. */ + if ((kwargs == NULL) || (obj = PyObject_GetItem(kwargs, key)) == NULL) { + PyErr_SetObject(PyExc_KeyError, key); + Py_DECREF(key); + goto error; + } + Py_DECREF(key); + } + else { + /* If args is NULL, we have a format string with a positional field + with only kwargs to retrieve it from. This can only happen when + used with format_map(), where positional arguments are not + allowed. */ + if (args == NULL) { + PyErr_SetString(PyExc_ValueError, "Format string contains " + "positional fields"); + goto error; + } + + /* 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, _PyUnicodeWriter *writer) +{ + int ok = 0; + PyObject *result = NULL; + PyObject *format_spec_object = NULL; + int (*formatter) (_PyUnicodeWriter*, PyObject *, PyObject *, Py_ssize_t, Py_ssize_t) = NULL; + int err; + + /* If we know the type exactly, skip the lookup of __format__ and just + call the formatter directly. */ + if (PyUnicode_CheckExact(fieldobj)) + formatter = _PyUnicode_FormatAdvancedWriter; + else if (PyLong_CheckExact(fieldobj)) + formatter = _PyLong_FormatAdvancedWriter; + else if (PyFloat_CheckExact(fieldobj)) + formatter = _PyFloat_FormatAdvancedWriter; + else if (PyComplex_CheckExact(fieldobj)) + formatter = _PyComplex_FormatAdvancedWriter; + + if (formatter) { + /* we know exactly which formatter will be called when __format__ is + looked up, so call it directly, instead. */ + err = formatter(writer, fieldobj, format_spec->str, + format_spec->start, format_spec->end); + return (err == 0); + } + else { + /* We need to create an object out of the pointers we have, because + __format__ takes a string/unicode object for format_spec. */ + if (format_spec->str) + format_spec_object = PyUnicode_Substring(format_spec->str, + format_spec->start, + format_spec->end); + else + format_spec_object = PyUnicode_New(0, 0); + if (format_spec_object == NULL) + goto done; + + result = PyObject_Format(fieldobj, format_spec_object); + } + if (result == NULL) + goto done; + + if (_PyUnicodeWriter_WriteStr(writer, result) == -1) + goto done; + ok = 1; + +done: + Py_XDECREF(format_spec_object); + Py_XDECREF(result); + return ok; +} + +static int +parse_field(SubString *str, SubString *field_name, SubString *format_spec, + Py_UCS4 *conversion) +{ + /* Note this function works if the field name is zero length, + which is good. Zero length field names are handled later, in + field_name_split. */ + + Py_UCS4 c = 0; + + /* initialize these, as they may be empty */ + *conversion = '\0'; + SubString_init(format_spec, NULL, 0, 0); + + /* Search for the field name. it's terminated by the end of + the string, or a ':' or '!' */ + field_name->str = str->str; + field_name->start = str->start; + while (str->start < str->end) { + switch ((c = PyUnicode_READ_CHAR(str->str, str->start++))) { + 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->start-1; + + /* the format specifier is the rest of the string */ + format_spec->str = str->str; + format_spec->start = str->start; + format_spec->end = str->end; + + /* see if there's a conversion specifier */ + if (c == '!') { + /* there must be another character present */ + if (format_spec->start >= format_spec->end) { + PyErr_SetString(PyExc_ValueError, + "end of format while looking for conversion " + "specifier"); + return 0; + } + *conversion = PyUnicode_READ_CHAR(format_spec->str, format_spec->start++); + + /* if there is another character, it must be a colon */ + if (format_spec->start < format_spec->end) { + c = PyUnicode_READ_CHAR(format_spec->str, format_spec->start++); + if (c != ':') { + PyErr_SetString(PyExc_ValueError, + "expected ':' after format specifier"); + return 0; + } + } + } + } + else + /* end of string, there's no format_spec or conversion */ + field_name->end = str->start; + + 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, PyObject *str, + Py_ssize_t start, Py_ssize_t end) +{ + SubString_init(&self->str, str, start, end); + 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, + int *field_present, SubString *field_name, + SubString *format_spec, Py_UCS4 *conversion, + int *format_spec_needs_expanding) +{ + int at_end; + Py_UCS4 c = 0; + Py_ssize_t start; + int count; + Py_ssize_t len; + int markup_follows = 0; + + /* initialize all of the output variables */ + SubString_init(literal, NULL, 0, 0); + SubString_init(field_name, NULL, 0, 0); + SubString_init(format_spec, NULL, 0, 0); + *conversion = '\0'; + *format_spec_needs_expanding = 0; + *field_present = 0; + + /* No more input, end of iterator. This is the normal exit + path. */ + if (self->str.start >= self->str.end) + return 1; + + start = self->str.start; + + /* 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.start < self->str.end) { + switch (c = PyUnicode_READ_CHAR(self->str.str, self->str.start++)) { + case '{': + case '}': + markup_follows = 1; + break; + default: + continue; + } + break; + } + + at_end = self->str.start >= self->str.end; + len = self->str.start - start; + + if ((c == '}') && (at_end || + (c != PyUnicode_READ_CHAR(self->str.str, + self->str.start)))) { + 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 == PyUnicode_READ_CHAR(self->str.str, self->str.start)) { + /* escaped } or {, skip it in the input. there is no + markup object following us, just this literal text */ + self->str.start++; + markup_follows = 0; + } + else + len--; + } + + /* record the literal text */ + literal->str = self->str.str; + literal->start = 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. */ + *field_present = 1; + count = 1; + + start = self->str.start; + + /* we know we can't have a zero length string, so don't worry + about that case */ + while (self->str.start < self->str.end) { + switch (c = PyUnicode_READ_CHAR(self->str.str, self->str.start++)) { + 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, self->str.str, start, self->str.start - 1); + if (parse_field(&s, field_name, format_spec, conversion) == 0) + 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, Py_UCS4 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 PyObject_Str(obj); + case 'a': + return PyObject_ASCII(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. + + field_name is allowed to be zero length, in which case we + are doing auto field numbering. +*/ + +static int +output_markup(SubString *field_name, SubString *format_spec, + int format_spec_needs_expanding, Py_UCS4 conversion, + _PyUnicodeWriter *writer, PyObject *args, PyObject *kwargs, + int recursion_depth, AutoNumber *auto_number) +{ + 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, auto_number); + if (fieldobj == NULL) + goto done; + + if (conversion != '\0') { + tmp = do_conversion(fieldobj, conversion); + if (tmp == NULL || PyUnicode_READY(tmp) == -1) + 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, + auto_number); + if (tmp == NULL || PyUnicode_READY(tmp) == -1) + 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, tmp, 0, PyUnicode_GET_LENGTH(tmp)); + actual_format_spec = &expanded_format_spec; + } + else + actual_format_spec = format_spec; + + if (render_field(fieldobj, actual_format_spec, writer) == 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, + _PyUnicodeWriter *writer, int recursion_depth, AutoNumber *auto_number) +{ + MarkupIterator iter; + int format_spec_needs_expanding; + int result; + int field_present; + SubString literal; + SubString field_name; + SubString format_spec; + Py_UCS4 conversion, maxchar; + Py_ssize_t sublen; + int err; + + MarkupIterator_init(&iter, input->str, input->start, input->end); + while ((result = MarkupIterator_next(&iter, &literal, &field_present, + &field_name, &format_spec, + &conversion, + &format_spec_needs_expanding)) == 2) { + sublen = literal.end - literal.start; + if (sublen) { + maxchar = _PyUnicode_FindMaxChar(literal.str, + literal.start, literal.end); + err = _PyUnicodeWriter_Prepare(writer, sublen, maxchar); + if (err == -1) + return 0; + _PyUnicode_FastCopyCharacters(writer->buffer, writer->pos, + literal.str, literal.start, sublen); + writer->pos += sublen; + } + + if (field_present) { + if (iter.str.start == iter.str.end) + writer->overallocate = 0; + if (!output_markup(&field_name, &format_spec, + format_spec_needs_expanding, conversion, writer, + args, kwargs, recursion_depth, auto_number)) + 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, AutoNumber *auto_number) +{ + _PyUnicodeWriter writer; + Py_ssize_t minlen; + + /* check the recursion level */ + if (recursion_depth <= 0) { + PyErr_SetString(PyExc_ValueError, + "Max string recursion exceeded"); + return NULL; + } + + minlen = PyUnicode_GET_LENGTH(input->str) + 100; + _PyUnicodeWriter_Init(&writer, minlen); + + if (!do_markup(input, args, kwargs, &writer, recursion_depth, + auto_number)) { + _PyUnicodeWriter_Dealloc(&writer); + return NULL; + } + + return _PyUnicodeWriter_Finish(&writer); +} + +/************************************************************************/ +/*********** 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; + + AutoNumber auto_number; + + if (PyUnicode_READY(self) == -1) + return NULL; + + AutoNumber_Init(&auto_number); + SubString_init(&input, self, 0, PyUnicode_GET_LENGTH(self)); + return build_string(&input, args, kwargs, recursion_depth, &auto_number); +} + +static PyObject * +do_string_format_map(PyObject *self, PyObject *obj) +{ + return do_string_format(self, NULL, obj); +} + + +/************************************************************************/ +/*********** 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 + PyObject *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; + Py_UCS4 conversion; + int format_spec_needs_expanding; + int field_present; + int result = MarkupIterator_next(&it->it_markup, &literal, &field_present, + &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; + + 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 = (field_present ? + 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 = PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, + &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_reserved */ + 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(PyObject *ignored, PyObject *self) +{ + formatteriterobject *it; + + if (!PyUnicode_Check(self)) { + PyErr_Format(PyExc_TypeError, "expected str, got %s", Py_TYPE(self)->tp_name); + return NULL; + } + + if (PyUnicode_READY(self) == -1) + return NULL; + + 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, (PyObject*)self, 0, PyUnicode_GET_LENGTH(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 + PyObject *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_reserved */ + 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(PyObject *ignored, PyObject *self) +{ + SubString first; + Py_ssize_t first_idx; + fieldnameiterobject *it; + + PyObject *first_obj = NULL; + PyObject *result = NULL; + + if (!PyUnicode_Check(self)) { + PyErr_Format(PyExc_TypeError, "expected str, got %s", Py_TYPE(self)->tp_name); + return NULL; + } + + if (PyUnicode_READY(self) == -1) + return 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; + + /* Pass in auto_number = NULL. We'll return an empty string for + first_obj in that case. */ + if (!field_name_split((PyObject*)self, 0, PyUnicode_GET_LENGTH(self), + &first, &first_idx, &it->it_field, NULL)) + 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; +} |