[Python-checkins] cpython: rewrite the parsing of field names to be more consistent wrt recursive expansion
benjamin.peterson
python-checkins at python.org
Sat May 18 01:23:10 CEST 2013
http://hg.python.org/cpython/rev/f914130c15bb
changeset: 83819:f914130c15bb
user: Benjamin Peterson <benjamin at python.org>
date: Fri May 17 18:22:31 2013 -0500
summary:
rewrite the parsing of field names to be more consistent wrt recursive expansion
files:
Lib/test/test_unicode.py | 10 +-
Objects/stringlib/unicode_format.h | 115 +++++++---------
2 files changed, 62 insertions(+), 63 deletions(-)
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -892,7 +892,7 @@
self.assertRaises(ValueError, "{0".format)
self.assertRaises(IndexError, "{0.}".format)
self.assertRaises(ValueError, "{0.}".format, 0)
- self.assertRaises(IndexError, "{0[}".format)
+ self.assertRaises(ValueError, "{0[}".format)
self.assertRaises(ValueError, "{0[}".format, [])
self.assertRaises(KeyError, "{0]}".format)
self.assertRaises(ValueError, "{0.[]}".format, 0)
@@ -944,6 +944,14 @@
'')
self.assertEqual("{[{}]}".format({"{}": 5}), "5")
+ self.assertEqual("{[{}]}".format({"{}" : "a"}), "a")
+ self.assertEqual("{[{]}".format({"{" : "a"}), "a")
+ self.assertEqual("{[}]}".format({"}" : "a"}), "a")
+ self.assertEqual("{[[]}".format({"[" : "a"}), "a")
+ self.assertEqual("{[!]}".format({"!" : "a"}), "a")
+ self.assertRaises(ValueError, "{a{}b}".format, 42)
+ self.assertRaises(ValueError, "{a{b}".format, 42)
+ self.assertRaises(ValueError, "{[}".format, 42)
def test_format_map(self):
self.assertEqual(''.format_map({}), '')
diff --git a/Objects/stringlib/unicode_format.h b/Objects/stringlib/unicode_format.h
--- a/Objects/stringlib/unicode_format.h
+++ b/Objects/stringlib/unicode_format.h
@@ -543,7 +543,7 @@
static int
parse_field(SubString *str, SubString *field_name, SubString *format_spec,
- Py_UCS4 *conversion)
+ int *format_spec_needs_expanding, 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
@@ -561,6 +561,15 @@
field_name->start = str->start;
while (str->start < str->end) {
switch ((c = PyUnicode_READ_CHAR(str->str, str->start++))) {
+ case '{':
+ PyErr_SetString(PyExc_ValueError, "unexpected '{' in field name");
+ return 0;
+ case '[':
+ for (; str->start < str->end; str->start++)
+ if (PyUnicode_READ_CHAR(str->str, str->start) == ']')
+ break;
+ continue;
+ case '}':
case ':':
case '!':
break;
@@ -570,41 +579,62 @@
break;
}
+ field_name->end = str->start - 1;
if (c == '!' || c == ':') {
+ Py_ssize_t count;
/* 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) {
+ if (str->start >= str->end) {
PyErr_SetString(PyExc_ValueError,
- "end of format while looking for conversion "
+ "end of string while looking for conversion "
"specifier");
return 0;
}
- *conversion = PyUnicode_READ_CHAR(format_spec->str, format_spec->start++);
+ *conversion = PyUnicode_READ_CHAR(str->str, str->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 (str->start < str->end) {
+ c = PyUnicode_READ_CHAR(str->str, str->start++);
+ if (c == '}')
+ return 1;
if (c != ':') {
PyErr_SetString(PyExc_ValueError,
- "expected ':' after format specifier");
+ "expected ':' after conversion specifier");
return 0;
}
}
}
+ format_spec->str = str->str;
+ format_spec->start = str->start;
+ count = 1;
+ while (str->start < str->end) {
+ switch ((c = PyUnicode_READ_CHAR(str->str, str->start++))) {
+ case '{':
+ *format_spec_needs_expanding = 1;
+ count++;
+ break;
+ case '}':
+ count--;
+ if (count == 0) {
+ format_spec->end = str->start - 1;
+ return 1;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ PyErr_SetString(PyExc_ValueError, "unmatched '{' in format spec");
+ return 0;
}
- else
- /* end of string, there's no format_spec or conversion */
- field_name->end = str->start;
+ else if (c != '}') {
+ PyErr_SetString(PyExc_ValueError, "expected '}' before end of string");
+ return 0;
+ }
return 1;
}
@@ -638,10 +668,9 @@
SubString *format_spec, Py_UCS4 *conversion,
int *format_spec_needs_expanding)
{
- int at_end, hit_format_spec;
+ int at_end;
Py_UCS4 c = 0;
Py_ssize_t start;
- int count;
Py_ssize_t len;
int markup_follows = 0;
@@ -713,50 +742,12 @@
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. */
+ /* this is markup; parse the field */
*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 */
- hit_format_spec = 0;
- while (self->str.start < self->str.end) {
- switch (c = PyUnicode_READ_CHAR(self->str.str, self->str.start++)) {
- case ':':
- hit_format_spec = 1;
- count = 1;
- break;
- case '{':
- /* the format spec needs to be recursively expanded.
- this is an optimization, and not strictly needed */
- if (hit_format_spec)
- *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;
+ if (!parse_field(&self->str, field_name, format_spec,
+ format_spec_needs_expanding, conversion))
+ return 0;
+ return 2;
}
--
Repository URL: http://hg.python.org/cpython
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