FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

gh-106052: Fix bug in the matching of possessive quantifiers by serhiy-storchaka · Pull Request #106515 · python/cpython · GitHub

/ cpython Public

gh-106052: Fix bug in the matching of possessive quantifiers #106515

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
serhiy-storchaka merged 1 commit into from
Aug 9, 2023
+21 −0
Conversation 11 Commits 1 Checks 0 Files changed 3
Merged

gh-106052: Fix bug in the matching of possessive quantifiers #106515

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension .py  (2) .rst  (1) All 2 file types selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
7 changes: 7 additions & 0 deletions Lib/re/_compiler.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -100,6 +100,13 @@ def _compile(code, pattern, flags):
emit(ANY_ALL)
else:
emit(ANY)
elif op is POSSESSIVE_REPEAT:
# gh-106052: Possessive quantifiers do not work when the
# subpattern contains backtracking, i.e. "(?:ab?c)*+".
# Implement it as equivalent greedy qualifier in atomic group.
p = [(MAX_REPEAT, av)]
p = [(ATOMIC_GROUP, p)]
_compile(code, p, flags)
elif op in REPEATING_CODES:
if _simple(av[2]):
emit(REPEATING_CODES[op][2])
Expand Down
12 changes: 12 additions & 0 deletions Lib/test/test_re.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -2398,6 +2398,16 @@ def test_bug_gh91616(self):
self.assertTrue(re.fullmatch(r'(?s:(?>.*?\.).*)\Z', "a.txt")) # reproducer
self.assertTrue(re.fullmatch(r'(?s:(?=(?P<g0>.*?\.))(?P=g0).*)\Z', "a.txt"))

def test_bug_gh106052(self):
self.assertEqual(re.match("(?>(?:ab?c)+)", "aca").span(), (0, 2))
self.assertEqual(re.match("(?:ab?c)++", "aca").span(), (0, 2))
self.assertEqual(re.match("(?>(?:ab?c)*)", "aca").span(), (0, 2))
self.assertEqual(re.match("(?:ab?c)*+", "aca").span(), (0, 2))
self.assertEqual(re.match("(?>(?:ab?c)?)", "a").span(), (0, 0))
self.assertEqual(re.match("(?:ab?c)?+", "a").span(), (0, 0))
self.assertEqual(re.match("(?>(?:ab?c){1,3})", "aca").span(), (0, 2))
self.assertEqual(re.match("(?:ab?c){1,3}+", "aca").span(), (0, 2))

@unittest.skipIf(multiprocessing is None, 'test requires multiprocessing')
def test_regression_gh94675(self):
pattern = re.compile(r'(?<=[({}])(((//[^\n]*)?[\n])([\000-\040])*)*'
Expand Down Expand Up @@ -2491,6 +2501,7 @@ def test_atomic_group(self):
17: SUCCESS
''')

@unittest.expectedFailure # gh-106052
def test_possesive_repeat_one(self):
self.assertEqual(get_debug_out(r'a?+'), '''\
POSSESSIVE_REPEAT 0 1
Expand All @@ -2503,6 +2514,7 @@ def test_possesive_repeat_one(self):
12: SUCCESS
''')

@unittest.expectedFailure # gh-106052
def test_possesive_repeat(self):
self.assertEqual(get_debug_out(r'(?:ab)?+'), '''\
POSSESSIVE_REPEAT 0 1
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2023-07-07-14-52-31.gh-issue-106052.ak8nbs.rst
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
:mod:`re` module: fix the matching of possessive quantifiers in the case of
a subpattern containing backtracking.
Back | FazBrowse Home | New Git URL