IronLanguages / IronLanguages/ironpython3
re fails to match ranges starting with escaped -
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- C#
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Description
re fails to match ranges starting with escaped -. For example:
assert re.match(r'[\--/]', '.') # fails
assert re.match(r'[--/]', '.') # works
This causes a failure in test_fnmatch (from 3.8).
Appears to be a bug in .NET: https://github.com/dotnet/runtime/issues/108335
Idea for a fix: have the re module alter the pattern to be something like [\-.-/] so it matches - and a range starting with . (the next character).
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the re module's handling of character-class ranges and compare it with the .NET behavior linked in the issue. Reproduce the escaped-hyphen cases and run test_fnmatch from Python 3.8. Done means both examples match as expected and the test_fnmatch failure is resolved.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- csharp, python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 55/100