As error logs are emitted often (they happen when Black's cache
directory is created after blib2to3 tries to write its cache) and cause
issues to be filed by users who think Black isn't working correctly.
These errors are expected for now and aren't a cause for concern so
let's remove them to stop worrying users (and new issues from being
opened). We can improve the blib2to3 caching mechanism to write its
cache at the end of a successful command line invocation later.
Otherwise they'd be deleted which was a regression in 22.1.0 (oops! my
bad!). Also type comments are now tracked in the AST safety check on all
compatible platforms to error out if this happens again.
Overall the line rewriting code has been rewritten to do "the right
thing (tm)", I hope this fixes other potential bugs in the code (fwiw I
got to drop the bugfix in blib2to3.pytree.Leaf.clone since now bracket
metadata is properly copied over).
Fixes#2873
This removes all but one usage of the `regex` dependency. Tricky bits included:
- A bug in test_black.py where we were incorrectly using a character range. Fix also submitted separately in #2643.
- `tokenize.py` was the original use case for regex (#1047). The important bit is that we rely on `\w` to match anything valid in an identifier, and `re` fails to match a few characters as part of identifiers. My solution is to instead match all characters *except* those we know to mean something else in Python: whitespace and ASCII punctuation. This will make Black able to parse some invalid Python programs, like those that contain non-ASCII punctuation in the place of an identifier, but that seems fine to me.
- One import of `regex` remains, in `trans.py`. We use a recursive regex to parse f-strings, and only `regex` supports that. I haven't thought of a better fix there (except maybe writing a manual parser), so I'm leaving that for now.
My goal is to remove the `regex` dependency to reduce the risk of breakage due to dependencies and make life easier for users on platforms without wheels.
The implementation of the new backtracking logic depends heavily on deepcopying the current state of the parser before seeing one of the new keywords, which by default is an very expensive operations. On my system, formatting these 3 files takes 1.3 seconds.
```
$ touch tests/data/pattern_matching_*; time python -m black -tpy310 tests/data/pattern_matching_* 19ms
All done! ✨🍰✨
3 files left unchanged.
python -m black -tpy310 tests/data/pattern_matching_* 2,09s user 0,04s system 157% cpu 1,357 total
```
which can be optimized 3X if we integrate the existing copying logic (`clone`) to the deepcopy system;
```
$ touch tests/data/pattern_matching_*; time python -m black -tpy310 tests/data/pattern_matching_* 1ms
All done! ✨🍰✨
3 files left unchanged.
python -m black -tpy310 tests/data/pattern_matching_* 0,66s user 0,02s system 147% cpu 0,464 total
```
This still might have some potential, but that would be way trickier than this initial patch.
* Improve Python 2 only syntax detection
First of all this fixes a mistake I made in Python 2 deprecation PR
using token.* to check for print/exec statements. Turns out that
for nodes with a type value higher than 256 its numeric type isn't
guaranteed to be constant. Using syms.* instead fixes this.
Also add support for the following cases:
print "hello, world!"
exec "print('hello, world!')"
def set_position((x, y), value):
pass
try:
pass
except Exception, err:
pass
raise RuntimeError, "I feel like crashing today :p"
`wow_these_really_did_exist`
10L
* Add octal support, more test cases, and fixup long ints
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
* Prepare for Python 2 depreciation
- Use BlackRunner and .stdout in command line test
So the next commit won't break this test. This is in its own commit so
we can just revert the depreciation commit when dropping Python 2
support completely.
* Deprecate Python 2 formatting support
Implementation stolen from PR davidhalter/parso#162. Thanks parso!
I could add support for these newer syntactical constructs in the
target version detection logic, but until I get diff-shades up
and running I don't feel very comfortable adding the code.
