(Supersedes #9152, authored by @LaBatata101)
## Summary
This PR replaces the current parser generated from LALRPOP to a
hand-written recursive descent parser.
It also updates the grammar for [PEP
646](https://peps.python.org/pep-0646/) so that the parser outputs the
correct AST. For example, in `data[*x]`, the index expression is now a
tuple with a single starred expression instead of just a starred
expression.
Beyond the performance improvements, the parser is also error resilient
and can provide better error messages. The behavior as seen by any
downstream tools isn't changed. That is, the linter and formatter can
still assume that the parser will _stop_ at the first syntax error. This
will be updated in the following months.
For more details about the change here, refer to the PR corresponding to
the individual commits and the release blog post.
## Test Plan
Write _lots_ and _lots_ of tests for both valid and invalid syntax and
verify the output.
## Acknowledgements
- @MichaReiser for reviewing 100+ parser PRs and continuously providing
guidance throughout the project
- @LaBatata101 for initiating the transition to a hand-written parser in
#9152
- @addisoncrump for implementing the fuzzer which helped
[catch](https://github.com/astral-sh/ruff/pull/10903)
[a](https://github.com/astral-sh/ruff/pull/10910)
[lot](https://github.com/astral-sh/ruff/pull/10966)
[of](https://github.com/astral-sh/ruff/pull/10896)
[bugs](https://github.com/astral-sh/ruff/pull/10877)
---------
Co-authored-by: Victor Hugo Gomes <labatata101@linuxmail.org>
Co-authored-by: Micha Reiser <micha@reiser.io>
Similar to tuples, a generator _can_ be parenthesized or
unparenthesized. Only search for bracketed comments if it contains its
own parentheses.
Closes https://github.com/astral-sh/ruff/issues/7623.
## Summary
The motivation here is that this enables us to implement `Ranged` in
crates that don't depend on `ruff_python_ast`.
Largely a mechanical refactor with a lot of regex, Clippy help, and
manual fixups.
## Test Plan
`cargo test`
## Summary
Closes https://github.com/astral-sh/ruff/issues/6384, although I think
the issue was fixed already on main, for the most part.
The linked issue is around formatting expressions like:
```python
def test():
(
yield
#comment 1
* # comment 2
# comment 3
test # comment 4
)
```
On main, prior to this PR, we now format like:
```python
def test():
(
yield (
# comment 1
# comment 2
# comment 3
*test
) # comment 4
)
```
Which strikes me as reasonable. (We can't test this, since it's a syntax
error after for our parser, despite being a syntax error in both cases
from CPython's perspective.)
Meanwhile, Black does:
```python
def test():
(
yield
# comment 1
* # comment 2
# comment 3
test # comment 4
)
```
So our formatting differs in that we move comments between the star and
the expression above the star.
As of this PR, we also support formatting this input, which is valid:
```python
def test():
(
yield
#comment 1
* # comment 2
# comment 3
test, # comment 4
1
)
```
Like:
```python
def test():
(
yield (
# comment 1
(
# comment 2
# comment 3
*test, # comment 4
1,
)
)
)
```
There were two fixes here: (1) marking starred comments as dangling and
formatting them properly; and (2) supporting parenthesized comments for
tuples that don't contain their own parentheses, as is often the case
for yielded tuples (previously, we hit a debug assert).
Note that this diff
## Test Plan
cargo test
## Summary
This PR moves `empty_parenthesized` such that it's peer to
`parenthesized`, and changes the API to better match that of
`parenthesized` (takes `&str` rather than `StaticText`, has a
`with_dangling_comments` method, etc.).
It may be intentionally _not_ part of `parentheses.rs`, but to me
they're so similar that it makes more sense for them to be in the same
module, with the same API, etc.
## Summary
We already support preserving the end-of-line comment in calls and type
parameters, as in:
```python
foo( # comment
bar,
)
```
This PR adds the same behavior for lists, sets, comprehensions, etc.,
such that we preserve:
```python
[ # comment
1,
2,
3,
]
```
And related cases.
**Summary** Add a `EmptyWithDanglingComments` format helper that formats
comments inside empty parentheses, brackets or curly braces. Previously,
this was implemented separately, and partially incorrectly, for each use
case.
Empty `()`, `[]` and `{}` are special because there can be dangling
comments, and they can be in
two positions:
```python
x = [ # end-of-line
# own line
]
```
These comments are dangling because they can't be assigned to any
element inside as they would
in all other cases.
**Test Plan** Added a regression test.
145 (from previously 149) instances of unstable formatting remaining.
```
$ cargo run --bin ruff_dev --release -- format-dev --stability-check --error-file formatter-ecosystem-errors.txt --multi-project target/checkouts > formatter-ecosystem-progress.txt
$ rg "Unstable formatting" target/formatter-ecosystem-errors.txt | wc -l
145
```
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## Summary
I started working on this because I assumed that I would need access to options inside of `NeedsParantheses` but it then turned out that I won't.
Anyway, it kind of felt nice to pass fewer arguments. So I'm gonna put this out here to get your feedback if you prefer this over passing individual fiels.
Oh, I sneeked in another change. I renamed `context.contents` to `source`. `contents` is too generic and doesn't tell you anything.
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## Test Plan
It compiles
## Summary
This PR implements the formatting of `raise` statements. I haven't
looked at the black implementation, this is inspired from from the
`return` statements formatting.
## Test Plan
The black differences with insta.
I also compared manually some edge cases with very long string and call
chaining and it seems to do the same formatting as black.
There is one issue:
```python
# input
raise OsError(
"aksjdhflsakhdflkjsadlfajkslhfdkjsaldajlahflashdfljahlfksajlhfajfjfsaahflakjslhdfkjalhdskjfa"
) from a.aaaaa(aksjdhflsakhdflkjsadlfajkslhfdkjsaldajlahflashdfljahlfksajlhfajfjfsaahflakjslhdfkjalhdskjfa).a(aaaa)
# black
raise OsError(
"aksjdhflsakhdflkjsadlfajkslhfdkjsaldajlahflashdfljahlfksajlhfajfjfsaahflakjslhdfkjalhdskjfa"
) from a.aaaaa(
aksjdhflsakhdflkjsadlfajkslhfdkjsaldajlahflashdfljahlfksajlhfajfjfsaahflakjslhdfkjalhdskjfa
).a(
aaaa
)
# ruff
raise OsError(
"aksjdhflsakhdflkjsadlfajkslhfdkjsaldajlahflashdfljahlfksajlhfajfjfsaahflakjslhdfkjalhdskjfa"
) from a.aaaaa(
aksjdhflsakhdflkjsadlfajkslhfdkjsaldajlahflashdfljahlfksajlhfajfjfsaahflakjslhdfkjalhdskjfa
).a(aaaa)
```
But I'm not sure this diff is the raise formatting implementation.
---------
Co-authored-by: Louis Dispa <ldispa@deezer.com>
## Summary
This is small refactoring to reuse the code that detects the magic
trailing comma across functions. I make this change now to avoid copying
code in a later PR. @MichaReiser is planning on making a larger
refactoring later that integrates with the join nodes builder
## Test Plan
No functional changes. The magic trailing comma behaviour is checked by
the fixtures.
## Motivation
While black keeps parentheses nearly everywhere, the notable exception
is in the body of for loops:
```python
for (a, b) in x:
pass
```
becomes
```python
for a, b in x:
pass
```
This currently blocks #5163, which this PR should unblock.
## Solution
This changes the `ExprTuple` formatting option to include one additional
option that removes the parentheses when not using magic trailing comma
and not breaking. It is supposed to be used through
```rust
#[derive(Debug)]
struct ExprTupleWithoutParentheses<'a>(&'a Expr);
impl Format<PyFormatContext<'_>> for ExprTupleWithoutParentheses<'_> {
fn fmt(&self, f: &mut Formatter<PyFormatContext<'_>>) -> FormatResult<()> {
match self.0 {
Expr::Tuple(expr_tuple) => expr_tuple
.format()
.with_options(TupleParentheses::StripInsideForLoop)
.fmt(f),
other => other.format().with_options(Parenthesize::IfBreaks).fmt(f),
}
}
}
```
## Testing
The for loop formatting isn't merged due to missing this (and i didn't
want to create more git weirdness across two people), but I've confirmed
that when applying this to while loops instead of for loops, then
```rust
write!(
f,
[
text("while"),
space(),
ExprTupleWithoutParentheses(test.as_ref()),
text(":"),
trailing_comments(trailing_condition_comments),
block_indent(&body.format())
]
)?;
```
makes
```python
while (a, b):
pass
while (
ajssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssa,
b,
):
pass
while (a,b,):
pass
```
formatted as
```python
while a, b:
pass
while (
ajssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssa,
b,
):
pass
while (
a,
b,
):
pass
```
This implements formatting ExprTuple, including magic trailing comma. I
intentionally didn't change the settings mechanism but just added a
dummy global const flag.
Besides the snapshots, I added custom breaking/joining tests and a
deeply nested test case. The diffs look better than previously, proper
black compatibility depends on parentheses handling.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
* A basic StmtAssign formatter and better dummies for expressions
The goal of this PR was formatting StmtAssign since many nodes in the black tests (and in python in general) are after an assignment. This caused unstable formatting: The spacing of power op spacing depends on the type of the two involved expressions, but each expression was formatted as dummy string and re-parsed as a ExprName, so in the second round the different rules of ExprName were applied, causing unstable formatting.
This PR does not necessarily bring us closer to black's style, but it unlocks a good porting of black's test suite and is a basis for implementing the Expr nodes.
* fmt
* Review
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## Summary
This PR replaces the `verbatim_text` builder with a `not_yet_implemented` builder that emits `NOT_YET_IMPLEMENTED_<NodeKind>` for not yet implemented nodes.
The motivation for this change is that partially formatting compound statements can result in incorrectly indented code, which is a syntax error:
```python
def func_no_args():
a; b; c
if True: raise RuntimeError
if False: ...
for i in range(10):
print(i)
continue
```
Get's reformatted to
```python
def func_no_args():
a; b; c
if True: raise RuntimeError
if False: ...
for i in range(10):
print(i)
continue
```
because our formatter does not yet support `for` statements and just inserts the text from the source.
## Downsides
Using an identifier will not work in all situations. For example, an identifier is invalid in an `Arguments ` position. That's why I kept `verbatim_text` around and e.g. use it in the `Arguments` formatting logic where incorrect indentations are impossible (to my knowledge). Meaning, `verbatim_text` we can opt in to `verbatim_text` when we want to iterate quickly on nodes that we don't want to provide a full implementation yet and using an identifier would be invalid.
## Upsides
Running this on main discovered stability issues with the newline handling that were previously "hidden" because of the verbatim formatting. I guess that's an upside :)
## Test Plan
None?
Alex Waygood
Micha Reiser
Dhruv Manilawala
Charlie Marsh
konsti
Chris Pryer
Louis Dispa