## Summary
This PR adds a new `ExpressionContext` struct which is used in
expression parsing.
This solves the following problem:
1. Allowing starred expression with different precedence
2. Allowing yield expression in certain context
3. Remove ambiguity with `in` keyword when parsing a `for ... in`
statement
For context, (1) was solved by adding `parse_star_expression_list` and
`parse_star_expression_or_higher` in #10623, (2) was solved by by adding
`parse_yield_expression_or_else` in #10809, and (3) was fixed in #11009.
All of the mentioned functions have been removed in favor of the context
flags.
As mentioned in #11009, an ideal solution would be to implement an
expression context which is what this PR implements. This is passed
around as function parameter and the call stack is used to automatically
reset the context.
### Recovery
How should the parser recover if the target expression is invalid when
an expression can consume the `in` keyword?
1. Should the `in` keyword be part of the target expression?
2. Or, should the expression parsing stop as soon as `in` keyword is
encountered, no matter the expression?
For example:
```python
for yield x in y: ...
# Here, should this be parsed as
for (yield x) in (y): ...
# Or
for (yield x in y): ...
# where the `in iter` part is missing
```
Or, for binary expression parsing:
```python
for x or y in z: ...
# Should this be parsed as
for (x or y) in z: ...
# Or
for (x or y in z): ...
# where the `in iter` part is missing
```
This need not be solved now, but is very easy to change. For context
this PR does the following:
* For binary, comparison, and unary expressions, stop at `in`
* For lambda, yield expressions, consume the `in`
## Test Plan
1. Add test cases for the `for ... in` statement and verify the
snapshots
2. Make sure the existing test suite pass
3. Run the fuzzer for around 3000 generated source code
4. Run the updated logic on a dozen or so open source repositories
(codename "parser-checkouts")
(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>
## Summary
This PR modifies our `Cargo.toml` files to use workspace dependencies
for _all_ dependencies, rather than the status quo of sporadically
trying to use workspace dependencies for those dependencies that are
used across multiple crates. I find the current situation more confusing
and harder to manage, since we have a mix of workspace and crate-local
dependencies, whereas this setup consistently uses the same approach for
all dependencies.
Update to [Rust
1.74](https://blog.rust-lang.org/2023/11/16/Rust-1.74.0.html) and use
the new clippy lints table.
The update itself introduced a new clippy lint about superfluous hashes
in raw strings, which got removed.
I moved our lint config from `rustflags` to the newly stabilized
[workspace.lints](https://doc.rust-lang.org/stable/cargo/reference/workspaces.html#the-lints-table).
One consequence is that we have to `unsafe_code = "warn"` instead of
"forbid" because the latter now actually bans unsafe code:
```
error[E0453]: allow(unsafe_code) incompatible with previous forbid
--> crates/ruff_source_file/src/newlines.rs:62:17
|
62 | #[allow(unsafe_code)]
| ^^^^^^^^^^^ overruled by previous forbid
|
= note: `forbid` lint level was set on command line
```
---------
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>
## Summary
This is a follow-up to #7469 that attempts to achieve similar gains, but
without introducing malachite. Instead, this PR removes the `BigInt`
type altogether, instead opting for a simple enum that allows us to
store small integers directly and only allocate for values greater than
`i64`:
```rust
/// A Python integer literal. Represents both small (fits in an `i64`) and large integers.
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct Int(Number);
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum Number {
/// A "small" number that can be represented as an `i64`.
Small(i64),
/// A "large" number that cannot be represented as an `i64`.
Big(Box<str>),
}
impl std::fmt::Display for Number {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Number::Small(value) => write!(f, "{value}"),
Number::Big(value) => write!(f, "{value}"),
}
}
}
```
We typically don't care about numbers greater than `isize` -- our only
uses are comparisons against small constants (like `1`, `2`, `3`, etc.),
so there's no real loss of information, except in one or two rules where
we're now a little more conservative (with the worst-case being that we
don't flag, e.g., an `itertools.pairwise` that uses an extremely large
value for the slice start constant). For simplicity, a few diagnostics
now show a dedicated message when they see integers that are out of the
supported range (e.g., `outdated-version-block`).
An additional benefit here is that we get to remove a few dependencies,
especially `num-bigint`.
## Test Plan
`cargo test`
## Summary
This PR updates the remaining lexer test cases to use the snapshots.
This is mainly a mechanical refactor.
## Motivation
The main motivation is so that when we add the token range values to the
test case output, it's easier to update the test cases.
The reason they were not using the snapshots before was because of the usage of
`test_case` macro. The macros is mainly used for different EOL test cases. If we
just generate the snapshots directly, then the snapshot name would be suffixed
with `-1`, `-2`, etc. as the test function is still the same. So, we'll create
the snapshot ourselves with the platform name for the respective EOL
test cases.
## Test Plan
`cargo test`
## Summary
This PR updates the lexer tests to use the snapshot testing framework.
It also
makes the following changes:
* Remove the use of macros in the lexer tests
* Use `test_case` for EOL tests
## Test Plan
```
cargo test --package ruff_python_parser --lib --all-features -- lexer::tests --no-capture
```
## Summary
This PR adds support for help end escape command in the lexer.
### What are "help end escape commands"?
First, the escape commands are special IPython syntax which enhances the
functionality for the IPython REPL. There are 9 types of escape kinds
which are recognized by the tokens which are present at the start of the
command (`?`, `??`, `!`, `!!`, etc.).
Here, the help command is using either the `?` or `??` token at the
start (`?str.replace` for example). Those 2 tokens are also supported
when they're at the end of the command (`str.replace?`), but the other
tokens aren't supported in that position.
There are mainly two types of help end escape commands:
1. Ending with either `?` or `??`, but it also starts with one of the
escape tokens (`%matplotlib?`)
2. On the other hand, there's a stricter version for (1) which doesn't
start with any escape tokens (`str.replace?`)
This PR adds support for (1) while (2) will be supported in the parser.
### Priority
Now, if the command starts and ends with an escape token, how do we
decide the kind of this command? This is where priority comes into
picture. This is simple as there's only one priority where `?`/`??` at
the end takes priority over any other escape token and all of the other
tokens are at the same priority. Remember that only `?`/`??` at the end
is considered valid.
This is mainly useful in the case where someone would want to invoke the
help command on the magic command itself. For example, in `%matplotlib?`
the help command takes priority which means that we want help for the
`matplotlib` magic function instead of calling the magic function
itself.
### Specification
Here's where things get a bit tricky. What if there are question mark
tokens at both ends. How do we decide if it's `Help` (`?`) kind or
`Help2` (`??`) kind?
| | Magic | Value | Kind |
| --- | --- | --- | --- |
| 1 | `?foo?` | `foo` | `Help` |
| 2 | `??foo?` | `foo` | `Help` |
| 3 | `?foo??` | `foo` | `Help2` |
| 4 | `??foo??` | `foo` | `Help2` |
| 5 | `???foo??` | `foo` | `Help2` |
| 6 | `??foo???` | `foo???` | `Help2` |
| 7 | `???foo???` | `?foo???` | `Help2` |
Looking at the above table:
- The question mark tokens on the right takes priority over the ones on
the left but only if the number of question mark on the right is 1 or 2.
- If there are more than 2 question mark tokens on the right side, then
the left side is used to determine the same.
- If the right side is used to determine the kind, then all of the
question marks and whitespaces on the left side are ignored in the
`value`, but if it’s the other way around, then all of the extra
question marks are part of the `value`.
### References
- IPython implementation using the regex:
292e3a2345/IPython/core/inputtransformer2.py (L454-L462)
- Priorities:
292e3a2345/IPython/core/inputtransformer2.py (L466-L469)
## Test Plan
Add a bunch of test cases for the lexer and verify that it matches the
behavior of
IPython transformer.
resolves: #6357
