## Summary
Garbage collect ASTs once we are done checking a given file. Queries
with a cross-file dependency on the AST will reparse the file on demand.
This reduces ty's peak memory usage by ~20-30%.
The primary change of this PR is adding a `node_index` field to every
AST node, that is assigned by the parser. `ParsedModule` can use this to
create a flat index of AST nodes any time the file is parsed (or
reparsed). This allows `AstNodeRef` to simply index into the current
instance of the `ParsedModule`, instead of storing a pointer directly.
The indices are somewhat hackily (using an atomic integer) assigned by
the `parsed_module` query instead of by the parser directly. Assigning
the indices in source-order in the (recursive) parser turns out to be
difficult, and collecting the nodes during semantic indexing is
impossible as `SemanticIndex` does not hold onto a specific
`ParsedModuleRef`, which the pointers in the flat AST are tied to. This
means that we have to do an extra AST traversal to assign and collect
the nodes into a flat index, but the small performance impact (~3% on
cold runs) seems worth it for the memory savings.
Part of https://github.com/astral-sh/ty/issues/214.
## 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
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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.
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
It compiles
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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?