ruff/crates/ruff_python_parser/tests/snapshots/valid_syntax@expressions__starred.py.snap
Ibraheem Ahmed c9dff5c7d5
[ty] AST garbage collection (#18482)
## 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.
2025-06-13 08:40:11 -04:00

405 lines
20 KiB
Text

---
source: crates/ruff_python_parser/tests/fixtures.rs
input_file: crates/ruff_python_parser/resources/valid/expressions/starred.py
---
## AST
```
Module(
ModModule {
node_index: AtomicNodeIndex(..),
range: 0..172,
body: [
Expr(
StmtExpr {
node_index: AtomicNodeIndex(..),
range: 0..2,
value: Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 0..2,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 1..2,
id: Name("a"),
ctx: Load,
},
),
ctx: Load,
},
),
},
),
Expr(
StmtExpr {
node_index: AtomicNodeIndex(..),
range: 3..11,
value: Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 3..11,
value: BinOp(
ExprBinOp {
node_index: AtomicNodeIndex(..),
range: 5..10,
left: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 5..6,
id: Name("a"),
ctx: Load,
},
),
op: Add,
right: NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 9..10,
value: Int(
1,
),
},
),
},
),
ctx: Load,
},
),
},
),
Expr(
StmtExpr {
node_index: AtomicNodeIndex(..),
range: 12..19,
value: Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 12..19,
value: Attribute(
ExprAttribute {
node_index: AtomicNodeIndex(..),
range: 13..19,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 13..14,
id: Name("x"),
ctx: Load,
},
),
attr: Identifier {
id: Name("attr"),
range: 15..19,
node_index: AtomicNodeIndex(..),
},
ctx: Load,
},
),
ctx: Load,
},
),
},
),
Assign(
StmtAssign {
node_index: AtomicNodeIndex(..),
range: 21..57,
targets: [
Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 21..32,
id: Name("array_slice"),
ctx: Store,
},
),
],
value: Subscript(
ExprSubscript {
node_index: AtomicNodeIndex(..),
range: 35..57,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 35..40,
id: Name("array"),
ctx: Load,
},
),
slice: Tuple(
ExprTuple {
node_index: AtomicNodeIndex(..),
range: 41..56,
elts: [
NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 41..42,
value: Int(
0,
),
},
),
Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 44..52,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 45..52,
id: Name("indexes"),
ctx: Load,
},
),
ctx: Load,
},
),
UnaryOp(
ExprUnaryOp {
node_index: AtomicNodeIndex(..),
range: 54..56,
op: USub,
operand: NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 55..56,
value: Int(
1,
),
},
),
},
),
],
ctx: Load,
parenthesized: false,
},
),
ctx: Load,
},
),
},
),
Assign(
StmtAssign {
node_index: AtomicNodeIndex(..),
range: 58..94,
targets: [
Subscript(
ExprSubscript {
node_index: AtomicNodeIndex(..),
range: 58..80,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 58..63,
id: Name("array"),
ctx: Load,
},
),
slice: Tuple(
ExprTuple {
node_index: AtomicNodeIndex(..),
range: 64..79,
elts: [
NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 64..65,
value: Int(
0,
),
},
),
Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 67..75,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 68..75,
id: Name("indexes"),
ctx: Load,
},
),
ctx: Load,
},
),
UnaryOp(
ExprUnaryOp {
node_index: AtomicNodeIndex(..),
range: 77..79,
op: USub,
operand: NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 78..79,
value: Int(
1,
),
},
),
},
),
],
ctx: Load,
parenthesized: false,
},
),
ctx: Store,
},
),
],
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 83..94,
id: Name("array_slice"),
ctx: Load,
},
),
},
),
Expr(
StmtExpr {
node_index: AtomicNodeIndex(..),
range: 95..140,
value: Subscript(
ExprSubscript {
node_index: AtomicNodeIndex(..),
range: 95..140,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 95..100,
id: Name("array"),
ctx: Load,
},
),
slice: Tuple(
ExprTuple {
node_index: AtomicNodeIndex(..),
range: 101..139,
elts: [
Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 101..119,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 102..119,
id: Name("indexes_to_select"),
ctx: Load,
},
),
ctx: Load,
},
),
Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 121..139,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 122..139,
id: Name("indexes_to_select"),
ctx: Load,
},
),
ctx: Load,
},
),
],
ctx: Load,
parenthesized: false,
},
),
ctx: Load,
},
),
},
),
Expr(
StmtExpr {
node_index: AtomicNodeIndex(..),
range: 141..171,
value: Subscript(
ExprSubscript {
node_index: AtomicNodeIndex(..),
range: 141..171,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 141..146,
id: Name("array"),
ctx: Load,
},
),
slice: Tuple(
ExprTuple {
node_index: AtomicNodeIndex(..),
range: 147..170,
elts: [
Slice(
ExprSlice {
node_index: AtomicNodeIndex(..),
range: 147..150,
lower: Some(
NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 147..148,
value: Int(
3,
),
},
),
),
upper: Some(
NumberLiteral(
ExprNumberLiteral {
node_index: AtomicNodeIndex(..),
range: 149..150,
value: Int(
5,
),
},
),
),
step: None,
},
),
Starred(
ExprStarred {
node_index: AtomicNodeIndex(..),
range: 152..170,
value: Name(
ExprName {
node_index: AtomicNodeIndex(..),
range: 153..170,
id: Name("indexes_to_select"),
ctx: Load,
},
),
ctx: Load,
},
),
],
ctx: Load,
parenthesized: false,
},
),
ctx: Load,
},
),
},
),
],
},
)
```